Skip to main content

The Valve Gear Club



The original monobloc casting for No. 2001 (left) and a 3D CAD of the revised arrangement for No. 2007 (right)

The Valve Gear Club seeks to fund the final major component for Gresley P2 Class No. 2007 Prince of Wales

The design of the valve gear is well advanced. Based on Lentz-Franklin, and adapted for our requirements, the rotary poppet valve gear will allow for greater steam efficiency and power output from the cylinders.

We are building a brand new P2 class steam locomotive, based on the original 1930s design, and developed for use on the modern rail network.

The Gresley class P2 ‘Mikados’ were the most powerful express passenger locomotives to operate in the UK. They were designed by Sir Nigel Gresley to haul 600-ton trains over the arduous Edinburgh to Aberdeen route.

The ultimate performance and economy of a steam locomotive is dependent on optimising the complete thermal system from the fire hole door to the top of the chimney. Assuming the boiler and smoke box are fundamentally sound, the most important areas for good design are the cylinders and valves.

The design and manufacture of the unique cylinder monobloc, delivered to Darlington Locomotive Works in autumn 2023, was the first step towards building the powerhouse of the P2. With that work complete, we turn our attention to the other side of that same coin: the valve gear.

Lentz poppet valve gear is a more efficient design than Walschaerts valve gear, which is commonly found on UK locomotives including Tornado. Lentz developed the concept by which an improved system of large passages, large areas through valves and suitably controlled valve events, would fully utilise the latent capacity of the boiler. Lentz poppet valve gear was fitted on the first P2, No. 2001 Cock o’ the North, and we will be taking this principle and applying it to the valve gear design for No.2007.

For manufacture and testing of the new design, we need to raise £300,000 - the first £50,000 of which will immediately go towards the building of a prototype and test rig. The Valve Gear Club seeks to raise these funds through donations of £1000, in a lump sum or smaller instalments.



The target for 'The Valve Gear Club' is £300,000, with supporters making donations of £1000 as a lump sum or in monthly installments of £100. 

We hope to raise the initial £50,000 in the first half of 2024 to allow for the manufacture of a prototype cam box and test rig, with the intention of the prototype then being fitted to the locomotive. Please sign up below using the online form, or download forms to print and return to the Darlington Office.

Special Benefits for Valve Gear Club members:

  • Exclusive Art Deco P2 Poster by Ed Laxton
  • Priority to buy a ticket (seat already reserved) on one of the first trains hauled by No. 2007 Prince of Wales
  • Reasonable access to No. 2007 at all times
  • First choice of other components to sponsor
  • Opportunity to attend ‘The Valve Gear Club Day’ when the prototype is tested. 

Section 2: download the form

If you would like to support No. 2007 by becoming a member of The Valve Gear Club by post then the form below will enable you to do so.

Please DOWNLOAD, print out, complete and return it to us at the address shown.

May we also draw your attention to the Trust’s privacy policy which details the manner in which we treat any personal data that you send us. Please also print this out and read carefully.

Section 3: recruit a friend

You can see full details of The Valve Gear Club here – please share this with your friends!

This club raises funds for the manufacture of the cylinder block for the new Gresley class P2 No. 2007 Prince of Wales. If there are surplus funds left over following the manufacture of the valve gear, we will use the money to purchase or manufacture other components for the Gresley class P2 that the charity would not otherwise have.