ISO-socket, double, Type: D92B

Common issues

• Brake band lining wear reducing holding capacity below the rated value
• Hydraulic leaks at swivel joints, motor seals or valve blocks
• Clutch (drum disengagement) slipping or failing to engage/disengage cleanly
• Wire rope/drum spooling misalignment causing uneven layering and rope damage
• Load cell or tension-monitoring sensor drift giving inaccurate line tension readings
• Corrosion of the brake drum surface affecting braking consistency
• Control system faults on the local or remote station, particularly on electric-drive variants
• Gearbox bearing wear from sustained high-load mooring operations

Inspection checklist

• Visual check of brake band lining thickness and drum surface condition
• Function test of brake apply/release and emergency release
• Verify brake holding capacity against the last class-witnessed render test record
• Check hydraulic oil level, condition and for external leaks
• Inspect clutch engagement/disengagement and drum freewheel operation
• Check mooring wire/rope condition and correct spooling on the drum
• Test local and remote control stations, including emergency stop
• Verify load monitoring/tension display against a known reference if fitted
• Check foundation bolts and structural mounting for looseness or cracking
• Test warping head/capstan operation if fitted

Service intervals

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• Brake band lining/friction material
• Hydraulic motor seal kit
• Clutch friction plates/lining
• Hydraulic control valve or solenoid assembly
• Load pin/load cell sensor
• Gearbox bearings
• Mooring wire (drum-length replacement)

Safety

• Stored energy in a loaded mooring line - snap-back zones must be respected during operation and maintenance
• Never test or adjust the brake with personnel in the bight or snap-back zone
• Hydraulic system under pressure - isolate before opening lines or components
• Uncontrolled drum release under load is a crush/struck-by hazard
• Brake holding capacity below the rated value is a mooring-line-parting and personnel-injury risk

Class survey

Brake holding capacity is typically verified by a class-witnessed render/no-render test at survey (commonly linked to the 5-year renewal cycle), checked against a percentage of the mooring line's minimum breaking load. Records of brake tests and lining renewals should be retained for survey.

Estimated lifetime: Mooring winches are typically designed for the vessel's operating life (20-25 years); wear parts (brake linings, seals, bearings) are renewed on a condition or interval basis rather than a fixed running-hour limit.