Workers in the city of Providence were using a blowtorch to cut it up for scrap when the blaze started, fire officials said.
The fire at a waterfront scrap yard sent a plume of black smoke over the city at about 9.30am local time but was quickly extinguished.
The hull is sheathed in a eight to 10-centimetre layer of rubber and that’s what caught fire as workers cut into it with a torch, Providence Deputy Assistant Fire Chief Steve Capracotta said.
After the Cold War, the submarine known as Juliett 484 was sold and used as a restaurant and vodka bar in Helsinki, Finland, and as a set for the 2002 Ford movie ‘K-19: The Widowmaker’.
The sub wound up in Providence because the Rhode Island-based USS Saratoga Museum Foundation bought it and opened it to the public as a floating museum in 2002.
It sank during a nor’easter in 2007 and was sold for scrap.
State environmental officials have been informed of the fire, Capracotta said.