Having spent a week out at sea on HMS Dauntless eleven years ago I am delighted to learn that this fine Type 45 Destroyer is now back out at sea following six years of having been tied up at Portsmouth Naval Base, and is now engaged on a number of tests, work on increasing available power having now been completed.
The major amount of work required in order to rectify powerplant design problems that impacted on all six Royal Navy Type 45 Destroyers and that has left all but a couple tied up at Portsmouth since 2016, is as regrettable as it could also have been avoided had the MOD chosen to pull out of the WR21 propulsion systems development programme when France and the US did.
HMS Dauntless has also had a full refit and I live in hope that this may have also included replacing one of the large windows on the Bridge which, if I remember correctly, had cracked through vibration when the ship fired its very first PAMS missile ten or eleven years ago!
I could probably write a book on the very unfortunate power plant design issues that have left the Royal Navy with a serious shortage of Destroyer capability for the best part of the last eight years. And let me make it very plane before anyone gets the wrong impressions as to who is to blame for fitting a power plant that was unable to produce sufficient levels of power leading to Type 45’s frequently breaking down when demand for power was high and worse, when the ship was brought to a halt a variety of design safety features on the ship then kicked in and effectively closed down everything else.
That last sentence may sound a bit too simplistic but it wasn’t far from the truth. So, who was to blame? In this case certainly not BAE Systems and who built all six Type 45 ships BUT importantly, where not involved in any part of the propulsion system design or decision process – there work merely being to place the system that the MOD had authorised into its proper space. I should add here that the original involvement of Rolls-Royce in the Type 45 propulsion system design and build was merely to supply the hugely successful RB-211 power source which would be at the core of the electronic propulsion system design.
So, what was the problem with the Type 45 WR21 propulsion system, one that has not only caused the majority of the ship class to have been laid up for long periods of time at Portsmouth but also one that would require a major design change in order to be able add the availability of an additional power source?
Being a subject matter that for reasons I won’t go into here and now I happened to know well and, complicated though it was, understood, back in 2016 when I was still acting as an advisor to the House of Commons Defence Select Committee, I was asked whether I would write a short paper for the Committee spelling out the issues involved and what had gone wrong. What follows are a few paragraphs from the paper that I wrote for the Committee at paper so that I hope you can understand the issues and complexities involved:
The WR-21 power plant was originally designed back in the early 1990’s as an international partnership between Rolls Royce and Northrop Grumman Marine Systems. The turbines are of sound design and have an intercooler-recuperator that is designed to recover heat from the exhaust and recycle this back into the system, making it more fuel-efficient and thus reducing the ship’s thermal signature.
Unfortunately, the intercooler and recuperator system unit (this is produced by Northrop Grumman) has a major design flaw in that when demand for capacity is very high causes the Gas Turbines to occasionally fail and, due to the vast increase in safety requirements associated with power propulsion systems, switch down. When this occurs, the electrical load on the diesel generators can then become far too great and they too ‘trip out’, leaving the ship with absolutely no source of power or propulsion until a process demanded allows the turbines to be restarted.
The MoD has not revealed how frequently the number of Type 45 blackouts have occurred but the first 2 ships, HMS Daring and HMS Dauntless would appear to have suffered the most. The first indication of problems was as far back as 2010 when it was admitted by the MOD that HMS Daring had lost all power in mid-Atlantic and had to be repaired in Canada.
Although the Type 45 Destroyers have continued to be active it is clear that significant mission commitments will have been missed. An indication that all is not well could be seen by the number of Type 45s alongside in Portsmouth at any given time during the last few years. When I was last at Portsmouth Naval Dockyard during December five of the six ships were visible although to be fair, on ship was just leaving the base.
Designed in the early 1990’s the WR-21 is an advanced cycle gas turbine designed to meet the requirements of both conventional propulsion and Integrated Electric Propulsion (IEP) systems. The WR-21 will not only meet the high-power prime mover requirements of future warships but also offer an efficient cruise/boost engine in one package. For Navies who use the traditional two engine ‘cruise’ and ‘boost’ fit, the engine gives ship designers the freedom to procure, install and maintain one engine to power the vessel over its entire operating profile in place of the two engines. Compared directly to the use of simple cycle high power engines, the WR-21 provides significant fuel savings which, besides reducing costs, offers operational advantages in ship range, speed, and time on station.
Warship operators would also have a new freedom to configure the warship propulsion plant to return unprecedented Platform Life Cycle Cost reductions in peacetime while retaining operational capability in time of conflict.
The Royal Navy is the first (and last) user of the WR-21 Intercooled and Recuperated (ICR) gas turbine engine for its Type 45 Air Defence destroyer, a 7,500-ton warship fitted with an IEP plant comprising two WR-21 Gas Turbine Alternators (GTAs) that are rated at 21 MWe, 4.16KV. The GTAs in combination with a pair of 2 Wartsila (Finland) diesel generators were designed to provide electrical power to two 20 MWe electric propulsion motors and the ship’s non propulsion based consumer electrical distribution system requirement (mission systems, accommodation, galley etc and that no matter what the capacity requirement demanded by the ships company that any combination of electrical power demanded could be met. To remind, the underlying Type 45 propulsion system issue is that with the current level of systems on board that require to be powered there is simply not enough electrical power capacity available to meet demand.
The prime contractor (originally Westinghouse Electric in the US – this was later acquired by Northrop Grumman) in the design and development programme of the WR-21 was Northrop Grumman Marine Systems (NGMS) in the US together with, drawing on the significant experience taken from the successful RB-211 and Trent gas turbine design, Rolls-Royce. The latter was appointed as the major subcontractor responsible for the primary gas turbine design. In addition, Honeywell in the US had been subcontracted for the design and supply of the intercooler, Ingersoll Rand Energy Systems (IRES) for the recuperator and CAE for the EEC.
The ICR propulsion system package was designed to occupy the same footprint as existing power plant installations and to deliver high levels of reliability, maintainability and component life. As an advanced cycle (intercooled and recuperated gas turbine system) the design targeted increased thermal efficiency, reduced signature, fuel savings, increased reliability, ease of maintenance, all of which would lead, it was hoped, to reduced cost of ownership. The power plant was developed with funding from the US, British and French governments and first contracts were place by the US Navy in December 1991.
The French Government was the first to pull out of the WR21 programme. They were followed by the US Government and, following submission of a revised design, by Northrop Grumman. That left the MOD and rather than do the sensible thing and go back to GE for the alternative, mature and already in-service power plant, the MOD chose to continue to back its original judgement and asked Rolls-Royce to take the whole project on – something that Rolls-Royce did, probably with a degree of reluctance,
I do not have the specific details to hand but what I can tell you is that the RR redesign was a great improvement on the original design but, just as the MOD must carry the mantle of approving such a high risk programme in the first place, so it was that it would be the MOD that did the final damage to the programme by refusing Rolls-Royce the time it had requested for testing by half.
Moving on, it was good to see BAE Systems announcing last week that that the first steel has now been cut for the third of the Dreadnought class nuclear deterrent submarine programme (HMS Warspite) and also, that Planning permission has now been granted for what is now termed as the huge £200m ‘Frigate Factory to be built for BAE Systems alongside its existing facilities at Govan on the Clyde.
CHW (London 13th February 2023)
Howard Wheeldon FRAeS
Wheeldon Strategic Advisory Ltd,
M: +44 7710 779785