OceanSphere
Engines

Flexible Coupling

high 71 / 71 models (Inspector)

A torsionally flexible coupling sits at the engine flywheel and absorbs torque pulses and misalignment that a rigid coupling cannot handle. Its stiffness and damping figures feed directly into the shaft line's torsional vibration calculation, and a worn coupling can quietly shift the resonance into the normal running range.

Read more — Flexible Coupling explained

What sets a flexible coupling apart

A torsionally flexible coupling sits between the engine and the rest of the shaft line, usually right at the engine flywheel or between engine and gearbox, and its job is to absorb torsional vibration and angular misalignment rather than simply transmit torque. A rigid flange coupling, by contrast, assumes the two shafts it joins are already close to perfectly aligned and torsionally compatible; it is fine further down a shaft line between two already-flexible sections, but it cannot be used straight off a diesel engine's crankshaft, where torque pulses from each cylinder firing would otherwise be passed straight into the gearbox and propeller shaft. The flexible coupling's rubber or steel-disc elements twist slightly under each torque pulse and damp it, which is what keeps the shaft line's torsional natural frequencies clear of the engine's normal running speed range.

Flexible coupling arrangement
Side section of a torsionally flexible coupling between the engine flywheel and the output shaft, showing the driving flange, the elastomer flexible elements, the driven flange and the coupling bolts.

Main components

Flexible element

Rubber-block or rubber-bushing couplings use pre-compressed rubber elements between metal segments to give both torsional flexibility and some vibration damping through internal hysteresis. Steel-disc couplings use thin flexing steel discs instead, giving high torque capacity and no rubber to age, at the cost of less inherent damping.

Hub flanges and bolting

Two hub flanges, one keyed or shrunk onto the engine flywheel or output shaft and one onto the driven shaft, sandwich the flexible elements and are held together with fitted bolts torqued to a specified value; correct bolt tension is what keeps the joint from working loose under cyclic torque.

Torque limiter or shear pin

Some couplings include a deliberately weaker element, a shear pin or friction-slip section, designed to fail or slip before an overload event, such as a fouled propeller, damages the engine or gearbox.

Selection and sizing

Coupling selection is driven by the shaft line's torsional vibration behaviour, not just by torque capacity:

  • Nominal and peak torque capacity, with margin for the engine's maximum continuous rating plus transient loads
  • Torsional stiffness and damping, since these figures feed directly into the ship's torsional vibration calculation and determine whether a barred speed range is needed
  • Permissible misalignment, angular, radial and axial, matched to the actual installation tolerances achievable at the engine seating

Regulations and class

Class societies require a torsional vibration analysis of the complete shaft line, from engine crankshaft to propeller, before the coupling is approved, and the coupling manufacturer's stiffness and damping data are a direct input to that calculation. Where the analysis shows a resonance within the normal operating range, class will impose a barred speed range that the engine must pass through quickly rather than run in continuously, and the coupling forms part of the survey scope at each shaft line examination.

Typical faults

  • Rubber elements hardening and cracking from oil contamination or sustained overheating, gradually shifting the coupling's torsional stiffness and moving the resonance point
  • Bolts loosening under cyclic load when not torqued or locked correctly at installation, leading to fretting and eventual failure
  • Undetected misalignment from engine seating settlement, showing up as uneven wear across the flexible elements
  • Wrong stiffness selection at the newbuilding stage producing a barred speed range that falls inside the ship's normal service speed

What to look for in a supplier

  • Full torsional stiffness and damping data for the exact coupling size, supplied in the format class societies require for the vibration calculation
  • Rubber compound rated for the expected engine room temperature and any oil mist exposure
  • Availability of flexible elements as a separate spare, so the whole coupling does not need replacing for a routine element change
  • Track record on comparable engine and gearbox combinations, since torsional behaviour is installation-specific

A coupling that looks fine on the outside can already have degraded torsional stiffness; if running speeds start drifting into a range that used to be barred, treat it as a shaft line problem, not a governor problem.

Technical drawings & plates

Historical engineering archive — public domain sources, cited per plate. Principles shown remain valid; always consult the OEM manual for model-specific data.

Grid-type flexible coupling.
Grid-type flexible coupling.
Boilerman 3 & 2, NAVPERS 10535-C, U.S. Navy (1955) — public domain
Pin-type flexible coupling.
Pin-type flexible coupling.
Boilerman 3 & 2, NAVPERS 10535-C, U.S. Navy (1955) — public domain
Flange type solid coupling.
Flange type solid coupling.
Diesel Engine Maintenance Training Manual, Bureau of Ships, U.S. Navy (1946) — public domain
Hydraulic coupling, quick dump type.
Hydraulic coupling, quick dump type.
Diesel Engine Maintenance Training Manual, Bureau of Ships, U.S. Navy (1946) — public domain
8000h
Service Interval
20 yr
Typical Lifetime

Typical Manufacturers

Vulkan Geislinger
Inspector Mode Show All 71 / 71 with inspector value

24 manufacturers · 71 models

Vulkan

9
Vulkan RATO S
RATO S
15000 kW · N/A (mechanical) · rubber-in-shear flexible coupling
Common Failures & Inspection Points
  • Misalignment or foundation movement causes vibration, bearing load changes and abnormal temperature
  • Bearing, bush or coupling wear causes noise, vibration, backlash or rising temperature
  • Seal deterioration causes lubricating-oil leakage or seawater ingress
  • Lubrication contamination or low supply damages bearings and produces temperature or pressure alarms
  • Control or hydraulic faults on controllable-pitch or PTO equipment cause incorrect response, alarms or loss of function
Service: Inspect alignment references, bearings, seals, couplings, lubrication, vibration and leakage. Review oil condition and bearing-temperature trends and check for shaft movement or abnormal wear. Test pitch, clutch or PTO controls under the approved procedure where applicable. Refer to manufacturer and class documentation for the exact figure for alignment, clearances and wear limits.
Spare Parts: Carry seals, filters, approved lubricants, coupling elements, bearing or bush service parts where practical, hydraulic-control spares and critical sensors.
Strengths
  • High torsional vibration damping due to rubber element
  • Compact design with relatively low weight for its torque class
  • Simple installation – bolted connection without need for complex alignment tools
  • Cost‑effective compared with hydraulic or fluid couplings for moderate power ranges
Weaknesses
  • Rubber element ages and can crack, requiring inspection every two years
  • Bolt loosening is a known failure mode if torque checks are not performed regularly
  • Limited speed capability relative to metal gear couplings
  • Misalignment beyond design limits leads to premature wear of the rubber
Typical Vessels: Bulk CarrierTankerContainer ShipGeneral Cargo VesselOffshore Supply Vessel
Decision Guide: Choose if: you need a low‑cost, compact coupling with good vibration damping for moderate torque and speed applications, and you can commit to regular rubber inspections. Avoid if: the propulsion system operates at high RPM, requires very tight alignment tolerances, or demands long intervals between maintenance.
Use Cases: Conventional shaft propulsion, controllable-pitch propellers and shaft-driven electrical or mechanical auxiliaries.
VULKARDAN L
8000 kW · N/A (mechanical) · elastic elastomeric coupling
Common Failures & Inspection Points
  • Misalignment or foundation movement causes vibration, bearing load changes and abnormal temperature
  • Bearing, bush or coupling wear causes noise, vibration, backlash or rising temperature
  • Seal deterioration causes lubricating-oil leakage or seawater ingress
  • Lubrication contamination or low supply damages bearings and produces temperature or pressure alarms
  • Control or hydraulic faults on controllable-pitch or PTO equipment cause incorrect response, alarms or loss of function
Service: Inspect alignment references, bearings, seals, couplings, lubrication, vibration and leakage. Review oil condition and bearing-temperature trends and check for shaft movement or abnormal wear. Test pitch, clutch or PTO controls under the approved procedure where applicable. Refer to manufacturer and class documentation for the exact figure for alignment, clearances and wear limits.
Spare Parts: Carry seals, filters, approved lubricants, coupling elements, bearing or bush service parts where practical, hydraulic-control spares and critical sensors.
Strengths
  • Excellent shock‑absorption reduces stress on downstream gearboxes and propellers
  • Allows moderate angular, axial and radial misalignment without re‑machining
  • Compact design simplifies installation in confined shaft line spaces
  • Standardized replacement schedule for elastomer elements eases maintenance planning
Weaknesses
  • Elastomer elements wear and must be replaced according to Vulkan’s schedule
  • Hub keyway fretting can develop, leading to increased vibration over time
  • Torque capacity is lower than that of rigid gear couplings, limiting use on high‑power shafts
  • Performance degrades at extreme temperatures (very low or very high)
  • Potential for vibration increase if wear is not monitored closely
Typical Vessels: Container shipBulk carrierTankerOffshore supply vesselCruise liner
Decision Guide: Choose if: you need a flexible, shock‑absorbing connection for moderate torque shafts and value easy alignment tolerance. Avoid if: the propulsion line requires maximum torque transmission, ultra‑low vibration levels, or operates in extreme temperature environments where elastomer degradation is critical.
Use Cases: Conventional shaft propulsion, controllable-pitch propellers and shaft-driven electrical or mechanical auxiliaries.
Vulkan RATO R 150 unverified
· 500.0 kW · torsionally resilient marine coupling
Coupling type
torsionally resilient marine coupling
Rated power (kW)
500
Application
marine flexible coupling
Common Failures & Inspection Points
  • Elastomer or resilient-element ageing causes cracking, permanent deformation or increased torsional vibration
  • Loose bolts or fretting at flanges causes metallic debris, movement or abnormal vibration
  • Misalignment overloads coupling elements and causes uneven wear or repeated element failure
  • Oil, heat or chemical contamination degrades resilient material and causes softening or swelling
  • Fatigue cracks or damaged metallic components cause increasing vibration and may threaten torque transmission
Service: Inspect resilient elements, flanges, bolts, alignment marks and signs of fretting, heat or contamination. Compare coupling condition with shaft vibration and torsional behaviour after propulsion changes. Verify fastener condition and alignment after replacement. Refer to the manufacturer documentation for the exact figure for allowable deflection, alignment and replacement criteria.
Spare Parts: Carry complete resilient-element sets, approved fasteners, locking devices and alignment or installation consumables for the installed coupling.
Strengths
  • High torque capacity (up to 500 kW) suitable for main propulsion shafts on medium‑size vessels
  • Provides axial, angular and radial flexibility, reducing shaft stress and vibration
  • Compact, lightweight design simplifies installation in confined engine rooms
  • Low maintenance – no lubrication required for the elastomeric elements
  • Designed to meet marine class standards for shock and fatigue resistance
Weaknesses
  • Maximum torque rating limits use on high‑power (>500 kW) propulsion systems
  • Elastomeric elements may require periodic inspection/replacement in harsh sea water environments
  • Not suitable for ultra‑high speed shafts where centrifugal forces exceed design limits
  • Initial purchase price higher than basic rigid couplings
  • Limited availability of spare parts outside Vulkan’s authorized network
Typical Vessels: TankerContainer shipBulk carrierOffshore supply vesselCruise liner
Decision Guide: Choose if: you need a reliable flexible coupling for propulsion or auxiliary shafts up to 500 kW, require vibration damping and misalignment tolerance, and operate on vessels where space is limited. Avoid if: the shaft power exceeds 500 kW, the application demands ultra‑high rotational speeds, or budget constraints favor a basic rigid coupling.
Use Cases: Propulsion and generator drive trains requiring torsional isolation or limited misalignment accommodation.
Vulkan RATO R 250 unverified
· 1500.0 kW · torsionally resilient marine coupling
Coupling type
torsionally resilient marine coupling
Rated power (kW)
1500
Application
marine flexible coupling
Common Failures & Inspection Points
  • Elastomer or resilient-element ageing causes cracking, permanent deformation or increased torsional vibration
  • Loose bolts or fretting at flanges causes metallic debris, movement or abnormal vibration
  • Misalignment overloads coupling elements and causes uneven wear or repeated element failure
  • Oil, heat or chemical contamination degrades resilient material and causes softening or swelling
  • Fatigue cracks or damaged metallic components cause increasing vibration and may threaten torque transmission
Service: Inspect resilient elements, flanges, bolts, alignment marks and signs of fretting, heat or contamination. Compare coupling condition with shaft vibration and torsional behaviour after propulsion changes. Verify fastener condition and alignment after replacement. Refer to the manufacturer documentation for the exact figure for allowable deflection, alignment and replacement criteria.
Spare Parts: Carry complete resilient-element sets, approved fasteners, locking devices and alignment or installation consumables for the installed coupling.
Strengths
  • High torsional flexibility reduces stress on shafts and bearings
  • Accommodates angular, axial and radial misalignments up to typical limits for marine drives
  • Compact design suitable for confined engine rooms
  • Low maintenance elastomeric elements with predictable wear life
  • Rated for 1500 kW, fitting a wide range of medium‑size vessel propulsion systems
Weaknesses
  • Elastomeric inserts have temperature and speed limits; extreme conditions may require special material grades
  • Limited overload capacity compared with rigid gear couplings
  • Periodic inspection/replacement of the flexible element adds scheduled downtime
  • Higher initial cost than basic gear or jaw couplings for the same power rating
  • Not ideal for applications with very high shock‑load frequency (e.g., heavy‑duty tug propulsion)
Typical Vessels: Product TankerFeeder Container ShipSmall to Mid‑size Bulk CarrierOffshore Supply VesselCruise Ferry
Decision Guide: Choose the Vulkan RATO R‑250 when you need a reliable, medium‑power (≤1500 kW) flexible coupling that can tolerate shaft misalignment and damp torsional vibrations in standard marine propulsion lines. Avoid it for ultra‑high shock‑load environments, very low‑maintenance requirements, or where temperature/ speed exceed the elastomeric limits.
Use Cases: Propulsion and generator drive trains requiring torsional isolation or limited misalignment accommodation.
Vulkan RATO R 400 unverified
· 3000.0 kW · torsionally resilient flexible coupling
Coupling type
torsionally resilient marine coupling
Rated power (kW)
3000
Application
marine flexible coupling
Common Failures & Inspection Points
  • Elastomer or resilient-element ageing causes cracking, permanent deformation or increased torsional vibration
  • Loose bolts or fretting at flanges causes metallic debris, movement or abnormal vibration
  • Misalignment overloads coupling elements and causes uneven wear or repeated element failure
  • Oil, heat or chemical contamination degrades resilient material and causes softening or swelling
  • Fatigue cracks or damaged metallic components cause increasing vibration and may threaten torque transmission
Service: Inspect resilient elements, flanges, bolts, alignment marks and signs of fretting, heat or contamination. Compare coupling condition with shaft vibration and torsional behaviour after propulsion changes. Verify fastener condition and alignment after replacement. Refer to the manufacturer documentation for the exact figure for allowable deflection, alignment and replacement criteria.
Spare Parts: Carry complete resilient-element sets, approved fasteners, locking devices and alignment or installation consumables for the installed coupling.
Strengths
  • High torque capacity (up to 3000 kW) suitable for main propulsion shafts
  • Marine‑grade corrosion‑resistant materials extend service life in saltwater environments
  • Built‑in torsional vibration damping reduces stress on bearings and gearboxes
  • Compact design saves space in crowded shaft line arrangements
Weaknesses
  • Rated only to 3000 kW; not applicable for very high‑power vessels (>4000 kW)
  • Installation requires careful alignment and torque control to achieve full performance
  • Specific certification (IMO D‑2, USCG Type Approval, etc.) is not publicly documented
Typical Vessels: Bulk CarrierTankerContainer ShipGeneral Cargo VesselRo‑Ro Ferry
Decision Guide: Choose the RATO R‑400 when a vessel needs a reliable, high‑torque flexible coupling for propulsion shafts up to 3000 kW and values built‑in vibration damping in a compact marine‑grade package. Avoid it if the required power exceeds its rating, if specific certification (e.g., IMO D‑2) is mandatory and not verified, or if the installation environment cannot guarantee the precise alignment needed for optimal performance.
Use Cases: Propulsion and generator drive trains requiring torsional isolation or limited misalignment accommodation.
Vulkan RATO R 600 unverified
· 6000.0 kW · torsionally resilient marine coupling
Coupling type
torsionally resilient marine coupling
Rated power (kW)
6000
Application
marine flexible coupling
Common Failures & Inspection Points
  • Elastomer or resilient-element ageing causes cracking, permanent deformation or increased torsional vibration
  • Loose bolts or fretting at flanges causes metallic debris, movement or abnormal vibration
  • Misalignment overloads coupling elements and causes uneven wear or repeated element failure
  • Oil, heat or chemical contamination degrades resilient material and causes softening or swelling
  • Fatigue cracks or damaged metallic components cause increasing vibration and may threaten torque transmission
Service: Inspect resilient elements, flanges, bolts, alignment marks and signs of fretting, heat or contamination. Compare coupling condition with shaft vibration and torsional behaviour after propulsion changes. Verify fastener condition and alignment after replacement. Refer to the manufacturer documentation for the exact figure for allowable deflection, alignment and replacement criteria.
Spare Parts: Carry complete resilient-element sets, approved fasteners, locking devices and alignment or installation consumables for the installed coupling.
Strengths
  • Handles up to 6 MW torque capacity, suitable for large propulsion shafts
  • Compensates angular, axial and radial misalignment, reducing alignment‑related wear
  • Built‑in torsional damping lowers vibration and protects downstream equipment
  • Compact design relative to its power rating, easing installation in confined spaces
  • Corrosion‑resistant marine‑grade materials extend service life
Weaknesses
  • Higher initial purchase cost compared with rigid couplings of similar size
  • Elastomeric or damping elements require periodic inspection and replacement
  • Maximum operating speed may be limited by the coupling’s design
  • Axial length can be a constraint in retro‑fit applications
  • Performance can degrade if operated outside specified temperature ranges
Decision Guide: Choose if you need a 6 MW flexible coupling that provides misalignment compensation and torsional damping for high‑power propulsion shafts, especially on new builds or major repower projects where space is limited. Avoid if the installation cannot accommodate the coupling’s axial length, if operating temperatures exceed the elastomer rating, or if budget constraints favor simpler rigid couplings.
Use Cases: Propulsion and generator drive trains requiring torsional isolation or limited misalignment accommodation.
Vulkan VULASTIK L 200 unverified
· 1000.0 kW · highly flexible marine coupling
Coupling type
highly flexible marine coupling
Rated power (kW)
1000
Application
marine flexible coupling
Common Failures & Inspection Points
  • Cavitation or erosion can damage blade surfaces, seen as pitting, roughness and loss of hydrodynamic finish
  • Impact with debris or grounding can bend or crack blades, noticed as vibration, imbalance or visible deformation
  • Corrosion or coating breakdown can attack exposed surfaces, seen as pitting or wastage
  • Poor shaft-line alignment or bearing condition can create uneven loading, noticed as vibration and abnormal bearing trends
  • For controllable-pitch arrangements, hub-seal or pitch-mechanism faults can impair pitch control, seen as oil leakage or inconsistent thrust response
Service: Inspect blade surfaces, leading and trailing edges, hub condition and evidence of impact, erosion, cracking or corrosion whenever access is available. Correlate propeller condition with shaft-line vibration and bearing observations. Repair dimensions, balancing criteria and allowable damage limits must follow class-approved and manufacturer procedures.
Spare Parts: Onboard spares are generally limited to approved hub seals, fasteners or CPP hydraulic/service items where applicable; major blade or hub repairs require yard or specialist support.
Strengths
  • Rated torque capacity of up to 1000 kW for medium‑size propulsion systems
  • Wide angular and axial misalignment tolerance reduces alignment‑related wear
  • Built‑in damping characteristics lower vibration and shock loads on the shaft line
  • Corrosion‑resistant alloy construction suitable for continuous seawater exposure
  • Compact, modular design simplifies installation and integration with existing shaft lines
Weaknesses
  • Maximum power rating limits use to vessels with engines ≤1000 kW
  • Requires periodic lubrication/maintenance of the elastomeric elements
  • Spare‑part availability may be constrained outside the manufacturer’s primary market
  • Weight is higher than some lightweight aluminium couplings, affecting overall shaft line mass
  • Initial purchase cost can be higher than basic rigid couplings
Typical Vessels: Product TankerOffshore Supply VesselFerrySmall Container ShipCoastal Bulk Carrier
Decision Guide: Choose if you need a robust, vibration‑damping coupling for propulsion shafts up to 1000 kW and expect significant misalignment or shock loading. Avoid if the engine power exceeds the rating, weight is a critical constraint, or you require a low‑cost, minimal‑maintenance rigid solution.
Use Cases: Used on conventional merchant, passenger, naval and offshore vessels as the primary device for producing ahead and astern thrust.
Vulkan VULASTIK L 350 unverified
· 2500.0 kW · elastomeric flexible coupling
Coupling type
highly flexible marine coupling
Rated power (kW)
2500
Application
marine flexible coupling
Common Failures & Inspection Points
  • Elastomer or resilient-element ageing causes cracking, permanent deformation or increased torsional vibration
  • Loose bolts or fretting at flanges causes metallic debris, movement or abnormal vibration
  • Misalignment overloads coupling elements and causes uneven wear or repeated element failure
  • Oil, heat or chemical contamination degrades resilient material and causes softening or swelling
  • Fatigue cracks or damaged metallic components cause increasing vibration and may threaten torque transmission
Service: Inspect resilient elements, flanges, bolts, alignment marks and signs of fretting, heat or contamination. Compare coupling condition with shaft vibration and torsional behaviour after propulsion changes. Verify fastener condition and alignment after replacement. Refer to the manufacturer documentation for the exact figure for allowable deflection, alignment and replacement criteria.
Spare Parts: Carry complete resilient-element sets, approved fasteners, locking devices and alignment or installation consumables for the installed coupling.
Strengths
  • High torsional flexibility reduces vibration and shock loads on the propulsion system
  • Accommodates angular, axial and radial misalignments up to several millimetres
  • Compact design saves space in crowded shaft line arrangements
  • Low maintenance – no lubrication required for the elastomer element
  • Simple installation with bolt‑on flanges
Weaknesses
  • Maximum torque rating (≈2500 kW) limits use on very high‑power main engines
  • Elastomer material has temperature and chemical exposure limits requiring periodic inspection
  • Not suitable for ultra‑high shaft speeds (>300 rpm) where heat buildup can degrade the elastomer
  • Replacement of the elastomer element may require dry‑dock time
Typical Vessels: Bulk CarrierProduct TankerContainer Ship (up to 3,000 TEU)Offshore Supply VesselCruise Ferry
Decision Guide: Choose if: shaft power does not exceed 2500 kW, you need built‑in vibration damping and misalignment tolerance, and space is at a premium. Avoid if: the propulsion system requires higher torque or operates at very high speeds where metal gear couplings are preferred.
Use Cases: Propulsion and generator drive trains requiring torsional isolation or limited misalignment accommodation.
Vulkan VULASTIK L 500 unverified
· 5000.0 kW · highly flexible marine coupling
Coupling type
highly flexible marine coupling
Rated power (kW)
5000
Application
marine flexible coupling
Common Failures & Inspection Points
  • Elastomer or resilient-element ageing causes cracking, permanent deformation or increased torsional vibration
  • Loose bolts or fretting at flanges causes metallic debris, movement or abnormal vibration
  • Misalignment overloads coupling elements and causes uneven wear or repeated element failure
  • Oil, heat or chemical contamination degrades resilient material and causes softening or swelling
  • Fatigue cracks or damaged metallic components cause increasing vibration and may threaten torque transmission
Service: Inspect resilient elements, flanges, bolts, alignment marks and signs of fretting, heat or contamination. Compare coupling condition with shaft vibration and torsional behaviour after propulsion changes. Verify fastener condition and alignment after replacement. Refer to the manufacturer documentation for the exact figure for allowable deflection, alignment and replacement criteria.
Spare Parts: Carry complete resilient-element sets, approved fasteners, locking devices and alignment or installation consumables for the installed coupling.
Strengths
  • Rated for up to 5 000 kW (≈5 MW) continuous power, suitable for large main‑propulsion lines
  • Compensates angular, axial and radial misalignments, reducing shaft stress
  • Absorbs torsional shock loads, protecting downstream gearboxes and propellers
  • Compact design with corrosion‑resistant alloy housings for marine environments
  • Low maintenance – sealed unit requiring only periodic visual inspection
Weaknesses
  • Higher initial purchase price compared with rigid couplings of similar rating
  • Limited to typical low‑speed propulsion shafts; not intended for very high rpm applications
  • Installation requires careful alignment and torque verification to achieve full flexibility benefits
  • Periodic oil‑lubrication checks are needed if the model uses an oil‑filled damping element
Typical Vessels: Crude Oil TankerContainer ShipBulk CarrierLNG/LPG CarrierCruise ShipOffshore Supply Vessel
Decision Guide: Choose if: you need a coupling that can handle ≥5 MW shaft power, tolerate misalignment and absorb shock loads on low‑speed propulsion shafts, and require high corrosion resistance for seawater service. Avoid if: the installation budget is very tight, the shaft speed exceeds typical low‑speed limits, or a simpler rigid coupling will meet the alignment tolerances.
Use Cases: Propulsion and generator drive trains requiring torsional isolation or limited misalignment accommodation.

Vulkan Kupplungs- und Getriebebau Bernhard Hackforth

9
VULKARDAN E
Model Number
TAM000015Y
Vulkan Kupplungs- und Getriebebau Bernhard Hackforth GmbH & Co. KG VULKARDAN F
VULKARDAN F
Model Number
TAM000016B
RATO R, RATO R+
Model Number
TAM000010C
VULASTIK L
Model Number
TAM000010R
Vulkan Kupplungs- und Getriebebau Bernhard Hackforth GmbH & Co. KG VULKARDAN G
VULKARDAN G
Model Number
TAM000010X
Vulkan Kupplungs- und Getriebebau Bernhard Hackforth GmbH & Co. KG RATO DG, RATO DG+
RATO DG, RATO DG+
Model Number
TAM000010G
RATO S, RATO S+
Model Number
TAM000010B
RATO DS, RATO DS+
Model Number
TAM000010A
VULKARDAN L
Model Number
TAM00000GK

Centa-Antriebe Kirschey

6
CENTAFLEX-R, CENTAFLEX-RF, CENTAFLEX-RV, CENTAFLEX-"HR" Roller, CENTAFLEX-"HD" Roller
Model Number
TAM0000076
CENTAMAX - Types S, HTC and B
Model Number
TAM00000XA
CENTAX-TT size 130 - 460
Model Number
TAM00000VW
CENTAX - SEC - system: Series G, L, N, NL, B, V and CENTALINK
Model Number
TAM00000FF
CD-C0G, CD-C1G, CD-C2G, CD-C3G, CD-C4G, CD-C0, CD-C1, CD-C2, CD-C3, CD-C4, CD-C5
Model Number
TAM00000A1
CENTAFLEX - Series D, Sizes 160, 198, 220, 275, 350, 425, 560, CENTAFLEX - Series E, Sizes 80, 105, 135, 160, 198, 220, 275, 350, 425, 560,
Model Number
TAM0000087

KTR Systems

6
REVOLEX KX-D
Model Number
TAM00000HR
BoWex-Elastic, HE, HEW, Monolastic, HEW Compact, HEG
Model Number
TAM00000J2
RIGIFLEX-N, RADEX-N
Model Number
TAM00000HZ
BoWex type M/I, AS, Spec.-I, SG, SSR, SD, M...C, FLE-PA, FLE-PAC.
Model Number
TAM00000J1
KTR Systems GmbH GEARex
GEARex
Model Number
TAM00000HS
ROTEX
Model Number
TAM00000J0

Renold Power Transmission

6
DCB-GS
Model Number
TAM00000J7
Renold Power Transmission Ltd. HTB-GS
HTB-GS
Model Number
TAM00000EK
Renold Power Transmission Ltd. HTB series
HTB series
Model Number
TAM00000JG
Renold Power Transmission Ltd. VF
VF
Model Number
TAM00000JA
DCB
Model Number
TAM00000JB
Renold Power Transmission Ltd. RB
RB
Model Number
TAM00000JE

Flender

5
ZAPEX ZW, ZN and ZI series,
Model Number
TAM000005D
ZAPEX ZWHV 230 drawing 8203800
Model Number
TAM00001EU
RUPEX RWS 450
Model Number
TAM00001E5
RUPEX
Model Number
TAM00000Z0
ARPEX Series: ARS-6, ARS-6 NEN 210-6, ARF-6, ARC-8/-10, ARH-8, ARN-6/-8/-10
Model Number
TAM00000Z1

Geislinger

4
Gesilco D
20000 kW · N/A (mechanical) · Steel-spring damping coupling
Common Failures & Inspection Points
  • Misalignment or foundation movement causes vibration, bearing load changes and abnormal temperature
  • Bearing, bush or coupling wear causes noise, vibration, backlash or rising temperature
  • Seal deterioration causes lubricating-oil leakage or seawater ingress
  • Lubrication contamination or low supply damages bearings and produces temperature or pressure alarms
  • Control or hydraulic faults on controllable-pitch or PTO equipment cause incorrect response, alarms or loss of function
Service: Inspect alignment references, bearings, seals, couplings, lubrication, vibration and leakage. Review oil condition and bearing-temperature trends and check for shaft movement or abnormal wear. Test pitch, clutch or PTO controls under the approved procedure where applicable. Refer to manufacturer and class documentation for the exact figure for alignment, clearances and wear limits.
Spare Parts: Carry seals, filters, approved lubricants, coupling elements, bearing or bush service parts where practical, hydraulic-control spares and critical sensors.
Strengths
  • High torsional vibration attenuation thanks to leaf‑spring design combined with oil damping
  • Compact and relatively lightweight compared with hydraulic couplings
  • Proven track record in merchant vessels; easy to install between engine and reduction gear
  • Oil damper allows fine tuning of damping characteristics
  • No external power required for operation
Weaknesses
  • Leaf‑spring fatigue can develop after many operating hours, requiring periodic inspection or replacement
  • Potential oil leakage from the damper chamber if seals deteriorate
  • Damping performance may change over time as oil viscosity varies with temperature and age
  • Limited overload capacity compared with hydraulic or elastomeric couplings
  • Requires regular oil‑level checks and maintenance of the damper
Typical Vessels: Bulk CarrierTankerContainer ShipGeneral Cargo VesselOffshore Supply Vessel
Certifications: ABSDNV GL
Decision Guide: Choose if: you need a robust, mechanically simple solution for medium‑power shafts where space is limited and proven vibration damping is required; you can commit to regular oil‑level checks and periodic spring inspections. Avoid if: the propulsion system experiences frequent high overload shocks, requires variable or adjustable damping on‑the‑fly, or an oil‑free solution is mandated.
Use Cases: Conventional shaft propulsion, controllable-pitch propellers and shaft-driven electrical or mechanical auxiliaries.
Geislinger Coupling, Flexlink and SAE
Model Number
TAM00000UD
CI, CF, BF, CS, MB, DI, SC
Model Number
TAM0000051
CT47, CT58
Model Number
TAM00000MA

Dipl.-Ing. Herwarth Reich

3
ARCUSAFLEX AC 1.5, AC 2.3, AC 2.6 / 2.7, AC 3, AC 4 / 4.1, AC 5 / 5.1, AC 6 / 6.1, AC 6.5, AC 7, AC 7,5, AC 8, AC 8D, AC 9, AC 9D, AC 10.2, AC 10.2D, AC 11, AC 11D, AC 11.7, AC 11.7D, AC 11.9, AC 12, AC 12D
Model Number
TAM0000054
Multi Mont - Sella, MMS 6,3, MMS 10, MMS 16, MMS 25, MMS 40, MMS 63, MMS 100, MMS 160, MMS 250, MMS 400, MMS 630, MMS 1000, MMS 1600, MMS 2500, MMS 4000, MMS 6300, MMS 10000, MMS 16000, MMS 25000, MMS 40000, MMS 63000, MMS 100000
Model Number
TAM0000059
Dipl.-Ing. Herwarth Reich GmbH ARCUSAFLEX-VSK, AC-VSK 15, AC-VSK 25, AC-VSK 35, AC-VSK 45, AC-VSK 50, AC-VSK 55, AC-VSK 60, AC-VSK 70, AC-VSK 85, Each in the versions EN, WN and NN. Application: Installation on combustion engines in connection with articulated shafts.
ARCUSAFLEX-VSK, AC-VSK 15, AC-VSK 25, AC-VSK 35, AC-VSK 45, AC-VSK 50, AC-VSK 55, AC-VSK 60, AC-VSK 70, AC-VSK 85, Each in the versions EN, WN and NN. Application: Installation on combustion engines in connection with articulated shafts.
Model Number
TAM00000D0

Kyushu Hasec

3
MSSH, MSSB-SP
Model Number
TAM0000134
MSV, MSEV type A & B, MSEB, MSE
Model Number
TAM0000106
NSSH
Model Number
TAM00000DR

REGAL BELOIT SPAIN, S.A. (JAURE)

3
JHC-HF-S, JHC-HF-S-UW, JHC-HF-F, JHC-S, JHC-S-UW, JHC-F
Model Number
TAM00001CH
LAMIDISC type: SX/ CC/ DO/ DOM Singleflex/ DOM/ DOI/ CC-E/ SXFD/ SXCF/ SXAC/ CX/ DX/ SU/ SC/ SXV/ SDT/ SXP/ SXAE/ SXL/ SX-SS/ SX-JS/ SX-JHSS/ SX-JSSS
Model Number
TAM000013C
MT, MTD, MTV, MTDFD, MTCO, MTS, MTAE, MTLI, MTXLE, MTG, MTX, MTP, MTT
Model Number
TAM0000075

Stromag

3
TRI, TRI-R
Model Number
TAM0000121
GE
Model Number
TAM0000120
PERIFLEX SERIES PVN / PVP
Model Number
TAM000011X

Kawasaki

2
KC couplings sizes KC2 to KC400
Model Number
TAM00000V8
Steelflex Coupling K-1090/1100/1110/1120/1130/1140/1150/1160 T-10
Model Number
TAM00000US

ALTRA INDUSTRIAL MOTION DO BRASIL EQUIPAMENTOS INDUSTRIAIS LTDA

1
Elastic Couplings
Model Number
TAM000019R

Daihatsu

1
KC380
Model Number
TAM000004M

Destinus OPRA

1
BOWEX G200 + RADEX-N136
Model Number
TAM000011U

EagleBurgmann Japan

1
Model 66, 67,74,99 and 100
Model Number
TAM00000A0

ISOFLEX TECHNOLOGIES

1
IsoFlex couplings size IFC4200 to IFC10325
Model Number
TAM00000H7

John Crane France SAS

1
HSFA/0096/KA/GA-253607
Model Number
TAM00001A1

KWD Kupplungswerk Dresden

1
ZK 4000-2
Model Number
TAM00001BD

Poly Flex Group

1
Poly Flex Shaft Coupling
Model Number
TAM00000FS

Renk

1
SB, SBL, SBG, SBR, SRL, SRG, SBD, SBT, VSB, HBk, SBk, SBLk, SBRk, SRLk, SRGk, SBkD, SBkT, LBk, LBLk, LBGk, LBRk, LBRkn, LRLk, LRLkn, SBGk, LRGk, LBkD, LBkT, VLBk, VTHB
Torque per Hersteller-Datenblatt · Hydraulic Oil
Model Number
TAM00000A8
Common Failures & Inspection Points
  • Vane seal leakage in rotary-vane type causes internal bypass
  • HPU motor bearing damage after 30,000+ operating hours
  • Solenoid valve sticking from oil contamination
  • Ruderlage-Rückmeldesystem Kalibrierungsdrift
Service: Hydraulic oil analysis every 6 months. Vane seal inspection at docking. SOLAS hard-over test (28 seconds). Emergency steering exercise monthly.
Spare Parts: Renk GmbH: Keep seal kits and solenoid valves on board. Lead time: 3-8 weeks.

Walterscheid

1
GKN Driveline/Aquadrive CV Drive Shafts
Model Number
TAM00000S5

Wärtsilä

1
WÄRTSILÄ IBERICA S.A. High friction treatment of inner surface of sleeve for, Shaft Coupling type OHSN-X, Shaft Coupling type OHSN-BX
High friction treatment of inner surface of sleeve for, Shaft Coupling type OHSN-X, Shaft Coupling type OHSN-BX
Model Number
TAM000001E

ZF Industrieantriebe Witten

1
SPIROFLEX KS
Model Number
TAM0000060