HMS Queen Elizabeth’s extended stop at Invergordon explained

HMS Queen Elizabeth has been alongside in the deepwater port of Invergordon for more than 10 days now and there is growing speculation about the reason for her extended stay. The planned stop at Invergordon had always been in the programme to allow refuelling and replenishment after 12 days at sea which included full power trials. Replenishment alone would not require 10 days, so it is clear there are engineering issues involved.

It has been confirmed that while conducting sea trials, sometime in early July, she hit an item of debris in the sea. Whether it was a discarded fishing net or something else, the exact nature of the debris is unknown as it had cleared itself before the ship arrived in Cromarty. What is certain is that she did not hit a rock or a Russian submarine as claimed by some credulous online sources. On arrival, the shaft and propellers were quickly inspected by divers.

Repairs alongside and returning to sea soon

Mercifully the propeller shafts have not sustained major damage which would require dry docking and a complete change to the trials schedule, not to mention at the accompanying negative headlines. However, in the course of the inspection, a defect was discovered that had the potential to have caused significant future problems if it had not been caught at an early stage. Divers have been working on the problem which is expected to be rectified soon. Unconfirmed reports suggest this involves one of the supports for the two shafts being slightly out of alignment. This reduces the efficiency of the propeller, causing vibration and noise. Engineering work that might have required dry-docking in the past can sometimes now be done underwater, thanks to pioneering developments by the offshore oil industry. QE had her propellers fitted underwater in the basin at Rosyth as she was originally fitted with brake blades that allowed the shafts to be turned to test the propulsion without moving the ship.

The supports for the QE propellor shafts seen here being mated with the hull while under construction in dry dock, February 2013. Photo via: ACA

There is confidence the ship will sail to resume trials in the next few days. These kind of issues are normal during the trials phase of any new vessel and are no cause for alarm. It should be remembered that QE is effectively a prototype design under testing and some way from being a fully capable warship. The trials programme was always flexible and likely to be subject to change. The ACA, who are still the owners of the ship, are understandably unwilling to discuss the details of every engineering problem that is encountered before the ship is handed to the RN and have not made a specific comment on this issue.

In the internet age, a flagship project like the QE is subject to extraordinary scrutiny and speculation that earlier generations of innovators and engineers never had to endure. Apart from the pub landlords in Invergordon, these delays are frustrating for everyone but should not be a huge surprise, and there maybe more. Keep calm and carry on. There is every confidence QE will prove to be a sound ship and remains well on course to meet the original target of handing her to the RN by the end of this year.

The dry dock conundrum

These events do raise an interesting question. In future where will the QE carriers be dry-docked and, if HMS Queen Elizabeth had required urgent docking, what are the options? Unfortunately Portsmouth Naval Base does not have a dry dock large enough for the QE carriers. HMS Prince of Wales, currently under construction, occupies the dry dock in Rosyth. As QE’s departure demonstrated, moving in or out of the dock in Rosyth is a very complex process, requiring 11 tugs and can only be done within certain tidal and weather windows. The King George V graving dock in Southampton, which would be convenient for a Portsmouth-based ship, has been closed since 2005. The Harland and Wolff dry dock in Belfast is currently involved in wind farm construction and would require some time to be prepared. No 5 Dock on Merseyside, or Inchgreen Dry Dock, Port Glasgow (both owned by Cammell Laird) are just large enough for the ship. In these cases, it is unclear if there would be appropriate personnel and facilities available to support work on QE. The nearest foreign option would be in Rotterdam but relying on overseas facilities is likely to be highly controversial. The expansion of D-Lock at Portsmouth would probably be the ideal solution but the funds for this are likely to be hard to find. Expect to see the QE carriers reliant on Roysth when needing to go into dry dock in the long term.

HMS Queen Elizabeth, Invergordon, July 2017. Main photo: Alan Pratt, via Flickr

 

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