Hercules is a steam powered tug built for ocean towing. The 151-foot ship, of riveted steel construction, still contains her original triple expansion steam engine. Built on the East Coast in 1907, she towed her sister ship from Camden, New Jersey around South America to San Francisco. Hercules also towed sailing ships, disabled vessels, barges, log rafts, a cassion (a steel structure used for closing the entrance to locks) for a dry dock at Pearl Harbor, and a caisson to help build a Panama Canal lock. The tug usually carried a crew of three firemen, three oilmen, a chief and two assistant engineers, three deckhands, cook, two mates and a captain.
