LIFEBOATS AND LIFERAFTS AND THEIR OPERATIONLIFEBOATS AND THEIR OPERATINGS There are wooden, steel, aluminium and glass-fibre reinforced plastic lifeboats. There are open, partially enclosed and totally enclosed types.
Rescue boats may also be made of rubber. Wooden, aluminium and steel lifeboats have a skin fitted over frames. Wooden or metal lifeboats require significant maintenance. Metal boats tend to corrode quickly if neglected; wooden ones can dry out and then become leaky. Glass-fibre reinforced plastic lifeboats on the other hand have a high corrosion resistance and a low maintenance requirement. For that reason, almost all lifeboats built nowadays are of GRP.
Totally enclosed lifeboats are self-righting if all openings are closed watertight and the persons on board are belted into their seats. That is the normal condition even at launch. If a totally enclosed boat capsizes with the access or ventilation openings open it will in adverse circumstances adopt an attitude which makes it still possible to leave it above water.
Partially enclosed lifeboats are also used, particularly on passenger vessels. They are not suitable for free-fall launching.
Free-fall boats are totally enclosed lifeboats stowed on specially designed launching appliance at the stern. They are fitted with special bucket seats and safety belts. Rescue boats have two principal purposes, namely:
the rapid rescue of persons floating in the water;
the gathering, keeping in position and towing liferafts.
Rescue boats may be of rigid or inflatable construction or of combination of both. Their length must be not less than 3.8 m and not more than 8.5 m. They may be capable of holding at least five persons seated and one person lying down. Rescue boats have either an inboard or an outboard motor. That enables them to achieve a speed of at least 6 knots running free and 2 knots towing. 1. Operating lifeboats.
Immediately after entering the water a lifeboat must leave the danger zone around the damaged ship as quickly as possible. The biggest danger to the boat and its occupants come from the damaged and sinking ship itself, by its capsizing, by explosions, the deck cargo going over the side, drifting pieces of cargo and fuel leaking out.
The best course is at right angles away from the damaged ship. Motor life - and rescue boats can in calm water reach speeds of up to 6 knots. In a seaway or when towing other survival craft, that speed will not be reached.
2. lashing . 3. Painter
l. Grab line
Extends two times the distance from the boat deck to the surface of the water with the ship at minimum draught, minimum length is 15 m. An additional painter of the same length is permanently fastened forward inside the boat.
1 What are the types of lifeboats?
2 What do wooden or metal lifeboats require?
3 What is the best course from the damaged ship?
Date: 2015-01-11; view: 1068
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