Royal Navy nuclear submarine dived towards 'danger zone' after malfunction - reports

A Royal Navy nuclear submarine descended towards dangerous depths because of a failed gauge, it has been reported.

A Vanguard-class submarine encountered a malfunction in its depth gauge, leading the crew to incorrectly perceive they were at a normal depth when, in reality, they were navigating at a deeper level, according to The Sun.

The Sun reported that the submarine was about to enter the "danger zone" when engineers spotted a second gauge at the back of the vessel that indicated the correct depth and disaster was averted.  

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It's said the submarine was in the Atlantic and was preparing to go on a patrol when the gauge stopped working, leading personnel to believe the boat was level when it was in fact still diving.

Vanguard-class submarines carry Trident ballistic missiles - the UK's nuclear deterrent - and are nearly 150 metres long with a displacement of 15,900 tonnes.

Reports say 140 crew members were on board when the gauge was said to have malfunctioned.

A source told The Sun: "It's not the engineers' job to control the sub's depth but they saw how deep they were and realised something was wrong.

"Technically the sub was still at a depth where we know it can operate, but if it ever has to go that deep the whole crew is piped to action-stations.

"That hadn’t happened. The sub wasn't supposed to be there, and it was still diving. And if it had carried on going, it doesn't really bear thinking about."

The Ministry of Defence typically doesn't comment on submarine operations.

A Royal Navy spokesperson said: "Our submarines continue to meet their commitments, deploying globally on operations, protecting national interests, and keeping us and our allies safe.

"While we do not comment on specific details regarding submarine operations, safety of our personnel is always the highest priority."

The Royal Navy's Vanguard-class consists of four nuclear-powered ballistic missile submarines – HMS Vanguard, Vengeance, Victorious and Vigilant. 

The subs are set to be replaced in the next decade by the new Dreadnought-class which are currently being built.

At least one British submarine carrying nuclear weapons has been on patrol continuously since 1969.