The Revolution Project – a new concept in steam.

Members who attended ASTT’s stand at the “Greatest Gathering” event in Derby in August or ASTT’s 2025 conference in Darlington in October, will have seen Revolution with its smokebox mounted on its chassis and its newly completed tender  – see image above taken outside the meeting room at the Hopetown  Museum in Darlington.

Revolution is a 10¼” gauge (fifth-scale) demonstrator designed to test and demonstrate several “revolutionary” design ideas.  It’s been designed by Jamie Keyte and veteran loco builder Richard Coleby both of whom deserve much credit for the development of this revolutionary new concept.  Jamie also deserves credit for manufacturing the majority of its components and for assembling the locomotive in his workshop, and for transporting it to and from the venues where it has been displayed.

 Other members involved in the project are Alex Powell, who has worked on the boiler design, and Martin Johnson who has provided invaluable advice on combustion matters.

Some of its novel features include:

  • a simple unstressed frame structure mounted on spring beams that house the axles;
  • bearings and wheelsets are all held at fixed distances from one another by the sprung beams;
  • the sprung beams transmit the traction forces directly from cylinder-block to drawgear, rather than through the frame;
  • fabricated cylinders fitted with steam jackets;
  • valves and valve gear in the form of a novel combination of Walschaerts and Bulleid concepts;
  • a suspension system that will be almost entirely formed from elastomers (following ideas first tried out in the early days of the railways and now used in modern traction).
  • a novel design of pony truck.

Whilst the prototype will take the form of a 2-6-0 Mogul, the design can be easily adapted to take on a variety of wheel arrangements and external guises – for instance, a 2-6-2T, 2-6-4T or even a 2-8-0, styled to replicate any of the “Big Four” railways or BR Standards – or anything else – as illustrated below.

The rolling chassis was successfully trial-run on the Stapleford Light Railway in September 2023 where it demonstrated the performance of the suspension system and pony truck.  Since then, the cylinders and valve gear have been manufactured and partially assembled on the chassis.  The tender has also been substantially completed.

Fund-raising has now reached almost 50% of the £100,000 estimated cost of the project and the locomotive is approximately 50% completed. The major work remaining to be done as at the end of 2025 is the manufacture and assembly of the boiler, superheater, steam pipes and exhaust system.

Please donate either by:

  • Bank transfer to ASTT’s account:  HSBC Letchworth; Sort Code: 40-28-14; Account No: 41760947;  IBAN: GB69MIDL40281441760947; Account Name: Advanced Steam Traction Trust.  (Please include your name in the “Reference” section.)
  • Cheque made out to the Advanced Steam Traction Trust and posted to the Treasurer at:  Flat 4, 2 Kimmerghame View, Edinburgh EH4 2GP.
  • Or by clicking on the PayPal “Donate” button below


Miscellaneous Images and Drawings 

Rolling chassis running trials – Stapleford Miniature Railway – Sept 2023

Chassis Details – Oct 2024

Smokebox details

Left – 3D image of smokebox interior showing layout of superheater, steam pipes and chimney.  Right – 3D image of front-end of locomotive.  Removeable panels are provided on smokebox shell to provide access to superheater and steam pipe connections. Valves are driven by an internal rocking mechanism allowing the use of “outside admission” of steam.  Design and drawings by Richard Coleby.

Component details

Cylinder and motion – design and drawings by Richard Coleby

Pony truck and driving wheels and axles.  Lead and driven axles are fitted with brake discs and chain sprockets, the sprockets will allow measuring rotation rate (for controlling a possible wheel-slip prevention device) and for fitting a chain drive to a dynamometer for “static” testing.
Design and fabrication supervision by Jamie Keyte.

Main frame (left and upside down) and sprung beam components (right).  Sprung beam components are “Arcor” coated.
Design and fabrication by Jamie Keyte.

Planning Meeting – 2019

Revolution “boiler meeting”, Edinburgh – 6th Nov 2019
l-r:  Martin Johnson; Alex Powell; Jamie Keyte; John Hind.