UK green lights three huge floating submarine repair docks

The Defence Investment Plan commits to three floating docks and new infrastructure at Faslane under Programme EUSTON, one more than previously planned, easing the out-of-water maintenance shortage behind the submarine fleet’s availability crisis.

The United Kingdom will acquire three new floating dry docks and supporting infrastructure at the Faslane submarine base, giving the green light to a long-stalled plan to ease the shortage of facilities for taking nuclear submarines out of the water for maintenance, the Defence Investment Plan said.

The plan committed to “acquiring three floating docks and infrastructure at Faslane,” which it said would enable resilient out-of-water engineering for all submarine classes, the work carried out under the Royal Navy programme known as EUSTON. The number marks an increase on the two docks the Navy had previously been planning, and the commitment moves a project that had sat in its concept phase for years, without a firm date, towards delivery.

Faslane, on the Clyde, is the home of the United Kingdom’s nuclear deterrent and, since the attack submarines moved north, of much of the rest of the boat fleet too, yet it has long been desperately short of the docks needed to lift a submarine clear of the water for deep maintenance, relying for years on a single ship lift whose failure at one point left no docking capacity at all for the Astute-class boats. The consequences have been severe, with submarines such as HMS Artful and HMS Ambush spending the best part of two years alongside while they waited for a dock, a bottleneck that has been one of the main drivers of an availability crisis in which the Royal Navy has at times been unable to put a single attack submarine to sea.

A floating dock is a mobile structure that can be flooded down, manoeuvred around a submarine and then pumped out to lift the boat clear of the water for work on its hull, and three of them would give the Navy the resilient out-of-water engineering capacity it has lacked, able to support the Vanguard deterrent submarines, the Astute attack boats, the Dreadnought class now entering the fleet and, in time, the SSN-AUKUS boats to come. Taking a submarine of seven or eight thousand tonnes, complete with a nuclear reactor, out of the water for weeks or months is a far more demanding task than docking an ordinary ship, which is part of why the capability has been so constrained, and the First Sea Lord, General Sir Gwyn Jenkins, has said plainly that “submarine maintenance throughput needs to drastically improve.”

Where the docks will be built is already a live question, since unions including GMB Scotland have pressed the government to place the work in the United Kingdom rather than overseas, pointing to yards such as Navantia UK’s site at Methil in Fife as candidates and warning against a repeat of contracts that have gone abroad.

The docks form part of a broader effort to rebuild Faslane for the decades ahead, sitting alongside the Clyde 2070 infrastructure programme and a new Trident training facility, all of it aimed at sustaining a submarine force that is being asked to do more as Russian activity beneath the waves increases.