The D52 is intended to be built into a boat hull. It consists of separate boiler and engine unit, with a propeller and stern tube.
The boiler is 45mm diameter x 110mm. It has a standard Wilesco style adjustable tablet burner. There is a circular water gauge window in one end. On the top of the boiler there is a safety valve and a filler plug. There is a short open ended steam feed pipe intended to be connected to a similar pipe on the engine unit using a plastic pipe section.
The engine is on a separate L shaped chassis. The cylinder is double acting with a cylindrically shaped slide valve (described by Wilesco as a "piston" valve). It is 13mm bore x 16mm stroke. There is a simple lubricator fitted to the valve chest.
I have mounted the boiler and engine onto a wooden base for convenience in steaming and display, with the propeller shaft driven via a pulley.