A red tugboat moving through the water.
The steam tug HERCULES, built in 1907, navigating on San Francisco Bay.

NPS Photo

HERCULES Statistics
Length 151 feet
26 feet
Draft 18 feet aft, 10 feet forward
Gross Tonnage
Engine 3 cylinder, triple expansion
Cylinders 17", 24", and 41" with 30" stroke. 500 Indicated Horsepower (ihp)
Fuel Type Bunker C oil
Boiler Scotch marine fire tube. 16' diameter, 11' 9" long. Four oil-burning furnaces

  • 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 cassion 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

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Mailing Address:

2 Marina Boulevard, Building E, 2nd Floor
San Francisco, CA 94123


(415) 561-7000
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