HMS Queen Elizabeth’s drydocking in Rosyth extended until August

The problems for the Royal Navy (RN) continue with its two new aircraft carriers. The RN flagship, HMS Queen Elizabeth is still in drydock at Babcock’s Rosyth Dockyard and won’t now return to its homeport of Portsmouth until August. 

HMS Queen Elizabeth arrived in Rosyth on March 22nd for drydocking to fix a major problem with the carrier’s starboard propeller shaft, which was revealed as the vessel sailed from Portsmouth to lead a NATO exercise.

The carrier’s two propeller shafts each have three couplings, joining sections together. These joints are needed, as the shaft line is too long to be manufactured or installed as a single piece.

The couplings have plastic covers that keep water out. However, during routine diving inspections of HMS Queen Elizabeth’s underwater hull, it was discovered that the cover on the starboard shaft had moved, allowing seawater ingress, and there was some corrosion.

In early, February, at the last minute before the carrier deployed on the NATO mission, the Ministry of Defence (MOD) decided that the corrosion presented enough risk of shaft line failure that HMS Queen Elizabeth had to be withdrawn from operations.

Following drydocking towards the end of March in Rosyth, it was announced that the carrier would only be in drydock for a few weeks and work would focus solely on rectifying the corrosion issue on the starboard shaft.

However, the decision had been made by the MOD to completely replace both shafts, replicating the same work carried out on sistership, HMS Prince of Wales, in 2023.

HMS Prince of Wales suffered a serious mechanical breakdown in 2022, when a shaft bearing completely failed, and subsequent examination and technical analysis revealed that a revised lubrication system for the shaft bearings and couplings was required.

Both shafts on HMS Prince of Wales were eventually replaced with a new design during a nine-month drydocking in Rosyth, between November 2022 and July 2023.

It had been intended that HMS Queen Elizabeth’s shaft replacement work be carried out during her scheduled refit in 2025, but this work has now been brought forward, extending her current stay in drydock in Rosyth.

Changing the carrier’s shaft now should also further reduce the vessel’s refit in 2025.

Traditionally, RN warship refits can last for several years. However, a new approach to maintenance is now being applied, whereby work on vessels or more heavily undertaken while they are alongside in homeports on an ongoing basis and time in drydock is minimised.

When HMS Queen Elizabeth returns to Rosyth next year, the carrier will need hull certification and work on the flight deck landing aids system, and will not be out of service for years.