Lifeboat
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For the 1944 movie, see Lifeboat (movie).
A lifeboat is a boat carried on board a ship and designed to allow passengers to escape, or a boat kept on land or in a harbour to rescue people in trouble at sea. Lifeboats are also kept at offshore platforms. As such, it is an elaborate version of a life raft. Lifeboats were historically rigid structures built with highly buoyant materials. More recently however, life rafts are inflatable, equipped with auto-inflation carbon dioxide canisters or mechanical pumps, and split into partitions, so that they are much less subject to the adverse effects of exposure to sea water and sunlight. A quick release and pressure release mechanism is fitted so that the canister or pump automatically inflates the lifeboat, and the lifeboat breaks free of the sinking vessel.
The first boat specialized as a lifeboat was tested on the River Tyne on January 29, 1790. William Wouldhave and Lionel Lukin both claimed to be the inventor of the first Lifeboat.
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Ship-launched lifeboats
These are large whaleboats designed to be lowered from davits on a ship's deck. They are designed to be unsinkable, with buoyancy that cannot be damaged. They have a cover that can be erected to form a storm shelter and sunshade. The cover can usually collect rainwater, and is visible from the air against the ocean. They usually carry flares and mirrors for signaling, three days of food and water, oars, an engine, heater and basic navigational equipment.
The International Convention for the Safety of Life at Sea (SOLAS) and the International Life-Saving Appliance Code (LSA) require a specific list of emergency equipment to be carried on each lifeboat and liferaft used on international voyages. Modern lifeboats should also carry an emergency position-indicating rescue beacon and either a radar reflector or search and rescue radar transponder.
Traditionally, lifeboats for passages in the Pacific or Indian Oceans were thought unsafe unless they permitted self-rescue. Thus these traditionally included sailing equipment, navigational equipment, solar water stills, rainwater catchments and fishing equipment. Lifeboats for the North Sea include an electric heater for the engine oil, which is left on in cold weather.
A very commonly used lifeboat in modern times is a 25-man inflatable; in the United States Navy it is named the Mark 6. The lifeboat is compact and made of separate compartments, or tubes, as a redundancy against puncture. Carbon dioxide canisters and hand pump facilitate inflation of the vessel. A built-in canopy is often included as part of a lifeboat against harsh weather. Lifeboats furthermore carry essential survival gear, including food, water, de-salter kits, bags, sea dye, first aid kits, fishing kits, light/smoke distress signals (Mark 13), and heliograph mirrors.
Most yachts carry lifeboats in some form. Some use dual-purpose dinghies, often with the express plan of self-rescue, while others use inflatable life-rafts. The equipment and arrangements are very similar to larger commercial lifeboats.
Origins of the lifeboats onboard ships
Lifeboat_tender.jpg
By the turn of the 20th Century larger ships meant more people could travel, but safety rules in regard with lifeboats stayed out of date. It was after the sinking of the RMS Titanic on April 15, 1912, that a movement began to require a sufficient number of lifeboats on passenger ships for all people on board.
The need for so many more lifeboats on the decks of passenger ships after 1912 led to the use of most of the deck space available even on the large ships, creating the problem of restricted passageways. This was resolved by the introduction of collapsible lifeboats, a number of which had been installed on the Titanic (see Birthon Boat Company).
The ship's tenders of modern cruise ships are often designed to double as lifeboats.
Also see the discussion in dinghy and liferaft.
Rescue lifeboats
These have diesel power and are fast. They can be launched from shore in any weather and perform rescues out to a hundred miles or so. Older lifeboats have sails, which are slower, and have an unlimited rescue radius. Both types remain in use. All lifeboats of this type have radios to help locate the ships, as well as whale-boats, slings to rescue injured persons, and medical and food supplies.
The most famous group maintaining lifeboats is the Royal National Lifeboat Institution (or RNLI) of the United Kingdom, composed of volunteers, and paid for by voluntary donation - web-site at www.rnli.org.uk. Most Scandinavian countries also have active volunteer lifeboat societies. The local branch of a society generally schedules practices, maintains a lifeboat and shed, and is contacted by commercial marine radio operators when a rescue is needed.
In Australasia, surf lifesaving clubs operate inflatable rescue boats (IRB) for in-shore rescues of swimmers and surfers. These boats are best typified by the rubber Zodiac and are powered by an outboard motor. The rescue personnel wear wet suits. The Rigid Hulled Inflatable Boat (RIB) is now seen as the best type of craft for in-shore rescues as they are less likely to be tipped over by the wind or breakers. Specially designed Jet rescue boats have also been used successfully. Unlike ordinary pleasure craft, these small to medium sized rescue craft often have very low freeboard so that victims can be taken aboard without lifting. This means that the boats are designed to operate with water inside the boat hull and rely on flotation tanks rather than hull displacement to stay afloat and upright.
Lifeboats are also operated inland at specific events, organisations such as the Royal Life Saving Society (RLSS UK) provide coverage of rivers, lakes and such like. Providing a response if needed. An example of a voluntary organisation that does this as a member of the RLSS UK is Colwick Park Lifeguards (http://www.colwickparklifeguards.com) who work throughout the UK.
Other usages
When the Apollo 13 command module was affected by an explosion in the service module, the lunar module was used as a lifeboat as it had separate life support, propulsion and guidance systems that remained functional (though it was not a lifeboat in the sense that it was detached from the main vehicle).
The International Space Station has as "lifeboat" a Soyuz spacecraft, currently the Soyuz TMA-5, for an emergency landing of the crew.
Any small self-contained spacecraft designed to operate as a life-preserving vehicle for the crew of a spacecraft in distress might also be termed a "lifeboat", and this usage frequently appears in science fiction.