Abstract: On May 16, 2009, Employee #1 was working for a metal peening and heat-treating shop and was repairing a large peening apparatus that shot metal from nozzles onto flat metal aerospace parts on a large table angled at approximately 45 degrees. The jet nozzles were fed by a rail-mounted loading cart that traveled up and down a track by a hydraulic cylinder. The machine had been locked out and access to the inside of the machine had been accomplished using a ladder. The employee placed a 2-ton capacity come-along winch between the loading cart and an eye bolt located at the top of the cart rail on the top wall. He then ratcheted the come-along to take the weight of the cart off the rail so the wheels could be chocked and the hydraulic cylinder could be disconnected and replaced. The employee was finishing ratcheting up the come-along when the cart jumped off its track and lacerated his left middle finger. The employee was hospitalized, and his finger tip was amputated. Further investigation revealed that the eye bolt mounted on the top wall to which the come along had been attached was off-center from the centerline of the rail track. In addition, after the accident, guarding had been placed along the rails to prevent the loading cart from coming off its rails.