P was the third assistant engineer. His duty station was the engine room where he stood the 8 to 12 watch each morning and evening. The ship was tied up to a dock and the chief engineer directed P to make some adjustments to a steam winch on the boat deck which was being used to hoist groceries aboard. Maintenance of winches on deck is one of the duties of the engine crew. While greasing one of the winches, P noticed that the deckhands were having trouble getting the groceries aboard, and he proceeded to the area where the work was being performed to help out. The hoisting cable ran so close to the side of the ship making the grocery basket scrape against the ship's plates. The basket was tipping over, and groceries were in danger of falling into the water. P grabbed the cable and pushed it away from the ship so the basket could be raised without coming into contact with the ship's side. The basket was being lifted by a steam winch which retracted the cable. There was a bridle attached to the basket and the cable was connected by a hook on top of the bridle. The cable ran back to the winch through a sheave which was rigged to a piece of angle iron above the deck. The sheave was within an arm's length above the P’s head. While P was holding the cable, the winch retracted it, and P's left thumb was carried into the sheave. The thumb was fractured and badly lacerated. The vessel was equipped with a supply davit which was available for loading groceries which was unusable at the time because its electric motor had been removed. The angle iron to which the sheave was attached extended no more than 21/2 feet horizontally beyond the deck, and this was not far enough to prevent baskets being hoisted from scraping the sides. P was left with a 50% permanent limitation to his ability to grip objects between his left thumb and other fingers and a limitation generally in work that required fine manual dexterity. The district court held that the proof presented a question of assumption of risk, but not of contributory negligence. Since the assumption of risk is not a defense to a seaman's claim for injuries aboard a ship, the district court ruled against the defendant on its affirmative defense. D appealed a verdict for P.