NATO nightmare: How British and French nuclear submarines collided

Everything you need to know: In 2009, a rare and worrying incident occurred when two nuclear-armed submarines – Britain's HMS Vanguard and France's Le Triomphant – collided deep under the Atlantic Ocean. Both ships had nuclear reactors and carried nuclear warheads, raising fears of possible nuclear leaks.

-Although no crew members were injured, both submarines sustained damage. Reports suggest the damage was more severe than officially admitted. A whistleblower claimed the British government downplayed the incident to avoid public concern.

– The collision highlighted the dangers associated with submarine operations and sparked a debate about whether Allied nations should share more information to prevent such accidents, given the need for strategic secrecy.

– Many have heard of submarines falling to the sea floor or colliding with underwater mountains, but it is harder to imagine that sometimes the greatest danger to a ship is simply another ship.

In 2009, two nuclear-armed submarines from France and the United Kingdom collided deep under the Atlantic Ocean. Although no radioactivity was released, both ships were damaged when the Royal Navy's HMS vanguard met France's Trident class The Triumphant Submarine. Neither crew nor injuries were reported by either country.

An overview of the incident

When the HMS vanguard When it returned to its base in Scotland a few days later, it had visible damage to the starboard side and near the missile compartment. A whistleblower working in the British nuclear submarine programme later claimed: “The French submarine had a huge chunk cut out of the front of HMS vanguard and grazed the side of the boat. The high pressure air (HPA) cylinder groups were hanging down and hitting the pressure hull. They had to return slowly to the base port because if one of the HPA cylinder groups had exploded, it would have set off a chain reaction and sent the submarine plummeting to the bottom.”

The British government may have been trying to downplay the damage to the submarine in order to allay public concerns about the potential dangers of a nuclear leak.

This unusual accident was particularly alarming because the vessels are powered by nuclear reactors and ships from both countries regularly carry nuclear warheads. Although NATO allies' “water space management” agreements instruct member states to inform each other of the approximate locations of submerged submarines, ships carrying ballistic missiles are exempt from this agreement.

France's The Triumphant The submarine could carry sixteen M45 ballistic missiles, and the vanguard could carry the same number of Trident II missiles. In addition, each submarine could carry 4 or 6 nuclear warheads.

The Triomphant-Vanguard incident was not the first time that two submarines collided. During the Cold War, Western and Soviet ships collided several times, including The New York TimesIn 1992, the American-made Baton Rouge Nuclear submarine was hit by a surfacing Russian submarine in the Barents Sea. Only one year after this accident K-407 collided with the USS GraylingDecades earlier, in the mid-1970s, the USS James Madison collided with a Soviet Victor-class attack submarine about 30 miles off the coast of Glasgow, near Holy Loch.

While some analysts argue that allies should share more data to reduce the risk of future collisions, others argue that keeping nuclear submarines secret is paramount. As Lee Willet of the Royal United Services Institute in London once put it, these ships are the “strategic crown jewels” of every nation, and sharing such sensitive information even with allies would be risky.

About Maya Carlin

Maya CarlinA national security writer for The National Interest, she is an analyst at the Center for Security Policy and a former Anna Sobol Levy Fellow at IDC Herzliya in Israel. She has been featured in numerous publications, including The National Interest, Jerusalem Post and Times of Israel. You can follow her on Twitter: @MayaCarlin

All images are Creative Commons.

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