Life Boat
June 10th, 2010A lifeboat is a small watercraft carried on a ship to provide a means of emergency evacuation in the event of a disaster aboard the ship. Lifeboats may be rigid or inflatable vessels; the inflatable type are sometimes referred to as liferafts. In the military, a lifeboat may be referred to as a whaleboat, dinghy, or gig. The ship’s tenders of modern cruise ships are often designed to double as lifeboats and “lifeboat drills” are a part of the cruise experience.
Inflatable lifeboats may be equipped with auto-inflation (carbon dioxide or nitrogen) canisters or mechanical pumps. A quick release and pressure release mechanism is fitted on board ships so that the canister or pump automatically inflates the lifeboat, and the lifeboat breaks free of the sinking vessel. Commercial aircraft are also required to carry auto-inflating life rafts in case of an emergency water landing, and are also kept on offshore platforms.
Ship-launched lifeboats are designed to be lowered from davits on a ship’s deck, and are unsinkable, with buoyancy that cannot be damaged. The cover serves as protection from sun, wind and rain, can be used to collect rainwater, and is normally made of a reflective or fluorescent material that is highly-visible. Lifeboats are usually equipped with flares and/ or mirrors for signaling, several days’ worth of food and water, basic first aid supplies and oars. Some lifeboats are even more capably equipped to permit self-rescue; containing such supplies as a radio, an engine and/ or sail, heater, basic navigational equipment, solar water stills, rainwater catchments and fishing equipment.
Liferafts in general are collapsible, and stored in a heavy-duty fiberglass canister, and also contain some high-pressure gas to allow automatic inflation to the operations size. SOLAS and military regulations require these to be sealed, never opened by the ship’s crew, they are removed at a set periodicity and sent to a certified facility to open and inspect the liferaft and contents. In contrast, a lifeboat is open, regulations require a crewmember to inspect it periodically and ensure all required equipment is present.
Most modern Lifeboats have some form of a motor; liferafts usually do not have a motor. Large lifeboats require some form of a davit or launching system (there might be multiple lifeboats on one), and that does require human intervention to commence or be involved in the launch process. Thus, launch of lifeboat is longer and has higher risk of failure due to human factor, however, lifeboats don’t suffer from inflation system failures like liferafts.
Recently, smaller self-rescue lifeboats have been introduced for use by boats with fewer people aboard: these are rigid dinghies with CO2-inflated exposure canopies and other safety equipment. Like the lifeboats used before the advent of the gasoline engine, these self-rescue dinghies are designed to let the passengers propel themselves to safety by sailing or rowing. In addition to their use as proactive lifeboats, these self-rescue dinghies are also meant to function as yacht tenders.