KITTERY — Setting sail aboard a nuclear-powered submarine that can travel deep underwater at speeds topping 30 mph with complicated equipment and an arsenal of weapons has inherent danger. But there’s potential for a bigger risk when the sub is in dock for major work.
Submarines that are being overhauled, like the USS Miami, which suffered $450 million in damage in a fire in May, are often crowded with shipyard workers and equipment. Temporary systems are established and there are cables running throughout the sub. Deck plating is sometimes removed, creating holes in passageways.
“Submarines face different dangers, perhaps bigger ones, when they’re being overhauled or repaired in an industrial setting,” said Peter Bowman, a retired Navy captain and former Portsmouth Naval Shipyard commander.
On the USS Miami, those who battled the fire that started May 23 said it knocked out lighting, and a crew member broke ribs when he fell into a hole.
It took the efforts of more than 100 firefighters to save the USS Miami in dry dock at Portsmouth Naval Shipyard after a civilian shipyard worker allegedly set a fire that quickly spread through its forward compartments.
Two Navy panels are continuing wide-ranging investigations aimed at identifying factors that contributed to the rapid spread of the fire as well as ways to reduce hazards and improve firefighting response in the future.
The Navy hopes to complete the investigations by month’s end.
Bowman and Jerry Holland, a retired Navy rear admiral and submarine commander, said that an industrial setting exposes submarines to hazards that normally wouldn’t be present at sea, when the ship’s entire crew is present and all equipment and systems are in shipshape and in full operating order.
Some of the most serious ship and submarine calamities in U.S. naval history have happened with a vessel at dock, in construction or under repair.
In 1960, another nuclear-powered submarine, USS Sargo, suffered serious damage and the loss of one crew member during an oxygen fire at Pearl Harbor in Hawaii. And 50 shipyard workers died when the aircraft carrier Constellation caught fire during construction at Brooklyn Naval Shipyard later that year in New York.
The submarine Guitarro sank during construction in 1969 at Mare Island Naval Shipyard in California; watertight doors and hatches couldn’t be closed because of cables and hoses.
Minor problems can become big problems when a vessel’s sophisticated damage control systems are offline, said Norman Polmar, a naval analyst and author.
“When the sub is not operational, you can’t count on the normal tried-and-tested damage control, firefighting and other safety systems,” Polmar said.
In the case of the USS Miami, firefighters reported that going into the sub was like stepping into a blast furnace, and a forensic study concluded that the temperature may have hit 1,000 degrees in areas, the Navy told The Associated Press.
The pressure hull was subjected to less heat, with isolated areas hitting 700 degrees. “However, for the most part, the hull was not exposed to temperatures above 350 degrees,” said Dale Eng, a Navy spokesman.
The Navy intends to repair the submarine, which is based in Groton, Conn., with a goal of returning it to service in 2015.
Former shipyard worker Casey James Fury of Portsmouth, N.H., who’s accused of setting the fire, remains held without bail while awaiting trial in federal court in Portland. Fury told Navy investigators that he set the fire because he was feeling anxiety and wanted to go home.
The criminal case could have bearing on the release of the Navy’s findings.
While investigators hope to complete their work by month’s end, they won’t make their findings public if it interferes with the criminal case, said Pat Dolan, spokeswoman for the Navy Sea Systems Command.