Reliable and efficient injury assessment for free-fall lifeboat occupants during water entry: correlation study between lifeboat acceleration indicators and simulated human injury responses

The evacuation of personnel from an offshore installation in severe weather conditions is generally ensured by free-fall lifeboats. During the water entry phase of the launch, the lifeboat may be subject to large acceleration loads that may cause harmful acceleration-induced loads on the occupants.

The present/common methodology for assessing the occupant safety of free-fall lifeboats uses one single characteristic launch to perform injury risk analysis for a given free-fall lifeboat launch condition that includes e.g. weather conditions, lifeboat and host installation loading conditions.

This paper describes an alternative methodology to fully assess the risk of injury for lifeboat occupants during water entry by introducing a correlation model between acceleration load indicators and injury responses. The results are presented in terms of seating matrices showing critical seat rows, in which the probability of being injured exceeds a pre-defined threshold.