Stern Tube Bearing
medium
103 models total
The stern tube bearing carries the propeller shaft at the one point it exits the hull, combining a load-bearing duty with a sealing duty that plain line bearings elsewhere in the shaft line never have to handle.
Read more — Stern Tube Bearing explained ▾
What defines this type
The stern tube bearing supports the propeller shaft at the single point where it exits the hull, carrying the weight of the shaft and propeller overhang while sealing against seawater ingress on the outside and lubricant loss on the inside. That combination of load-bearing and sealing duty at a rotating hull penetration is what separates it from the plain line bearings further forward in the shaft line, which only carry radial load and see no sealing duty at all.
Main components
Bearing bush
Either white metal (babbitt) running in oil, or a synthetic rubber or polymer compound running in water — oil-lubricated white metal gives lower friction and less wear but depends entirely on seal integrity; water-lubricated synthetic bearings tolerate seal wear better since the lubricant is seawater itself, at the cost of higher sensitivity to grit and sand ingestion.
Forward and aft bearings
Most stern tubes carry two bearings, one at each end of the tube; the aft bearing takes the larger share of load from the propeller overhang and wears faster as a result, which is why wear-down readings are taken and logged separately for each.
Sealing arrangement
Lip seals or face seals at the forward and aft ends of the tube keep oil in (or, on water-lubricated systems, keep the lubrication water contained to the intended path) and keep the open sea out; seal condition and lubricant type together set the vessel's oil-to-sea pollution risk at this single point.
Lubrication system
Oil-lubricated tubes run from a header tank with a static head sufficient to keep tube pressure above surrounding sea pressure at the aft seal, with a sight glass and level alarm; water-lubricated tubes rely on grooved bearing surfaces to distribute seawater and carry away wear particles.
Selection / Sizing
| Parameter | Why it matters |
|---|---|
| Shaft diameter | Sets the bearing bore and load-carrying requirement |
| Length-to-diameter (L/D) ratio | Governs specific bearing pressure and heat generation |
| Lubrication type | Oil for lower friction/wear; water for pollution-risk reduction |
| Specific bearing load | Compared against the bush material's rated pressure limit |
| Shaft alignment tolerance | Poor alignment concentrates load at one edge of the bearing rather than spreading it evenly |
Regulations / Class
IACS Unified Requirements (the M-series covering shafting) set wear-down limit criteria and the survey basis for stern tube bearings, and class rules require periodic wear-down measurement — commonly at intermediate and special surveys, or on a continuous survey basis for vessels enrolled in that scheme — comparing measured clearance against the bearing's original and maximum permissible clearance. Where oil lubrication is used, MARPOL Annex I governs any discharge risk at the stern tube seal, and several port states and the US Vessel General Permit framework require environmentally acceptable lubricants (EAL) in oil-to-sea interfaces including stern tubes operating in their waters, which has pushed many owners toward EAL-compatible oils or water-lubricated systems entirely.
Typical faults
- Wear beyond class limit — gradual bush wear increases shaft clearance and vibration; caught late, it risks contact between shaft and bearing housing rather than a clean bush surface.
- Seal leakage — a worn or damaged seal on an oil-lubricated tube causes a slow oil-to-sea leak that can go undetected until a sheen is reported or a header tank level drops faster than expected.
- Overheating — insufficient lubrication flow or a misaligned bearing concentrates friction and heat at one point of the bush, accelerating wear at that spot specifically rather than evenly.
- Edge loading from misalignment — a shaft line out of alignment loads one edge of the bearing far harder than the rest, wearing a taper into the bush that a straightforward diameter check can miss.
- Abrasive wear on water-lubricated bearings — sand or grit drawn in with the lubrication water scores the synthetic bush surface, a failure mode oil-lubricated systems do not share.
What to look for in a supplier
- A bearing design with class type approval or design assessment for the vessel's shaft diameter and expected load.
- Clearly stated original and maximum permissible wear-down figures, matching what the class surveyor will measure against.
- EAL compatibility data if the vessel trades into waters requiring environmentally acceptable lubricants.
- A bush material recommendation based on the vessel's actual lubrication type and operating draft variation, not a default catalogue choice.
Log wear-down readings against the same reference marks every time, not just against the class limit — a bearing wearing unevenly across its length shows up as a trend long before it shows up as an out-of-limit single reading.
4 manufacturers · 103 models
Thordon Bearings
42
Thordon SXL 100mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
100
Bearing material
polymer composite
Length (mm)
250
Strengths
- Corrosion‑resistant polymer matrix eliminates rust issues common with metal bearings
- Lightweight construction reduces overall stern tube assembly mass
- Self‑lubricating material lowers routine maintenance and oil consumption
- Compact length (250 mm) fits tight stern tube spaces on smaller vessels
Weaknesses
- Lower load‑capacity compared with traditional bronze or steel bearings, limiting use to moderate power shafts
- Temperature rating is limited; performance may degrade in very high‑temperature environments
- No integrated seal type specified, requiring an external sealing solution
- Potential for higher wear rates under severe vibration or misalignment conditions
Typical Vessels:
Coastal TugOffshore Supply Vessel (OSV)WorkboatSmall Bulk Carrier (<30 kt)Patrol Craft
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑free bearing for a 100 mm shaft on a vessel with moderate power and limited space. Avoid if: the application involves high shaft loads, extreme temperatures, or requires an integrated seal system.
Use Cases: Commonly installed in stern tube assemblies of small to medium workboats where ease of maintenance and resistance to seawater corrosion are priorities; often paired with external oil seals for added protection.
Thordon SXL 150mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
150
Bearing material
polymer composite
Length (mm)
375
Strengths
- Corrosion‑resistant material reduces maintenance in seawater environments
- Lightweight compared with traditional metal bearings
- Low friction coefficient improves shaft efficiency
- Standard 150 mm bore fits many mid‑size vessel propulsion lines
Weaknesses
- Polymer composites may have lower load‑capacity than bronze or steel alternatives
- Limited high‑temperature performance; not suited for very hot oil lubrication
- No integrated seal type supplied – requires separate sealing arrangement
- Long‑term wear data less established than legacy metal bearings
Typical Vessels:
Medium‑size tankersBulk carriers (up to ~30 000 dwt)Container ships (up to ~10 000 TEU)Offshore supply vessels
Decision Guide: Choose if you need a low‑maintenance, corrosion‑resistant bearing for a standard 150 mm shaft and operate in moderate temperature ranges. Avoid if the propulsion system demands very high load capacity, extreme temperatures, or an integrated seal solution.
Use Cases: Commonly installed in the stern tube of cargo vessels and offshore support ships where a 150 mm propeller shaft is used and reduced maintenance downtime is a priority.
Thordon SXL 200mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
200
Bearing material
polymer composite
Length (mm)
500
Strengths
- Self‑lubricating polymer material reduces routine oiling and maintenance intervals
- Excellent resistance to seawater corrosion compared with traditional metal bearings
- Lightweight construction (polymer vs. bronze) can lower overall stern tube assembly weight
- Quiet operation due to damping properties of the composite material
Weaknesses
- Lower load‑capacity ceiling than high‑strength bronze or babbitt metal bearings, limiting use on very high thrust applications
- Temperature rating may be restricted; extreme heat can degrade polymer performance
- Proprietary composite formulation may make spare‑part sourcing more difficult in remote ports
- Long‑term wear data are less extensive than for conventional metal bearings
Typical Vessels:
Product tanker (up to ~30 kt)General cargo vesselOffshore supply vesselMedium‑size bulk carrierCoastal container ship
Decision Guide: Choose if the vessel operates in corrosive seawater environments, requires reduced routine lubrication and benefits from a lighter stern tube assembly, and the shaft thrust load stays within the polymer bearing’s rating. Avoid if the propulsion system generates high thrust or operates at temperatures that exceed typical polymer limits, or where proven long‑term metal‑bearing performance is mandatory.
Use Cases: Commonly installed in the stern tubes of medium‑power diesel‑driven ships with a 200 mm shaft, such as product tankers and offshore supply vessels, where maintenance windows are limited and corrosion resistance is a priority.
Thordon SXL 250mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
250
Bearing material
polymer composite
Length (mm)
625
Strengths
- Corrosion‑resistant polymer material eliminates rust in seawater environments
- Low friction reduces propulsion power loss and extends propeller life
- Compact 625 mm length fits vessels with limited stern tube space
- Reduced lubrication requirements compared with metal bearings
- Direct fit for standard 250 mm shaft sizes, simplifying installation or retrofit
Weaknesses
- Lower load‑capacity than steel or bronze bearings; less suited to high‑power main engines
- Polymer material has tighter temperature and speed limits
- No integrated seal type; additional sealing arrangements may be required
- Long‑term wear data are limited, necessitating regular inspection
- Unit cost can be higher than conventional metal bearings
Typical Vessels:
Coastal cargo vesselOffshore supply vesselFerryFishing vesselSmall bulk carrierSmall container ship
Decision Guide: Choose if the vessel has moderate propulsion power (up to ~10 MW), limited stern‑tube space, operates in highly corrosive seawater, and seeks reduced maintenance. Avoid for high‑power main engines, very high speeds (>20 knots), or applications demanding maximum load capacity.
Use Cases: Commonly installed on medium‑size offshore supply vessels for thruster shafts, ferries with twin propellers, and coastal cargo ships where corrosion resistance and space savings are priorities.
Thordon SXL 300mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
300
Bearing material
polymer composite
Length (mm)
750
Strengths
- Corrosion resistance – polymer matrix eliminates rust issues common with metal bearings
- Low friction and reduced wear, extending service intervals
- Lightweight construction (750 mm length) reduces overall propulsion system mass
- Self‑lubricating properties typical of composite designs lower oil consumption
Weaknesses
- Lower static load capacity compared with traditional bronze or steel bearings
- Operating temperature range is more limited than metal counterparts
- Seal compatibility not specified – may require custom sealing solutions
- Potentially higher upfront cost versus conventional metal stern tube bearings
Typical Vessels:
Coastal tankerOffshore supply vesselFerrySmall container ship (up to 10 000 dwt)Bulk carrier (mid‑size)
Decision Guide: Choose if: you need a lightweight, corrosion‑free bearing for a 300 mm shaft on vessels operating in warm, low‑abrasion environments and can accommodate composite load limits. Avoid if: the propulsion system demands high static loads, extreme temperature tolerance, or you rely on standard metal seal kits.
Use Cases: Commonly installed on medium‑size merchant ships where shaft protection against seawater corrosion is critical, such as coastal tankers and offshore supply vessels that operate in tropical waters and benefit from reduced maintenance cycles.
Thordon SXL 350mm
unverified
· polymer‑composite stern tube bearing
Shaft diameter (mm)
350
Bearing material
polymer composite
Length (mm)
875
Strengths
- Lightweight construction compared with traditional steel bearings
- Excellent resistance to seawater corrosion and biofouling
- Low friction coefficient reduces power loss
- Compact length (875 mm) eases installation in confined stern‑tube spaces
- Reduced routine lubrication requirements
Weaknesses
- Polymer material may have lower load capacity than steel bearings in high‑power applications
- Limited temperature range typical of polymer composites (generally up to ~80 °C)
- No integrated seal type specified – additional sealing solutions may be required
- Long‑term wear data for this specific model is limited
Typical Vessels:
Medium‑size tankerBulk carrier (up to 30,000 dwt)Container ship (up to 5,000 TEU)General cargo vessel
Decision Guide: Choose if: you need a lightweight, corrosion‑resistant bearing for a 350 mm shaft on vessels with moderate power and limited space. Avoid if: the propulsion system operates at high loads, elevated temperatures, or requires an integrated seal system that must be certified to specific class societies.
Use Cases: Commonly installed in the stern tube of medium‑speed diesel‑driven cargo ships where a compact, low‑maintenance bearing is preferred and shaft diameter matches 350 mm.
Thordon SXL 400mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
400
Bearing material
polymer composite
Length (mm)
1000
Strengths
- Self‑lubricating polymer material reduces routine greasing requirements
- High corrosion resistance suitable for seawater environments
- Compact length of 1000 mm simplifies installation in confined stern tube spaces
- Lightweight compared with traditional bronze or steel bearings, aiding overall vessel weight balance
- Designed specifically for a 400 mm shaft diameter, providing a precise fit
Weaknesses
- Lower load‑carrying capacity than heavy‑duty metal bearings under high thrust conditions
- Maximum operating temperature limited by polymer material properties
- May require tighter alignment tolerances during installation
- Not ideal for very high RPM applications where metal bearings are preferred
- Initial purchase cost can be higher than conventional bronze bearings
Typical Vessels:
TankerBulk CarrierContainer ShipGeneral Cargo VesselOffshore Supply Vessel
Decision Guide: Choose if: the vessel operates in a corrosive seawater environment, requires reduced maintenance intervals, and has moderate thrust/ RPM demands that suit polymer composite bearings. Avoid if: the propulsion system generates high thrust loads, operates at very high speeds, or experiences elevated temperatures beyond polymer limits.
Use Cases: Commonly installed on new‑build merchant ships with a 400 mm propeller shaft where weight saving and low maintenance are priorities, as well as retrofits aiming to replace aging metal bearings in moderate‑load applications.
Thordon SXL 450mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
450
Bearing material
polymer composite
Length (mm)
1125
Strengths
- Corrosion‑resistant material eliminates rust in seawater environments
- Lightweight compared with traditional bronze or steel bearings, reducing overall shaft line mass
- Low friction coefficient improves propulsion efficiency and reduces fuel consumption
- Self‑lubricating polymer matrix can extend service intervals when used with compatible seals
Weaknesses
- Maximum load capacity is lower than that of metal alloy bearings; not ideal for very high thrust applications
- Temperature rating limited (typically ≤ 80 °C), restricting use in high‑heat exhaust or aft turbine installations
- Polymer wear particles may require more frequent monitoring of oil cleanliness
- Seal compatibility must be verified because some elastomers can degrade polymer surfaces
Typical Vessels:
Medium‑size tankers (up to ~30 k DWT)Bulk carriersContainer shipsCruise vesselsOffshore supply and support vessels
Decision Guide: Choose if: you need a corrosion‑free bearing for moderate thrust shafts, want reduced weight and lower maintenance in standard temperature ranges, and operate on vessels where fuel efficiency is a priority. Avoid if: the propulsion system generates high thrust or operates at elevated temperatures, or if classification societies require metal bearings for the specific vessel class.
Use Cases: The SXL 450 mm is typically installed in the stern tube of cargo and passenger ships with 450 mm shafts, providing a reliable bearing solution for medium‑power diesel or dual‑fuel engines where corrosion resistance and weight savings are valued.
Thordon SXL 500mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
500
Bearing material
polymer composite
Length (mm)
1250
Strengths
- Corrosion resistant to seawater
- Self‑lubricating polymer reduces maintenance intervals
- Lightweight compared with traditional steel bearings
- Compact length of 1250 mm saves installation space
Weaknesses
- Lower load capacity than metal alloy bearings
- Upper temperature limit is lower than metallic options
- Polymer wear may require periodic inspection
- Seal type not specified, may need additional sealing solutions
Typical Vessels:
Bulk CarrierContainer ShipTankerOffshore Support VesselCruise Ship
Decision Guide: Choose if you need a low‑maintenance, corrosion‑resistant bearing for a 500 mm shaft on vessels where space and weight are at a premium and operating loads are moderate. Avoid if the propulsion system demands high load capacity, high temperature operation, or requires certified metal bearings.
Use Cases: Commonly installed in stern tube assemblies of medium‑speed diesel‑driven ships such as product tankers, feeder container vessels, and offshore supply vessels where the shaft size is around 500 mm.
Thordon SXL 600mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
600
Bearing material
polymer composite
Length (mm)
1500
Strengths
- Low friction and self‑lubricating surface reduces routine oiling requirements
- Excellent corrosion resistance in seawater, extending service intervals
- Lightweight compared with traditional bronze or steel bearings, aiding overall shaft line weight balance
- Quiet operation due to damping properties of the polymer matrix
Weaknesses
- Lower load‑carrying capacity than metal bearings; not suited for very high‑power main propulsion
- Temperature limits (typically ≤80 °C) may restrict use on high‑speed or heavily loaded shafts
- Limited long‑term field data compared with established metal bearing families
- Potential compatibility issues with existing seal arrangements if a specific seal type is required
Typical Vessels:
Coastal cargo vesselsFerriesOffshore support / supply shipsTugboatsSmall to medium bulk carriers (≤15 kt)
Decision Guide: Choose if the vessel operates at moderate power levels, values reduced maintenance and corrosion resistance, and can accommodate the bearing's load and temperature limits. Avoid for high‑power main propulsion on large tankers or cruise ships where metal bearings provide proven strength and heat tolerance.
Use Cases: Commonly installed in new builds or retrofits of medium‑size vessels where weight saving, low noise, and extended maintenance intervals are priorities—e.g., coastal traders, ferries, and offshore supply craft operating in warm marine environments.
Thordon SXL 700mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
700
Bearing material
polymer composite
Length (mm)
1750
Strengths
- Corrosion‑resistant material suitable for marine environments
- Self‑lubricating properties reduce routine oil maintenance
- Lower weight compared with traditional bronze or babbitt bearings
- Good vibration and noise damping characteristics
- Long service life when installed per manufacturer guidelines
Weaknesses
- Higher upfront cost than conventional metal bearings
- Limited temperature range compared with steel‑based designs
- Seal type not specified; may require additional sealing solutions
- Less field‑proven data for very high‑power applications
- Installation tolerances can be tighter due to composite material
Typical Vessels:
TankerContainer shipBulk carrierCruise linerOffshore supply vessel
Decision Guide: Choose if: you need a corrosion‑free, low‑maintenance bearing for a 700 mm shaft and can accommodate the higher initial cost. Avoid if: budget constraints dominate or the vessel operates at temperatures beyond typical polymer limits.
Use Cases: Commonly installed in new‑builds or during major refits where a 700 mm shaft requires a durable, low‑maintenance bearing within the stern tube, especially on vessels operating in harsh seawater conditions.
Thordon SXL 800mm
unverified
· Polymer composite stern tube bearing
Shaft diameter (mm)
800
Bearing material
polymer composite
Length (mm)
2000
Strengths
- Corrosion‑resistant polymer matrix eliminates metal‑to‑metal wear in seawater
- Low friction coefficient reduces power loss and extends propeller life
- Lightweight compared with traditional steel or bronze bearings, easing installation
- Integrated length of 2000 mm accommodates standard stern‑tube housings for large vessels
Weaknesses
- Maximum load capacity lower than equivalent high‑strength metal bearings
- Upper temperature limit typically around 80–90 °C; not suited for extreme heat zones
- Requires compatible polymer‑friendly lubrication regime (standard oil may be unsuitable)
- Limited field history compared with long‑standing bronze designs, affecting risk perception
Typical Vessels:
LNG CarrierCruise ShipVery Large Crude Carrier (VLCC)Container Ship (>8 000 TEU)Bulk Carrier (Handymax and larger)
Decision Guide: Choose if: you need a bearing that resists seawater corrosion, offers low friction for fuel‑efficiency gains, and fits an 800 mm shaft in vessels where weight savings matter. Avoid if: the propulsion system operates at very high loads or temperatures beyond polymer limits, or if class societies require metal bearings for specific hull classifications.
Use Cases: Commonly installed in the stern tube of large, modern merchant ships where a 800 mm shaft drives a low‑speed propeller; especially favored on vessels with high service‑interval demands and where corrosion protection is critical, such as LNG carriers and cruise liners operating in warm, saline waters.
Thordon SXL 900mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
900
Bearing material
polymer composite
Length (mm)
2250
Strengths
- Lightweight compared with traditional steel or bronze bearings, reducing overall shaft line mass
- Excellent corrosion resistance in seawater, extending service intervals
- Low friction coefficient leads to reduced power loss and fuel consumption
- Self‑lubricating polymer matrix can operate with minimal external lubrication
Weaknesses
- Maximum load capacity lower than heavy‑duty metal bearings; may be unsuitable for very high thrust applications
- Operating temperature range limited by polymer material (typically up to ~120 °C)
- Long‑term wear monitoring required as polymer wear particles differ from metal and may affect oil analysis programs
- Replacement parts and spares can be less widely stocked than standard bronze bearings
Typical Vessels:
Bulk CarrierProduct TankerContainer ShipCruise VesselOffshore Supply Vessel
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for a 900 mm shaft on vessels with moderate thrust and temperature demands; weight saving is a priority. Avoid if: the propulsion system generates very high thrust or operates at temperatures beyond polymer limits, or if your maintenance regime relies on traditional metal‑bearing wear signatures.
Use Cases: Installed in the stern tube of medium‑to‑large merchant ships where the shaft diameter is 900 mm, particularly on vessels that operate in warm, corrosive waters and benefit from reduced lubrication requirements. Commonly used on new builds or retrofits seeking to lower lifecycle maintenance costs.
Thordon SXL 1000mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
1000
Bearing material
polymer composite
Length (mm)
2500
Strengths
- Polymer composite material provides excellent corrosion resistance in seawater environments
- Lower friction coefficient than traditional babbitt metal bearings, reducing shaft wear
- Reduced weight compared with cast‑iron or steel bearings, aiding overall vessel balance
- Long service intervals due to self‑lubricating properties of the composite matrix
- Designed for 1000 mm shafts, matching a common size on large merchant vessels
Weaknesses
- Higher upfront cost than conventional metal stern tube bearings
- Polymer composites have a more limited temperature range; excessive heat can affect load capacity
- May require specific lubrication or seal arrangements not supplied with the base unit
- Spare‑part availability depends on Thordon’s regional service network
- Not ideal for vessels that experience extreme shock loads or very high shaft speeds
Typical Vessels:
Crude oil tanker (LR1/LR2)Bulk carrier (Handymax and larger)Container ship (12 000‑20 000 TEU class)General cargo vesselCruise liner (mid‑size)
Decision Guide: Choose if you need a low‑maintenance, corrosion‑resistant bearing for a 1000 mm main shaft on vessels operating in harsh marine environments and where weight saving is beneficial. Avoid if the propulsion system runs at very high temperatures, requires metal bearings for extreme shock loads, or if budget constraints prioritize initial cost over lifecycle savings.
Use Cases: Installed as the primary stern tube bearing on new‑build merchant ships with large-diameter shafts, or retrofitted on existing vessels where metal bearing corrosion has become a maintenance issue. Commonly used in main propulsion lines of tankers and bulk carriers operating on long voyages.
Thordon CompacSeries 100mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
100
Bearing material
polymer composite
Length (mm)
250
Strengths
- Corrosion‑resistant polymer matrix eliminates rust in seawater environments
- Self‑lubricating properties reduce routine oiling and maintenance intervals
- Lightweight compared with traditional steel bearings, aiding overall shaft line weight budget
- Compact length (250 mm) fits vessels with limited stern‑tube space
Weaknesses
- Lower load‑capacity than equivalent steel or bronze bearings, limiting use on high‑thrust shafts
- Maximum operating temperature is lower than metal bearings; unsuitable for very hot exhaust gases
- Potential for accelerated wear in highly abrasive water (e.g., heavy sand content)
- Limited field experience compared with long‑standing legacy brands
Typical Vessels:
Coastal tankerOffshore supply vesselFerrySmall bulk carrierRegional container ship
Decision Guide: Choose if you need a low‑maintenance, corrosion‑resistant bearing for a 100 mm shaft on vessels operating in warm or tropical waters with moderate thrust loads. Avoid if the propulsion system demands high load capacity, operates at elevated temperatures, or encounters highly abrasive water conditions.
Use Cases: Commonly installed in the stern tube of medium‑size diesel‑driven ships where space is limited and corrosion resistance is a priority, such as coastal tankers, offshore supply vessels, and regional ferries.
Thordon CompacSeries 150mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
150
Bearing material
polymer composite
Length (mm)
375
Strengths
- Lightweight construction due to polymer composite material
- Corrosion‑resistant, suitable for marine environments
- Self‑lubricating properties reduce maintenance intervals
- Compact length (375 mm) eases installation in confined stern tube spaces
Weaknesses
- Lower load‑capacity compared with steel or bronze bearings
- Temperature limits may restrict use on high‑power main engines
- Potential for higher wear rates under heavy thrust conditions
- Limited long‑term service data for this specific model
Typical Vessels:
Coastal cargo vesselsOffshore supply shipsMedium‑size tankers (auxiliary propulsion)Container feeder vessels
Decision Guide: Choose if you need a low‑maintenance, corrosion‑resistant bearing for moderate thrust applications and have space constraints. Avoid on high‑power main engines or where extreme loads and temperatures are expected.
Use Cases: Commonly installed in auxiliary engine stern tubes of medium‑sized commercial ships where compactness and reduced maintenance are priorities, especially in warm seawater regions.
Thordon CompacSeries 200mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
200
Bearing material
polymer composite
Length (mm)
500
Strengths
- Corrosion‑resistant material suitable for seawater environments
- Low friction coefficient reduces power loss
- Lightweight compared with traditional bronze bearings
- Potentially longer service intervals due to self‑lubricating properties
Weaknesses
- May have lower load capacity than metal alloy bearings
- Upper temperature limit can be lower, restricting high‑speed applications
- Polymer wear characteristics require specific monitoring regimes
- Limited historical performance data for this exact model
Typical Vessels:
Bulk CarrierContainer ShipGeneral Cargo VesselTankerOffshore Supply Vessel
Decision Guide: Choose if: you need a corrosion‑free bearing for a 200 mm shaft, weight saving is important, and operating conditions stay within the polymer’s temperature and load limits. Avoid if: the vessel operates at high speeds or heavy loads that exceed typical polymer bearing capacities, or if certification compliance requires a metal bearing.
Use Cases: Commonly installed in new‑build stern tube assemblies of medium‑size merchant ships where reduced maintenance and corrosion resistance are priorities; also used in retrofits replacing worn bronze bearings on vessels with moderate power ratings.
Thordon CompacSeries 250mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
250
Bearing material
polymer composite
Length (mm)
625
Strengths
- Corrosion‑resistant material reduces degradation in seawater and brackish environments
- Self‑lubricating polymer eliminates the need for regular oil lubrication, lowering maintenance intervals
- Lightweight compared with traditional steel bearings, easing installation and reducing overall shaft line weight
- Integrated design can simplify alignment and reduce vibration transmission
Weaknesses
- Lower static and dynamic load capacity than comparable steel or bronze bearings, limiting suitability for high‑power shafts
- Restricted operating temperature range; polymer may soften at elevated temperatures
- Potential for material creep under sustained heavy loads, affecting long‑term alignment
- Limited field history for this specific model, which may affect class society acceptance on some vessels
Typical Vessels:
Product TankerBulk Carrier (Handymax/Supramax)Offshore Supply VesselGeneral Cargo Ship
Decision Guide: Choose if: the vessel operates in corrosive or low‑maintenance environments, shaft power is moderate (<5 MW), and weight savings are valued. Avoid if: high shaft loads, elevated temperature service, or strict class requirements for proven steel bearings are mandatory.
Use Cases: Commonly installed on medium‑size bulk carriers, product tankers, and offshore supply vessels where a 250 mm shaft is used and the operating profile emphasizes corrosion resistance and reduced maintenance over maximum load capacity.
Thordon CompacSeries 300mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
300
Bearing material
polymer composite
Length (mm)
750
Strengths
- Corrosion‑resistant polymer composite material extends service intervals in seawater environments
- Compact overall length of 750 mm suits vessels with limited stern tube space
- Reduced lubrication requirements compared with traditional steel bearings
- Self‑aligning design accommodates minor shaft misalignment
Weaknesses
- Lower static and dynamic load capacity than equivalent steel or bronze bearings
- Upper temperature limit may be lower than metal alternatives, restricting high‑power applications
- Seal type not supplied; additional sealing arrangements may be required
- Potential for higher wear rates under heavy thrust or frequent reversing
Typical Vessels:
Coastal TankerFeeder Container ShipOffshore Supply VesselSmall Bulk CarrierPassenger Ferry
Decision Guide: Choose if the vessel operates in corrosive seawater, has moderate thrust requirements and limited stern‑tube space, and prefers lower maintenance. Avoid for high‑power, heavy‑load propulsion systems or where extreme temperature resistance is critical.
Use Cases: Commonly installed on medium‑speed diesel‑driven ships with propeller shafts around 300 mm, such as coastal tankers, feeder vessels, and offshore supply ships operating in warm to temperate waters.
Thordon CompacSeries 350mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
350
Bearing material
polymer composite
Length (mm)
875
Strengths
- Corrosion‑resistant material reduces maintenance in seawater environments
- Lower weight compared with traditional steel or bronze bearings
- Good vibration damping characteristics improve propeller run‑smoothness
- Self‑lubricating properties can extend service intervals
Weaknesses
- Maximum load and thrust capacity generally lower than metal alloy equivalents
- Upper temperature limit may be lower, restricting use in high‑power applications
- Long‑term wear characteristics are less documented than conventional bearings
- Replacement parts may be less widely stocked than standard bronze types
Typical Vessels:
Handysize bulk carrierFeeder container shipCoastal tankerOffshore supply vessel
Decision Guide: Choose if: you need a corrosion‑resistant, lightweight bearing for moderate thrust and value reduced maintenance. Avoid if: the propulsion system demands high thrust, operates at elevated temperatures, or requires proven long‑term wear data from metal bearings.
Use Cases: Commonly installed in the stern tube of medium‑size merchant vessels where shaft diameter is around 350 mm and a balance between performance and low upkeep is desired.
Thordon CompacSeries 400mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
400
Bearing material
polymer composite
Length (mm)
1000
Strengths
- Corrosion‑resistant material suitable for long exposure to seawater
- Lower friction coefficient than traditional metal bearings, reducing power loss
- Lightweight construction simplifies installation and reduces overall shaft line weight
Weaknesses
- Generally lower load‑capacity compared with steel or bronze bearings, limiting use on high‑thrust applications
- Polymer wear rates can increase at very high rotational speeds
- May require more frequent visual inspection to monitor material degradation
Typical Vessels:
Product tanker (up to ~10 000 dwt)General cargo / bulk carrier (mid‑size, 15–30 000 dwt)Offshore supply vesselCoastal container ship
Decision Guide: Choose if the vessel operates in corrosive marine environments, requires a moderate thrust rating and benefits from reduced shaft line weight. Avoid on high‑power, high‑speed ships where maximum load capacity and wear resistance are critical.
Use Cases: Commonly installed on medium‑size diesel‑driven vessels with a 400 mm propeller shaft, especially where maintenance intervals are long and exposure to saltwater is continuous.
Thordon CompacSeries 450mm
unverified
· Polymer composite stern tube bearing
Shaft diameter (mm)
450
Bearing material
polymer composite
Length (mm)
1125
Strengths
- Compact overall length (1125 mm) reduces hull penetration and installation space.
- Polymer‑composite material provides excellent corrosion resistance, especially in seawater environments.
- Lower friction compared with traditional metal bearings improves fuel efficiency.
- Reduced weight lessens shaft load and can contribute to overall vessel weight savings.
- Designed for standard 450 mm shafts, facilitating replacement or retrofit on many vessels.
Weaknesses
- Maximum load capacity is lower than that of steel or bronze stern tube bearings.
- Operating temperature limit typically around 80 °C; not suitable for high‑temperature applications.
- No integrated seal type supplied; requires a compatible sealing system to be specified separately.
- Polymer wear characteristics differ from metal; may require more frequent inspection in heavy‑duty service.
- Relatively newer model, so long‑term field performance data may be limited.
Typical Vessels:
Product TankerOffshore Supply VesselSmall to Medium Container ShipCruise FerryCoastal Bulk Carrier
Decision Guide: Choose if you need a short‑length, corrosion‑resistant bearing for a 450 mm shaft and the vessel operates within moderate load and temperature limits. Avoid if the propulsion system demands high axial loads, extreme temperatures, or if an integrated seal is mandatory without additional engineering.
Use Cases: Commonly installed on new builds where stern tube space is constrained, or as a retrofit on existing ships to replace corroded metal bearings with a lighter, low‑maintenance solution. Frequently used in coastal and offshore vessels that operate in warm seawater but do not experience extreme propulsion loads.
Thordon CompacSeries 500mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
500
Bearing material
polymer composite
Length (mm)
1250
Strengths
- Lightweight material reduces overall shaft line weight
- Corrosion‑resistant polymer suitable for seawater exposure
- Compact 1250 mm length fits tight stern tube spaces
- Low friction coefficient improves propeller efficiency
- Self‑lubricating properties can reduce maintenance intervals
Weaknesses
- Lower load capacity compared with traditional steel or bronze bearings
- Limited high‑temperature capability; polymer may soften above ~80 °C
- Higher wear risk if misaligned or contaminated with debris
- Seal type not integrated, requiring an additional sealing solution
- Polymer can be more vulnerable to mechanical impact damage
Typical Vessels:
Medium‑size TankerBulk CarrierContainer ShipOffshore Supply VesselGeneral Cargo Vessel
Decision Guide: Choose if: you need a lightweight, corrosion‑resistant bearing for a 500 mm shaft and have space constraints; the vessel operates within normal temperature ranges and thrust loads are moderate. Avoid if: high thrust or shock loads are expected, operating temperatures exceed polymer limits, or an integrated seal is required without adding extra components.
Use Cases: Commonly installed on new‑build medium cargo vessels where weight and space savings are critical, or as a retrofit replacement for aging metal stern tube bearings in ships operating primarily in temperate to tropical waters.
Thordon CompacSeries 600mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
600
Bearing material
polymer composite
Length (mm)
1500
Strengths
- Polymer composite material provides excellent corrosion resistance in seawater environments
- Reduced friction compared with traditional metal bearings, leading to lower fuel consumption
- Compact design (1500 mm length) eases installation in confined stern tube spaces
- Lightweight relative to steel bearings, decreasing overall shaft line mass
- Low maintenance interval due to self‑lubricating properties of the composite
Weaknesses
- Load capacity generally lower than that of high‑strength steel or babbitt bearings
- Maximum operating temperature limited compared with metal alternatives
- May require specific oil formulations compatible with polymer surfaces
- Limited field history for very large propulsion systems, so some owners may be cautious
Typical Vessels:
Bulk CarrierTankerContainer ShipGeneral Cargo VesselCruise Ship
Decision Guide: Choose if: you need a corrosion‑resistant, low‑maintenance bearing for medium‑size shafts and have moderate load/temperature requirements. Avoid if: the vessel operates at very high shaft loads, extreme temperatures, or you require proven performance on ultra‑large propulsion units.
Use Cases: Commonly installed in new‑builds or retrofits of medium‑speed diesel‑driven vessels where a compact, low‑maintenance stern tube bearing is desired, especially in corrosive service areas such as tropical routes.
Thordon CompacSeries 700mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
700
Bearing material
polymer composite
Length (mm)
1750
Strengths
- Corrosion‑resistant polymer matrix eliminates metal‑to‑metal wear in seawater environments
- Lower friction coefficient compared with traditional babbitt or bronze bearings, improving fuel efficiency
- Self‑lubricating properties reduce routine greasing intervals
- Lightweight construction relative to all‑metal alternatives simplifies handling during installation
Weaknesses
- Maximum operating temperature lower than steel/bronze bearings; may require additional cooling on high‑power vessels
- Limited proven service life under extreme cyclic loading for very large propulsion plants
- Absence of an integrated seal type in the catalog entry means a separate sealing solution must be specified
- Polymer composites can be more costly upfront than conventional metal bearings
Typical Vessels:
TankerBulk CarrierContainer ShipCruise VesselOffshore Supply Vessel
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for a 700 mm shaft on vessels operating primarily in warm to moderate sea temperatures and where weight savings are valuable. Avoid if: the propulsion system runs at very high power levels with extreme temperature spikes or if budget constraints prioritize initial cost over long‑term maintenance reduction.
Use Cases: Commonly installed on newbuilds of medium‑to‑large merchant ships where a 700 mm propeller shaft is used, especially in vessels that operate in tropical or temperate waters and seek to minimise stern tube maintenance cycles.
Thordon CompacSeries 800mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
800
Bearing material
polymer composite
Length (mm)
2000
Strengths
- Lightweight construction compared with traditional steel bearings
- Excellent resistance to seawater corrosion and biofouling
- Low friction coefficient reduces power loss in the propulsion line
- No need for lubrication oil within the bearing material itself
Weaknesses
- No integrated seal; requires an external sealing system to prevent water ingress
- Polymer composites generally have lower load‑capacity limits than steel bearings, restricting use on very high‑power shafts
- Potential temperature sensitivity – performance may degrade at elevated operating temperatures
- Limited long‑term field data for this specific model
Typical Vessels:
Crude oil tankerProduct tankerBulk carrierContainer ship (large class)Ro‑Ro vessel
Decision Guide: Choose if: you need a corrosion‑resistant, low‑maintenance bearing for an 800 mm shaft on vessels where weight saving and reduced friction are priorities, and you can provide an external seal. Avoid if: the propulsion system demands maximum load capacity or operates at high temperatures that exceed polymer limits, or if you require a fully sealed, self‑contained unit.
Use Cases: Typically installed in the stern tube of large merchant ships with 800 mm propeller shafts, especially where exposure to aggressive seawater environments makes corrosion protection critical. Often paired with external gland seals and used on vessels that value reduced maintenance intervals.
Thordon CompacSeries 900mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
900
Bearing material
polymer composite
Length (mm)
2250
Strengths
- Corrosion‑resistant material eliminates rust problems in seawater environments
- Lower friction coefficient than traditional bronze bearings reduces power loss
- Lightweight compared with metal counterparts, easing installation and handling
- Self‑lubricating properties can extend service intervals when used with compatible oil systems
Weaknesses
- Maximum load capacity is lower than that of heavy‑duty metal bearings; not suited for extreme thrust applications
- Limited operating temperature range compared with steel or bronze designs
- Polymer composites may be more sensitive to abrasive particles if filtration is inadequate
- Replacement parts and repair expertise can be less widely available than for conventional bearings
Typical Vessels:
Crude oil tankerProduct tankerBulk carrierContainer shipCruise linerOffshore supply vessel
Decision Guide: Choose if: you need a corrosion‑free bearing for a 900 mm shaft, operate in warm to moderate temperature zones, and value reduced maintenance. Avoid if: the propulsion system imposes very high thrust loads, operates at extreme temperatures, or requires a proven metal bearing for regulatory reasons.
Use Cases: Commonly installed in the stern tube of large merchant vessels where a 900 mm propeller shaft is used, especially on ships that run on low‑sulphur fuels and operate in warm seas where corrosion control is critical. It is also favoured on new builds seeking weight savings and lower lifecycle lubrication costs.
Thordon CompacSeries 1000mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
1000
Bearing material
polymer composite
Length (mm)
2500
Strengths
- Lightweight compared with traditional steel bearings, reducing overall vessel weight
- High corrosion resistance, suitable for saltwater environments
- Low friction coefficient leading to lower fuel consumption
- Integrated length of 2500 mm fits standard stern‑tube housings without modification
Weaknesses
- No built‑in seal type; additional sealing arrangements may be required
- Polymer composites can have lower load‑carrying capacity than steel under extreme thrust conditions
- Limited long‑term field data for this specific model, raising reliability concerns
- Potential temperature limitations of the composite material in high‑heat applications
Typical Vessels:
TankerBulk CarrierContainer ShipCruise VesselOffshore Support Vessel
Decision Guide: Choose if: you need a corrosion‑resistant, lightweight bearing for a 1000 mm shaft and can accommodate an external seal solution; the vessel operates in moderate thrust and temperature regimes. Avoid if: the propulsion system demands very high thrust loads, extreme temperatures, or you require a fully integrated sealing package from the manufacturer.
Use Cases: Commonly installed on new builds or retrofits where weight saving and corrosion protection are priorities—e.g., modern tankers, bulk carriers, and offshore support vessels operating in harsh marine environments.
Thordon TG100 100mm
unverified
Shaft diameter (mm)
100
Bearing material
polymer composite
Length (mm)
250
Strengths
- Polymer composite construction gives inherent corrosion resistance, suitable for seawater environments
- Lightweight compared with traditional steel or bronze bearings, easing installation and reducing overall stern tube mass
- Compact length (250 mm) facilitates fitting in limited space arrangements
Weaknesses
- Generally lower static and dynamic load capacity than equivalent metal bearings
- Operating temperature range may be more restricted than steel designs
- Potential for higher wear rates under high‑speed or heavy‑load conditions
Decision Guide: Choose if the vessel operates with moderate power, requires a corrosion‑resistant bearing, and has space/weight constraints. Avoid if the propulsion system demands high load ratings, extreme temperature tolerance, or long‑term heavy‑duty operation.
Use Cases: Commonly installed in the stern tube of small to medium coastal vessels, ferries, offshore support ships, or any craft using a 100 mm propeller shaft where corrosion resistance and weight savings are priorities.
Thordon TG100 150mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
150
Bearing material
polymer composite
Length (mm)
375
Strengths
- Low friction coefficient reduces power loss
- Corrosion‑resistant material suitable for saltwater environments
- Lightweight compared with traditional steel bearings, easing installation
- Self‑lubricating polymer eliminates need for frequent oil replenishment
- Standard length (375 mm) fits common stern tube housings
Weaknesses
- Lower load‑capacity than comparable steel or bronze bearings
- Maximum operating temperature is limited; high‑speed/high‑power shafts may exceed limits
- Requires an external seal system because the bearing itself has no built‑in seal type
- Long‑term wear data are less extensive for polymer composites in heavy‑duty service
- Potential for abrasive wear if debris enters the stern tube
Typical Vessels:
Bulk CarrierProduct TankerContainer Ship (up to 8,000 gt)FerryOffshore Supply Vessel
Decision Guide: Choose if: the vessel operates at moderate shaft power, values low maintenance and corrosion resistance, and can accommodate an external seal. Avoid if: the propulsion system demands high thrust, very high RPM, or extreme temperature conditions where metal bearings are preferred.
Use Cases: Commonly installed on medium‑size cargo vessels and ferries with a 150 mm propeller shaft, especially in warm marine climates where corrosion is a concern. Also used on offshore support ships that prefer lightweight, low‑maintenance stern tube solutions.
Thordon TG100 200mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
200
Bearing material
polymer composite
Length (mm)
500
Strengths
- Corrosion‑resistant material eliminates rust issues in seawater environments
- Reduced lubrication requirements compared with traditional metal bearings
- Lightweight construction helps lower overall shaft line weight
- Quiet operation due to damping properties of the polymer matrix
- Straightforward installation on standard 200 mm shafts
Weaknesses
- Lower load‑carrying capacity than steel or bronze alternatives
- Limited high‑temperature performance; may require cooling in hot climates
- No integrated seal type, so external sealing arrangements are needed
- Potential for accelerated wear under very high thrust or shock loads
- Long‑term durability data less extensive than for conventional metal bearings
Typical Vessels:
Coastal tankerFeeder container shipOffshore supply vesselSmall bulk carrier
Decision Guide: Choose if you need a corrosion‑free, low‑maintenance bearing for moderate thrust applications and value weight savings. Avoid on vessels with very high shaft loads, extreme temperature conditions, or where an integrated seal is mandatory.
Use Cases: Commonly installed in the stern tube of medium‑size propulsion systems where a 200 mm shaft is used, such as coastal tankers, feeder ships, and offshore support vessels operating in warm to temperate waters.
Thordon TG100 250mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
250
Bearing material
polymer composite
Length (mm)
625
Strengths
- Corrosion‑resistant material eliminates the need for regular greasing cycles
- Low friction coefficient reduces power loss across the shaft line
- Lightweight compared with traditional bronze or steel bearings, easing installation
- Self‑lubricating polymer matrix can extend maintenance intervals in moderate service conditions
Weaknesses
- Maximum load capacity is lower than that of metal alloy bearings, limiting use on high‑thrust shafts
- Temperature rating is typically limited to around 80 °C; performance degrades at higher engine room temperatures
- Polymer wear particles may require filtration if the bearing operates near its design limit
- Limited historical service data for this exact model compared with legacy metal bearings
Typical Vessels:
Medium‑size tankers (up to ~30,000 dwt)Bulk carriers (Handysize to Supramax)Container ships (feeder class)Offshore supply vesselsCruise ship auxiliary propulsion units
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑free bearing for shafts up to 250 mm on vessels with moderate thrust and operating temperatures below ~80 °C. Avoid if: the propulsion system demands high load capacity, operates at elevated temperatures, or requires proven long‑term performance data from metal bearings.
Use Cases: The TG100 is typically installed in the stern tube of medium‑speed diesel propulsion lines on tankers, bulk carriers and offshore supply vessels where space constraints and corrosion resistance are priorities. It is also used on auxiliary shafts of cruise ships where reduced maintenance downtime is valuable.
Thordon TG100 300mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
300
Bearing material
polymer composite
Length (mm)
750
Strengths
- Lightweight construction reduces overall shaft line weight and can improve vessel stability.
- High resistance to seawater corrosion extends service intervals compared with traditional metal bearings.
- Low friction coefficient lowers power loss, contributing to modest fuel savings.
- Self‑lubricating polymer matrix reduces the need for oil lubrication and associated maintenance.
- Modular design simplifies installation and alignment during new builds or retrofits.
Weaknesses
- Lower load‑bearing capacity than conventional babbitt metal bearings; not suited for very high‑power shafts.
- Temperature limitation of the polymer matrix (typically <120 °C) restricts use on high‑temperature propulsion systems.
- Less field‑proven history than legacy designs, which may affect operator confidence and spare‑parts availability.
- Not recommended for ultra‑high speed or high‑rpm applications where metal bearings remain standard.
Typical Vessels:
TankerBulk CarrierContainer ShipRo‑Ro Vessel
Decision Guide: Choose if the vessel prioritises weight reduction, corrosion resistance and lower maintenance within moderate shaft power and temperature limits. Avoid if the propulsion system demands high load capacity, operates at elevated temperatures, or requires a long‑standing, widely documented bearing type.
Use Cases: Commonly installed on medium‑speed diesel propulsion shafts of tankers, bulk carriers and container ships during new builds or retrofits where weight saving and reduced maintenance are valued. Also used in auxiliary shaft lines for generators where load and speed are moderate.
Thordon TG100 350mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
350
Bearing material
polymer composite
Length (mm)
875
Strengths
- Corrosion‑resistant material eliminates rust‑related wear in seawater environments
- Self‑lubricating polymer reduces need for frequent oil replenishment
- Lightweight compared with traditional bronze or steel bearings, easing installation
- Long service intervals due to reduced metal‑to‑metal contact
Weaknesses
- Lower load‑capacity than high‑strength alloy bearings; not ideal for very high‑power shafts
- Temperature limits of polymer composites may restrict use in high‑heat applications
- Limited field data compared with legacy metal designs, requiring careful monitoring during early service
- Seal type not specified; additional sealing solutions may be required
Typical Vessels:
TankerBulk CarrierContainer ShipCruise VesselOffshore Supply Vessel
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑free bearing for shafts up to ~350 mm on vessels where power and torque are moderate and weight saving is beneficial. Avoid if: the propulsion system exceeds the load or temperature limits of polymer composites, or if you require proven long‑term performance data for ultra‑high‑power applications.
Use Cases: Commonly installed in new‑builds or mid‑life retrofits where the shaft line operates in aggressive seawater conditions and operators seek to minimise routine bearing oil changes. Typical on medium‑speed diesel propulsion units of tankers, bulk carriers and offshore vessels.
Thordon TG100 400mm
unverified
· polymer composite stern‑tube bearing
Shaft diameter (mm)
400
Bearing material
polymer composite
Length (mm)
1000
Strengths
- Corrosion‑resistant material eliminates metal‑to‑metal galvanic issues in seawater environments
- Self‑lubricating polymer reduces need for regular greasing and lowers maintenance intervals
- Lightweight compared with traditional bronze or steel bearings, easing installation and reducing overall shaft line weight
- Integrated sealing lip (if present) offers basic protection against water ingress without additional external seals
Weaknesses
- Lower load‑carrying capacity than heavy‑duty metal bearings; may be unsuitable for very high thrust applications
- Temperature limits of polymer composites can restrict use in high‑heat zones or during prolonged high‑speed operation
- Long‑term wear characteristics are less documented than conventional materials, requiring closer monitoring
Typical Vessels:
Product tankerOffshore supply vesselMedium‑size container shipGeneral cargo vessel
Decision Guide: Choose if the vessel operates in corrosive seawater, requires reduced maintenance and lower shaft line weight, and the thrust load is within moderate limits. Avoid if the propulsion system demands high thrust or operates at elevated temperatures where polymer performance may degrade.
Use Cases: Commonly installed on medium‑size commercial ships where a 400 mm propeller shaft is used, especially in vessels that prioritize low maintenance cycles and corrosion resistance, such as product tankers and offshore supply ships operating in warm marine climates.
Thordon TG100 450mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
450
Bearing material
polymer composite
Length (mm)
1125
Strengths
- Lightweight compared with traditional bronze or steel bearings, reducing overall stern tube mass
- Excellent corrosion resistance in seawater, extending service intervals
- Low coefficient of friction, improving propulsion efficiency
- Self‑lubricating polymer matrix reduces reliance on external oil feeds
Weaknesses
- Maximum load capacity is lower than heavy‑duty metal bearings; unsuitable for very high thrust applications
- Operating temperature range is limited (typically up to ~120 °C), restricting use with high‑temperature exhaust gases
- Polymer wear particles may require filtration in the bearing oil system
Typical Vessels:
TankerBulk CarrierContainer ShipRo‑Ro Vessel
Decision Guide: Choose if: you need a lightweight, corrosion‑resistant bearing for a medium‑size propulsion shaft and the vessel operates within moderate thrust and temperature limits. Avoid if: the installation demands very high thrust loads, extreme temperatures, or proven metal‑bearing heritage is required by classification societies.
Use Cases: Installed in the stern tube of merchant vessels with a 450 mm propeller shaft, typically on medium‑speed diesel propulsion systems where reduced maintenance and weight savings are valued.
Thordon TG100 500mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
500
Bearing material
polymer composite
Length (mm)
1250
Strengths
- Corrosion‑resistant polymer composite eliminates rust in seawater environments
- Low friction operation reduces power loss and wear on the shaft
- No lubrication system required, simplifying maintenance routines
- Lightweight compared with traditional steel bearings, decreasing overall stern‑tube mass
Weaknesses
- Lower load capacity than high‑strength metal bearings for extreme torque conditions
- Higher coefficient of thermal expansion may require tighter alignment tolerances
- Polymer material can be more vulnerable to impact damage or foreign object intrusion
- Long‑term aging of polymer under UV and chemical exposure may affect performance
Decision Guide: Choose if the vessel operates in corrosive seawater, requires reduced maintenance and weight savings, and the shaft torque stays within the load limits of polymer composites. Avoid if the propulsion system demands very high torque or experiences frequent shock loads that exceed typical polymer bearing capacities.
Use Cases: Commonly installed in the stern tube of large commercial ships—such as tankers, bulk carriers, and container vessels—with a 500 mm propeller shaft, where corrosion resistance and low maintenance are priorities.
Thordon TG100 600mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
600
Bearing material
polymer composite
Length (mm)
1500
Strengths
- Polymer‑composite material offers excellent corrosion resistance in seawater environments.
- Eliminates the need for regular lubrication, reducing maintenance intervals.
- Sized for a 600 mm shaft and 1500 mm length, suitable for high‑power main engines.
- Lightweight compared with traditional steel bearings, potentially lowering overall stern‑tube weight.
Weaknesses
- Load‑capacity may be lower than equivalent steel or bronze bearings under extreme overload conditions.
- Limited field history; few documented installations to verify long‑term performance.
- May require additional certification or approval from classification societies for certain vessel classes.
- Temperature limits of polymer composites can be lower than metal bearings in high‑heat applications.
Typical Vessels:
Crude oil tankerProduct tankerBulk carrierContainer ship (large‑size)Cruise liner
Decision Guide: Choose if you need a low‑maintenance, corrosion‑resistant bearing for a 600 mm shaft on vessels operating in harsh marine environments and where classification societies accept polymer‑composite solutions. Avoid if the propulsion system is subject to very high peak loads, extreme temperature excursions, or if required class approvals are not yet available for this specific model.
Use Cases: Typically installed within the stern tube of ocean‑going tankers, bulk carriers and other large vessels where a 600 mm shaft transmits power from a low‑speed diesel engine to the propeller. The bearing’s polymer construction is favored in warm tropical waters or when minimizing lubrication logistics is a priority.
Thordon TG100 700mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
700
Bearing material
polymer composite
Length (mm)
1750
Strengths
- Corrosion‑resistant material suitable for seawater exposure
- Reduced friction compared with traditional metal bearings
- Lightweight relative to comparable metal designs, easing installation handling
- Self‑lubricating properties can lower routine maintenance intervals
Weaknesses
- Lower load‑capacity limits than high‑strength steel or bronze alternatives
- Temperature sensitivity; performance may degrade above typical marine ambient ranges
- May require specialized seals or backup rings because seal_type is not specified
- Limited long‑term field data for very large shafts (700 mm) compared with legacy designs
Typical Vessels:
Bulk CarrierContainer ShipGeneral Cargo VesselOffshore Supply Vessel
Decision Guide: Choose if: you need a corrosion‑free bearing for a 700 mm shaft on vessels where weight and maintenance reduction are priorities, and the operating loads/temperatures stay within polymer limits. Avoid if: the propulsion system demands high load capacity, extreme temperature resilience, or proven long‑term performance data from extensive service history.
Use Cases: Commonly installed in new builds or retrofits of medium‑size merchant ships where a 700 mm propeller shaft is used and the operating profile is moderate (e.g., routes without excessive high‑speed runs). It fits within standard stern tube assemblies, replacing traditional bronze bearings to gain corrosion resistance.
Thordon TG100 800mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
800
Bearing material
polymer composite
Length (mm)
2000
Strengths
- Corrosion‑resistant polymer material reduces maintenance intervals compared with traditional bronze bearings
- Low friction coefficient improves propeller efficiency and can lower fuel consumption
- Lightweight construction relative to all‑metal designs helps reduce overall shaft line weight
- Self‑lubricating properties allow longer dry‑run periods before oil replenishment is required
Weaknesses
- Polymer composites have lower load‑carrying capacity than high‑grade bronze, limiting use on very high‑power shafts
- Maximum operating temperature is typically lower than metal bearings, requiring careful monitoring in hot climates
- Limited field experience for this specific model may affect confidence in long‑term durability
- Replacement parts and specialised repair kits may be less widely stocked than standard bearing types
Typical Vessels:
Medium‑size tankers (10 000–30 000 dwt)Bulk carriers up to 40 000 dwtContainer ships in the 5 000–15 000 TEU rangeGeneral cargo vessels with medium‑power propulsion
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for an 800 mm shaft on vessels where peak power and temperature are within the polymer’s limits. Avoid if: the installation demands maximum load capacity or operates in extreme high‑temperature environments where metal bearings are preferred.
Use Cases: The TG100 is typically installed in new builds or retrofits of medium‑size merchant ships where the propulsion shaft size matches an 800 mm diameter and operators seek to minimise routine bearing servicing while maintaining acceptable performance under moderate power loads.
Thordon TG100 900mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
900
Bearing material
polymer composite
Length (mm)
2250
Strengths
- Lightweight compared with traditional steel bearings, reducing overall propulsion system weight
- Excellent corrosion resistance in seawater, extending service intervals
- Self‑lubricating properties can lower oil consumption and maintenance frequency
- Longer fatigue life for high‑speed or variable‑load applications
Weaknesses
- Higher initial cost than conventional steel bearings
- Limited proven track record on very large vessels; some operators prefer metal for ultra‑high power shafts
- Polymer composites may be more sensitive to temperature extremes, requiring careful monitoring
- Replacement procedures differ from standard steel bearings, needing specialised tooling
Typical Vessels:
Container ship (up to 8 000 gt)General cargo vesselCoastal tankerOffshore support vessel
Decision Guide: Choose if: you need a lightweight, corrosion‑resistant bearing for a 900 mm shaft and are willing to invest in the higher upfront cost for reduced maintenance. Avoid if: the vessel operates at very high power levels where proven steel bearings are mandated by class societies or owners.
Use Cases: Commonly installed on medium‑size merchant ships where propeller shaft speed and corrosion exposure demand a low‑friction, long‑life bearing solution, especially in warm tropical waters.
Thordon TG100 1000mm
unverified
· polymer composite stern tube bearing
Shaft diameter (mm)
1000
Bearing material
polymer composite
Length (mm)
2500
Strengths
- Self‑lubricating polymer matrix reduces routine oiling and maintenance intervals
- Excellent resistance to seawater corrosion and bio‑fouling compared with traditional metal bearings
- Lower overall weight helps reduce stern tube assembly loads
- Long service life when operated within the material’s temperature and load limits
Weaknesses
- Maximum static and dynamic load capacity is lower than that of steel or bronze bearings, limiting use on very high‑power propulsion systems
- Upper temperature limit (~120 °C) may be restrictive for some high‑speed diesel engines
- Installation requires careful alignment to avoid point loading that can damage the composite material
- Limited field experience compared with legacy metal bearing families
Typical Vessels:
Crude oil tankerProduct tankerBulk carrierContainer shipGeneral cargo vessel
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for shafts up to 1000 mm on vessels operating in aggressive seawater environments and the propulsion power stays within the polymer’s load rating. Avoid if: the engine delivers very high torque or operates at temperatures above the composite’s limit, or if you require proven metal‑bearing performance for extreme overload conditions.
Use Cases: Typically installed in the stern tube of large merchant ships where a 1000 mm shaft transmits power from the main engine to the propeller. It is favoured on routes with high salinity or temperature variations, and on vessels that aim to minimise routine bearing oil changes and associated downtime.
Duramax Marine
32
Johnson Cutless 50mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
50
Bearing material
nitrile rubber
Length (mm)
150
Strengths
- Eliminates scheduled bearing removal – reduces dry‑dock time
- Nitrile rubber liner offers good corrosion resistance in seawater
- Compact length (≈150 mm) fits tight stern tube spaces on smaller vessels
- Simple installation with standard 50 mm shaft interface
Weaknesses
- Nitrile rubber may degrade faster than bronze or polymer composites under high‑temperature service
- Limited load capacity compared with heavy‑duty metal bearings
- No integrated seal type listed – additional sealing may be required
- Cut‑less design can be less tolerant of misalignment than replaceable bearing packs
Typical Vessels:
Coastal cargo vesselsOffshore supply boatsTugboatsFerries (≤10 m draft)Small fishing vessels with inboard diesel engines
Decision Guide: Choose if: you need a low‑maintenance bearing for a 50 mm shaft on a vessel where dry‑dock intervals are costly and operating loads are moderate. Avoid if: the propulsion system operates at high power, high temperature, or requires heavy‑load capacity beyond what nitrile rubber can sustain.
Use Cases: Typically installed in the stern tube of small to medium diesel‑driven vessels for auxiliary propulsion or main drive where space is limited and maintenance windows are infrequent. Common on offshore supply craft and coastal traders that run at moderate speeds (≤12 kn) and have shaft power under ~1,500 kW.
Johnson Cutless 75mm
unverified
· Cutless stern tube bearing
Shaft diameter (mm)
75
Bearing material
nitrile rubber
Length (mm)
225
Strengths
- No need to cut or machine the propeller shaft during installation
- Quick replacement with minimal dry‑dock time
- Nitrile rubber provides good vibration damping and corrosion resistance in seawater
- Compact 225 mm length fits confined stern‑tube spaces
- Specifically sized for standard 75 mm shafts used on many mid‑size vessels
Weaknesses
- Load capacity lower than steel or babbitt bearings
- Nitrile rubber degrades above ~80 °C, limiting high‑temperature operation
- No integrated seal; additional sealing arrangement required
- Not suited for high‑speed or high‑power propulsion systems
- Requires periodic hydraulic pressure checks to maintain proper preload
Typical Vessels:
Product TankerChemical TankerOffshore Supply VesselMultipurpose VesselCoastal Cargo Ship
Decision Guide: Choose if you need a quick‑install, low‑maintenance bearing for a 75 mm shaft on vessels with moderate power and speed where dry‑dock time must be minimized. Avoid if the propulsion system operates at high speeds, high loads, or elevated temperatures, or if an integrated seal is required.
Use Cases: Commonly installed in the stern tube of medium‑size tankers and offshore supply vessels equipped with low‑speed diesel engines; used where rapid bearing replacement and reduced shaft machining are priorities.
Johnson Cutless 100mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
100
Bearing material
nitrile rubber
Length (mm)
300
Strengths
- Eliminates shaft cutting and associated alignment issues
- Nitrile rubber liner offers good oil retention and wear resistance for moderate speeds
- Relatively simple installation and replacement compared with traditional bearings
- Compact length (300 mm) suitable for limited stern tube space
Weaknesses
- Nitrile rubber may have lower temperature tolerance than advanced polymer composites
- Limited to shaft diameters around 100 mm; not suitable for larger main propulsion shafts
- Requires regular oil monitoring to avoid dry‑run wear
Typical Vessels:
Coastal tankerFerryOffshore supply vesselSmall bulk carrier
Decision Guide: Choose if: you need a low‑maintenance bearing for a 100 mm shaft on vessels where space is limited and cutting the shaft is undesirable. Avoid if: the propulsion system operates at very high speeds or temperatures, or if a larger shaft diameter is required.
Use Cases: Commonly installed in the stern tube of medium‑size merchant ships and offshore support vessels that use auxiliary diesel engines or smaller propeller shafts, where ease of maintenance and quick replacement are priorities.
Johnson Cutless 125mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
125
Bearing material
nitrile rubber
Length (mm)
375
Strengths
- No need to cut or modify the propeller shaft, reducing installation time and risk of misalignment
- Nitrile rubber liner provides good corrosion resistance in seawater environments
- Integrated design allows for straightforward retro‑fit on existing vessels
- Low friction surface helps improve propulsion efficiency for moderate thrust applications
Weaknesses
- Limited to shaft diameters around 125 mm; not suitable for larger high‑power shafts
- Nitrile rubber may degrade faster under very high temperatures or ozone exposure
- Maximum load capacity lower than heavy‑duty metal (bronze/steel) bearings, limiting use on high‑thrust vessels
- Requires periodic inspection and possible re‑lubrication of the rubber liner
Typical Vessels:
Container shipBulk carrierTankerGeneral cargo vesselOffshore supply vessel
Decision Guide: Choose if you need a quick, cut‑less installation on a vessel with a 125 mm shaft and moderate thrust requirements, and you value corrosion resistance and ease of maintenance. Avoid if the propulsion system demands very high load capacity, operates at extreme temperatures, or uses larger shaft sizes where metal bearings are preferred.
Use Cases: Commonly installed as the main stern‑tube bearing on new builds or during retrofits where cutting the propeller shaft is impractical; used in medium‑speed diesel propulsion lines of merchant ships and offshore vessels.
Johnson Cutless 150mm
unverified
· cutless bearing
Shaft diameter (mm)
150
Bearing material
nitrile rubber
Length (mm)
450
Strengths
- Oil‑free operation eliminates the need for lubrication pumps and reduces contamination risk
- Simple installation – no machining of the stern tube required
- Corrosion‑resistant nitrile rubber liner suitable for seawater environments
- Lower routine maintenance costs compared with traditional journal bearings
- Compact length (450 mm) fits into limited stern tube spaces
Weaknesses
- Load capacity lower than full‑size oil‑lubricated journal bearings, limiting use on high‑power shafts
- Nitrile rubber can degrade at elevated temperatures (>80 °C) or with aggressive chemicals
- Replacement intervals typically shorter (2–4 years) than for oil‑filled bearings
- Limited suitability for very high‑speed propulsion systems
- Spare part availability may be restricted to Duramax Marine distribution network
Typical Vessels:
Coastal cargo vesselsOffshore supply shipsFerries (up to ~10 MW propulsion)Small tankers and product carriersYachts and high‑speed craft with moderate shaft loads
Decision Guide: Choose if: you need a low‑maintenance, oil‑free bearing for shafts up to 150 mm on vessels with moderate power and limited stern‑tube space. Avoid if: the propulsion system requires high load capacity, operates at very high speeds, or will be exposed to temperatures that exceed the rubber liner’s limits.
Use Cases: Typically installed in the stern tube of medium‑size diesel‑driven ships where a compact, maintenance‑light bearing is preferred—e.g., offshore supply vessels operating in harsh marine environments, coastal cargo carriers with shaft powers under 10 MW, and ferries that benefit from reduced lubrication system complexity.
Johnson Cutless 175mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
175
Bearing material
nitrile rubber
Length (mm)
525
Strengths
- Oil‑free operation eliminates the need for lubrication systems and reduces leakage risk
- Nitrile rubber liner offers good corrosion resistance in seawater environments
- Compact length (525 mm) eases installation in confined stern tube spaces
- Low maintenance – no oil changes or bearing re‑grinding required
- Suitable for shaft diameters up to 200 mm, covering a wide range of medium‑size vessels
Weaknesses
- Load capacity is lower than that of traditional metal journal bearings, limiting use on high‑power shafts
- Nitrile rubber has temperature and chemical limits; performance degrades above ~80 °C or with certain contaminants
- Periodic visual inspection is still required to detect wear or cracking of the rubber liner
- May not be optimal for very high‑speed propulsion systems where metal bearings are preferred
Typical Vessels:
Product TankerBulk Carrier (Handymax/Handysize)Container Ship (Feeder)Offshore Supply VesselGeneral Cargo Vessel
Decision Guide: Choose if: you need a low‑maintenance, oil‑free bearing for a shaft up to 175 mm on a medium‑speed vessel and want to minimise environmental leakage risk. Avoid if: the propulsion system operates at very high speeds or carries loads that exceed the capacity of a rubber‑lined cutless bearing.
Use Cases: Typically installed in the stern tube of mid‑size cargo and offshore vessels where reliability, ease of installation and reduced maintenance are priorities, especially on ships operating in warm climates or with strict environmental controls on oil discharge.
Johnson Cutless 200mm
unverified
· nitrile rubber cut‑less bearing
Shaft diameter (mm)
200
Bearing material
nitrile rubber
Length (mm)
600
Strengths
- Cut‑less design eliminates the need for oil lubricants and associated maintenance.
- Nitrile rubber offers good corrosion resistance in seawater environments.
- Relatively easy to install and replace compared with metal journal bearings.
- Suitable for moderate speed vessels where shaft loads are within typical nitrile bearing limits.
Weaknesses
- Limited load‑carrying capacity versus steel or babbitt metal bearings; not ideal for high‑power, high‑speed applications.
- Temperature sensitivity – performance can degrade at elevated operating temperatures.
- No integrated seal type specified; additional sealing may be required to prevent water ingress.
Typical Vessels:
Coastal tankerOffshore supply vesselFerryTugboatSmall bulk carrier
Decision Guide: Choose if: you need a low‑maintenance, oil‑free bearing for a 200 mm shaft on a moderate‑speed vessel and the expected loads are within nitrile rubber limits. Avoid if: the propulsion system operates at high speed or high torque where metal bearings provide greater strength and heat tolerance.
Use Cases: Commonly installed in the stern tube of medium‑size diesel‑driven ships to support the propeller shaft, especially on vessels that prioritize reduced maintenance intervals and corrosion resistance.
Johnson Cutless 250mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
250
Bearing material
nitrile rubber
Length (mm)
750
Strengths
- Directly matches 250 mm shaft diameter – no custom machining required.
- Nitrile rubber liner offers good resistance to seawater corrosion and oil contamination.
- Compact 750 mm length reduces stern‑tube envelope space, useful on vessels with limited aft clearance.
- Cutless design eliminates the need for a removable bearing shoe, simplifying installation and maintenance.
Weaknesses
- Nitrile rubber has a more limited temperature range than PTFE or metal‑on‑metal liners.
- No integrated seal type is specified; an external sealing arrangement must be provided.
- Designed only for shafts up to 250 mm – unsuitable for larger propulsion lines.
Typical Vessels:
Bulk CarrierContainer ShipProduct TankerGeneral Cargo VesselOffshore Supply Vessel
Decision Guide: Choose if you need a compact, corrosion‑resistant bearing for a 250 mm shaft and are prepared to fit an external seal. Avoid if the propulsion system operates at high temperatures, requires a larger shaft size, or mandates an integrated seal certification.
Use Cases: Commonly installed in the stern tube assemblies of medium‑size cargo and offshore vessels where space is limited and a reliable, low‑maintenance bearing is required for shafts up to 250 mm.
Johnson Cutless 300mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
300
Bearing material
nitrile rubber
Length (mm)
900
Strengths
- Cutless design eliminates the need to cut the shaft, reducing installation time and risk of misalignment.
- Nitrile rubber liner offers good wear resistance and flexibility in typical marine temperature ranges.
- Integrated water lubrication reduces the requirement for external oil‑lubricated bearings.
- Standard length of 900 mm fits most conventional stern tube housings for 300 mm shafts.
Weaknesses
- Absence of a dedicated seal may permit some ingress of debris if alignment is not perfect.
- Nitrile rubber can degrade faster than metal alloys under high‑temperature or high‑load conditions.
- Load‑capacity data are not publicly available, limiting confidence for high‑power applications.
- Catalog information flagged as needing verification; specifications may differ from actual product.
Typical Vessels:
Product TankerOffshore Supply VesselSmall Bulk CarrierContainer Feeder
Decision Guide: Choose if: you need a quick‑install, water‑lubricated bearing for a 300 mm shaft on vessels with moderate thrust and temperature conditions. Avoid if: the propulsion system requires high thrust capacity, operates at elevated temperatures, or mandates specific class society approvals that are not confirmed for this model.
Use Cases: Commonly installed in the stern tube of medium‑size merchant ships where maintenance access is limited and a cutless bearing simplifies shaft line assembly while providing reliable water lubrication.
Johnson Cutless 350mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
350
Bearing material
nitrile rubber
Length (mm)
1050
Strengths
- Oil‑free operation eliminates the risk of lubricant leakage into the sea.
- Reduced routine maintenance compared with traditional lubricated bearings.
- Compact design (1050 mm length) fits tight stern tube spaces.
- Nitrile rubber element offers good abrasion resistance for typical service loads.
- Straightforward installation on new builds or during major overhauls.
Weaknesses
- Higher upfront cost than conventional lubricated bearings.
- Load capacity may be lower than heavy‑duty oil‑lubricated alternatives.
- Nitrile rubber can degrade at elevated temperatures (>80 °C).
- Retrofit on existing stern tubes may require precise alignment and possible tube modification.
- Limited availability of spare parts in remote ports compared with more common brands.
Typical Vessels:
Bulk CarrierProduct TankerContainer ShipOffshore Supply VesselCruise Ship
Decision Guide: Choose if: you need an oil‑free, low‑maintenance bearing for a 350 mm shaft and operate in environments where lubricant discharge is prohibited; vessel design allows the 1050 mm length. Avoid if: the propulsion system demands very high load capacity or operates at temperatures exceeding nitrile rubber limits, or if budget constraints prioritize lower initial cost.
Use Cases: Commonly installed on new builds of medium‑size cargo vessels and offshore support ships where environmental regulations restrict oil discharge and maintenance windows are limited. Also used in retrofits when owners seek to eliminate stern tube oil systems for reliability and compliance reasons.
Johnson Cutless 400mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
400
Bearing material
nitrile rubber
Length (mm)
1200
Strengths
- Cut‑less design allows bearing replacement without dismantling the shaft line, reducing dry‑dock time.
- Nitrile rubber provides good vibration damping and corrosion resistance in seawater environments.
- Compact 1200 mm length fits tighter stern‑tube arrangements on modern hull forms.
- Self‑aligning rubber element accommodates minor misalignment of the shaft.
Weaknesses
- Rubber material has a lower temperature rating than metal bearings, limiting use in high‑heat applications.
- Potential for accelerated wear under very high thrust or shock loads compared with steel/bronze liners.
- Seal type not specified; additional sealing arrangements may be required to prevent water ingress.
- Limited documented service history for this exact model, requiring closer monitoring during early service.
Typical Vessels:
TankerBulk CarrierContainer ShipGeneral Cargo VesselOffshore Supply Vessel
Decision Guide: Choose if: you need a low‑maintenance, quick‑replace bearing for a 400 mm shaft on vessels where dry‑dock intervals are long and space is at a premium. Avoid if: the propulsion system operates at temperatures above the rubber’s rating or experiences frequent high‑impact loads that exceed typical rubber bearing limits.
Use Cases: Installed in the stern tube of ocean‑going merchant ships to support main propulsion shafts, especially on vessels retrofitted with newer, more compact hull designs where rapid bearing replacement is a priority.
Johnson Cutless 450mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
450
Bearing material
nitrile rubber
Length (mm)
1350
Strengths
- No packing gland adjustment – easier installation and reduced maintenance downtime
- Nitrile rubber liner provides good corrosion resistance in seawater environments
- Integrated alignment tolerance accommodates minor shaft mis‑alignment
- Compact length (1350 mm) fits standard stern tube housings for 450 mm shafts
Weaknesses
- Nitrile rubber has a limited temperature range compared with metal or composite liners
- Wear rate can increase in high‑speed or heavily loaded applications, requiring more frequent inspections
- Not suitable for shafts exceeding the rated diameter or for very high‑power propulsion units without engineering review
Typical Vessels:
Bulk carrierProduct tankerContainer ship (up to 8 000 gt)Offshore supply vesselGeneral cargo vessel
Decision Guide: Choose if: you need a low‑maintenance, easy‑install bearing for a 450 mm shaft on vessels with moderate power and speed, and you prefer a cutless design to avoid packing adjustments. Avoid if: the propulsion system operates at high speeds or temperatures beyond nitrile limits, or if the vessel requires a bearing certified for ultra‑high‑power applications.
Use Cases: Typically installed in the stern tube of medium‑size merchant ships where shaft diameters are around 450 mm and operating conditions are standard seawater temperatures. Used on new builds and retrofits to replace traditional packed bearings, especially where reduced maintenance intervals are a priority.
Johnson Cutless 500mm
unverified
· cut‑less stern tube bearing
Shaft diameter (mm)
500
Bearing material
nitrile rubber
Length (mm)
1500
Strengths
- Eliminates oil lubrication and associated maintenance tasks thanks to its cut‑less design
- Nitrile rubber liner offers good shock absorption and resistance to seawater corrosion
- Modular length (1500 mm) simplifies installation and alignment on the shaft line
- Suitable for standard propulsion shafts up to 500 mm, common on many merchant vessels
- Lower operating temperature range compared with metal‑to‑metal bearings reduces heat buildup
Weaknesses
- Nitrile rubber may degrade faster at elevated temperatures (>80 °C) or under high load cycles
- Not intended for very high power or high‑speed applications where metal bearings are required
- No integrated seal type provided, requiring an additional sealing solution to prevent water ingress
- Potentially heavier than advanced composite bearing alternatives
- Spare‑part availability may be limited if the manufacturer has a narrow distribution network
Typical Vessels:
Bulk CarrierGeneral CargoContainer ShipProduct TankerCoastal Trader
Decision Guide: Choose if: you need a reliable, low‑maintenance bearing for a 500 mm shaft on a vessel with moderate power and speed, and you prefer to avoid oil‑filled systems. Avoid if: the propulsion system operates at high speeds or temperatures, requires an integrated seal, or demands the higher load capacity of metal bearings.
Use Cases: Commonly installed in the stern tube of medium‑size merchant ships—such as new‑build bulk carriers, container vessels, and product tankers—where a cut‑less bearing simplifies installation and reduces maintenance intervals for standard propulsion shafts up to 500 mm.
Johnson Cutless 600mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
600
Bearing material
nitrile rubber
Length (mm)
1800
Strengths
- Cutless design eliminates need for periodic grinding or re‑cutting of the bearing surface, reducing maintenance downtime.
- Nitrile rubber liner offers good shock absorption and noise reduction, improving crew comfort.
- Corrosion‑resistant material suitable for marine environments, extending service life in saltwater.
- Standard 600 mm shaft compatibility simplifies retrofits on many existing vessels.
- Relatively compact length (1800 mm) fits into constrained stern tube spaces.
Weaknesses
- Nitrile rubber has a limited temperature range; performance may degrade in very high‑temperature applications.
- Load capacity is lower than that of metal or composite bearings, making it less suitable for high‑power propulsion units.
- No integrated seal type specified, potentially requiring an additional sealing solution to prevent water ingress.
- Rubber wear over time can lead to increased clearances if not monitored regularly.
- May not be ideal for vessels operating at very high shaft speeds where metal bearings are preferred.
Typical Vessels:
Bulk CarrierProduct TankerContainer Ship (mid‑size)Offshore Supply VesselGeneral Cargo Ship
Decision Guide: Choose if: you need a low‑maintenance, vibration‑damping bearing for a 600 mm shaft on vessels with moderate power and speed, and space constraints favor a compact design. Avoid if: the propulsion system operates at high speeds or loads that exceed rubber bearing limits, or if an integrated seal is required without adding extra components.
Use Cases: Commonly installed in new builds or as a retrofit on medium‑size merchant vessels where shaft power is moderate and maintenance windows are limited. It is favored for routes with frequent port calls where downtime must be minimized, and in offshore support ships that benefit from reduced vibration transmission to onboard equipment.
Johnson Cutless 700mm
unverified
· cutless elastomeric stern tube bearing
Shaft diameter (mm)
700
Bearing material
nitrile rubber
Length (mm)
2100
Strengths
- Oil‑free operation eliminates the risk of oil leakage in the stern tube.
- Low maintenance – no lubrication system required.
- Compact length (2100 mm) fits confined installation spaces.
- Nitrile rubber offers good resistance to seawater corrosion.
Weaknesses
- Load capacity is lower than that of traditional metal journal bearings.
- Performance limited by the temperature range of nitrile rubber.
- May require periodic visual inspection and eventual replacement of the elastomeric element.
- Not ideal for very high‑speed or high‑power propulsion shafts.
Decision Guide: Choose if you need a compact, oil‑free bearing for a 700 mm shaft on vessels with moderate power and speed where low maintenance is a priority. Avoid if the propulsion system demands high load capacity, operates at very high speeds, or experiences extreme temperature conditions.
Use Cases: Typically installed in the stern tube of medium‑size merchant ships (e.g., coastal tankers, general cargo vessels) where a reliable, oil‑free bearing solution is preferred to reduce maintenance and environmental risk.
Johnson Cutless 800mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
800
Bearing material
nitrile rubber
Length (mm)
2400
Strengths
- Oil‑free design eliminates leakage and reduces environmental risk
- Nitrile rubber liner offers good corrosion resistance in seawater
- Easy installation with cutless mounting system, no need for oil pumps or reservoirs
- Suitable for large shaft diameters (up to 800 mm) common on tankers and bulk carriers
- Low routine maintenance compared with traditional lubricated bearings
Weaknesses
- Nitrile rubber has a limited temperature range; performance degrades above ~80 °C
- Not ideal for very high‑speed propulsion shafts where metal‑on‑metal bearings are preferred
- Seal type not specified; water ingress must be managed with external seals or protective sleeves
- Service life can be reduced under excessive radial loads or frequent shock loading
Typical Vessels:
Crude oil tankerProduct tankerBulk carrierContainer ship (mid‑size)Offshore supply vessel
Certifications:
DNVABS
Decision Guide: Choose if you need a low‑maintenance, oil‑free bearing for an 800 mm propulsion shaft on vessels with moderate RPM and operating temperatures. Avoid if the installation demands high‑temperature resistance, very high shaft speeds, or if external sealing cannot be guaranteed.
Use Cases: Commonly installed as the main stern‑tube bearing in new‑build tankers and bulk carriers, or as a retrofit replacement to reduce maintenance costs on existing ships with large shafts.
Duramax Cutless 50mm
unverified
· Cutless stern tube bearing
Shaft diameter (mm)
50
Bearing material
nitrile rubber
Length (mm)
150
Strengths
- No oil or grease required – eliminates routine lubrication and reduces contamination risk
- Simple installation with a split‑ring design that can be fitted around an existing shaft
- Nitrile rubber offers good resistance to seawater corrosion and moderate temperature ranges
- Compact length (150 mm) suitable for vessels with limited stern tube space
Weaknesses
- Limited load‑carrying capacity compared with oil‑lubricated bronze bearings, making it unsuitable for high‑power propulsion shafts
- Operating life can be reduced in very warm water or under heavy cyclic loads
- No integrated seal; external sealing must be provided to prevent water ingress
Typical Vessels:
Coastal tankersOffshore supply vesselsFerries (up to ~10 m draught)Medium‑size fishing vesselsWorkboats
Decision Guide: Choose if: you need a low‑maintenance, compact bearing for a 50 mm shaft on a vessel with moderate power and limited stern‑tube space. Avoid if: the propulsion system operates at high torque, high speed, or in very warm tropical waters where a lubricated bronze bearing would give longer service life.
Use Cases: Commonly installed on small to medium auxiliary propulsion shafts, stern thrusters, and pump drives where simplicity and corrosion resistance are priorities, especially on vessels that prefer oil‑free solutions for environmental compliance.
Duramax Cutless 75mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
75
Bearing material
nitrile rubber
Length (mm)
225
Strengths
- Oil‑free operation eliminates the need for bearing oil circulation and related maintenance.
- Compact length (225 mm) fits into tight stern tube spaces on smaller vessels.
- Nitrile rubber material provides good corrosion resistance in seawater environments.
- Easy retrofit onto existing shafts of 75 mm diameter, reducing installation time.
Weaknesses
- Load‑capacity lower than metal or composite bearings; not suited for high‑power propulsion.
- Temperature limits of nitrile rubber may restrict use in very hot operating conditions.
- No integrated seal (seal_type is null), requiring an external sealing solution to prevent water ingress.
- Rubber wear over time can lead to higher replacement frequency compared with hardened steel bearings.
Typical Vessels:
Offshore supply vesselTugboatCoastal cargo shipFerryFishing vessel
Decision Guide: Choose if: you need a low‑maintenance, oil‑free bearing for a 75 mm shaft on vessels with moderate power and limited stern tube space. Avoid if: the propulsion system demands high load capacity, operates at elevated temperatures, or requires an integrated seal system.
Use Cases: Commonly installed in the stern tubes of medium‑size workboats and coastal carriers as a retrofit to reduce bearing oil systems, or on new builds where simplicity and corrosion resistance are priorities.
Duramax Cutless 100mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
100
Bearing material
nitrile rubber
Length (mm)
300
Strengths
- Cut‑less design eliminates the need for oil‑filled bearing shells, reducing maintenance and risk of oil leaks.
- Nitrile rubber lining offers good corrosion resistance in seawater environments.
- Compact length (≈300 mm) eases installation in confined stern‑tube spaces.
- Suitable for vessels with moderate power ratings where a 100 mm shaft is standard.
Weaknesses
- Rubber bearing material has lower load‑carrying capacity than metal or composite bearings, limiting use on high‑power main engines.
- Temperature range of nitrile rubber may be restricted (typically up to ~80 °C), making it less suitable for very hot operating conditions.
- No integrated seal type is specified; additional sealing arrangements may be required.
- Long‑term wear characteristics are less documented than for conventional oil‑filled bearings.
Typical Vessels:
Coastal tankersOffshore supply vesselsWorkboats / tugsFerries with medium‑speed diesel propulsion
Decision Guide: Choose if: you need a low‑maintenance, compact bearing for a 100 mm shaft on a vessel with moderate power and operating temperatures within the rubber’s limits. Avoid if: the propulsion system demands high load capacity, very high speeds, or operates in extreme temperature environments where metal bearings are preferred.
Use Cases: Commonly installed in the stern tube of medium‑speed diesel‑driven ships where ease of installation and reduced oil handling are priorities, such as coastal cargo carriers, supply vessels to offshore platforms, and harbor tugs.
Duramax Cutless 125mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
125
Bearing material
nitrile rubber
Length (mm)
375
Strengths
- Eliminates oil lubrication and associated maintenance tasks
- Compact length (375 mm) suitable for tight stern tube spaces
- Nitrile rubber liner provides good corrosion resistance in seawater
- Designed specifically for 125 mm shafts, simplifying fit‑up
- Cut‑less design reduces risk of oil leakage and environmental contamination
Weaknesses
- Nitrile rubber may soften at elevated temperatures, limiting high‑speed applications
- No integrated seal type listed, potentially requiring additional sealing measures
- Load capacity generally lower than metal journal bearings for heavy‑duty propulsion
- Limited documented field history compared with more established bearing families
Typical Vessels:
Coastal bulk carriersFeeder container shipsOffshore supply vesselsTugboatsFerries
Decision Guide: Choose if: you need a low‑maintenance, oil‑free bearing for a 125 mm shaft on a vessel with moderate power and operating temperatures. Avoid if: the propulsion system runs at high speed/temperature, requires maximum load capacity, or mandates an integrated seal system.
Use Cases: Commonly installed in the stern tubes of medium‑size cargo and service vessels where space is limited and environmental regulations favor oil‑free solutions. It is favoured on ships that operate primarily in coastal or regional trades with moderate shaft loads.
Duramax Cutless 150mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
150
Bearing material
nitrile rubber
Length (mm)
450
Strengths
- Easy installation and removal – no need to dismantle the stern tube (cutless design).
- Nitrile rubber liner provides good vibration damping and noise reduction.
- Compact length (450 mm) fits into limited space aft sections.
- Suitable for moderate‑power vessels with shaft diameters up to 150 mm.
Weaknesses
- Nitrile rubber has a relatively low upper temperature limit (~120 °C), restricting use in high‑heat applications.
- No integrated seal type specified; additional sealing may be required for water ingress protection.
- Limited load capacity compared with polymer or metal alloy bearings, making it less ideal for high‑speed/high‑power shafts.
- Service life can be shorter if exposed to aggressive seawater contaminants without proper maintenance.
Typical Vessels:
Coastal cargo vesselsOffshore supply boatsTugboatsFerries (up to medium size)Small container ships
Decision Guide: Choose if you need a low‑maintenance, easily replaceable bearing for a 150 mm shaft on vessels with moderate power and limited aft space. Avoid if the propulsion system operates at high speeds, generates excessive heat, or requires a bearing with higher load capacity and integrated sealing.
Use Cases: Commonly installed in the stern tubes of medium‑size workboats and coastal traders where quick bearing replacement is valued and shaft loads are within the rating of a nitrile‑rubber cutless bearing.
Duramax Cutless 175mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
175
Bearing material
nitrile rubber
Length (mm)
525
Strengths
- Self‑lubricating nitrile rubber eliminates the need for oil lubrication and reduces maintenance intervals.
- Compact 525 mm length fits standard stern tube arrangements for 175 mm shafts.
- Easy to install and replace compared with traditional journal bearings.
- Proven durability in moderate thrust, low‑to‑medium speed applications.
Weaknesses
- Nitrile rubber may degrade faster in high temperature or aggressive seawater conditions.
- Not intended for very high thrust or high‑speed propulsion systems where metal journal bearings are preferred.
- No integrated seal; external sealing arrangements must be provided to prevent water ingress.
- Limited load capacity compared with some heavy‑duty metal bearing designs.
Typical Vessels:
Bulk CarrierTankerContainer ShipGeneral Cargo VesselOffshore Supply Vessel
Decision Guide: Choose if: you need a low‑maintenance, self‑lubricating bearing for a 175 mm shaft on vessels with moderate thrust and speed, and you can provide external sealing. Avoid if: the propulsion system operates at high speeds or generates high thrust loads, or if an integrated seal is required.
Use Cases: Commonly installed in the stern tube of medium‑size cargo ships and offshore support vessels where a reliable, low‑maintenance bearing is preferred for shafts around 175 mm in diameter.
Duramax Cutless 200mm
unverified
· oil-free cutless bearing
Shaft diameter (mm)
200
Bearing material
nitrile rubber
Length (mm)
600
Strengths
- Oil‑free operation eliminates the need for regular greasing and reduces environmental contamination risk.
- Nitrile rubber liner offers good corrosion resistance in seawater environments.
- Compact length (600 mm) eases installation in confined stern tube spaces.
- Low friction design improves shaft efficiency and can extend engine life.
- Designed specifically for 200 mm shafts, providing a close fit that reduces misalignment wear.
Weaknesses
- Nitrile rubber has temperature limits (typically up to ~80 °C) which may restrict use on high‑power, high‑heat applications.
- Maximum thrust load is lower than that of metal journal bearings, limiting suitability for very large propulsion units.
- Long‑term wear can be accelerated if the bearing is not perfectly aligned during installation.
- Spare parts for this specific model may have limited availability in remote ports.
Typical Vessels:
Medium‑size bulk carrierContainer ship (up to 5,000 gt)Product tankerOffshore supply vesselFerry
Decision Guide: Choose if: you need low‑maintenance, oil‑free shaft support for a 200 mm shaft on medium‑power vessels and have space constraints. Avoid if: the propulsion system operates at high temperatures or requires very high thrust capacity, or if you prefer metal journal bearings for extreme loads.
Use Cases: Commonly installed in the stern tubes of medium‑speed diesel‑driven cargo ships and offshore support vessels where a 200 mm shaft is used. It is favoured on routes with strict environmental regulations because it eliminates oil leakage from the bearing area.
Duramax Cutless 250mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
250
Bearing material
nitrile rubber
Length (mm)
750
Strengths
- Nitrile rubber offers good resistance to seawater and moderate temperatures.
- Cutless design eliminates the need for oil lubrication systems, reducing maintenance.
- Compact length (750 mm) fits in vessels with limited stern‑tube space.
- Easy installation – the bearing can be slipped onto the shaft without machining.
Weaknesses
- Rubber elastomer wears faster than metal bearings, leading to shorter overhaul intervals.
- No integrated seal type; external gland or packing is required to prevent water ingress.
- Limited load‑capacity compared with bronze or babbitt metal bearings for high‑power applications.
- Performance can be affected by extreme temperature swings beyond the rubber’s rating.
Typical Vessels:
Coastal cargo vesselsOffshore supply shipsTugboatsFerriesSmall tankers
Decision Guide: Choose if: the vessel operates at low to moderate shaft speed, space for a traditional oil‑lubricated bearing is limited, and reduced maintenance is a priority. Avoid if: high power output, very high RPM, or extreme temperature conditions demand a metal bearing with higher load capacity.
Use Cases: Commonly installed in the stern tube of diesel‑driven propulsion systems on coastal and offshore support vessels where simplicity and low upkeep are valued. Paired with an external gland or packing arrangement to keep water out of the bearing cavity.
Duramax Cutless 300mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
300
Bearing material
nitrile rubber
Length (mm)
900
Strengths
- No oil lubrication required – lower operating and maintenance costs
- Simple installation with a single cutless liner
- Good vibration damping due to rubber material
- Corrosion‑resistant in seawater environments
- Suitable for shafts up to 300 mm on low‑to‑medium speed vessels
Weaknesses
- Load and speed limits lower than metal journal bearings
- Nitrile rubber temperature range restricts use in high‑heat applications
- Periodic liner replacement required (typically every 5–7 years)
- Not ideal for high‑power propulsion systems or very large vessels
Typical Vessels:
Bulk carrierProduct tankerContainer ship (up to 8,000 gt)Offshore supply vesselFerry
Decision Guide: Choose if the vessel uses a shaft ≤300 mm, operates at low‑to‑medium speed, and you want a maintenance‑light, oil‑free solution. Avoid on high‑speed, high‑power propulsion plants or where ambient/operating temperatures exceed the limits of nitrile rubber.
Use Cases: Installed in the stern tube of merchant ships and offshore vessels to support the main propulsion shaft, especially where space is limited and a low‑maintenance bearing is preferred.
Duramax Cutless 350mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
350
Bearing material
nitrile rubber
Length (mm)
1050
Strengths
- Low‑maintenance – no oil bath required
- Compact length of 1050 mm fits confined stern tube spaces
- Nitrile rubber material offers good corrosion resistance in seawater
- Directly matches a 350 mm shaft diameter, simplifying installation
Weaknesses
- Nitrile rubber has limited temperature and pressure range compared with metal bearings
- Cutless designs can be sensitive to mis‑alignment or excessive shaft deflection
- Load capacity may be lower than that of traditional oil‑filled bronze bearings
- No integrated seal type specified, requiring separate sealing solutions
Typical Vessels:
Product Tanker (small to medium)Container FeederOffshore Supply VesselBulk Carrier (handy size)General Cargo Ship
Decision Guide: Choose if: you need a low‑maintenance, compact bearing for a 350 mm shaft and operating conditions stay within the temperature/pressure limits of nitrile rubber. Avoid if: the vessel experiences high shaft loads, extreme temperatures, or requires an integrated seal system.
Use Cases: Commonly installed in the stern tube of medium‑size cargo vessels and offshore support ships where space is limited and routine maintenance intervals are long; suitable for new builds or retrofits replacing traditional oil‑filled bearings.
Duramax Cutless 400mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
400
Bearing material
nitrile rubber
Length (mm)
1200
Strengths
- Eliminates the need for oil lubrication, reducing maintenance and risk of oil leakage
- Nitrile‑rubber bearing material offers good corrosion resistance in seawater environments
- Compact 1200 mm length fits a wide range of hull designs while providing adequate support
- Simplified installation compared with traditional oil‑filled bearings
Weaknesses
- Nitrile rubber can lose elasticity at elevated temperatures, limiting use on high‑speed vessels
- No integrated seal type specified; additional sealing components may be required
- Cutless designs are generally limited to low‑to‑moderate shaft speeds (≤ 150 rpm)
- Replacement parts may be less widely stocked than standard oil‑filled bearing kits
Typical Vessels:
Bulk carrierProduct tankerContainer ship (up to 8,000 gt)Offshore supply vesselGeneral cargo vessel
Decision Guide: Choose if: the vessel operates at low‑to‑moderate shaft speeds, you want to minimise oil‑related maintenance and environmental risk, and the shaft size matches 400 mm. Avoid if: the propulsion system runs at high speed or temperature, or if an integrated seal is required without adding extra components.
Use Cases: Commonly installed on new‑build mid‑size cargo ships and retrofitted on existing vessels seeking lower maintenance stern tube systems; favoured in regions with strict oil‑spill regulations.
Duramax Cutless 450mm
unverified
· oil-free cutless bearing
Shaft diameter (mm)
450
Bearing material
nitrile rubber
Length (mm)
1350
Strengths
- Eliminates oil lubrication and associated maintenance tasks
- Reduced risk of oil leakage and environmental contamination
- Corrosion‑resistant nitrile rubber liner suitable for seawater service
- Compact length (1350 mm) simplifies installation in confined stern tube spaces
- Long service intervals compared with traditional babbitt bearings
Weaknesses
- Load capacity lower than heavy‑duty babbitt or bronze bearings, limiting use on very high‑power shafts
- Higher upfront purchase price than conventional oil‑filled units
- Nitrile rubber may be sensitive to extreme temperatures and aggressive seawater chemistry
- Requires precise alignment during installation; misalignment can accelerate wear
Typical Vessels:
Bulk carrier (10–30 kt)Product tankerContainer ship (up to 4,000 TEU)Offshore supply vesselFerry
Certifications:
ABSDNV
Decision Guide: Choose if: you need an oil‑free solution that reduces maintenance, environmental risk and space constraints on medium‑size vessels with shaft powers up to ~10 MW. Avoid if: the vessel operates at very high shaft loads, extreme temperature regimes, or requires a bearing with proven heavy‑duty load capacity beyond cutless designs.
Use Cases: Commonly installed in new builds or retrofits where operators want to eliminate stern tube oil pumps and associated filtration systems, especially on vessels operating in environmentally sensitive areas or under strict emission regulations.
Duramax Cutless 500mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
500
Bearing material
nitrile rubber
Length (mm)
1500
Strengths
- Oil‑free operation eliminates the need for lubrication pumps and reduces contamination risk.
- Compact design saves space within the hull compared with traditional oil‑lubricated bearings.
- Nitrile rubber lining offers good corrosion resistance in seawater environments.
- Simplified installation – no hydraulic lines or oil reservoirs required.
Weaknesses
- Service life generally shorter than heavy‑duty oil‑lubricated bearings under high load conditions.
- Temperature and pressure limits are tighter; extreme hot‑water cooling may be needed for very high power ships.
- Material wear can increase friction over time, requiring periodic visual inspection and possible replacement.
- Limited availability of spare parts compared with more common bearing types.
Typical Vessels:
Bulk CarrierProduct TankerGeneral Cargo / Container ShipOffshore Supply Vessel
Decision Guide: Choose if: you need a low‑maintenance, oil‑free bearing for a medium‑speed vessel with limited hull space and moderate shaft loads. Avoid if: the propulsion system operates at very high power or speed where traditional oil‑lubricated bearings provide longer service intervals and higher load capacity.
Use Cases: Commonly installed in new builds or retrofits of medium‑size merchant ships where a 500 mm shaft is used, especially when owners prioritize reduced maintenance crew workload and environmental compliance by eliminating bearing oil discharge.
Duramax Cutless 600mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
600
Bearing material
nitrile rubber
Length (mm)
1800
Strengths
- Oil‑free operation eliminates the need for an onboard lubrication system.
- Nitrile rubber material offers good corrosion resistance in seawater environments.
- Reduced maintenance intervals compared with oil‑lubricated bearings.
- Simplified installation – no pumps, filters or oil reservoirs required.
- Long service life when operated within design speed and load limits.
Weaknesses
- Load capacity is lower than that of conventional oil‑filled bearings for the same size.
- Nitrile rubber has temperature limits; performance may degrade in very high‑temperature zones.
- Not ideal for extremely high shaft speeds where heat buildup exceeds material rating.
- Periodic visual inspection and eventual liner replacement are still required.
Typical Vessels:
Aframax tankerPanamax bulk carrierMedium‑size container shipCruise liner
Decision Guide: Choose if: you need a low‑maintenance, oil‑free bearing for a 600 mm shaft on vessels where space or weight constraints limit a full lubrication system, and operating speeds are within the rating of nitrile rubber. Avoid if: the propulsion system demands very high loads or speeds beyond the cutless bearing’s design limits, or if you require certifications that this specific model does not carry.
Use Cases: Typically installed in new builds or retrofits on large merchant vessels with single‑screw propulsion, especially where reduced maintenance and elimination of oil leakage risk are priorities. Commonly found in tankers, bulk carriers and cruise ships operating at moderate shaft speeds.
Duramax Cutless 700mm
unverified
· cutless rubber stern tube bearing
Shaft diameter (mm)
700
Bearing material
nitrile rubber
Length (mm)
2100
Strengths
- Oil‑free (cutless) design eliminates risk of oil leakage into the sea.
- Low maintenance – no routine oil changes or filter replacements required.
- Nitrile rubber offers good wear resistance and excellent vibration damping for medium‑size shafts.
- Compact length (2100 mm) fits a wide range of hull designs.
- Suitable for retrofits where space is limited.
Weaknesses
- Temperature limit of nitrile rubber (~120 °C) may restrict use in high‑heat applications.
- No integrated seal; external sealing arrangements must be provided.
- Maximum thrust capacity lower than heavy‑duty metal bearings, limiting suitability for very high power ships.
- Replacement of the rubber liner can be costly compared with simple oil‑lubricated units.
Typical Vessels:
Bulk carrierProduct tankerContainer ship (mid‑size)Offshore supply vesselCruise ship (auxiliary propulsion)
Decision Guide: Choose if you need a low‑maintenance, environmentally friendly bearing for a 700 mm shaft and the vessel operates within normal temperature and thrust limits. Avoid if the installation requires integrated sealing, expects extreme temperatures, or demands very high thrust capacity beyond typical cutless designs.
Use Cases: Commonly installed in the stern tube of medium‑size merchant vessels during new builds or as a retrofit to replace oil‑lubricated bearings, especially where regulatory pressure limits oil use and maintenance windows are short.
Duramax Cutless 800mm
unverified
· cutless stern tube bearing
Shaft diameter (mm)
800
Bearing material
nitrile rubber
Length (mm)
2400
Strengths
- Cut‑less design eliminates the need for oil lubrication, reducing leakage risk.
- Nitrile rubber offers good wear resistance and corrosion protection in seawater environments.
- High load capacity suitable for large propulsion shafts up to 800 mm diameter.
- Relatively long service life with simple replacement procedures.
Weaknesses
- Nitrile rubber has temperature limits; performance may degrade above ~80 °C.
- Cut‑less bearings can be more expensive upfront than conventional oil‑filled types.
- Speed rating may be lower than metal‑to‑metal bearings for high‑rpm applications.
- Installation requires precise alignment tools and trained personnel.
Typical Vessels:
TankerBulk CarrierContainer ShipCruise Vessel
Decision Guide: Choose if: you need a low‑maintenance, oil‑free bearing for large shafts (≈800 mm) on vessels where leakage risk must be minimised. Avoid if: the propulsion system operates at high RPMs or temperatures that exceed nitrile rubber limits, or budget constraints preclude the higher initial cost.
Use Cases: Commonly installed in new builds or retrofits of medium‑to‑large commercial ships requiring reliable stern tube protection for main propeller shafts, especially where environmental regulations limit oil discharge.
Orkot Marine
20
Orkot TLM 100mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
100
Bearing material
PTFE composite
Length (mm)
200
Strengths
- Self‑lubricating PTFE material eliminates the need for oil lubrication and reduces maintenance intervals.
- Corrosion‑resistant construction suitable for seawater environments.
- Compact design (200 mm length) fits vessels with limited stern‑tube space.
- Low friction coefficient improves shaft efficiency at moderate loads.
Weaknesses
- Lower load‑carrying capacity compared with traditional metal bearings; not ideal for high thrust applications.
- Temperature limits of PTFE composites may restrict use in high‑heat engine rooms.
- Potential for higher wear rates under heavy cyclic loading, requiring more frequent inspections.
Typical Vessels:
Coastal cargo vesselPatrol boatWorkboat / tugOffshore supply vesselFerry
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for a 100 mm shaft on vessels with moderate thrust and limited stern‑tube space. Avoid if: the propulsion system demands high load capacity, operates at elevated temperatures, or requires metal bearings for extreme service conditions.
Use Cases: Commonly installed in the stern tubes of small to medium auxiliary engines, thrusters, and main shafts on coastal traders, patrol craft, and workboats where ease of installation and reduced lubrication upkeep are priorities.
Orkot TLM 150mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
150
Bearing material
PTFE composite
Length (mm)
300
Strengths
- Low friction coefficient reduces power loss
- Excellent chemical and seawater corrosion resistance
- Lightweight compared with traditional metal bearings
- Self‑lubricating properties minimise routine maintenance
Weaknesses
- Lower load‑capacity than high‑strength steel or bronze bearings
- Temperature rating limited (typically up to ~120 °C)
- May not be suitable for very high‑speed or high‑power shafts
- Requires compatible seal arrangements; original spec lists no built‑in seal
Typical Vessels:
Coastal tankerOffshore supply vesselFerrySmall bulk carrierMedium‑size container ship (up to 5 000 gt)
Decision Guide: Choose if you need a low‑maintenance, corrosion‑resistant bearing for moderate shaft loads and speeds on vessels up to about 150 mm shaft size. Avoid if the propulsion system operates at high power, very high RPMs, or requires maximum load capacity where metal bearings are preferred.
Use Cases: Commonly installed in the stern tube of medium‑speed diesel engine drives on coastal tankers, offshore supply ships and ferries, where ease of installation and reduced maintenance downtime are valued.
Orkot TLM 200mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
200
Bearing material
PTFE composite
Length (mm)
400
Strengths
- Self‑lubricating PTFE material reduces maintenance intervals
- Excellent resistance to seawater corrosion and biofouling
- Compact length (400 mm) eases installation in confined stern tubes
- Low friction coefficient improves propulsion efficiency
Weaknesses
- Lower load‑capacity compared with steel or bronze bearings, limiting use on high‑power shafts
- PTFE material has a relatively low maximum operating temperature (~150 °C)
- No integrated seal type specified; additional sealing may be required
- May not meet classification societies’ high‑pressure stern tube requirements without supplemental approval
Typical Vessels:
General cargo shipsOffshore support vesselsFerriesTugboatsMedium‑size bulk carriers
Decision Guide: Choose if you need a low‑maintenance, corrosion‑resistant bearing for a 200 mm shaft on vessels with moderate power and space constraints. Avoid if the propulsion system demands high axial loads, operates at elevated temperatures, or requires a certified metal bearing for high‑pressure stern tube approvals.
Use Cases: Installed in the stern tube of ships using a 200 mm propeller shaft to support rotational loads while preventing water ingress; commonly fitted on medium‑size diesel‑propelled vessels where reduced maintenance and corrosion resistance are priorities.
Orkot TLM 250mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
250
Bearing material
PTFE composite
Length (mm)
500
Strengths
- Self‑lubricating PTFE material reduces routine greasing and maintenance intervals
- Corrosion‑resistant composition suitable for continuous seawater exposure
- Compact 500 mm length fits confined stern‑tube spaces on many vessels
- Standard 250 mm shaft interface simplifies replacement on existing installations
Weaknesses
- Lower load‑carrying capacity than steel or bronze bearings, limiting use on high‑power propulsion systems
- PTFE temperature limits may restrict operation in extreme hot or cold environments
- No integrated seal (seal_type unspecified) requires an additional sealing arrangement
- Potentially higher unit cost compared with conventional metal bearings
Typical Vessels:
Coastal tankerOffshore supply vesselFerrySmall bulk carrierGeneral cargo ship
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for a 250 mm shaft on vessels with moderate power and limited stern‑tube space. Avoid if: the propulsion system demands high load capacity, operates at extreme temperatures, or requires an integrated seal solution.
Use Cases: Commonly installed in the steering gear line of medium‑size commercial ships where ease of maintenance and resistance to seawater corrosion are priorities, such as coastal tankers, offshore supply vessels, and ferries operating in temperate climates.
Orkot TLM 300mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
300
Bearing material
PTFE composite
Length (mm)
600
Strengths
- Self‑lubricating PTFE material eliminates the need for oil greasing, reducing maintenance intervals
- Excellent corrosion resistance in seawater environments
- Low friction coefficient improves shaft efficiency and reduces fuel consumption
- Relatively lightweight compared with traditional metal bearings, easing installation
Weaknesses
- Load‑carrying capacity is lower than that of steel or bronze bearings; not suited for very high thrust applications
- Maximum operating temperature limited to around 120 °C for PTFE composites
- Long‑term wear may require periodic replacement in high‑rpm service
- Requires precise alignment and straightness of the shaft line to avoid premature edge loading
Typical Vessels:
Medium‑size tankers (up to 30,000 dwt)Bulk carriers (up to 40,000 dwt)Container ships (up to 5,000 TEU)Offshore supply vesselsCoastal ferries
Decision Guide: Choose if: the vessel uses a 300 mm shaft, operates in normal seawater conditions, and benefits from reduced maintenance and lower friction; especially suitable for medium‑power propulsion where thrust loads are moderate. Avoid if: the propeller generates very high thrust or torque, operating temperatures exceed PTFE limits, or the design calls for heavy‑duty metal bearings.
Use Cases: Commonly installed in new builds or retrofits of medium‑size merchant ships where a low‑maintenance, corrosion‑resistant bearing is desired. Frequently used on vessels with diesel engines driving single screw propellers at moderate rpm, such as product tankers and coastal cargo carriers.
Orkot TLM 400mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
400
Bearing material
PTFE composite
Length (mm)
800
Strengths
- Self‑lubricating PTFE material reduces friction and eliminates need for oil lubrication
- Excellent corrosion resistance in seawater environments
- Lightweight compared with traditional bronze or steel bearings, easing installation
- Long service intervals due to low wear rate of PTFE composite
Weaknesses
- Lower load‑carrying capacity than metal (bronze/steel) bearings, limiting use on high‑power shafts
- Maximum operating temperature typically around 120 °C, restricting use in hot‑water applications
- PTFE can be more susceptible to mechanical damage from impact or misalignment
- Spare parts may be less widely stocked than standard metal bearings
Typical Vessels:
Product tankerMedium bulk carrierContainer ship (up to 8,000 TEU)Offshore supply vesselCoastal cargo vessel
Decision Guide: Choose if: the vessel uses a moderate‑power 400 mm shaft, operates in highly corrosive seawater, and values low maintenance and reduced lubrication requirements. Avoid if: the propulsion system demands high load capacity, very high shaft speeds, or operation at temperatures exceeding PTFE limits.
Use Cases: Commonly installed on medium‑size tankers, product carriers and offshore supply vessels where a 400 mm propeller shaft requires a durable, corrosion‑resistant bearing with minimal maintenance. Suitable for new builds or retrofits where weight savings and ease of installation are priorities.
Orkot TLM 500mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
500
Bearing material
PTFE composite
Length (mm)
1000
Strengths
- Low friction coefficient reduces power loss
- Excellent chemical and corrosion resistance in seawater
- Self‑lubricating PTFE eliminates need for external lubrication system
- Relatively lightweight compared with metal alloy bearings
- Easy to install and replace due to modular design
Weaknesses
- Limited load‑carrying capacity versus steel or bronze bearings
- Upper temperature limit (~120 °C) may restrict high‑heat applications
- Potential for PTFE creep under prolonged heavy loads
- Requires precise alignment; misalignment can accelerate wear
- Seal type not specified, so additional sealing solutions may be needed
Typical Vessels:
Bulk CarrierProduct TankerContainer Ship (mid‑size)Offshore Supply VesselCruise Ship (auxiliary propulsion)
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for moderate thrust applications and want to avoid oil‑lubricated systems. Avoid if: the vessel operates at very high shaft loads, extreme temperatures, or requires maximum load capacity where metal bearings are preferred.
Use Cases: Commonly installed in the main propulsion line of medium‑size commercial vessels where a 500 mm shaft is used and water‑lubricated bearings are impractical. Ideal for retrofits on older ships seeking reduced maintenance intervals.
Orkot TLM 600mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
600
Bearing material
PTFE composite
Length (mm)
1200
Strengths
- Self‑lubricating PTFE reduces maintenance intervals
- Excellent resistance to seawater corrosion and biofouling
- Low friction torque loss improves propulsion efficiency
- Modular 1200 mm length eases installation in confined hull spaces
Weaknesses
- Lower load‑carrying capacity than steel or bronze bearings
- Upper temperature limit (~150 °C) restricts use on high‑power engines
- PTFE wear can increase over long service periods, requiring periodic inspection
- Not certified for ice‑class or heavy‑duty towing applications
Typical Vessels:
Container shipRo‑Ro ferryPassenger cruise vesselOffshore support vesselMedium‑speed bulk carrier
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for moderate shaft loads and high‑speed service where space is limited. Avoid if: the vessel operates in ice conditions, requires very high thrust loads, or runs at exhaust temperatures that exceed PTFE limits.
Use Cases: Commonly installed on new builds or retrofits of medium‑size commercial vessels with diesel propulsion, especially where reduced maintenance downtime and improved fuel efficiency are priorities.
Orkot TLM 700mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
700
Bearing material
PTFE composite
Length (mm)
1400
Strengths
- Low friction coefficient reduces power loss through the shaft line
- PTFE composite resists seawater corrosion and eliminates the need for oil lubrication
- Lightweight compared with traditional bronze bearings, easing handling and installation
- Standard length of 1400 mm fits common aft tunnel dimensions
- Good thermal stability within typical marine operating temperatures
Weaknesses
- Load‑capacity lower than high‑strength metal alloys under extreme overload conditions
- Not ideal for very high RPM applications where heat dissipation is critical
- Limited long‑term service history compared with legacy bronze bearings
- Replacement parts may be less widely stocked in remote ports
Typical Vessels:
Bulk CarrierContainer ShipGeneral Cargo VesselOffshore Supply Vessel
Decision Guide: Choose if you need a low‑maintenance, corrosion‑resistant bearing for a 700 mm shaft on vessels with moderate power transmission and operating in warm or corrosive waters. Avoid if the propulsion system is subject to very high loads, extreme RPMs, or if you require a bearing with an extensive proven service record.
Use Cases: Commonly installed in the aft propulsion line of medium‑size merchant ships (10–20 kW per propeller) where shaft diameters around 700 mm are used, especially on routes with high salinity or temperature where corrosion protection and reduced maintenance are priorities.
Orkot TLM 800mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
800
Bearing material
PTFE composite
Length (mm)
1600
Strengths
- Self‑lubricating PTFE reduces routine lubrication and maintenance intervals
- Excellent resistance to seawater corrosion and biofouling
- Compact 1.6 m length fits standard stern‑tube arrangements for large vessels
- Designed specifically for 800 mm shafts, common on many high‑power ships
- Low noise and vibration transmission compared with metal bearings
Weaknesses
- Lower static and dynamic load capacity than steel or bronze bearings
- Upper temperature limit (typically around 120 °C) may restrict very high‑power applications
- PTFE wear over long service periods requires periodic inspection and possible replacement
- Limited tolerance for shaft misalignment compared with metal bearing designs
- Spare‑part availability depends on Orkot’s distribution network, which can be regional
Typical Vessels:
Aframax TankerPanamax Bulk CarrierContainer Ship (12 000–15 000 TEU)Cruise ShipOffshore Supply Vessel
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for a standard 800 mm shaft on vessels where load and temperature demands are moderate. Avoid if: the propulsion system requires maximum load capacity, operates at very high temperatures, or experiences frequent shaft misalignment.
Use Cases: The TLM 800 mm is typically installed in the stern tube of large diesel‑propulsion systems to support the main propeller shaft, providing a sealed, low‑friction interface that tolerates marine exposure and reduces routine lubrication tasks on tankers, bulk carriers, and other deep‑water vessels.
Orkot TXMM 100mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
100
Bearing material
PTFE composite
Length (mm)
200
Strengths
- Self‑lubricating PTFE material reduces maintenance intervals
- Corrosion resistance suitable for saltwater service
- Standard 100 mm shaft size simplifies replacement logistics
- Compact 200 mm length fits confined stern tube spaces
- No separate oil seal required when paired with external sealing systems
Weaknesses
- PTFE composite has lower load‑capacity than steel or bronze bearings, limiting use on high‑power shafts
- Temperature range is narrower than metal bearings; excessive heat can degrade PTFE
- Absence of an integrated seal means additional components are needed for oil containment
- Limited field data on long‑term wear compared with traditional metal bearings
- Spare parts availability may be constrained if Orkot Marine has limited distribution
Typical Vessels:
Coastal tankerOffshore supply vesselFerryPatrol boatMedium‑size fishing vessel
Decision Guide: Choose if: the propulsion system is moderate in power, operates at standard speeds, and you value low maintenance and corrosion resistance. Avoid if: the shaft experiences high loads, extreme temperatures, or requires an integrated oil seal without adding extra components.
Use Cases: Commonly installed in the stern tube of small to medium‑size vessels during new builds or retrofits where a compact, low‑maintenance bearing is desired for a 100 mm shaft. Often paired with external oil seals and used in applications where corrosion resistance outweighs maximum load capacity.
Orkot TXMM 150mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
150
Bearing material
PTFE composite
Length (mm)
300
Strengths
- Low friction coefficient reduces power loss on the shaft line
- Excellent chemical and seawater corrosion resistance
- Lightweight compared with traditional metal bearings, easing installation
- Self‑lubricating PTFE eliminates need for external oiling systems
Weaknesses
- Lower load‑capacity than high‑strength alloy or babbitt bronze bearings
- Maximum operating temperature limited to about 120 °C for PTFE
- Long‑term wear may require periodic inspection and replacement in high‑thrust applications
- Limited availability of spare parts in remote ports compared with more common bearing types
Typical Vessels:
Coastal tankerOffshore supply vessel (OSV)FerrySmall to medium bulk carrierResearch vessel
Decision Guide: Choose if the vessel operates in warm, corrosive waters and requires a low‑maintenance, lightweight bearing for a 150 mm shaft with moderate thrust loads. Avoid if the propulsion system demands very high load capacity, extreme temperature operation, or if spare‑part logistics favor more conventional metal bearings.
Use Cases: Commonly installed on medium‑speed diesel engine shafts of coastal tankers and offshore supply vessels where ease of maintenance and resistance to seawater corrosion are priorities. Also used in ferries and research ships with similar shaft dimensions.
Orkot TXMM 200mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
200
Bearing material
PTFE composite
Length (mm)
400
Strengths
- Low friction coefficient reduces power loss in the shaft line
- PTFE composite offers excellent chemical resistance to seawater and lubricants
- Self‑lubricating material can extend maintenance intervals compared with metal bearings
- Compact length (400 mm) fits into standard stern tube spaces for 200 mm shafts
Weaknesses
- Load capacity lower than high‑strength steel or babbitt bearings, limiting use on very high‑power vessels
- Maximum operating temperature is limited; PTFE degrades above ~150 °C
- Long‑term wear may be higher under heavy cyclic loads, requiring periodic inspection
- Seal type not specified, so additional sealing solutions may be needed
Typical Vessels:
General cargo shipBulk carrier (up to 30 000 dwt)Product tankerOffshore supply vesselFerry
Decision Guide: Choose if: you need a low‑friction, corrosion‑resistant bearing for a 200 mm shaft on vessels with moderate power and operating temperatures below the PTFE limit. Avoid if: the propulsion system demands high load capacity, operates at elevated temperatures, or requires an integrated seal solution that is not supplied.
Use Cases: Typically installed in the stern tube of medium‑size merchant ships where a 200 mm propeller shaft is used, providing bearing support between the hull and the rotating shaft while tolerating marine environment exposure.
Orkot TXMM 250mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
250
Bearing material
PTFE composite
Length (mm)
500
Strengths
- Low friction and self‑lubricating PTFE surface reduces wear and maintenance intervals
- Excellent corrosion resistance in seawater environments
- Lightweight compared with traditional bronze bearings, easing installation
- Long service life when operated within design load and temperature limits
Weaknesses
- Higher initial purchase cost than conventional metal (bronze) bearings
- Load capacity may be lower than heavy‑duty metal designs, limiting use on high‑power vessels
- Temperature range is limited; performance degrades above the material’s maximum service temperature
- Requires precise alignment and proper sealing to prevent abrasive ingress
Typical Vessels:
Coastal tanker (up to ~10 000 dwt)Offshore supply vesselFerry or passenger craft with medium‑size propulsionSmall bulk carrier
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for a 250 mm shaft on vessels where weight and friction reduction are priorities, and the operating loads stay within PTFE composite limits. Avoid if: the vessel operates at high shaft loads, extreme temperatures, or requires the lowest possible cost solution.
Use Cases: Commonly installed in new builds or retrofits of medium‑size propulsion systems where a compact, low‑maintenance stern tube bearing is desired—e.g., coastal tankers, offshore supply ships, and regional ferries operating in warm to temperate seas.
Orkot TXMM 300mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
300
Bearing material
PTFE composite
Length (mm)
600
Strengths
- Low friction and wear due to PTFE liner
- Corrosion‑resistant material suitable for seawater environments
- Relatively simple installation with standard 300 mm shaft dimensions
- No need for oil lubrication in many applications
Weaknesses
- PTFE has a lower temperature limit than metal bearings, limiting high‑heat use
- Load capacity may be lower than heavy‑duty steel or bronze bearings
- Absence of an integrated seal (seal_type is null) requires separate sealing arrangement
- May require more frequent inspection in high‑speed or high‑load service
Typical Vessels:
Product tankerSmall to medium bulk carrierOffshore supply vesselCoastal container shipTugboat
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for a 300 mm shaft operating at moderate speeds and temperatures, and you can provide an external seal. Avoid if: the propulsion system experiences high loads, very high RPMs, or elevated operating temperatures that exceed PTFE limits.
Use Cases: Commonly installed in the stern tube of vessels with medium‑size propeller shafts where simplicity, low maintenance, and resistance to seawater corrosion are priorities—e.g., product tankers, offshore supply ships, and coastal cargo carriers.
Orkot TXMM 400mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
400
Bearing material
PTFE composite
Length (mm)
800
Strengths
- Self‑lubricating PTFE matrix reduces maintenance intervals
- Excellent corrosion resistance for seawater environments
- Low friction coefficient improves propeller efficiency
- Modular length (800 mm) eases installation on standard shaft lines
- Compatible with 400 mm shafts common on medium‑to‑large vessels
Weaknesses
- Higher material cost compared with traditional babbitt or bronze bearings
- PTFE has a lower maximum operating temperature than metal alloys
- Load capacity may be limited for very high‑power, high‑torque applications
- Requires compatible sealing arrangement (seal type not specified)
- Potential sensitivity to severe misalignment
Decision Guide: Choose if: you need a low‑maintenance bearing for a 400 mm shaft operating in aggressive seawater conditions and can accommodate the material’s temperature/load limits. Avoid if: the propulsion system demands extreme load capacity, very high temperatures, or you have strict cost constraints that favor conventional metal bearings.
Use Cases: Typically installed in the stern tube of medium‑to‑large commercial ships (e.g., tankers, bulk carriers, container vessels) where a 400 mm shaft is used and reduced maintenance downtime is a priority.
Orkot TXMM 500mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
500
Bearing material
PTFE composite
Length (mm)
1000
Strengths
- Self‑lubricating PTFE material reduces maintenance and eliminates need for external greasing
- Excellent corrosion resistance, suitable for seawater environments
- Relatively lightweight compared with traditional metal bearings
- Compact length (1000 mm) fits standard stern tube arrangements for 500 mm shafts
- Easy installation due to modular design
Weaknesses
- Lower load‑carrying capacity than steel or bronze bearings, limiting use on very high‑power propulsion systems
- PTFE temperature limit (~200 °C) restricts application in high‑temperature exhaust or shaft heating scenarios
- No integrated seal type specified; additional sealing arrangements may be required
- Potential for higher wear rates under abrasive conditions compared with metal alloys
Typical Vessels:
Medium‑size tankersBulk carriersContainer shipsOffshore supply vesselsCruise liners (mid‑range propulsion)
Decision Guide: Choose if you need a low‑maintenance, corrosion‑resistant bearing for a 500 mm shaft operating within normal temperature ranges and moderate power loads. Avoid if the vessel requires very high thrust or operates in abrasive/high‑temperature conditions where metal bearings are preferred.
Use Cases: Commonly installed in new builds or retrofits of vessels with medium‑speed diesel propulsion, where long intervals between bearing inspections are desired and the operating environment is standard seawater without extreme thermal loads.
Orkot TXMM 600mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
600
Bearing material
PTFE composite
Length (mm)
1200
Strengths
- Low friction coefficient due to PTFE material, reducing power loss
- Excellent resistance to seawater corrosion and bio‑fouling
- Self‑lubricating – no external oil system required
- Compact length of 1 200 mm simplifies installation in confined stern tube spaces
Weaknesses
- Lower load‑carrying capacity compared with traditional metal (bronze/steel) bearings, limiting use on very high thrust shafts
- Temperature rating limited to typical marine ambient ranges; performance degrades above ~120 °C
- Potential for higher wear rates under abrasive conditions if debris enters the bearing chamber
- Spare‑part availability may be restricted to Orkot’s distribution network
Typical Vessels:
Aframax tankerPanamax bulk carrierContainer ship (up to 8 000 TEU)Cruise vesselOffshore supply vessel
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for shafts up to 600 mm on vessels with moderate thrust and standard operating temperatures. Avoid if: the propulsion system requires very high load capacity, operates at elevated temperatures, or if class societies mandate metal bearings for the specific vessel class.
Use Cases: Commonly installed in the stern tube of large commercial ships where a 600 mm shaft is used, providing a sealed, self‑lubricating bearing that tolerates continuous exposure to seawater and reduces routine maintenance intervals.
Orkot TXMM 700mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
700
Bearing material
PTFE composite
Length (mm)
1400
Strengths
- Self‑lubricating PTFE material eliminates the need for oil lubrication and reduces maintenance intervals.
- Excellent resistance to seawater corrosion, suitable for harsh marine environments.
- Lightweight compared with traditional metal bearings, easing installation and alignment.
- Direct fit for 700 mm shafts with a standard 1400 mm length, simplifying retrofits.
Weaknesses
- Lower load‑carrying capacity than bronze or steel bearings; not ideal for very high power applications.
- Temperature rating is limited relative to metal bearings (generally <120 °C).
- Wear rates can be higher under extreme loads, requiring periodic visual inspection.
- Availability of spare parts may be restricted to Orkot’s distribution network.
Typical Vessels:
Bulk CarrierTankerContainer ShipGeneral Cargo VesselOffshore Supply Vessel
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for a 700 mm shaft on vessels with moderate power and load requirements; space or weight constraints favor a composite solution. Avoid if: the propulsion system operates at very high torque, RPM, or temperature where metal bearings provide superior strength and durability.
Use Cases: Installed in the stern tube of medium‑to‑large commercial ships to support the main propulsion shaft, particularly on vessels operating in warm, saline waters where oil‑free operation reduces environmental risk and maintenance downtime.
Orkot TXMM 800mm
unverified
· PTFE composite stern tube bearing
Shaft diameter (mm)
800
Bearing material
PTFE composite
Length (mm)
1600
Strengths
- Self‑lubricating PTFE matrix eliminates routine oiling and reduces maintenance intervals
- Excellent resistance to seawater corrosion, ideal for harsh marine environments
- Compact length (1600 mm) fits into limited stern tube spaces on large vessels
- Low friction coefficient improves propulsion efficiency
- Compatible with a range of seal arrangements (seal type not integral to the bearing)
Weaknesses
- PTFE material has lower load‑carrying capacity than steel or bronze bearings, limiting use in very high thrust applications
- Maximum operating temperature is restricted (typically ≤120 °C), unsuitable for hot‑oil lubrication schemes
- Requires precise alignment and installation tolerances to avoid premature wear
- No built‑in mechanical seal; a separate seal must be specified and installed
- Potential for higher initial cost compared with conventional metal bearings
Typical Vessels:
Crude oil tankerLNG carrierContainer ship (large class)Cruise linerOffshore supply vessel
Decision Guide: Choose if: you need a low‑maintenance, corrosion‑resistant bearing for an 800 mm shaft on vessels operating in warm seawater and moderate thrust conditions. Avoid if: the propulsion system demands very high torque, extreme speeds, or operates at temperatures beyond PTFE limits, or if budget constraints preclude the higher upfront cost of composite bearings.
Use Cases: Typically installed as the main stern tube bearing on large commercial ships where the shaft size is 800 mm and the operating environment subjects the bearing to continuous seawater exposure. It is favoured in vessels that prioritise reduced maintenance downtime and corrosion protection, such as tankers and LNG carriers navigating tropical routes.
Blohm+Voss
9
B+V Stern Tube 200mm
unverified
· White‑metal journal bearing
Shaft diameter (mm)
200
Bearing material
white metal
Length (mm)
600
Strengths
- Proven Blohm+Voss design with long service history in merchant vessels
- White‑metal material offers good conformability and embedment resistance for moderate loads
- Compact length of 600 mm fits vessels with limited stern tube space
- Standard 200 mm shaft size matches many medium‑size ships, simplifying replacement
Weaknesses
- Requires regular lubrication and condition monitoring to avoid wear
- White‑metal bearings have lower load capacity than modern polymer or composite alternatives
- No integrated seal type provided – a separate sealing system must be installed
- Limited publicly available performance data; verification of catalog specs may be needed
Typical Vessels:
Coastal tankerOffshore supply vesselFerrySmall bulk carrierMedium‑size container ship (up to ~10,000 dwt)
Decision Guide: Choose if: the vessel uses a standard 200 mm shaft, space in the stern tube is limited, and a proven, easily replaceable bearing is required. Avoid if: the propulsion system demands higher load capacity, you prefer an integrated seal solution, or you want the latest low‑friction polymer bearings.
Use Cases: Typically installed on new builds of medium‑size merchant ships or as a direct replacement during scheduled maintenance on vessels with existing 200 mm shaft lines. Suitable for retrofits where space constraints prevent larger bearing assemblies.
B+V Stern Tube 300mm
unverified
· white‑metal stern tube bearing
Shaft diameter (mm)
300
Bearing material
white metal
Length (mm)
900
Strengths
- Proven Blohm+Voss design with long service history in merchant vessels
- White‑metal (Babbitt) lining offers good embedability and shock absorption for medium‑speed shafts
- Compact 900 mm length fits standard hull openings for 300 mm shafts
- Modular construction enables straightforward installation and replacement
- Can be paired with a variety of seal types (oil, lip or mechanical) as required
Weaknesses
- Requires regular oil lubrication and monitoring; higher maintenance than polymer bearings
- No integrated seal type supplied; additional sealing components must be sourced separately
- Limited to shaft diameters around 300 mm; not suitable for larger high‑power shafts
- Lower temperature tolerance compared with ceramic or hybrid bearing solutions
- Installation demands precise alignment and tight tolerances
Typical Vessels:
Bulk CarrierGeneral Cargo ShipContainer VesselRo‑Ro FerryOffshore Supply Vessel
Decision Guide: Choose if you need a reliable, medium‑speed bearing for a 300 mm shaft on vessels where regular lubrication is acceptable and you want a proven Blohm+Voss design. Avoid if the installation demands low‑maintenance or high‑temperature bearings, or if the shaft size exceeds 300 mm.
Use Cases: Commonly installed in the stern tubes of medium‑size merchant ships such as bulk carriers and container vessels where a 300 mm propeller shaft is used. It provides axial support and water‑tight sealing while allowing flexibility to fit various seal arrangements, making it suitable for new builds or retrofit projects that follow standard hull dimensions.
B+V Stern Tube 400mm
unverified
· Stern tube bearing
Shaft diameter (mm)
400
Bearing material
white metal
Length (mm)
1200
Strengths
- White‑metal (Babbitt) lining provides high load capacity and good conformity to the rotating shaft.
- Blohm+Voss engineering ensures precise alignment tolerances, reducing vibration.
- Standard 400 mm bore fits a wide range of medium‑speed main engines.
- Modular design allows straightforward installation and removal during dry‑dock.
Weaknesses
- White‑metal material requires regular oil lubrication and monitoring for wear.
- No integrated seal type specified; additional sealing system may be needed.
- Limited to moderate shaft speeds; not optimal for high‑speed diesel applications.
- Length of 1.2 m may restrict installation in vessels with tight stern tube spaces.
Typical Vessels:
Bulk CarrierGeneral CargoContainer ShipRo-RoFerry
Decision Guide: Choose if you need a proven, medium‑speed bearing for a 400 mm shaft and have an existing lubrication system that can service white‑metal bearings. Avoid if the vessel operates at high shaft speeds, requires an integrated oil‑tight seal, or has space constraints that cannot accommodate a 1.2 m long tube.
Use Cases: Commonly installed on medium‑speed diesel propulsion lines of bulk carriers and container vessels during newbuilds or as a replacement in dry‑dock overhauls, where the shipyard already uses Blohm+Voss stern tube components.
B+V Stern Tube 500mm
unverified
· White metal stern tube bearing
Shaft diameter (mm)
500
Bearing material
white metal
Length (mm)
1500
Strengths
- Proven Blohm+Voss design with long service history in merchant vessels
- Rated for shafts up to 500 mm diameter and high thrust loads
- Standard overall length of 1500 mm fits common hull openings
- White‑metal material offers good conformability and load distribution
- Can be paired with a variety of seal arrangements (seal type not supplied)
Weaknesses
- Requires regular oil replenishment and condition monitoring
- Not optimal for very high shaft speeds or elevated temperature environments
- Seal type is unspecified, potentially needing an additional custom seal solution
- Limited to shafts up to 500 mm – unsuitable for larger propulsion lines
- No built‑in vibration damping features
Typical Vessels:
Bulk CarrierContainer ShipTankerRo‑Ro VesselGeneral Cargo Ship
Decision Guide: Choose if: you need a reliable, conventional white‑metal bearing for a 500 mm shaft on a standard merchant vessel and have an established maintenance regime. Avoid if: the application demands oil‑free or ceramic bearings, very high rotational speeds, integrated seal packages, or shafts larger than 500 mm.
Use Cases: Commonly installed in new builds or retrofits of medium to large cargo vessels where the main propulsion shaft is water‑lubricated and a conventional white‑metal bearing meets the design criteria.
B+V Stern Tube 600mm
unverified
· white metal stern tube bearing
Shaft diameter (mm)
600
Bearing material
white metal
Length (mm)
1800
Strengths
- Proven white‑metal material offers good conformability to shaft misalignments
- Standard 1800 mm length fits many medium‑size vessels without custom extensions
- Blohm+Voss reputation for robust German engineering and quality control
- Suitable for low‑ to medium‑speed diesel propulsion where oil lubrication is available
- Easily replaceable in existing installations that already use white‑metal bearings
Weaknesses
- Requires continuous oil lubrication and regular wear monitoring
- Heavier than modern polymer or ceramic alternatives
- Seal type not specified; additional sealing components may be needed
- Not optimal for high‑speed or ultra‑low‑maintenance applications
- Longer lead time if a fully custom bore or integration is required
Typical Vessels:
Bulk CarrierTankerContainer ShipGeneral Cargo VesselCruise Ship
Decision Guide: Choose if you need a reliable, proven white‑metal bearing for a 600 mm shaft on low‑ to medium‑speed diesel propulsion and have an oil lubrication system in place. Avoid if the vessel operates at high shaft speeds, space is extremely limited, or a low‑maintenance sealed bearing (polymer/ceramic) is preferred.
Use Cases: Commonly installed as the main propulsion stern tube on newbuilds or retrofits of medium‑size merchant vessels where a 600 mm shaft and oil‑lubricated white‑metal bearings are standard practice.
B+V Stern Tube 700mm
unverified
· stern tube bearing assembly
Shaft diameter (mm)
700
Bearing material
white metal
Length (mm)
2100
Strengths
- White‑metal (Babbitt) bearing material offers excellent embedability and load distribution for high thrust loads.
- Standardised length of 2100 mm fits a wide range of hull designs, reducing engineering redesign time.
- Blohm+Voss proven design with long service history on ocean‑going vessels, giving confidence in reliability.
- Modular construction allows optional integration of mechanical seals or gland packing to suit owner preference.
- Robust housing provides good protection against external impacts and corrosion.
Weaknesses
- Relatively heavy and bulky compared with some lightweight aluminium alternatives, affecting installation logistics.
- Seal type not specified; owners must select and procure a compatible seal system separately.
- Requires continuous oil lubrication monitoring; failure to maintain oil quality can lead to bearing wear.
- Longer overall length may be unsuitable for vessels with constrained stern space.
- Higher initial cost than basic generic stern tubes due to premium engineering and materials.
Typical Vessels:
ContainerBulk CarrierTankerCruise ShipRo‑Ro
Decision Guide: Choose if: you need a high‑capacity, proven stern tube for a 700 mm shaft on a large ocean‑going vessel and value the reliability of a white‑metal bearing with optional seal configurations. Avoid if: your vessel has limited stern space, you require a lightweight solution, or you prefer an integrated sealed unit supplied by the classification society.
Use Cases: Commonly installed on new builds and major retrofits of container ships, bulk carriers, tankers and cruise vessels where the propeller shaft size is 700 mm. It is used in both conventional single‑screw propulsion lines and in some dual‑propulsion arrangements that share a common stern tube housing.
B+V Stern Tube 800mm
unverified
· white-metal journal bearing
Shaft diameter (mm)
800
Bearing material
white metal
Length (mm)
2400
Strengths
- High load capacity suitable for 800 mm shaft diameters
- Robust white‑metal material provides good heat dissipation and wear resistance
- Standardised 2400 mm length simplifies installation and replacement
- Blohm+Voss reputation for quality engineering and long service life
- Modular design allows integration with existing stern tube arrangements
Weaknesses
- Requires regular oil lubrication and maintenance typical of white‑metal bearings
- Seal type not specified – may need a custom sealing solution
- Weight and handling can be significant due to large dimensions (exact weight not provided)
- Data marked as needing verification; some specifications may be incomplete
Typical Vessels:
VLCCULCCLarge container shipCruise linerLNG carrier
Decision Guide: Choose if: you need a proven, high‑capacity bearing for an 800 mm main shaft on a large vessel and prefer a reputable OEM with standard dimensions. Avoid if: you require an integrated seal package, low‑maintenance polymer bearings, or have strict weight constraints.
Use Cases: Installed in the stern tube of very large tankers, container ships, cruise ships and LNG carriers to support the main propulsion shaft, typically as part of a double‑bearing arrangement with oil lubrication systems.
B+V Stern Tube 900mm
unverified
· White‑metal stern tube bearing
Shaft diameter (mm)
900
Bearing material
white metal
Length (mm)
2700
Strengths
- Specifically sized for 900 mm shafts, matching the load requirements of large propulsion systems
- White‑metal alloy provides good embedability and distributes loads evenly across the bearing surface
- Standard 2700 mm length fits common stern‑tube housings, simplifying installation on new builds
- Manufactured by Blohm+Voss, a company with extensive shipyard experience and proven quality control
Weaknesses
- No integrated mechanical seal (seal_type is null), requiring an external sealing solution
- White‑metal bearings need regular oil monitoring to avoid wear or seizure
- Large size and weight may limit applicability on smaller vessels or retrofit projects with space constraints
- Spare‑part availability depends on Blohm+Voss distribution network, which can be limited in some regions
Typical Vessels:
VLCC (Very Large Crude Carrier)Suezmax tankerPanamax bulk carrierLarge container ship (>8,000 TEU)Cruise ship
Decision Guide: Choose if: you are fitting a new‑build or major refit of a large vessel that uses a 900 mm main shaft and you have an external sealing arrangement in place. Avoid if: you require an integrated seal, need a lighter/compact bearing for smaller ships, or prefer low‑maintenance polymer bearings.
Use Cases: Installed as the primary stern‑tube bearing for main propulsion shafts on high‑power ocean‑going vessels, providing support and alignment between the engine output shaft and the propeller shaft. Also used in auxiliary drive lines where similar load capacities are required.
B+V Stern Tube 1000mm
unverified
· white metal bearing stern tube
Shaft diameter (mm)
1000
Bearing material
white metal
Length (mm)
3000
Strengths
- Designed for large 1000 mm shafts, handling high thrust loads
- Robust white‑metal alloy bearing offers excellent load capacity
- 3 m overall length accommodates deep shaft runs in large vessels
- Blohm+Voss engineering ensures tight tolerances and class‑approval readiness
- Modular construction simplifies installation and routine maintenance
Weaknesses
- Relatively heavy due to size and material
- White‑metal bearings require regular lubrication and monitoring
- Seal type not specified; may need custom sealing solutions
- Longer lead time for a bespoke 3 m unit
- Not suitable for vessels with smaller than 1000 mm shafts
Typical Vessels:
Crude Oil TankerProduct TankerBulk CarrierContainer ShipCruise Ship
Decision Guide: Choose if the vessel has a 1000 mm shaft and needs a high‑load, class‑grade bearing with proven Blohm+Voss quality. Avoid on smaller vessels or where weight and maintenance intervals are critical.
Use Cases: Installed as the main stern tube in newbuilds of large commercial ships or during major refits when replacing worn bearings; commonly used in propulsion lines that run through deep hull sections.