The recent loss in mid-Atlantic of the a.s.v. CHEEKI RAFIKI and the sad loss of four lives has brought very clearly to public and professional attention the problem of fin or pendulum keel detachment and consequent capsize of many apparently perfectly good boats. Keel failure is a very serious problem from a marine surveying point of view and the author has made a detailed study of a very similar loss that took place in February 2007 in the English Channel.
To put the matter into perspective it was first necessary to look into some published historic data. Because of their concern over the number of reported keel failures, the International Sailing Federation (ISAF) developed a Keel Structure Working Party to investigate and report on the problem. As a starter they produced a data base of known failures and investigated 72 of those that had been reported since 1984 and which involved no fewer than 24 deaths by drowning. The problem with the data, however, is that it records only the worst cases in which the keel had been pulled off or otherwise lost from the hull usually resulting in a capsize and an actual total loss. The marine surveyor investigating such a casualty will frequently find that it is very difficult to establish the prime cause of failure and, in particular, to differentiate between a loss caused by a design and/or manufacturing fault and a casualty resulting from human error such as a collision or a grounding. He must be particularly careful to avoid listening and paying credence to usually ill informed bar room or internet gossip.
It may be considered that the number of deaths when compared to the number of people sailing for pleasure is very small BUT IT IS STILL TWENTY FIVE DEATHS TOO MANY! Continue reading “A study of a keel failure and the loss of the Cheeki Rafiki”
