Launching appliances
Governing: STCW Code Table A-VI/2-1; REG Yacht Code Part A 13.4, Part B 7.20 and Common Annex C1. Builds on: L1.1.
Table A-VI/2-1 requires knowledge of the various types of device used for launching survival craft and rescue boats, launching into a rough sea, and methods of recovery. On yachts that mostly means single-arm davits and hydraulic cranes, often combined with shell doors or side garages.
What the Code requires
500 GT and over (Part A 13.4(2))
- Each rescue boat is served by its own appliance, approved to the LSA Code.
- A power-operated crane must work by hand or from an emergency source if main power fails; shell doors, platforms and fashion plates that obstruct launching need main and emergency power unless they can be worked manually.
- Each hydraulic davit has its own hydraulic power unit close to it.
- The appliance is sized for the boat with its full complement of at least six persons at 82.5 kg each, plus fuel and equipment.
- Without lifeboats, the yacht must launch its rescue boat(s) at up to 10 degrees trim combined with 20 degrees list, or the damaged trim if less.
Under 500 GT (Part A 13.4(3))
- A man-riding appliance is sized for the boat with at least two persons at 82.5 kg, plus fuel and equipment.
- Non-LSA appliances must take a static proof load of not less than 2.2 x the maximum working load, with factors of safety of 6 for wires, hooks and sheaves and 4.5 for the rest, and a dynamic test at 1.1 x.
- Appliances not for man-riding are marked 'NOT TO BE USED FOR MAN RIDING'.
- Stern platforms are not accepted for embarkation; other craft may not be used to assist launch or recovery.
Worked example (illustrative figures)
| Item | Mass |
|---|---|
| Rescue boat | 650 kg |
| Fuel and equipment | 120 kg |
| Two persons at 82.5 kg | 165 kg |
| Maximum working load | 935 kg |
| Static proof, 2.2 x | 2,057 kg |
| Dynamic test, 1.1 x | 1,028.5 kg |
If someone adds a larger outboard or a heavier boat, the working load goes up and the appliance may no longer be rated for it.
Launching well
- Launch down a straight side, clear of propellers, stabiliser fins and overhangs.
- Where headway is needed for steerage, use the painter and keep speed minimal.
- Part B 7.20: every survival craft needed for abandonment must be launchable with full complement within 30 minutes of the abandon signal, once everyone is assembled with lifejackets on.
WARNING - Drills with way on REG Annex C1(12): if lifeboat or rescue boat drills are done with the ship making headway, they are practised in sheltered waters only, under an officer experienced in such drills.
Rough seas
Launch on the lee side, time the release to the top of a swell so the boat drops with the falling water, and get clear of the hull immediately. Recovery is harder than launch: bring the boat under the hook in the trough, hook on quickly and lift as the swell rises. Motion compensation, where fitted, helps; it does not replace timing.
TIP - Know the emergency lowering Every davit has a manual or gravity lowering method. Find it, read the placard and, with the engineer, practise it at a drill. When main power fails is exactly when you will need it.