A ROYAL Navy submarine which was fully armed with nuclear missiles was forced to abort a highly sensitive operation after a fire broke out beneath the waves.

HMS Victorious, built in Barrow and part of the town's proud shipbuilding heritage, was carrying Trident 2 missiles when the electrical blaze broke out, according to a report published by a national newspaper.

The £3billion Vanguard-class nuclear submarine, one of Britain’s four Trident submarines, had been sailing to a base overseas when the fire started six weeks ago, the paper said.

The captain declared 'emergency stations as the vessel was quickly surfaced, and the fire, which destroyed an electrical converter, was promptly extinguished before the submarine returned to His Majesty's Naval Base Clyde in Faslane, Scotland.

More than 130  crew members were on board, and none were injured, but all those aboard, including those off duty, were called into action to contain the blaze, it was reported.

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The crew put on hazmat suits as smoke poured from a compartment housing an electrical conversion system.

One naval source reportedly said: "The fire destroyed an AC to DC electrical converter. 

"The incident was taken very seriously, but nobody was injured and there was no serious damage to the submarine.

"Every seagoing member of the Royal Navy is a qualified fire-fighter. 

"This ensures that our ships and submarines are able to respond to incidents swiftly and efficiently, assuring operational outputs are not affected."

HMS Victorious, which was built in 1993 by Vickers Shipbuilding and Engineering Ltd, later BAE Systems, and launched from the town in 1993, is overdue a major refit.

The 16,000-tonne sub is one of four that provides non-stop nuclear deterrent patrols - but was understood not to be in that role at the time.

A Royal Navy spokesman said: "The continuous at-sea deterrent is unaffected but we do not comment on the detail of submarine operations."