Question to the Ministry of Defence:

To ask the Secretary of State for Defence, with reference to the engine modification programme for the six Type-45 destroyers, if he will publish for each destroyer the (a) nature of the original engine design fault; (b) proposed remedy; (c) estimated sea-time lost annually; (d) scheduled completion date for each upgraded vessel; (e) estimate of the additional cost of the upgrade and (f) recovery of the additional cost of making the ships seaworthy to be borne by (i) the engine designer, (ii) defence manufacturers and (iii) the public purse; and if he will make a statement.

In 2011, an independent study commissioned by the Ministry of Defence (MOD) reported there was "no single root cause underlying the low reliability" experienced in the Type 45 Destroyers but a "large group of unconnected individual causes". It nevertheless concluded that Integrated Full Electric Propulsion remained a sound choice for the Type 45 Class. The nature of the interrelated defects associated with the fully integrated propulsion system masked the true extent of the inherent design shortcomings.

Subsequent experience gained by deploying the ships to the most demanding operational environments revealed that the original design intent of operating the ship whilst running the WR21 gas turbine alone was flawed. The system in this mode was still not capable of delivering the desired level of reliability and the power generated by the ships' diesels meant that they could not provide the resilience required. Only the installation of additional diesel generators would allow these shortfalls to be addressed.

For further details of the technical issues with the Type 45 Power and Propulsion System I would refer the rt. hon. Member to the Independent Power and Propulsion System Performance Review, dated March 2011, a copy of which, redacted in accordance with the provisions of the Freedom of Information Act 2000, was placed in the Library of the House on 13 May 2016.

In 2014, Project Napier was established with two core strands. First, the Equipment Improvement Plan (EIP) which has built on the work to enhance system reliability and to meet the original design intent in the near term. This work has delivered positive results with increases to availability across the fleet. In the longer term, the Power Improvement Plan (PIP) will improve system resilience by adding upgraded diesel generators to provide the electrical generation capacity required to meet many propulsion and power requirements without reliance on WR21 gas turbine.

All Type 45 Destroyers will receive new diesel generators under the £160 million PIP conversion programme. Work is currently underway on HMS DAUNTLESS, the first ship to enter the programme, and she will return to sea for trials in 2021. Following completion of these sea trials, she will re-join the fleet. It is planned that all six Type 45 ships will have received the upgrade by the mid-2020s.

The programme is dependent on the availability of ships to undertake the upgrade, balanced against the Royal Navy's current and future operational commitments. PIP conversions will be planned to take into account the regular Upkeep cycle to maximise the overall class availability. The first of class embodiment is expected to take 13 months from docking to enable a comprehensive suite of sea trials to prove the capability.

The issue of liability stems from decisions taken early in the programme. This includes the main investment decision by the MOD in July 2000 to proceed with a Type 45 design based on an Integrated Full Electric Propulsion solution and subsequent selection of the WR21 gas turbine. As the issues now being addressed result from those earlier decisions, it is appropriate that liability for funding this work now rests with the MOD. A number of early modifications were implemented under the Type 45 Destroyer Contract for Availability arrangement with BAE Systems at no additional cost to the MOD.

The Type 45 Destroyers are hugely capable ships and have been deployed successfully on a range of operations world-wide and they continue to make an enormous contribution to the defence of the UK and our international partners.