The relationship of vessel stability to vessel related casualties in the fishery industries was examined. Vessel accident and casualty statistics were based primarily on data from the United States Coast Guard (USCG). The physics and engineering aspects (buoyancy, gravity, and design) of vessel stability were discussed. Traditionally, in the United States, fishing vessels were exempt from most regulations applied to other commercial vessels, and in the 1960s fish tenders and fish processing vessels were added to those exempted. The regulatory measures of 1983 and 1988 on tender vessel exemptions and fishing vessel safety were discussed. The stability portion of the regulations applied to vessels over 79 feet (ft) long, and different regulations were applied to vessels under 79ft in length (those less than 50ft, and those between 50ft to 79ft). Righting arm curves for an Alaskan crab vessel of 107ft overall length and different holds filled, an 84ft vessel which capsized on operation with the forward hold filled, and an 86ft crab boat with a large number of pots on deck and different holds filled were considered. A common problem encountered at sea was that of partial flooding. The consequences of lazarette flooding were examined in the case of a 123.5ft long crab fishing vessel. Reduction in stability was dramatic, and put the vessel in an extremely dangerous situation. Righting arm curves for a limit seiner with and without a poop deck, with various levels of icing, a 98ft trawler with various levels of icing, and a 98ft crabber/trawler with and without added sponsons were analyzed and figured. In the last case, when the vessel keeled over, a large restoring moment was provided by the sponson, which increased stability. Ways by which an owner/operator of a vessel could ascertain vessel stability and safety were addressed. Results of USCG investigations into the loss of the F/V Americus and F/V Altair were discussed. The author concludes that the single most important factor to be recognized is that the stability characteristics for each vessel are unique.
Proceedings of the National Fishing Industry Safety and Health Workshop, Anchorage, Alaska, October 9-11, 1992