Sliding Hatch Cover

critical IMO Required 20 / 20 models (Inspector)

Sliding hatch covers move horizontally on wheels along the hatch coaming, either stacking to one side or riding piggyback over an adjacent panel, and are the standard choice on container ships where deck space beside the hatch is needed for lashed containers rather than parked cover panels.

Read more — Sliding Hatch Cover explained ▾

What sets sliding hatch covers apart

Unlike folding covers that hinge upward or pontoon covers lifted clear by crane, sliding covers travel horizontally on wheeled bogies running in tracks along the hatch coaming. In a side-stacking arrangement each panel parks beside the opening; in a piggyback arrangement one panel rides up and over the neighbouring panel on ramped tracks, so the whole set stacks at one end without needing coaming-side parking space. Container ships favour sliding designs because the coaming top must stay clear for container stacks and lashing bridges, and because opening and closing needs to be fast between calls.

Sliding hatch cover in plan view — Plan view of a hatch coaming with panels sliding on wheels along guide rails and stacking piggyback to one side, leaving the hold open for cargo access.

Main components

Panel structure

Steel panels stiffened for the deck cargo loads stacked on top, since container ships routinely stack lashed boxes directly on closed hatch covers.

Wheels and track

Bogie wheels running in a machined track set into the coaming, with ramped sections on piggyback designs to lift one panel clear of the next as it travels.

Cleating and compression system

Hydraulic or mechanical cleats pull the panel down onto a rubber gasket seated in the coaming, compressing it to the watertight standard the cover must meet.

Drive system

Hydraulic rams or a wire haulage system move the panels; larger covers on modern container ships are often driven hydraulically panel by panel from a local or remote control station.

Drainage channels

Coaming gutters and non-return drain valves carry away any water that gets past the primary seal before it can reach the hold.

Selection and sizing

Parameter	Relevance
Deck cargo load rating	Container stacking loads on the closed cover can exceed the weight of the cover itself many times over
Side-stacking vs piggyback	Piggyback saves coaming-side deck width at the cost of a taller stack height when open
Panel weight and drive power	Larger beam hatches need more powerful hydraulics and heavier track structure
Weathertightness class	Sets gasket compression force and cleat spacing needed for the intended trading area

Regulations and class

Hatch covers are certified against class weathertightness and structural rules that size plate thickness and stiffening for the wave loads and green sea pressures expected at the fitted position on deck, with higher requirements the further forward the hatch sits. The International Load Line Convention sets minimum coaming heights and requires covers to be weathertight to the standard appropriate for the ship's freeboard. Periodic class surveys include a hose or ultrasonic test of the seal and a check of the securing and drive gear, since a cover that looks closed can still leak if cleats are not fully engaged.

Typical faults

Track wear and debris - cargo residue or corrosion in the coaming track binds the wheels and forces the drive system to work harder than designed, accelerating further wear.
Gasket compression loss - a hardened or torn gasket, or cleats not fully engaged, lets water past even though the panel looks fully closed.
Wheel or bogie failure - a seized wheel can derail the panel partway through opening or closing, jamming operations until it is freed.
Drain valve fouling - a blocked non-return valve lets water that gets past the seal sit in the coaming gutter instead of draining away.

What to look for in a supplier

Structural certification matching the actual deck cargo stacking loads the ship intends to carry, not a nominal figure
Track and wheel material specified for the corrosion environment, since replacement mid-service life is disruptive on a working container ship
Spare gasket profiles matched exactly to the coaming groove, as generic gasket stock rarely seals correctly
Documented hose or ultrasonic test results from commissioning as a baseline for future surveys

Walk the coaming track and check gasket condition before every load line survey rather than relying on a single ultrasonic test - track debris and gasket wear are progressive and are far cheaper to catch early than after a hold has taken water.

4000h

Service Interval

Typical Manufacturers

MacGregor

Inspector Mode Show All 20 / 20 with inspector value

3 manufacturers · 20 models

MacGregor

Sliding Piggyback HC

1.75 t/m² load capacity · Cargo Hold Access · hydraulic piggy‑back sliding hatch cover

Technical Specifications

Antriebssystem: Hydraulic cylinders or motors with slow to medium speed, integrated load-holding valves
Paneelbauart: Two to six panels per cargo hatch, double steel skins (folded covers) or single steel skins (rolling covers)
Dichtungssysteme: FlexSeal, Cat-Profile, C-Seal, Omega, Omega Lite or foam rubber with compression rods
Lagerpads: Fixpad, Flexipad, Lubripad or Unipad — weight transfer during ship movement
Hydraulik-Befüllung: Speziell für Seeeinsatz ausgelegt, integrierte Heiz-/Kühlanlage, Tank-Größe minimal zur Decklatzersparnis
Korrosionsschutz: Stainless steel piston rods or stainless steel sleeves, bronze ball bearings, lubrication nipples between seal rings

Product Lines

Side-Rolling (standard Panamax/Capesize)
Folding (Handysize/Handymax)
Piggy-Back (space-constrained decks)
Lift-On/Lift-Off (multi-purpose)
Single-Flap (compact design)
Stacking (weather decks)
Hydraulic-Pivoting (vertical stowage)

Common Failures & Inspection Points

Area: Rubber seals (gaskets) age/harden through ozone and UV or show wear signs
Check: Visual inspection for discoloration, cracks, deformation; tactile inspection of elasticity. Damaged sections (minimum 1 m length) must be replaced. Do not apply oil/grease products. Validate with ultrasonic leak detection test.
Area: Compression rods corrode, bend or show rough surfaces — compromises sealing and destroys rubber
Check: Surface inspection for corrosion and scratches. Check straightness with steel ruler. Damaged rods must be properly replaced/repaired and realigned (alignment critical for even compression).
Area: Hydraulic cylinder leaks, piston rods corroded or oil contamination reduces functionality
Check: Check oil level. Take oil samples and analyze quarterly for contamination. Oil change every 5 years; replace filter annually. Inspect piston rods for corrosion/scratches. For leaks inspect seal rings and cylinder block. Lubricate grease nipples between seal rings.
Area: Drainage system clogged or check valves not functioning — water backs up and causes rusting/water ingress into cargo hold
Check: Inspect drainage channels for blockage (visual, if necessary with wire probe). Test check valves opening/closing manually (ball should move freely, not be hardened). Inspect drainage holes in cargo hold corners. Clean or replace if fouled.
Area: Bearing pads (Bearing Pads: Fixpad, Flexipad, Lubripad, Unipad) worn — reduced height no longer compresses rubber correctly or increases wear
Check: Measure pad height against manufacturer specification. Wear of 4 mm or more destroys rubber seal. Damaged pads must be replaced with original spare parts of same size and material (involve specialists). Check movement between panel and cargo hold edge with pencil test.
Area: Leaks at compression/sealing joints undetectable or compression strength insufficient (flat or corroded steel surfaces)
Check: Perform ultrasonic tightness test: place ultrasonic generator in closed cargo hold, run sensor receiver outside around all joints. Signal strength shows compression quality. Additionally chalk test: rub compression rods with chalk, imprint shows uneven compression. Hose test in empty cargo holds (0.5 m/s, 12 mm nozzle, 1–1.5 m distance) as validation.

Typ-universelle Inspektions-/Wartungspunkte fuer Hatch Covers & Cargo Access (MacGregor + DNV/OSHA, 2026-06). Per-Modell-Specs NICHT auto-gefuellt.

Service: Chain tension adjustment every 2000 hrs. Roller wheel replacement at dry-dock.

Spare Parts: MacGregor: spare parts per manufacturer. Lead time: 3–8 weeks. Keep seals and valve inserts on board.

Strengths

Space‑saving design – panels fold and slide, ideal for decks with limited headroom or clearance
Fast opening/closing cycle (slow‑to‑medium speed) reduces cargo handling time
Integrated drainage and optional heated hydraulic fluid prevent water accumulation and freezing in harsh climates
Robust sealing options (FlexSeal, Cat‑Profile, Omega etc.) give high watertight integrity
Corrosion‑resistant components (stainless‑steel rods, bronze bearings) extend service life

Weaknesses

Complex hydraulic system requires regular oil analysis, filter changes and specialist maintenance
Higher initial capital cost compared with simple single‑flap or side‑rolling covers
Alignment tolerances are critical; mis‑alignment can cause uneven compression and premature gasket wear
Limited panel size due to piggy‑back arrangement may restrict maximum hatch opening width
More moving parts (folding hinges, bearing pads) increase inspection workload

Typical Vessels: Handysize Bulk CarrierHandymax Bulk CarrierMulti‑Purpose Cargo VesselOffshore Supply VesselGeneral Cargo Ship with restricted deck space

Certifications: DNV Class ApprovalIMO SOLAS Hatch Cover Requirements

Decision Guide: Choose if the vessel has limited deck/headroom space, requires fast hatch operation and high watertight integrity in demanding environments. Avoid if budget constraints dominate, maintenance resources are scarce, or a simpler single‑flap cover meets cargo handling needs.

Use Cases: Commonly installed on bulk carriers of Handysize/Handymax size where multiple holds share limited deck area, on multi‑purpose vessels carrying mixed cargoes that need quick turn‑around, and on offshore supply ships operating in cold or high‑wave regions where drainage and heated hydraulics are essential.

Manufacturer Datasheet

Datasheet

Sliding Type MV

Weather-tight per ICLL · Cargo Hold Access · hydraulic sliding hatch cover

Type

sliding_stacking

Actuation

hydraulic

Technical Specifications

Antriebssystem: Hydraulic cylinders or motors with slow to medium speed, integrated load-holding valves
Paneelbauart: Two to six panels per cargo hatch, double steel skins (folded covers) or single steel skins (rolling covers)
Dichtungssysteme: FlexSeal, Cat-Profile, C-Seal, Omega, Omega Lite or foam rubber with compression rods
Lagerpads: Fixpad, Flexipad, Lubripad or Unipad — weight transfer during ship movement
Hydraulik-Befüllung: Speziell für Seeeinsatz ausgelegt, integrierte Heiz-/Kühlanlage, Tank-Größe minimal zur Decklatzersparnis
Korrosionsschutz: Stainless steel piston rods or stainless steel sleeves, bronze ball bearings, lubrication nipples between seal rings

Product Lines

Side-Rolling (standard Panamax/Capesize)
Folding (Handysize/Handymax)
Piggy-Back (space-constrained decks)
Lift-On/Lift-Off (multi-purpose)
Single-Flap (compact design)
Stacking (weather decks)
Hydraulic-Pivoting (vertical stowage)

Common Failures & Inspection Points

Area: Rubber seals (gaskets) age/harden through ozone and UV or show wear signs
Check: Visual inspection for discoloration, cracks, deformation; tactile inspection of elasticity. Damaged sections (minimum 1 m length) must be replaced. Do not apply oil/grease products. Validate with ultrasonic leak detection test.
Area: Compression rods corrode, bend or show rough surfaces — compromises sealing and destroys rubber
Check: Surface inspection for corrosion and scratches. Check straightness with steel ruler. Damaged rods must be properly replaced/repaired and realigned (alignment critical for even compression).
Area: Hydraulic cylinder leaks, piston rods corroded or oil contamination reduces functionality
Check: Check oil level. Take oil samples and analyze quarterly for contamination. Oil change every 5 years; replace filter annually. Inspect piston rods for corrosion/scratches. For leaks inspect seal rings and cylinder block. Lubricate grease nipples between seal rings.
Area: Drainage system clogged or check valves not functioning — water backs up and causes rusting/water ingress into cargo hold
Check: Inspect drainage channels for blockage (visual, if necessary with wire probe). Test check valves opening/closing manually (ball should move freely, not be hardened). Inspect drainage holes in cargo hold corners. Clean or replace if fouled.
Area: Bearing pads (Bearing Pads: Fixpad, Flexipad, Lubripad, Unipad) worn — reduced height no longer compresses rubber correctly or increases wear
Check: Measure pad height against manufacturer specification. Wear of 4 mm or more destroys rubber seal. Damaged pads must be replaced with original spare parts of same size and material (involve specialists). Check movement between panel and cargo hold edge with pencil test.
Area: Leaks at compression/sealing joints undetectable or compression strength insufficient (flat or corroded steel surfaces)
Check: Perform ultrasonic tightness test: place ultrasonic generator in closed cargo hold, run sensor receiver outside around all joints. Signal strength shows compression quality. Additionally chalk test: rub compression rods with chalk, imprint shows uneven compression. Hose test in empty cargo holds (0.5 m/s, 12 mm nozzle, 1–1.5 m distance) as validation.

Typ-universelle Inspektions-/Wartungspunkte fuer Hatch Covers & Cargo Access (MacGregor + DNV/OSHA, 2026-06). Per-Modell-Specs NICHT auto-gefuellt.

Service: Lubricate stacking pins monthly; flush hydraulic manifold annually.

Spare Parts: MacGregor: spare parts per manufacturer. Lead time: 3–8 weeks. Keep seals and valve inserts on board.

Strengths

Fast, repeatable operation with hydraulic actuation (slow to medium speed) reduces cargo handling time
Robust sealing systems (FlexSeal, Cat‑Profile, Omega etc.) give excellent water‑tightness for SOLAS compliance
Stacking design allows weather‑deck protection and maximises deck space utilisation
Corrosion‑resistant components (stainless‑steel rods, bronze bearings) lower long‑term degradation risk
Integrated hydraulic heating/cooling limits fluid viscosity changes in extreme sea temperatures

Weaknesses

Complex hydraulic circuitry requires regular flushing, oil analysis and periodic filter replacement
Gasket materials can harden from UV/ozone exposure; frequent inspection and replacement are mandatory
Bearing pads (Fixpad/Flexipad/Lubripad) wear and must be monitored to avoid loss of compression
Higher initial weight compared with simple flap‑type covers may demand additional deck reinforcement
Installation space for hydraulic manifolds and tanks can be limited on older vessels

Typical Vessels: Handysize Bulk CarrierHandymax / Panamax Bulk CarrierCapesize Ore CarrierGeneral Cargo Vessel with large side‑opening holds

Certifications: IMO SOLASDNVABS

Decision Guide: Choose if you need fast, reliable access to large cargo holds, require high watertight integrity for grain or ore transport, and have the maintenance capability for hydraulic systems. Avoid if vessel weight limits are critical, deck space for hydraulics is constrained, or operating budgets cannot support regular gasket and bearing‑pad inspections.

Use Cases: Widely fitted on new‑build Panamax and Capesize bulk carriers for coal, grain and iron ore shipments where rapid turn‑around and weather‑deck protection are essential. Also used in retrofit projects to replace older manual covers with a more automated, leak‑tight solution.

Manufacturer Datasheet

Datasheet

MacGregor Sliding Type SL 12m

12m hold · Hydraulic Sliding

Hatch Type

sliding

Cargo hold length (m)

Weathertight

Technical Specifications

Antriebssystem: Hydraulic cylinders or motors with slow to medium speed, integrated load-holding valves
Paneelbauart: Two to six panels per cargo hatch, double steel skins (folded covers) or single steel skins (rolling covers)
Dichtungssysteme: FlexSeal, Cat-Profile, C-Seal, Omega, Omega Lite or foam rubber with compression rods
Lagerpads: Fixpad, Flexipad, Lubripad or Unipad — weight transfer during ship movement
Hydraulik-Befüllung: Speziell für Seeeinsatz ausgelegt, integrierte Heiz-/Kühlanlage, Tank-Größe minimal zur Decklatzersparnis
Korrosionsschutz: Stainless steel piston rods or stainless steel sleeves, bronze ball bearings, lubrication nipples between seal rings

Product Lines

Side-Rolling (standard Panamax/Capesize)
Folding (Handysize/Handymax)
Piggy-Back (space-constrained decks)
Lift-On/Lift-Off (multi-purpose)
Single-Flap (compact design)
Stacking (weather decks)
Hydraulic-Pivoting (vertical stowage)

Common Failures & Inspection Points

Area: Rubber seals (gaskets) age/harden through ozone and UV or show wear signs
Check: Visual inspection for discoloration, cracks, deformation; tactile inspection of elasticity. Damaged sections (minimum 1 m length) must be replaced. Do not apply oil/grease products. Validate with ultrasonic leak detection test.
Area: Compression rods corrode, bend or show rough surfaces — compromises sealing and destroys rubber
Check: Surface inspection for corrosion and scratches. Check straightness with steel ruler. Damaged rods must be properly replaced/repaired and realigned (alignment critical for even compression).
Area: Hydraulic cylinder leaks, piston rods corroded or oil contamination reduces functionality
Check: Check oil level. Take oil samples and analyze quarterly for contamination. Oil change every 5 years; replace filter annually. Inspect piston rods for corrosion/scratches. For leaks inspect seal rings and cylinder block. Lubricate grease nipples between seal rings.
Area: Drainage system clogged or check valves not functioning — water backs up and causes rusting/water ingress into cargo hold
Check: Inspect drainage channels for blockage (visual, if necessary with wire probe). Test check valves opening/closing manually (ball should move freely, not be hardened). Inspect drainage holes in cargo hold corners. Clean or replace if fouled.
Area: Bearing pads (Bearing Pads: Fixpad, Flexipad, Lubripad, Unipad) worn — reduced height no longer compresses rubber correctly or increases wear
Check: Measure pad height against manufacturer specification. Wear of 4 mm or more destroys rubber seal. Damaged pads must be replaced with original spare parts of same size and material (involve specialists). Check movement between panel and cargo hold edge with pencil test.
Area: Leaks at compression/sealing joints undetectable or compression strength insufficient (flat or corroded steel surfaces)
Check: Perform ultrasonic tightness test: place ultrasonic generator in closed cargo hold, run sensor receiver outside around all joints. Signal strength shows compression quality. Additionally chalk test: rub compression rods with chalk, imprint shows uneven compression. Hose test in empty cargo holds (0.5 m/s, 12 mm nozzle, 1–1.5 m distance) as validation.

Typ-universelle Inspektions-/Wartungspunkte fuer Hatch Covers & Cargo Access (MacGregor + DNV/OSHA, 2026-06). Per-Modell-Specs NICHT auto-gefuellt.

Manufacturer Datasheet

MacGregor sliding hatch cover for 12m hold

Datasheet

MacGregor Sliding Type SL 15m

15m hold · Hydraulic Sliding

Hatch Type

sliding

Cargo hold length (m)

Weathertight

Technical Specifications

Antriebssystem: Hydraulic cylinders or motors with slow to medium speed, integrated load-holding valves
Paneelbauart: Two to six panels per cargo hatch, double steel skins (folded covers) or single steel skins (rolling covers)
Dichtungssysteme: FlexSeal, Cat-Profile, C-Seal, Omega, Omega Lite or foam rubber with compression rods
Lagerpads: Fixpad, Flexipad, Lubripad or Unipad — weight transfer during ship movement
Hydraulik-Befüllung: Speziell für Seeeinsatz ausgelegt, integrierte Heiz-/Kühlanlage, Tank-Größe minimal zur Decklatzersparnis
Korrosionsschutz: Stainless steel piston rods or stainless steel sleeves, bronze ball bearings, lubrication nipples between seal rings

Product Lines

Side-Rolling (standard Panamax/Capesize)
Folding (Handysize/Handymax)
Piggy-Back (space-constrained decks)
Lift-On/Lift-Off (multi-purpose)
Single-Flap (compact design)
Stacking (weather decks)
Hydraulic-Pivoting (vertical stowage)

Common Failures & Inspection Points

Area: Rubber seals (gaskets) age/harden through ozone and UV or show wear signs
Check: Visual inspection for discoloration, cracks, deformation; tactile inspection of elasticity. Damaged sections (minimum 1 m length) must be replaced. Do not apply oil/grease products. Validate with ultrasonic leak detection test.
Area: Compression rods corrode, bend or show rough surfaces — compromises sealing and destroys rubber
Check: Surface inspection for corrosion and scratches. Check straightness with steel ruler. Damaged rods must be properly replaced/repaired and realigned (alignment critical for even compression).
Area: Hydraulic cylinder leaks, piston rods corroded or oil contamination reduces functionality
Check: Check oil level. Take oil samples and analyze quarterly for contamination. Oil change every 5 years; replace filter annually. Inspect piston rods for corrosion/scratches. For leaks inspect seal rings and cylinder block. Lubricate grease nipples between seal rings.
Area: Drainage system clogged or check valves not functioning — water backs up and causes rusting/water ingress into cargo hold
Check: Inspect drainage channels for blockage (visual, if necessary with wire probe). Test check valves opening/closing manually (ball should move freely, not be hardened). Inspect drainage holes in cargo hold corners. Clean or replace if fouled.
Area: Bearing pads (Bearing Pads: Fixpad, Flexipad, Lubripad, Unipad) worn — reduced height no longer compresses rubber correctly or increases wear
Check: Measure pad height against manufacturer specification. Wear of 4 mm or more destroys rubber seal. Damaged pads must be replaced with original spare parts of same size and material (involve specialists). Check movement between panel and cargo hold edge with pencil test.
Area: Leaks at compression/sealing joints undetectable or compression strength insufficient (flat or corroded steel surfaces)
Check: Perform ultrasonic tightness test: place ultrasonic generator in closed cargo hold, run sensor receiver outside around all joints. Signal strength shows compression quality. Additionally chalk test: rub compression rods with chalk, imprint shows uneven compression. Hose test in empty cargo holds (0.5 m/s, 12 mm nozzle, 1–1.5 m distance) as validation.

Typ-universelle Inspektions-/Wartungspunkte fuer Hatch Covers & Cargo Access (MacGregor + DNV/OSHA, 2026-06). Per-Modell-Specs NICHT auto-gefuellt.

Manufacturer Datasheet

MacGregor sliding hatch cover for 15m hold

Datasheet

MacGregor Sliding Type SL 18m

18m hold · Hydraulic Sliding

Hatch Type

sliding

Cargo hold length (m)

Weathertight

Technical Specifications

Antriebssystem: Hydraulic cylinders or motors with slow to medium speed, integrated load-holding valves
Paneelbauart: Two to six panels per cargo hatch, double steel skins (folded covers) or single steel skins (rolling covers)
Dichtungssysteme: FlexSeal, Cat-Profile, C-Seal, Omega, Omega Lite or foam rubber with compression rods
Lagerpads: Fixpad, Flexipad, Lubripad or Unipad — weight transfer during ship movement
Hydraulik-Befüllung: Speziell für Seeeinsatz ausgelegt, integrierte Heiz-/Kühlanlage, Tank-Größe minimal zur Decklatzersparnis
Korrosionsschutz: Stainless steel piston rods or stainless steel sleeves, bronze ball bearings, lubrication nipples between seal rings

Product Lines

Side-Rolling (standard Panamax/Capesize)
Folding (Handysize/Handymax)
Piggy-Back (space-constrained decks)
Lift-On/Lift-Off (multi-purpose)
Single-Flap (compact design)
Stacking (weather decks)
Hydraulic-Pivoting (vertical stowage)

Common Failures & Inspection Points

Area: Rubber seals (gaskets) age/harden through ozone and UV or show wear signs
Check: Visual inspection for discoloration, cracks, deformation; tactile inspection of elasticity. Damaged sections (minimum 1 m length) must be replaced. Do not apply oil/grease products. Validate with ultrasonic leak detection test.
Area: Compression rods corrode, bend or show rough surfaces — compromises sealing and destroys rubber
Check: Surface inspection for corrosion and scratches. Check straightness with steel ruler. Damaged rods must be properly replaced/repaired and realigned (alignment critical for even compression).
Area: Hydraulic cylinder leaks, piston rods corroded or oil contamination reduces functionality
Check: Check oil level. Take oil samples and analyze quarterly for contamination. Oil change every 5 years; replace filter annually. Inspect piston rods for corrosion/scratches. For leaks inspect seal rings and cylinder block. Lubricate grease nipples between seal rings.
Area: Drainage system clogged or check valves not functioning — water backs up and causes rusting/water ingress into cargo hold
Check: Inspect drainage channels for blockage (visual, if necessary with wire probe). Test check valves opening/closing manually (ball should move freely, not be hardened). Inspect drainage holes in cargo hold corners. Clean or replace if fouled.
Area: Bearing pads (Bearing Pads: Fixpad, Flexipad, Lubripad, Unipad) worn — reduced height no longer compresses rubber correctly or increases wear
Check: Measure pad height against manufacturer specification. Wear of 4 mm or more destroys rubber seal. Damaged pads must be replaced with original spare parts of same size and material (involve specialists). Check movement between panel and cargo hold edge with pencil test.
Area: Leaks at compression/sealing joints undetectable or compression strength insufficient (flat or corroded steel surfaces)
Check: Perform ultrasonic tightness test: place ultrasonic generator in closed cargo hold, run sensor receiver outside around all joints. Signal strength shows compression quality. Additionally chalk test: rub compression rods with chalk, imprint shows uneven compression. Hose test in empty cargo holds (0.5 m/s, 12 mm nozzle, 1–1.5 m distance) as validation.

Typ-universelle Inspektions-/Wartungspunkte fuer Hatch Covers & Cargo Access (MacGregor + DNV/OSHA, 2026-06). Per-Modell-Specs NICHT auto-gefuellt.

Manufacturer Datasheet

MacGregor sliding hatch cover for 18m hold

Datasheet

MacGregor Sliding Type SL 21m

21m hold · Hydraulic Sliding

Hatch Type

sliding

Cargo hold length (m)

Weathertight

Technical Specifications

Antriebssystem: Hydraulic cylinders or motors with slow to medium speed, integrated load-holding valves
Paneelbauart: Two to six panels per cargo hatch, double steel skins (folded covers) or single steel skins (rolling covers)
Dichtungssysteme: FlexSeal, Cat-Profile, C-Seal, Omega, Omega Lite or foam rubber with compression rods
Lagerpads: Fixpad, Flexipad, Lubripad or Unipad — weight transfer during ship movement
Hydraulik-Befüllung: Speziell für Seeeinsatz ausgelegt, integrierte Heiz-/Kühlanlage, Tank-Größe minimal zur Decklatzersparnis
Korrosionsschutz: Stainless steel piston rods or stainless steel sleeves, bronze ball bearings, lubrication nipples between seal rings

Product Lines

Side-Rolling (standard Panamax/Capesize)
Folding (Handysize/Handymax)
Piggy-Back (space-constrained decks)
Lift-On/Lift-Off (multi-purpose)
Single-Flap (compact design)
Stacking (weather decks)
Hydraulic-Pivoting (vertical stowage)

Common Failures & Inspection Points

Area: Rubber seals (gaskets) age/harden through ozone and UV or show wear signs
Check: Visual inspection for discoloration, cracks, deformation; tactile inspection of elasticity. Damaged sections (minimum 1 m length) must be replaced. Do not apply oil/grease products. Validate with ultrasonic leak detection test.
Area: Compression rods corrode, bend or show rough surfaces — compromises sealing and destroys rubber
Check: Surface inspection for corrosion and scratches. Check straightness with steel ruler. Damaged rods must be properly replaced/repaired and realigned (alignment critical for even compression).
Area: Hydraulic cylinder leaks, piston rods corroded or oil contamination reduces functionality
Check: Check oil level. Take oil samples and analyze quarterly for contamination. Oil change every 5 years; replace filter annually. Inspect piston rods for corrosion/scratches. For leaks inspect seal rings and cylinder block. Lubricate grease nipples between seal rings.
Area: Drainage system clogged or check valves not functioning — water backs up and causes rusting/water ingress into cargo hold
Check: Inspect drainage channels for blockage (visual, if necessary with wire probe). Test check valves opening/closing manually (ball should move freely, not be hardened). Inspect drainage holes in cargo hold corners. Clean or replace if fouled.
Area: Bearing pads (Bearing Pads: Fixpad, Flexipad, Lubripad, Unipad) worn — reduced height no longer compresses rubber correctly or increases wear
Check: Measure pad height against manufacturer specification. Wear of 4 mm or more destroys rubber seal. Damaged pads must be replaced with original spare parts of same size and material (involve specialists). Check movement between panel and cargo hold edge with pencil test.
Area: Leaks at compression/sealing joints undetectable or compression strength insufficient (flat or corroded steel surfaces)
Check: Perform ultrasonic tightness test: place ultrasonic generator in closed cargo hold, run sensor receiver outside around all joints. Signal strength shows compression quality. Additionally chalk test: rub compression rods with chalk, imprint shows uneven compression. Hose test in empty cargo holds (0.5 m/s, 12 mm nozzle, 1–1.5 m distance) as validation.

Typ-universelle Inspektions-/Wartungspunkte fuer Hatch Covers & Cargo Access (MacGregor + DNV/OSHA, 2026-06). Per-Modell-Specs NICHT auto-gefuellt.

Manufacturer Datasheet

MacGregor sliding hatch cover for 21m hold

Datasheet

MacGregor Sliding Type SL 24m

24m hold · Hydraulic Sliding

Hatch Type

sliding

Cargo hold length (m)

Weathertight

Technical Specifications

Antriebssystem: Hydraulic cylinders or motors with slow to medium speed, integrated load-holding valves
Paneelbauart: Two to six panels per cargo hatch, double steel skins (folded covers) or single steel skins (rolling covers)
Dichtungssysteme: FlexSeal, Cat-Profile, C-Seal, Omega, Omega Lite or foam rubber with compression rods
Lagerpads: Fixpad, Flexipad, Lubripad or Unipad — weight transfer during ship movement
Hydraulik-Befüllung: Speziell für Seeeinsatz ausgelegt, integrierte Heiz-/Kühlanlage, Tank-Größe minimal zur Decklatzersparnis
Korrosionsschutz: Stainless steel piston rods or stainless steel sleeves, bronze ball bearings, lubrication nipples between seal rings

Product Lines

Side-Rolling (standard Panamax/Capesize)
Folding (Handysize/Handymax)
Piggy-Back (space-constrained decks)
Lift-On/Lift-Off (multi-purpose)
Single-Flap (compact design)
Stacking (weather decks)
Hydraulic-Pivoting (vertical stowage)

Common Failures & Inspection Points

Area: Rubber seals (gaskets) age/harden through ozone and UV or show wear signs
Check: Visual inspection for discoloration, cracks, deformation; tactile inspection of elasticity. Damaged sections (minimum 1 m length) must be replaced. Do not apply oil/grease products. Validate with ultrasonic leak detection test.
Area: Compression rods corrode, bend or show rough surfaces — compromises sealing and destroys rubber
Check: Surface inspection for corrosion and scratches. Check straightness with steel ruler. Damaged rods must be properly replaced/repaired and realigned (alignment critical for even compression).
Area: Hydraulic cylinder leaks, piston rods corroded or oil contamination reduces functionality
Check: Check oil level. Take oil samples and analyze quarterly for contamination. Oil change every 5 years; replace filter annually. Inspect piston rods for corrosion/scratches. For leaks inspect seal rings and cylinder block. Lubricate grease nipples between seal rings.
Area: Drainage system clogged or check valves not functioning — water backs up and causes rusting/water ingress into cargo hold
Check: Inspect drainage channels for blockage (visual, if necessary with wire probe). Test check valves opening/closing manually (ball should move freely, not be hardened). Inspect drainage holes in cargo hold corners. Clean or replace if fouled.
Area: Bearing pads (Bearing Pads: Fixpad, Flexipad, Lubripad, Unipad) worn — reduced height no longer compresses rubber correctly or increases wear
Check: Measure pad height against manufacturer specification. Wear of 4 mm or more destroys rubber seal. Damaged pads must be replaced with original spare parts of same size and material (involve specialists). Check movement between panel and cargo hold edge with pencil test.
Area: Leaks at compression/sealing joints undetectable or compression strength insufficient (flat or corroded steel surfaces)
Check: Perform ultrasonic tightness test: place ultrasonic generator in closed cargo hold, run sensor receiver outside around all joints. Signal strength shows compression quality. Additionally chalk test: rub compression rods with chalk, imprint shows uneven compression. Hose test in empty cargo holds (0.5 m/s, 12 mm nozzle, 1–1.5 m distance) as validation.

Typ-universelle Inspektions-/Wartungspunkte fuer Hatch Covers & Cargo Access (MacGregor + DNV/OSHA, 2026-06). Per-Modell-Specs NICHT auto-gefuellt.

Manufacturer Datasheet

MacGregor sliding hatch cover for 24m hold

Datasheet

Foundation Container Sliding Double TF-12B-QQ/110H

Per Hersteller-Datenblatt · Cargo Hold Access · hydraulic sliding hatch cover

Technical Specifications

Antriebssystem: Hydraulic cylinders or motors with slow to medium speed, integrated load-holding valves
Paneelbauart: Two to six panels per cargo hatch, double steel skins (folded covers) or single steel skins (rolling covers)
Dichtungssysteme: FlexSeal, Cat-Profile, C-Seal, Omega, Omega Lite or foam rubber with compression rods
Lagerpads: Fixpad, Flexipad, Lubripad or Unipad — weight transfer during ship movement
Hydraulik-Befüllung: Speziell für Seeeinsatz ausgelegt, integrierte Heiz-/Kühlanlage, Tank-Größe minimal zur Decklatzersparnis
Korrosionsschutz: Stainless steel piston rods or stainless steel sleeves, bronze ball bearings, lubrication nipples between seal rings

Product Lines

Side-Rolling (standard Panamax/Capesize)
Folding (Handysize/Handymax)
Piggy-Back (space-constrained decks)
Lift-On/Lift-Off (multi-purpose)
Single-Flap (compact design)
Stacking (weather decks)
Hydraulic-Pivoting (vertical stowage)

Common Failures & Inspection Points

Area: Rubber seals (gaskets) age/harden through ozone and UV or show wear signs
Check: Visual inspection for discoloration, cracks, deformation; tactile inspection of elasticity. Damaged sections (minimum 1 m length) must be replaced. Do not apply oil/grease products. Validate with ultrasonic leak detection test.
Area: Compression rods corrode, bend or show rough surfaces — compromises sealing and destroys rubber
Check: Surface inspection for corrosion and scratches. Check straightness with steel ruler. Damaged rods must be properly replaced/repaired and realigned (alignment critical for even compression).
Area: Hydraulic cylinder leaks, piston rods corroded or oil contamination reduces functionality
Check: Check oil level. Take oil samples and analyze quarterly for contamination. Oil change every 5 years; replace filter annually. Inspect piston rods for corrosion/scratches. For leaks inspect seal rings and cylinder block. Lubricate grease nipples between seal rings.
Area: Drainage system clogged or check valves not functioning — water backs up and causes rusting/water ingress into cargo hold
Check: Inspect drainage channels for blockage (visual, if necessary with wire probe). Test check valves opening/closing manually (ball should move freely, not be hardened). Inspect drainage holes in cargo hold corners. Clean or replace if fouled.
Area: Bearing pads (Bearing Pads: Fixpad, Flexipad, Lubripad, Unipad) worn — reduced height no longer compresses rubber correctly or increases wear
Check: Measure pad height against manufacturer specification. Wear of 4 mm or more destroys rubber seal. Damaged pads must be replaced with original spare parts of same size and material (involve specialists). Check movement between panel and cargo hold edge with pencil test.
Area: Leaks at compression/sealing joints undetectable or compression strength insufficient (flat or corroded steel surfaces)
Check: Perform ultrasonic tightness test: place ultrasonic generator in closed cargo hold, run sensor receiver outside around all joints. Signal strength shows compression quality. Additionally chalk test: rub compression rods with chalk, imprint shows uneven compression. Hose test in empty cargo holds (0.5 m/s, 12 mm nozzle, 1–1.5 m distance) as validation.

Typ-universelle Inspektions-/Wartungspunkte fuer Hatch Covers & Cargo Access (MacGregor + DNV/OSHA, 2026-06). Per-Modell-Specs NICHT auto-gefuellt.

Service: Rubber seal inspection every 6 months. Ultrasonic leak testing annually (IMO MSC/Circ.1325). Hydraulic system check before each cargo operation.

Spare Parts: MacGregor Finland Oy: spare parts per manufacturer. Lead time: 3-8 weeks. Seals and valve inserts to be kept on board.

Strengths

Double‑panel design provides a wide opening while maintaining structural strength.
Hydraulic drive with built‑in heating/cooling reduces ice formation and improves seal integrity in extreme climates.
Multiple sealing options (FlexSeal, Cat‑Profile, Omega) allow customization for cargo protection.
Corrosion‑resistant components (stainless‑steel rods, bronze bearings) extend service life in marine environments.
Modular bearing pads (Fixpad, Flexipad, Lubripad) accommodate ship motions and reduce wear on gaskets.

Weaknesses

Complex hydraulic system requires regular oil analysis, filter changes and periodic ultrasonic leak testing.
Gasket and compression‑rod maintenance is intensive; failure can lead to water ingress.
Higher initial capital cost compared with single‑flap or side‑rolling alternatives.
Double‑panel thickness may limit clearance on decks with tight vertical space constraints.
Requires skilled personnel for installation and routine inspection of bearing pads and seals.

Typical Vessels: Panamax Container ShipPost‑Panamax Container ShipHandymax / Handymax‑type Multi‑Purpose Vessel

Decision Guide: Choose if you need a large, fast‑acting hatch opening with robust sealing for container cargo and have the maintenance infrastructure to support hydraulic and gasket upkeep. Avoid if deck height is limited, budget constraints preclude higher upfront cost, or vessel operators lack capability for regular ultrasonic and bearing‑pad inspections.

Use Cases: Commonly installed on new‑build Panamax and Post‑Panamax container vessels where rapid hatch operation and reliable weather sealing are critical; also used in retrofits where existing side‑rolling covers require upgrade to double‑panel strength and integrated temperature control.

Manufacturer Datasheet

Datasheet

Sliding Foundation SF-11L

Per Hersteller-Datenblatt · Cargo Hold Access · Hydraulic side‑rolling hatch cover

Technical Specifications

Antriebssystem: Hydraulic cylinders or motors with slow to medium speed, integrated load-holding valves
Paneelbauart: Two to six panels per cargo hatch, double steel skins (folded covers) or single steel skins (rolling covers)
Dichtungssysteme: FlexSeal, Cat-Profile, C-Seal, Omega, Omega Lite or foam rubber with compression rods
Lagerpads: Fixpad, Flexipad, Lubripad or Unipad — weight transfer during ship movement
Hydraulik-Befüllung: Speziell für Seeeinsatz ausgelegt, integrierte Heiz-/Kühlanlage, Tank-Größe minimal zur Decklatzersparnis
Korrosionsschutz: Stainless steel piston rods or stainless steel sleeves, bronze ball bearings, lubrication nipples between seal rings

Product Lines

Side-Rolling (standard Panamax/Capesize)
Folding (Handysize/Handymax)
Piggy-Back (space-constrained decks)
Lift-On/Lift-Off (multi-purpose)
Single-Flap (compact design)
Stacking (weather decks)
Hydraulic-Pivoting (vertical stowage)

Common Failures & Inspection Points

Area: Rubber seals (gaskets) age/harden through ozone and UV or show wear signs
Check: Visual inspection for discoloration, cracks, deformation; tactile inspection of elasticity. Damaged sections (minimum 1 m length) must be replaced. Do not apply oil/grease products. Validate with ultrasonic leak detection test.
Area: Compression rods corrode, bend or show rough surfaces — compromises sealing and destroys rubber
Check: Surface inspection for corrosion and scratches. Check straightness with steel ruler. Damaged rods must be properly replaced/repaired and realigned (alignment critical for even compression).
Area: Hydraulic cylinder leaks, piston rods corroded or oil contamination reduces functionality
Check: Check oil level. Take oil samples and analyze quarterly for contamination. Oil change every 5 years; replace filter annually. Inspect piston rods for corrosion/scratches. For leaks inspect seal rings and cylinder block. Lubricate grease nipples between seal rings.
Area: Drainage system clogged or check valves not functioning — water backs up and causes rusting/water ingress into cargo hold
Check: Inspect drainage channels for blockage (visual, if necessary with wire probe). Test check valves opening/closing manually (ball should move freely, not be hardened). Inspect drainage holes in cargo hold corners. Clean or replace if fouled.
Area: Bearing pads (Bearing Pads: Fixpad, Flexipad, Lubripad, Unipad) worn — reduced height no longer compresses rubber correctly or increases wear
Check: Measure pad height against manufacturer specification. Wear of 4 mm or more destroys rubber seal. Damaged pads must be replaced with original spare parts of same size and material (involve specialists). Check movement between panel and cargo hold edge with pencil test.
Area: Leaks at compression/sealing joints undetectable or compression strength insufficient (flat or corroded steel surfaces)
Check: Perform ultrasonic tightness test: place ultrasonic generator in closed cargo hold, run sensor receiver outside around all joints. Signal strength shows compression quality. Additionally chalk test: rub compression rods with chalk, imprint shows uneven compression. Hose test in empty cargo holds (0.5 m/s, 12 mm nozzle, 1–1.5 m distance) as validation.

Typ-universelle Inspektions-/Wartungspunkte fuer Hatch Covers & Cargo Access (MacGregor + DNV/OSHA, 2026-06). Per-Modell-Specs NICHT auto-gefuellt.

Service: Rubber seal inspection every 6 months. Ultrasonic leak testing annually (IMO MSC/Circ.1325). Hydraulic system check before each cargo operation.

Spare Parts: MacGregor Finland Oy: spare parts per manufacturer. Lead time: 3-8 weeks. Seals and valve inserts to be kept on board.

Strengths

Fast, controllable opening/closing using hydraulic cylinders or motors
Modular panel layout (2–6 panels) allows adaptation to various hatch sizes
Multiple certified sealing systems (FlexSeal, Omega, C‑Dichtung, etc.) ensure water‑tightness
Integrated bearing pads (Fixpad, Flexipad, Lubripad, Unipad) reduce hull stress and compensate for ship motion
Corrosion‑resistant components (stainless‑steel rods, bronze bearings) extend service life

Weaknesses

Complex hydraulic system requires regular inspection, oil analysis and filter changes
Higher capital cost compared with simple manual or pivoting covers
Sensitivity to hydraulic fluid contamination can lead to cylinder leaks or reduced performance
Bearing‑pad wear must be monitored; excessive wear degrades seal compression
Side‑rolling tracks occupy deck space and may limit other equipment placement

Typical Vessels: Panamax bulk carrierCapesize bulk carrierHandymax/Handysize bulk carrierMulti‑purpose dry‑bulk vessel

Certifications: DNV

Decision Guide: Choose if the ship requires high‑speed cargo access, operates on routes with rapid loading/unloading cycles, and needs a proven water‑tight sealing system for harsh environments. Avoid if budget constraints dominate, deck space is limited for side‑rolling tracks, or the vessel handles low‑frequency cargo operations where a simpler cover suffices.

Use Cases: Deployed on large dry‑bulk carriers that load via shore‑based grabs or conveyor systems, especially in ports where turnaround time is critical. Also used on vessels that need flexible hatch configurations for mixed cargoes and on ships operating in cold climates where heated hydraulic circuits prevent fluid thickening.

Manufacturer Datasheet

Datasheet

Sliding Foundation SF-11T

Per Hersteller-Datenblatt · Cargo Hold Access · Hydraulic sliding hatch cover

Technical Specifications

Antriebssystem: Hydraulic cylinders or motors with slow to medium speed, integrated load-holding valves
Paneelbauart: Two to six panels per cargo hatch, double steel skins (folded covers) or single steel skins (rolling covers)
Dichtungssysteme: FlexSeal, Cat-Profile, C-Seal, Omega, Omega Lite or foam rubber with compression rods
Lagerpads: Fixpad, Flexipad, Lubripad or Unipad — weight transfer during ship movement
Hydraulik-Befüllung: Speziell für Seeeinsatz ausgelegt, integrierte Heiz-/Kühlanlage, Tank-Größe minimal zur Decklatzersparnis
Korrosionsschutz: Stainless steel piston rods or stainless steel sleeves, bronze ball bearings, lubrication nipples between seal rings

Product Lines

Side-Rolling (standard Panamax/Capesize)
Folding (Handysize/Handymax)
Piggy-Back (space-constrained decks)
Lift-On/Lift-Off (multi-purpose)
Single-Flap (compact design)
Stacking (weather decks)
Hydraulic-Pivoting (vertical stowage)

Common Failures & Inspection Points

Area: Rubber seals (gaskets) age/harden through ozone and UV or show wear signs
Check: Visual inspection for discoloration, cracks, deformation; tactile inspection of elasticity. Damaged sections (minimum 1 m length) must be replaced. Do not apply oil/grease products. Validate with ultrasonic leak detection test.
Area: Compression rods corrode, bend or show rough surfaces — compromises sealing and destroys rubber
Check: Surface inspection for corrosion and scratches. Check straightness with steel ruler. Damaged rods must be properly replaced/repaired and realigned (alignment critical for even compression).
Area: Hydraulic cylinder leaks, piston rods corroded or oil contamination reduces functionality
Check: Check oil level. Take oil samples and analyze quarterly for contamination. Oil change every 5 years; replace filter annually. Inspect piston rods for corrosion/scratches. For leaks inspect seal rings and cylinder block. Lubricate grease nipples between seal rings.
Area: Drainage system clogged or check valves not functioning — water backs up and causes rusting/water ingress into cargo hold
Check: Inspect drainage channels for blockage (visual, if necessary with wire probe). Test check valves opening/closing manually (ball should move freely, not be hardened). Inspect drainage holes in cargo hold corners. Clean or replace if fouled.
Area: Bearing pads (Bearing Pads: Fixpad, Flexipad, Lubripad, Unipad) worn — reduced height no longer compresses rubber correctly or increases wear
Check: Measure pad height against manufacturer specification. Wear of 4 mm or more destroys rubber seal. Damaged pads must be replaced with original spare parts of same size and material (involve specialists). Check movement between panel and cargo hold edge with pencil test.
Area: Leaks at compression/sealing joints undetectable or compression strength insufficient (flat or corroded steel surfaces)
Check: Perform ultrasonic tightness test: place ultrasonic generator in closed cargo hold, run sensor receiver outside around all joints. Signal strength shows compression quality. Additionally chalk test: rub compression rods with chalk, imprint shows uneven compression. Hose test in empty cargo holds (0.5 m/s, 12 mm nozzle, 1–1.5 m distance) as validation.

Typ-universelle Inspektions-/Wartungspunkte fuer Hatch Covers & Cargo Access (MacGregor + DNV/OSHA, 2026-06). Per-Modell-Specs NICHT auto-gefuellt.

Service: Rubber seal inspection every 6 months. Ultrasonic leak testing annually (IMO MSC/Circ.1325). Hydraulic system check before each cargo operation.

Spare Parts: MacGregor Finland Oy: spare parts per manufacturer. Lead time: 3-8 weeks. Seals and valve inserts to be kept on board.

Strengths

Fast opening/closing speed suitable for Panamax and Capesize bulk carriers
Modular panel layout (2–6 panels) adapts to a wide range of hatch dimensions
Integrated hydraulic heating/cooling keeps fluid viscosity stable in extreme temperatures
Robust corrosion protection with stainless‑steel rods, bronze bearings and stainless‑steel sleeves
Multiple seal options (FlexSeal, Omega, C‑profile etc.) provide excellent water tightness

Weaknesses

Complex hydraulic system requires regular inspection, oil analysis and skilled maintenance personnel
Higher capital cost compared with simple single‑flap or manual covers
Bearing pads (Fixpad/Flexipad/Lubripad) wear and must be measured periodically to maintain compression
Panel stack height can limit clearance on decks with low headroom
Leakage risk if gasket inspection interval (every 6 months) is missed

Typical Vessels: Panamax Bulk CarrierCapesize Bulk CarrierHandymax/Handysize Bulk CarrierLarge General Cargo Vessel

Certifications: SOLAS (Regulation II‑1)DNV Class Notation

Decision Guide: Choose the SF-11T when you need rapid hatch operation on large openings, operate in cold or Arctic waters where hydraulic heating is valuable, and have access to qualified hydraulic maintenance. Avoid it if deck headroom is severely limited, budget constraints preclude a complex hydraulic system, or the vessel lacks personnel/equipment for regular seal and bearing‑pad inspections.

Use Cases: The SF-11T is typically installed on bulk carriers loading grain, coal or ore where quick turnaround is essential; on vessels sailing in high‑latitude routes that require heated hydraulics to prevent fluid thickening; and as a retrofit on older ships seeking improved watertight performance without sacrificing hatch size.

Manufacturer Datasheet

Datasheet

Sliding Foundation SF-12/ISO-GAP

Per Hersteller-Datenblatt · Cargo Hold Access · Hydraulic sliding hatch cover

Technical Specifications

Antriebssystem: Hydraulic cylinders or motors with slow to medium speed, integrated load-holding valves
Paneelbauart: Two to six panels per cargo hatch, double steel skins (folded covers) or single steel skins (rolling covers)
Dichtungssysteme: FlexSeal, Cat-Profile, C-Seal, Omega, Omega Lite or foam rubber with compression rods
Lagerpads: Fixpad, Flexipad, Lubripad or Unipad — weight transfer during ship movement
Hydraulik-Befüllung: Speziell für Seeeinsatz ausgelegt, integrierte Heiz-/Kühlanlage, Tank-Größe minimal zur Decklatzersparnis
Korrosionsschutz: Stainless steel piston rods or stainless steel sleeves, bronze ball bearings, lubrication nipples between seal rings

Product Lines

Side-Rolling (standard Panamax/Capesize)
Folding (Handysize/Handymax)
Piggy-Back (space-constrained decks)
Lift-On/Lift-Off (multi-purpose)
Single-Flap (compact design)
Stacking (weather decks)
Hydraulic-Pivoting (vertical stowage)

Common Failures & Inspection Points

Area: Rubber seals (gaskets) age/harden through ozone and UV or show wear signs
Check: Visual inspection for discoloration, cracks, deformation; tactile inspection of elasticity. Damaged sections (minimum 1 m length) must be replaced. Do not apply oil/grease products. Validate with ultrasonic leak detection test.
Area: Compression rods corrode, bend or show rough surfaces — compromises sealing and destroys rubber
Check: Surface inspection for corrosion and scratches. Check straightness with steel ruler. Damaged rods must be properly replaced/repaired and realigned (alignment critical for even compression).
Area: Hydraulic cylinder leaks, piston rods corroded or oil contamination reduces functionality
Check: Check oil level. Take oil samples and analyze quarterly for contamination. Oil change every 5 years; replace filter annually. Inspect piston rods for corrosion/scratches. For leaks inspect seal rings and cylinder block. Lubricate grease nipples between seal rings.
Area: Drainage system clogged or check valves not functioning — water backs up and causes rusting/water ingress into cargo hold
Check: Inspect drainage channels for blockage (visual, if necessary with wire probe). Test check valves opening/closing manually (ball should move freely, not be hardened). Inspect drainage holes in cargo hold corners. Clean or replace if fouled.
Area: Bearing pads (Bearing Pads: Fixpad, Flexipad, Lubripad, Unipad) worn — reduced height no longer compresses rubber correctly or increases wear
Check: Measure pad height against manufacturer specification. Wear of 4 mm or more destroys rubber seal. Damaged pads must be replaced with original spare parts of same size and material (involve specialists). Check movement between panel and cargo hold edge with pencil test.
Area: Leaks at compression/sealing joints undetectable or compression strength insufficient (flat or corroded steel surfaces)
Check: Perform ultrasonic tightness test: place ultrasonic generator in closed cargo hold, run sensor receiver outside around all joints. Signal strength shows compression quality. Additionally chalk test: rub compression rods with chalk, imprint shows uneven compression. Hose test in empty cargo holds (0.5 m/s, 12 mm nozzle, 1–1.5 m distance) as validation.

Typ-universelle Inspektions-/Wartungspunkte fuer Hatch Covers & Cargo Access (MacGregor + DNV/OSHA, 2026-06). Per-Modell-Specs NICHT auto-gefuellt.

Service: Rubber seal inspection every 6 months. Ultrasonic leak testing annually (IMO MSC/Circ.1325). Hydraulic system check before each cargo operation.

Spare Parts: MacGregor Finland Oy: spare parts per manufacturer. Lead time: 3-8 weeks. Seals and valve inserts to be kept on board.

Strengths

Modular panel layout (2–6 panels) adapts to a wide range of hatch sizes.
Integrated bearing‑pad system (Fixpad, Flexipad, Lubripad, Unipad) compensates for ship motions and reduces hull stress.
Corrosion‑resistant components (stainless‑steel rods, bronze bearings) extend service life in harsh sea environments.
High sealing performance with interchangeable gasket families (FlexSeal, Cat‑Profile, Omega, etc.) meeting IMO MSC 1325 requirements.
Compact stowage footprint compared with side‑rolling designs, freeing deck space for additional cargo handling equipment.

Weaknesses

Hydraulic drive adds system complexity and requires regular oil analysis and filter changes.
Gasket wear (UV/Ozone) demands semi‑annual inspection; failure can lead to water ingress.
Bearing pads are wear items; replacement involves lifting the panels and may incur downtime.
Initial capital cost is higher than simple manual or side‑rolling hatch covers.
Maintenance access to compression rods and seals can be restricted on very low deck heights.

Typical Vessels: Handysize Bulk CarrierHandymax Bulk CarrierPanamax Bulk CarrierCapesize Bulk CarrierGeneral Cargo Vessel

Certifications: DNV Class ApprovalIMO MSC/Circ.1325 compliance

Decision Guide: Choose if you need a high‑capacity, weather‑tight hatch cover on vessels that carry dry bulk or heavy general cargo and where deck space is at a premium. The system’s modular panels and bearing pads make it ideal for ships operating in rough seas with frequent opening/closing cycles. Avoid if budget constraints favour simpler manual covers, if the vessel has very narrow openings that exceed the sliding travel limits, or if you lack the technical support to maintain hydraulic systems and gasket inspections on schedule.

Use Cases: Deployed on bulk carriers loading coal, iron ore, grain or similar dry cargoes where rapid hatch opening is required for high‑throughput gear. Also used on general cargo ships that need robust weather protection while maintaining a compact deck layout, especially in regions with strong wave action and temperature extremes.

Manufacturer Datasheet

Datasheet

Sliding Foundation SF-12/Iso-Gap, <>279

Per Hersteller-Datenblatt · Cargo Hold Access · Hydraulic sliding hatch cover

Technical Specifications

Antriebssystem: Hydraulic cylinders or motors with slow to medium speed, integrated load-holding valves
Paneelbauart: Two to six panels per cargo hatch, double steel skins (folded covers) or single steel skins (rolling covers)
Dichtungssysteme: FlexSeal, Cat-Profile, C-Seal, Omega, Omega Lite or foam rubber with compression rods
Lagerpads: Fixpad, Flexipad, Lubripad or Unipad — weight transfer during ship movement
Hydraulik-Befüllung: Speziell für Seeeinsatz ausgelegt, integrierte Heiz-/Kühlanlage, Tank-Größe minimal zur Decklatzersparnis
Korrosionsschutz: Stainless steel piston rods or stainless steel sleeves, bronze ball bearings, lubrication nipples between seal rings

Product Lines

Side-Rolling (standard Panamax/Capesize)
Folding (Handysize/Handymax)
Piggy-Back (space-constrained decks)
Lift-On/Lift-Off (multi-purpose)
Single-Flap (compact design)
Stacking (weather decks)
Hydraulic-Pivoting (vertical stowage)

Common Failures & Inspection Points

Area: Rubber seals (gaskets) age/harden through ozone and UV or show wear signs
Check: Visual inspection for discoloration, cracks, deformation; tactile inspection of elasticity. Damaged sections (minimum 1 m length) must be replaced. Do not apply oil/grease products. Validate with ultrasonic leak detection test.
Area: Compression rods corrode, bend or show rough surfaces — compromises sealing and destroys rubber
Check: Surface inspection for corrosion and scratches. Check straightness with steel ruler. Damaged rods must be properly replaced/repaired and realigned (alignment critical for even compression).
Area: Hydraulic cylinder leaks, piston rods corroded or oil contamination reduces functionality
Check: Check oil level. Take oil samples and analyze quarterly for contamination. Oil change every 5 years; replace filter annually. Inspect piston rods for corrosion/scratches. For leaks inspect seal rings and cylinder block. Lubricate grease nipples between seal rings.
Area: Drainage system clogged or check valves not functioning — water backs up and causes rusting/water ingress into cargo hold
Check: Inspect drainage channels for blockage (visual, if necessary with wire probe). Test check valves opening/closing manually (ball should move freely, not be hardened). Inspect drainage holes in cargo hold corners. Clean or replace if fouled.
Area: Bearing pads (Bearing Pads: Fixpad, Flexipad, Lubripad, Unipad) worn — reduced height no longer compresses rubber correctly or increases wear
Check: Measure pad height against manufacturer specification. Wear of 4 mm or more destroys rubber seal. Damaged pads must be replaced with original spare parts of same size and material (involve specialists). Check movement between panel and cargo hold edge with pencil test.
Area: Leaks at compression/sealing joints undetectable or compression strength insufficient (flat or corroded steel surfaces)
Check: Perform ultrasonic tightness test: place ultrasonic generator in closed cargo hold, run sensor receiver outside around all joints. Signal strength shows compression quality. Additionally chalk test: rub compression rods with chalk, imprint shows uneven compression. Hose test in empty cargo holds (0.5 m/s, 12 mm nozzle, 1–1.5 m distance) as validation.

Typ-universelle Inspektions-/Wartungspunkte fuer Hatch Covers & Cargo Access (MacGregor + DNV/OSHA, 2026-06). Per-Modell-Specs NICHT auto-gefuellt.

Service: Rubber seal inspection every 6 months. Ultrasonic leak testing annually (IMO MSC/Circ.1325). Hydraulic system check before each cargo operation.

Spare Parts: MacGregor Finland Oy: spare parts per manufacturer. Lead time: 3-8 weeks. Seals and valve inserts to be kept on board.

Strengths

Fast opening/closing with hydraulic cylinders designed for sea‑water service and integrated heating/cooling to maintain fluid viscosity.
Modular panel design (2–6 panels) allows adaptation to various hatch sizes and ship classes (Panamax, Capesize, Handymax).
Multiple sealing systems (FlexSeal, Cat‑Profile, Omega, etc.) provide high watertight integrity and meet IMO MSC 1325 ultrasonic test requirements.
Corrosion‑resistant components – stainless‑steel rods, bronze bearings and optional protective coatings – extend service life in harsh marine environments.
Compact hydraulic tank layout saves deck space compared with traditional side‑rolling systems.

Weaknesses

Complex maintenance: regular inspection of seals, bearing pads and hydraulic cylinders is required to avoid leaks or loss of compression.
Higher initial capital cost than simple single‑flap covers due to multiple panels and integrated hydraulics.
Weight of the system (steel panels, cylinders and pads) can add significant deadweight, affecting payload on weight‑critical vessels.
Sensitivity to seal degradation; UV/ozone exposure can harden gaskets, necessitating six‑monthly checks.
Retrofit on older ships may be limited by available hatch opening dimensions and deck reinforcement needs.

Typical Vessels: Bulk Carrier (Panamax, Capesize, Handymax)General Cargo VesselMulti‑purpose / RoRo‑cargo ship with side‑rolling hatches

Certifications: DNV Class approvalIMO SOLAS compliance (MSC Circ 1325 ultrasonic test)

Decision Guide: Choose if: you need a fast, reliable hatch opening for large bulk cargoes, have sufficient deck space for hydraulic tanks, and can commit to regular seal and hydraulic maintenance. Avoid if: vessel weight limits are tight, budget constraints preclude higher upfront cost, or the ship’s existing hatch geometry cannot accommodate a multi‑panel sliding system.

Use Cases: The SF‑12/Iso‑Gap is typically installed on new‑build bulk carriers where rapid cargo operations are critical, such as grain, coal or ore shipments. It is also used on retrofitted general cargo vessels that require improved watertight integrity and the ability to handle variable hatch sizes without sacrificing deck space.

Manufacturer Datasheet

Datasheet

Coaming Systems

Coaming Systems Weathertight Sliding 12m unverified

12m hold · Hydraulic Sliding

Hatch Type

sliding

Cargo hold length (m)

Weathertight

Common Failures & Inspection Points

Compression-bar or seal damage can cause water ingress, detected by hose, chalk or ultrasonic testing and by wet cargo-space evidence
Wheel, hinge, roller or track wear can make opening difficult, noticed as skewing or high operating load
Hydraulic leakage or actuator faults can stop powered movement, seen as slow or incomplete opening
Corrosion or structural cracking at panels and coamings can weaken the closure, found by visual or NDT inspection
Cleat or locking-device wear can prevent even gasket compression, seen as local leakage or loose securing

Service: Inspect panels, coamings, seals, compression bars, cleats, hinges/rollers, drainage and hydraulic or mechanical operating gear. Verify even closing and weather-tight condition using the vessel’s approved test method. Dimensional wear limits and repair tolerances must follow class and manufacturer documentation.

Spare Parts: Carry hatch-cover rubber or sealing sections, cleat and roller service items, hydraulic seals/hoses and common fasteners specified by the maker.

Use Cases: Used on bulk carriers, general cargo ships, multipurpose vessels and other ships with deck-access cargo holds.

Coaming Systems weathertight hatch cover

Datasheet

Coaming Systems Weathertight Sliding 15m unverified

15m hold · Hydraulic Sliding

Hatch Type

sliding

Cargo hold length (m)

Weathertight

Common Failures & Inspection Points

Compression-bar or seal damage can cause water ingress, detected by hose, chalk or ultrasonic testing and by wet cargo-space evidence
Wheel, hinge, roller or track wear can make opening difficult, noticed as skewing or high operating load
Hydraulic leakage or actuator faults can stop powered movement, seen as slow or incomplete opening
Corrosion or structural cracking at panels and coamings can weaken the closure, found by visual or NDT inspection
Cleat or locking-device wear can prevent even gasket compression, seen as local leakage or loose securing

Spare Parts: Carry hatch-cover rubber or sealing sections, cleat and roller service items, hydraulic seals/hoses and common fasteners specified by the maker.

Use Cases: Used on bulk carriers, general cargo ships, multipurpose vessels and other ships with deck-access cargo holds.

Coaming Systems weathertight hatch cover

Datasheet

Coaming Systems Weathertight Sliding 18m unverified

18m hold · Hydraulic Sliding

Hatch Type

sliding

Cargo hold length (m)

Weathertight

Common Failures & Inspection Points

Compression-bar or seal damage can cause water ingress, detected by hose, chalk or ultrasonic testing and by wet cargo-space evidence
Wheel, hinge, roller or track wear can make opening difficult, noticed as skewing or high operating load
Hydraulic leakage or actuator faults can stop powered movement, seen as slow or incomplete opening
Corrosion or structural cracking at panels and coamings can weaken the closure, found by visual or NDT inspection
Cleat or locking-device wear can prevent even gasket compression, seen as local leakage or loose securing

Spare Parts: Carry hatch-cover rubber or sealing sections, cleat and roller service items, hydraulic seals/hoses and common fasteners specified by the maker.

Use Cases: Used on bulk carriers, general cargo ships, multipurpose vessels and other ships with deck-access cargo holds.

Coaming Systems weathertight hatch cover

Datasheet

Coaming Systems Weathertight Sliding 21m unverified

21m hold · Hydraulic Sliding

Hatch Type

sliding

Cargo hold length (m)

Weathertight

Common Failures & Inspection Points

Compression-bar or seal damage can cause water ingress, detected by hose, chalk or ultrasonic testing and by wet cargo-space evidence
Wheel, hinge, roller or track wear can make opening difficult, noticed as skewing or high operating load
Hydraulic leakage or actuator faults can stop powered movement, seen as slow or incomplete opening
Corrosion or structural cracking at panels and coamings can weaken the closure, found by visual or NDT inspection
Cleat or locking-device wear can prevent even gasket compression, seen as local leakage or loose securing

Spare Parts: Carry hatch-cover rubber or sealing sections, cleat and roller service items, hydraulic seals/hoses and common fasteners specified by the maker.

Use Cases: Used on bulk carriers, general cargo ships, multipurpose vessels and other ships with deck-access cargo holds.

Coaming Systems weathertight hatch cover

Datasheet

TTS Marine

TTS Marine Sliding Hatch Cover 12m unverified

12m hold · Hydraulic Sliding

Hatch Type

sliding

Cargo hold length (m)

Weathertight

Vessel types

bulk_carrier
container

Common Failures & Inspection Points

Wire-rope, chain, roller or line-contact wear caused by loaded movement, corrosion or poor lubrication, resulting in visible damage, rough operation or accelerated rope wear
Brake, locking or clutch deterioration caused by repeated loading or contamination, resulting in poor holding or excessive travel
Hydraulic or electric drive failure caused by leakage, motor faults or control problems, resulting in slow, weak or unavailable movement
Bearing, pin, hinge or structural wear caused by cyclic loading and corrosion, resulting in play, vibration, misalignment or abnormal noise
Limit, interlock or control-system fault caused by sensor, wiring or calibration problems, resulting in inhibited movement, alarms or loss of protective functions

Service: Inspect load-bearing structure, brakes, locks, ropes or chains, rollers or sheaves, pins, bearings, drives, controls and foundations as applicable. Lubricate specified points and inspect hydraulic hoses or electrical equipment according to drive type. Function-test local and remote controls, limit devices, emergency stops and interlocks using approved procedures. Examine high-load welds and line-contact areas for corrosion, cracking, deformation or sharp edges. Keep personnel clear of suspended loads and snap-back or pinch zones during tests. Refer to the manufacturer documentation for the exact figure for load tests, allowable wear, brake settings and inspection criteria.

Spare Parts: Keep brake or locking service parts, seals, bearings, hydraulic hose or valve consumables, control switches, sensors and manufacturer-recommended rope, roller or sheave wear parts. Heavy structural, gear and load-bearing components are normally strategic spares.

Use Cases: It is used for cargo-hold access and weather protection on merchant ships, passenger vessels, offshore units or other vessel types where this equipment category is fitted.

TTS Marine sliding hatch cover for bulk/container vessels

Datasheet

TTS Marine Sliding Hatch Cover 15m unverified

15m hold · Hydraulic Sliding

Hatch Type

sliding

Cargo hold length (m)

Weathertight

Vessel types

bulk_carrier
container

Common Failures & Inspection Points

Wire-rope, chain, roller or line-contact wear caused by loaded movement, corrosion or poor lubrication, resulting in visible damage, rough operation or accelerated rope wear
Brake, locking or clutch deterioration caused by repeated loading or contamination, resulting in poor holding or excessive travel
Hydraulic or electric drive failure caused by leakage, motor faults or control problems, resulting in slow, weak or unavailable movement
Bearing, pin, hinge or structural wear caused by cyclic loading and corrosion, resulting in play, vibration, misalignment or abnormal noise
Limit, interlock or control-system fault caused by sensor, wiring or calibration problems, resulting in inhibited movement, alarms or loss of protective functions

Use Cases: It is used for cargo-hold access and weather protection on merchant ships, passenger vessels, offshore units or other vessel types where this equipment category is fitted.

TTS Marine sliding hatch cover for bulk/container vessels

Datasheet

TTS Marine Sliding Hatch Cover 18m unverified

18m hold · Hydraulic Sliding

Hatch Type

sliding

Cargo hold length (m)

Weathertight

Vessel types

bulk_carrier
container

Common Failures & Inspection Points

Wire-rope, chain, roller or line-contact wear caused by loaded movement, corrosion or poor lubrication, resulting in visible damage, rough operation or accelerated rope wear
Brake, locking or clutch deterioration caused by repeated loading or contamination, resulting in poor holding or excessive travel
Hydraulic or electric drive failure caused by leakage, motor faults or control problems, resulting in slow, weak or unavailable movement
Bearing, pin, hinge or structural wear caused by cyclic loading and corrosion, resulting in play, vibration, misalignment or abnormal noise
Limit, interlock or control-system fault caused by sensor, wiring or calibration problems, resulting in inhibited movement, alarms or loss of protective functions

Use Cases: It is used for cargo-hold access and weather protection on merchant ships, passenger vessels, offshore units or other vessel types where this equipment category is fitted.

TTS Marine sliding hatch cover for bulk/container vessels

Datasheet

TTS Marine Sliding Hatch Cover 21m unverified

21m hold · Hydraulic Sliding

Hatch Type

sliding

Cargo hold length (m)

Weathertight

Vessel types

bulk_carrier
container

Common Failures & Inspection Points

Wire-rope, chain, roller or line-contact wear caused by loaded movement, corrosion or poor lubrication, resulting in visible damage, rough operation or accelerated rope wear
Brake, locking or clutch deterioration caused by repeated loading or contamination, resulting in poor holding or excessive travel
Hydraulic or electric drive failure caused by leakage, motor faults or control problems, resulting in slow, weak or unavailable movement
Bearing, pin, hinge or structural wear caused by cyclic loading and corrosion, resulting in play, vibration, misalignment or abnormal noise
Limit, interlock or control-system fault caused by sensor, wiring or calibration problems, resulting in inhibited movement, alarms or loss of protective functions

Use Cases: It is used for cargo-hold access and weather protection on merchant ships, passenger vessels, offshore units or other vessel types where this equipment category is fitted.

TTS Marine sliding hatch cover for bulk/container vessels

Datasheet