Abstract: On May 8, 1995, Employee #1, a foreman, and a coworker, of Bragg Crane and Rigging, were attempting to elevate one end of a vessel they were preparing for on-the-road transportation. The two employees were working as contractor employees at the vessel manufacturer's facility. They were using two 50-ton, double acting William Pine jacks, housing # PHJ-5010. The jack had a Enerpac hydraulic hose coupler, 10,000 psi, CH604/6040 OG7C, on each side of the cylinder. However, since Employee #1, had not used the hydraulic pump before, he was instructed to use the hand pumps, which were built into the jack. After about 15 or 20 pump actuations, the hose coupler serving the upper portion of the cylinder failed, sending pieces into Employee #1's scrotum. Surgery was required to remove the foreign matter. The coupler had a ball check valve built into it, apparently to keep hydraulic fluid from leaking when the coupler is disconnected. The company believes that the jacks are about 25 years old. Neither the employer nor the company it uses to repair or modify the jacks has an instruction manual. The repair company states that Simplex, which bought out William Pine, also does not have an instruction manual. Simplex states that the pumps mounted on the jack have internal relief valves that can be adjusted by Allen screws and that the pump is capable of developing more than 10,000 psi if the relief valve is not properly set. Causal factors are as follows: the vent screw plug serving the top cylinder was closed while the upper portion of the cylinder was full of fluid; and the relief valve in the hand pump was improperly set and/or the Enerpac hose coupler was defective or not adequately rated.