Officials are investigating why a crane and its operator ended up in the water Monday at a San Francisco ship repair company at Pier 70.
The operator was treated and released at the hospital. His name was not released.
During the approximately four hours the crane was in the water it released lubricating oil, said U.S. Coast Guard Petty Officer Dawn Lamb. The crane held a total of 50 gallons of hydraulic oil, but inspectors are not sure how much of that seeped into the water.
The amount was "nothing detrimental" to the environment, Lamb said. Also, the company arranged for a boom to be placed around the area within 45 minutes of the incident, she said.
The company, BAE Systems San Francisco Ship Repair, the Coast Guard and the California Division of Occupational Safety and Health are investigating the incident to determine what caused the 100-foot crane to slip off the rail, said Dan Ebert, BAE human resources manager.
The crane, which is used to transport parts to and from ships, was moving but was not at a ship when it fell, so the operator and crane landed in water. Typically, a large vessel is lowered underwater, allowing water to fill it and a ship to be positioned over the dry dock vessel. Then the vessel is raised, lifting the ship to land for repair.
"We have not had this happen here," in the 40 years since a dry dock has operated at Pier 70 on San Francisco's eastern edge, Ebert said.