Ocean-going log towing was one of the most dangerous and demanding operations in Pacific Coast maritime history. Rafts of logs, chained together and towed behind tugs like the Hercules, could be hundreds of feet long. In rough seas, the raft could surge against the towline, pulling the tug backward. In fog, the tug and raft became navigational hazards for other vessels. Hercules was built with the engine power and hull strength to handle these conditions, her triple-expansion steam engine driving her through seas that would have overwhelmed smaller vessels. She also performed general towing duties in San Francisco Bay and along the coast.

Hercules worked through the era of Pacific Coast industrialization, when timber, oil, and minerals moved by water because roads and railways could not reach the remote coastline. She towed barges and log rafts, assisted ships in distress, and performed the unglamorous but essential work that kept maritime commerce moving. Her career extended from the age of steam through the transition to diesel, and she was still operational when the era of ocean-going log towing came to an end as trucking and rail transport replaced water-borne timber movement.

Hercules was preserved at the San Francisco Maritime National Historical Park, joining the collection of historic vessels at Hyde Street Pier. She represents a class of working vessel that was essential to Pacific Coast commerce but has largely vanished from the waterfront. Her steam engine, her reinforced hull, her heavy towing gear -- all speak to a kind of maritime labor that was physically demanding, technically skilled, and economically vital. At Hyde Street Pier, she sits alongside vessels that carried passengers and cargo, but Hercules carried neither: her cargo was the cable behind her, and her passengers were the crew who kept the engine running and the towline taut through whatever the Pacific threw at them.