Hot Water: An Economical Approach to Increased Diver Performance and Safety In the Offshore Oil Industry

Abstract

Abstract Since the beginning of diving, cold has been one of the limiting factors to man's performance in the sea. An economical approach to solving this problem was introduced utilizing hot water to replace the heat normally lost by the diver to the cold water. Since its introduction in 1965, several improvements have been made to insure efficient diver performance in the offshore oil industry. This system has supported divers in the open sea for periods in excess of eight hours, and in depths down to 850 feet. This approach increases the diver's performance when properly applied and makes an everyday reality of what was once considered technically and economically impossible. Introduction/Origin The most readily available heat transfer medium for keeping a diver warm cheaply and effectively anywhere in the world is the very water in which he is swimming. The divers worst enemy, cold water, can be his best friend, warm water, once it is heated and flooded over his body. In this way the water's properties of high specific heat and high thermal conductivity can be utilized to form thermally protective barrier within which he can comfortably perform useful work. The first use of hot water to keep a diver warm is not known, although a recorded attempt was made in France in 1935. The inspiration for this probably occurred as a result of swimming in the discharge of a water-cooled marine engine, with an intermediate step of sticking the end of a hose carrying hot water inside a diver's suit at dockside. In this country lobster divers in New England and abalone divers on the West Coast used variations on this theme with some success. The first really successful use of hot water to keep a working diver warm was in 1965 by the Westinghouse Cachalot team headed by Jerry O'Neill and Alan Krasber. In preparation for the first commercial saturation diving job at Smith Mountain Dam, Virginia, they designed, built, and tested an open-circuit hot water suit and support system. It was recognized that supplemental heat must be supplied the diver if the longer bottom times offered by the saturation diving technique were to be utilized. Since decompression from saturation is the same regardless of time spent in the water, a diver could theoretically spend six to eight hours working each shift. However, in 400 F water a diver using the then conventional wet or dry suit could perform useful work for only one or two hours. Utilizing the hot water system, the Westinghouse team was able to work routinely for two to three hours with the longest dive in excess of five hours. The hot water system was then introduced to the offshore oil community when the Westinghouse Cachalot System was brought to the Gulf of Mexico in the spring of 1966. The job was to salvage two oil production platforms toppled by Hurricane Betsy off the coast of Louisiana. The hot water system was used extensively over the next five months and was instrumental in compiling 4,600 hours in underwater work.