Further supplementary memorandum submitted by the Ministry of Defence
At the oral evidence session on 20th July in support of your inquiry into Naval Procurement: Type 26 and Type 45, you asked for a considered response to a paper presented in written evidence to the Defence Select Committee by former Lieutenant Commanders (Lt Cdr) Alan Cartwright and Robert Barnes who raised a number of concerns about the selection of the WR21 gas turbine engine for the Type 45 Destroyers. The evidence presented by Lt Cdrs Cartwright and Barnes draws on historic precedent and includes a number of examples of the contribution made by the National Gas Turbine Establishment at Pyestock, in successfully introducing earlier gas turbines into service. Their evidence questions the basis upon which the WR21 engine was selected for the Type 45 Destroyer.
The National Gas Turbine Establishment, and subsequent organisations based at Pyestock, were involved in the testing of gas turbines for the Royal Navy from 1952 until its closure in 2000, after which the site was operated by QinetiQ. Its role was to assess the performance that could be expected of an already developed gas turbine engine and make a judgement about whether it could reach the required levels of availability, reliability and maintainability prior to introduction into service. This endurance style of testing was adapted so that it represented, as closely as possible, how the engine would operate in service.
The Pyestock facility was involved in the early developmental stages of the WR21 engine. It had a key role in the programme and all of the development testing was carried out at the site. It is worth noting that to fulfil this role, a significant upgrade was made to the facilities at Pyestock, which was able to generate data from the test engine that was significantly greater in scope and volume than would have been necessary in a typical endurance testing regime. The data examined in development of the WR21 engine has been estimated at being some ten times greater than that used previously in endurance testing.
To both oversee trials and gain operating experience of the plant, four Royal Navy engineer officers were based at Pyestock for the WR21 testing. These officers became the primary operators of the engine and then used this experience to develop the in-service Standing Operating Procedures for the engine and wider propulsion plant.
This involvement in the development of the new engine was significant as it allowed the Ministry of Defence (MOD) to be engaged from the earliest stages of system development and therefore able to shape the test programme in a way that had not previously been possible. This level of involvement ensured that decisions about the WR21 were informed by the vast experience built up at the Pyestock facility over many years.
The close working relationships between the MOD and our contractors should also be taken into account. The MOD had higher levels of access to the early risk reduction work carried out by Northrop Grumman Marine Systems than had been the case historically with gas turbine engines developed for Royal Navy warships. This should reassure the Committee on the concerns expressed about the reliability of output from the early risk reduction work carried out by industry. In addition, training for the first T45 crews was delivered through a bespoke package provided by the Original Equipment Manufacturers, ensuring sufficient depth of knowledge was transferred to operators.
It is also worth re-stating that this system represented a significant advance in propulsion design, acting in a more integrated fashion and promising greater fuel efficiency and operational flexibility, as well as through life savings in maintenance and personnel costs, and a lower environmental impact. It is therefore difficult to draw direct comparisons between the simple gas turbines used to power surface warships historically, with the more complex intercooled and recuperated system employed on the Type 45 Destroyer. The MOD does not, therefore, accept the validity of the example referred to by Lt Cdrs Cartwright and Barnes of the results of tests on the RM60 gas turbine in 1955 as a direct comparator.
The decision in 2000 to opt for an Integrated Full Electric Propulsion system was underpinned by a development and endurance testing programme totalling 8,000 hours. The decision to proceed with the programme was test-supported by the MOD and industry based on a judgement by all parties that the inherent risk had been mitigated.
Clearly, there are lessons that we will learn from this and the MOD has already acknowledged that, initially, the Type 45 power and propulsion system did not meet the expected levels of performance and reliability. However, through the progressive incorporation of design changes, adoption of the measures outlined in the March 2011 independent report ‘Type 45 Destroyer - Independent Power and Propulsion System Performance Review’ and the further improvements in reliability achieved through the Equipment Improvement Project, which we initiated in 2014, reliability and availability have improved and platform reliability is now at 94 per cent. As a result, the Type 45 Destroyers continue to provide a valuable contribution to UK Defence and are able to provide their world-beating air defence capability in ongoing operations involving US and French carrier strike groups.
18 August 2016