It is not uncommon for crewmembers of large cargo ships to have to enter an enclosed space. Without proper equipment and training this can quickly turn deadly due to a possible lack of oxygen in the space. Tragedies have occurred where a fellow crewmember, while attempting to rescue someone else, also dies. In 2013, the Safety of Life at Sea Convention (SOLAS) required that, beginning January 1, 2015, all crewmembers that enter enclosed spaces must participate in closed entry drills at least every 2 months.

The London P& I Club publication Stop Loss recently published an article on this requirement at this link.