The aims of the locomotive are;

-It must be cheap to run and maintain.

-Speed, Acceleration and Braking must be (On most medium length trains) be equal to similar diesel units.

-It must appeal to enthusiasts.

-It will run on coal, however the fuel economy must be considerably improved, in order to make firing the locomotive a relative pleasure.

-It must NOT run at the expence of other more valuable locomotives.

The Principles are;

-It will be a 4-6-2 wheel arrangement. This has relatively good adheasive properties and will be more able to ride smoothly on todays poorly maintained railway network. More importantly, the axle loading of the engine will be less, and therefore its route availability will be increased.

-The locomotive will not use compound working,as this will have little benifit compared to some of the other features and will be expensive to adjust if its original design is unsatisfactory.

-All wheels will be braked. The driving wheels will be fitted with block brakes for stopping the locomotive at low speeds and removing leaf residue. Disc retarders will be fitted to all axles for high speed deceleration.    

-The locomotive will also produce a vacuum for any work on preserved lines.

-The valvegear will work using a rotary drum system which is currently being designed. This will be driven using outside cardan shafts and will work onto the inside valves by use of transverse shafts.

-A divided drive system will be used with the inside cylinders driving the leading coupled axle and the outside cylinders driving the center axle.

-Wheels will only be weighted to counteract the effect of the crankpins, bosses and coupling rods, rather than all working componants. This, combined with four cylinder drive should virtually eliminate hammerblow.

-By using Cardan-Shaft drive, the only componants which will require periodical replacement are the roller bearing units. Due to the small number of these and their easily accessible nature, heavy repairs should be simplified.

-Motion componants will be deeply fluted to reduce weight.

-A high degree of superheat will be used to maximise the use of poor quality fuel.

-All internal pasages will be streamlined to improve efficiency.

-Exhaust gasses will be expelled through a modified Lemaitre blastpipe. The chimney will be ovular rather than round to improve external appearance. Internally, the exhaust will split into smaller tubes to present a larger surface area to the boiler front plate.

-An exhaust steam ejector and injector will be fitted for improved efficiency.  

-Spoked wheels will be used.

-A system of pipes will be instaled around the ash-pan. This should improve working conditions for maintainance staff, as a mist of water sprayed around the hopper when emptying occurs should reduce the amount of dust in the atmosphere.