What to check on a MOB Recovery System.
A rescue boat gets a trained crew to a casualty; a MOB recovery system gets the casualty out of the water once someone reaches them. The two are complementary, not interchangeable. A recovery system is built around a davit-mounted crane, winch, or telescopic arm with a sling, net, or cradle at the working end, sized so that one or two crew members on deck, not a swimmer in the water, can lift a person who may be unconscious, injured, or hypothermic and therefore unable to help with their own recovery.
What sets a MOB recovery system apart
A rescue boat gets a trained crew to a casualty; a MOB recovery system gets the casualty out of the water once someone reaches them. The two are complementary, not interchangeable. A recovery system is built around a davit-mounted crane, winch, or telescopic arm with a sling, net, or cradle at the working end, sized so that one or two crew members on deck, not a swimmer in the water, can lift a person who may be unconscious, injured, or hypothermic and therefore unable to help with their own recovery.
Main components
- Deployment arm or davit — swings or extends over the ship's side, fixed or telescopic, rated for the system's safe working load plus dynamic loading from ship motion.
- Winch and wire or webbing — powered or geared manual lift, with a load limiter to stop the lift if resistance suggests the casualty has snagged.
- Recovery device — sling, cradle, net, or purpose-made stretcher basket that holds the casualty horizontally where possible, since vertical lifting of an immersed, hypothermic person carries its own circulatory risk.
- Control station — positioned so the operator keeps the casualty in sight throughout the lift, usually with a dead-man or hold-to-run control.
- Power source — hydraulic, electric, or manual backup, since a MOB event can coincide with a power failure elsewhere on the ship.
Selection and sizing
Safe working load is set by the heaviest realistic casualty plus equipment, not by an average crew weight. Reach and freeboard clearance are ship-specific: a system sized for a low-freeboard workboat will not clear the side of a large bulk carrier in ballast. Deployment time under real sea-state conditions, not calm-water trials, is the number that actually matters, since most man-overboard incidents happen in weather bad enough to have contributed to the fall.
Regulations and class
SOLAS Chapter III, Regulation 26 and related LSA Code provisions require means of recovery for man-overboard situations on passenger and cargo ships, either as a dedicated system or built into the rescue boat arrangement. Where a dedicated recovery system is fitted, it is subject to the same type-approval and periodic testing regime as other lifesaving appliances, including load testing at survey intervals set by class.
Typical faults
| Fault | Consequence |
|---|---|
| Winch wire corrosion from saltwater exposure | Reduced breaking strength, risk of failure under load during a real recovery. |
| Load limiter not tested or bypassed | Winch continues pulling against a snagged casualty or line, causing injury. |
| Deployment arm not exercised regularly | Seized hinges or hydraulic seals fail exactly when speed matters most. |
| Crew unfamiliar with the control station | Deployment takes minutes longer than the drill time recorded in the log. |
What to look for in a supplier
- Type approval certificate covering the specific recovery device, not just the davit or winch as separate items.
- Stated safe working load with the margin used above average adult weight made explicit.
- Documented deployment time under a stated sea state, not only calm-water figures.
- Spares availability for the winch and load limiter, the parts most likely to need servicing after saltwater exposure.
Drill the recovery system with a weighted dummy, not just a walk-through — the difference between a crew that has actually lifted 80 kg of dead weight over the rail and one that has only talked through it shows up in the first real minute.