Royal Navy nuclear submarine nearly crashes into passenger ferry

The Stena Superfast VII avoided a collision with a submerged Royal Navy submarine in 2018. The Marine Accident Investigation Branch (MAIB) shared details of the events leading to the incident today. The accidental collision was avoided by the ferry, which turned away in time. The chief-inspector of MAIB recommended the Royal Navy to conduct an independent investigation into the incident to take remedial steps.

On November 6, 2018, the Stena Superfast VII was on its route between Belfast, Northern Ireland and Cairnryan, Scotland. While it was on its journey on the North Channel, it came dangerously close to a submerged nuclear submarine. The crash was avoided when the lookout on board the passenger vessel was able to spot the submarine's periscope breaking the surface of the water. The ferry carrying 215 passengers and 67 crew members was able to move out of the other vessel's path in time.

According to the MAIB report, the incident was a result of an error made by the control room team of the Royal Navy vessel. They estimated that the ship was travelling at a much slower speed than it actually was.

The submarine, based in Faslane, was supposed to be patrolling an area south of the ferry route. They also overestimated the range of the submarine, leading to it coming too close to the ferry.

According to the BBC, the control crew estimated the ferry's speed to be 15 knots while the speed of the ship was actually 21 knots. When they visually detected the vessel, they estimated it to be 9,000-10,000 yards away. Based on their knowledge of Stena Superfast VII's speed, they estimated that it would take 12 minutes to cover 6,000 yards. However, the Stena Superfast VII was able to cover the 6,000-yard distance in eight minutes and 34 seconds. The estimation error put the lives of those on board both the vessels at risk.

Andrew Moll, Chief Inspector of MIAB, in his official statement pointed out that this was the third such incident in the past four years. Moll confirmed that the Royal Navy had cooperated with the MIAB. He encouraged the Royal Navy to investigate the incident separately and take remedial steps to ensure such incidents are not repeated.