Why Cargo Ships Drop Their Lifeboats Instead of Lowering Them

A lifeboat can leave a cargo ship over the stern: released, with the people already aboard, and nothing holding it on the way down. The older way is a davit and wires. That ride has a minimum speed in the LSA Code, and a list swings a hanging boat while the crew is sitting in it. A free-fall boat sits bow-down on a ramp, and two actions from inside let it go. The rules then require it to move away from the ship without using the engine. This video follows that drop, the seat and harness that take the stop, a 61.53-meter sandbag test (201.9 feet) of one model certified to 47 meters, and the drill rule that stopped putting the whole crew on the fall.

Heights and speeds marked as our arithmetic are calculated from the cited figures. They are not a measured entry speed, and the 20-meter davit example is not a typical ship.

CHAPTERS
0:00 The drop
1:02 The cables
3:07 The ramp
5:00 Nose first
7:04 The seat
9:36 Sixty-one meters
11:44 The drill
13:20 Why drop it

Diagrams and animations are our own schematics, not to scale. Photos are real photographs (Wikimedia Commons / U.S. government public domain) and are credited on screen. The script was researched and written by us.

#engineering #howitworks #ships #lifeboat