Dry docking the Royal Navy’s aircraft carriers – what are the options?
The two Queen Elizabeth Class (QEC) aircraft carriers will require dry-docking periodically throughout their lives. The dry docks at Portsmouth and Devonport naval bases are not large enough to accommodate them so the RN must choose between a very limited selection of other UK facilities. Here we examine some of the options.
In the summer of 2019 HMS Queen Elizabeth will return to Rosyth for her first dry-docking so contractors can carry out a routine hull survey and maintenance of her underwater systems. This £5M project will sustain 100 jobs with Babcock at its peak but should only take a matter of weeks. The MoD has been considering tenders for this work for over a year but it is not surprising that Rosyth was selected at this point. HMS Prince of Wales is still being fitted out and much of the workforce that built QE is still employed there. The support facilities are in place and the site has a high standard of security.
In the longer term, the RN needs to select which dock in the UK will be used for both short planned maintenance and the major refits which will be needed every 6-7 years. The decision to build large 280m long aircraft carriers has many operational and technical benefits but one of the drawbacks of their size is the lack of choices for dry docking the ships. The list below summarises the UK sites that are large enough to take the QEC but the minimum dimensions of the docks are just the starting point, as there are other factors to consider.Carrier-Dry-Docks-1
Having built the ships and won the first docking contract, Rosyth looks in pole position to be the choice for all future dry docking of the aircraft carriers. The site benefits from its heritage as a naval dockyard, modern facilities, good security, and an experienced workforce. However the access for large ships is poor and its long term future is uncertain. Entry and exit for the QEC into the basin at Rosyth is a very demanding operation. When HMS Queen Elizabeth left her birthplace in June 2017 there was a narrow window of just 6 days during that month when the tidal conditions were suitable. Eleven tugs were needed to make a carefully orchestrated move that could only be done in good visibility and light winds. Although the basin entrance was substantially rebuilt in 2010, there is less than a metre of clearance on either side and just 50cm between the keel and the seabed. All these factors restrict access the facilities in Rosyth to limited periods of opportunity, far from ideal, especially if dry docking is urgent. Every entry and exit at Rosyth will involve a much greater risk of delay or even damage to the ship than almost all the other alternative docks in the UK. Investment in dredging and modifying the basin entrance could be a sensible option if the MoD decides to make the site its permanent choice for carrier drydocking.
Although submarine recycling will continue slowly on the site and Sandown class minehunter refits will be conducted in the shiphall for a few more years, there is no certainty about other naval work at Rosyth. Despite the closure of the Appledore yard, Babcock would like to increase its shipbuilding business and is leading a consortium bidding for the Type 31 frigate. It is also part of an alliance bidding to build the Fleet Solid Support ships in the UK. Winning either competition could help sustain Rosyth’s future as a naval construction and repair yard. This would keep a larger workforce on site ready to conduct aircraft carrier refits. Many people would like to see the FSS assembled at Rosyth, potentially in number 1 Dock using the Goliath crane, although the build schedule would need to be carefully balanced with the timing of QEC refits. This is just conjecture and whether there is any kind of joined-up plan by the MoD and Babcock to sustain Rosyth is yet to be seen.
There were occasions in the past when the Invincible class carriers (CVS) were put into dry dock in Portsmouth at short notice. Without a suitable dock in Portsmouth and reliant on commercial dry docks, the QEC carriers may not have the luxury of being able to ‘dock on demand’. This could become a serious issue restricting the aspiration for continuous carrier capability. Either the MoD and industry must come up with a sustainable plan to keep one of the facilities ready for carrier work, or accept the risk that a suitable dock will not always be available at short notice. In June 2017 HMS Queen Elizabeth experienced a propulsion problem during her initial sea trials. A misaligned propellor blade caused vibration that revealed the thrust blocks were of inadequate strength and were on the verge of failure. Fortunately, the propellor blade issue was rectified by divers while alongside in Invergordon and the thrust block was reinforced. Let us imagine for a moment this problem had been more serious, there were no dry docks immediately ready to take the ship as HMS PoW was then under construction in the dry dock at Rosyth. The whole carrier programme could have been delayed for months until a suitable dock was available.
The Portsmouth proposal
As can be decerned from the table above the optimum solution would be to dry dock the carriers in their home in Portsmouth. The site is the homeport of the ship’s company, has plenty of space, is secure and has an experienced workforce suited to naval work. It is believed the MoD has conducted some feasibility studies to look at expanding D-lock. It is currently about 280m but would need to be extended to at least 310m, widened and have bigger caissons added at both ends. There is also an alternative option of converting the tidal Number 2 Basin into a dry dock. Constructions costs would clearly be very significant, on top of the £100million already invested in the Princess Royal Jetty and other naval base infrastructure to support the carriers. (The NAO reported in June 2020 that the estimated cost would be £500M!)
The QEC carriers are expected to have a service life of around 50 years. Assuming each of the two ships required dry-docking on average once every 3 years, that is a total of more than 30 times. If each docking requires hefty payments to one or more commercial providers it would probably be considerably cheaper over the lifetime of the carriers to pay the upfront cost of expanding D-Lock in Portsmouth. Unfortunately, this seems unlikely in the current financial climate. The MoD frequently has to prioritise its short term budget even if delaying expenditure will add significantly to the long term overall cost. Another reason government may not be too keen to make the investment at Portsmouth would be the potential political benefits of spreading the work around the UK. BAE Systems already have the contract to maintain the carriers when they are alongside in Portsmouth but using drydocks elsewhere would also help diversify contractor choice.
Other UK facilities
Built using public money in the early 1960s, Inchgreen Dry Dock in Greenock is now owned by Peel Ports and managed by its subsidiary company, Cammell Laird. The dock has been used to repair ocean liners including the QE2 and has been subject to closures and takeovers over the years. In more recent times it has been used to repair large commercial vessels and refit RFA ships. The last major project at the site was in 2009, the construction of the floating concrete Valiant jetty to support Astute class submarines across the Clyde at Faslane. Cranes and dockside facilities at the site have been removed and but the dry dock is intact and its owners, and many in Scotland, hope its potential can be harnessed again as a ship repair site.
Cammell Laird acknowledges the site needs investment before it could be viable for work on a complex naval vessel but were confident enough to place a (failed) bid for the first drydocking of QE. With easy access from the deep water in the Firth of Clyde, it could be revived and new facilities put in place to support both commercial and aircraft carrier work. Cammell Laird still hopes this can be done. In theory, their number 5 dock on Merseyside could take the QEC but the company favour their more spacious alternative in Scotland. Inchgreen seems to be stuck between the need for investment that can only come from a guarantee of work, while that work is unlikely to be won without expenditure on improving facilities first.
Able UK owns the largest dry dock in the UK at Seaton Port on Teesside. In 2003 the dismantling of former US Navy vessels and the ex-French navy aircraft carrier Foch attracted controversy over environmental objections to the toxic materials contained in the ships. This put a stop to ship-breaking work, although disused oil rigs are still dismantled on the site. Able UK is now primarily employed in support of the offshore industry and can take the largest rigs, platforms and heavy lift vessels as well as constructing wind farm components. A multi-million-pound upgrade of the dry dock to include a new wider concrete caisson dry dock gate and the creation of a new inner dock area is underway. It is unclear if Able UK are interested or readily equipped to undertake aircraft carrier drydocking at the site in an area with no history of naval work.
The Belfast dry dock owned by Harland and Wolff Heavy Engineering Ltd could accommodate the QEC. This famous shipbuilder is now predominantly employed on offshore and renewable energy engineering and has not built a complete ship since MV Anvil Point in 2003. The company would like to return to the naval shipbuilding business and is participating in two of the three consortiums bidding for the Type 31e frigate.
Devonport is a non-starter due to the very tight access to the port itself. It’s is doubtful if the QEC will even come alongside in the dockyard which lacks the dedicated infrastructure at Portsmouth. Although the 50,000 tonne HMS Ark Royal (IV) was dry-docked in Devonport until the late 1970s, access and space in 5 basin is inadequate and the largest (10) dock is still too small. The famous King George V dock in Southampton was built at great expense in the 1930s to service the ocean liners of the period. Regrettably, the 366m-long dock closed in 2005 and is now a wet dock-only, with the caisson gates and keel blocks removed.
In extremis, there are several dry docks in Europe that could take the QEC carriers. Saint Nazaire, Rotterdam or Antwerp are nearest but they are employed in constructing cruise liners or refitting large commercial vessels so not always available. The public perception and political dimensions of utilising European docks would probably be unfavourable and a last resort only.
In August 2017 the Defence Secretary announced that the UK had signed a formal agreement with Oman for the use of facilities at Duqm Port which is capable of drydocking the aircraft carriers. The UK Joint Logistics Support Base is a joint venture between Babcock International and the Oman Dry dock Company aimed at expanding its commercial services to support naval vessels in the region. Full refits of the carriers are unlikely to be conducted in Oman but this facility is of significant strategic value and provides another option for maintaining the carriers when deployed at distance from the UK.
In the next 50 years, the carriers will have to undergo complex major refits and upgrades which will need to be done in appropriate facilities. The final dimensions of the QEC carriers were agreed in December 2005 allowing nearly a decade and a half to plan the docking arrangements for the ships. Despite this considerable time, no ideal site has been prepared and choices are limited. Rosyth is the least unattractive solution in the short term but more work must be done to give the aircraft carriers a maintenance facility in keeping with their national importance.