Two nuclear submarines collided off the west coast of Scotland at the height of the Cold War, a recently declassified CIA document has revealed.
A cable marked “secret eyes only” addressed to US secretary of state Henry Kissenger detailed the collision between the American and Russian submarines near Holy Loch, then a US naval base, in November 1974.
The note, one of millions unclassified and released online this month by the CIA, did not detail the extent of the damage but it has been reported that the US submarine, SSBN James Madison, had to be taken back to base for repairs to its hull.
The memo, typed by Brent Scowcroft, reads: “Have just received word from the Pentagon that one of our Poseidon submarines has just collided with a Soviet submarine.
“The SSBN James Madison was departing Holy Loch to take up station when it collided with a Soviet submarine waiting outside the port to take up trial.
“Both submarines surfaced and the Soviet boat subsequently submerged again.
“There is no report yet of the extent of the damage. Will keep you posted.”
It was common during the Cold War for US and Russian submarines to track each other’s activities and a number of collisions have been speculated about.
No further details have been released on the Holy Loch incident, but the James Madison remained in service until 1992 when it was decommissioned.
Holy Loch, in the Firth of Clyde, had been a British naval base during the Second World War and was used by the US from 1961 to 1992, situated close to the current Faslane base for the UK’s Trident submarines.
SNP defence spokesman Brendan O’Hara MP, who represents the area, described the incident as a “lucky escape” and compared it to the recent reports of a failed test of a Trident missile.
He said: ‘’This is deeply worrying. What happened in 1974 looks like a very, very lucky escape - it could have been completely devastating.
‘’The truth is - as we saw with the Trident malfunction revelations - nothing has changed, it could happen again.
‘’We keep asking the UK Government to realise how dangerous, how unsafe, how unreliable these weapons of mass destruction are.
‘’But again in Parliament on Monday they tried to hide behind ‘national security’ to avoid answering legitimate questions and continue to insist on dumping these weapons on the Clyde - so close to Scotland’s biggest city.
“Once again we are dependent on the United States rather than our own Government to find out what is happening.”