The 13/5 is relatively conventional for Cyldon. The overall layout is typical of many stationary steam toys. It is unusual in the extensive use of aluminium. The base, engine frame, valve block, flywheel, firebox and chimney all appear to be aluminium and/or mazac, Most of the rest of the engine is brass. There is very little steel used, only the crank shaft, piston/valve rods and a few other minor items.
The burner is an unusual four wick design, fixed to the base with the cylindrical tank outside of the firebox, at right angles to the wick holders inside. Lighting the wicks has to be done through a slot in the firebox. Adjusting or replacing the wicks requires removing nuts from two screws to detach the burner from the base.
The boiler is a pretty standard design, very similar to early Mamod boilers in appearance. Its dimensions are 45mm dia x 150mm. The lever type whistle has a Mamod-esque look to it. The safety valve, however, is a distinctive shape. The boiler is attached to the firebox by means of two aluminium straps. It has an overflow level plug and, unusually, a separate filler hole.
Steam feed is taken through the bottom of the boiler, through the burner flame for superheating, and out through a hole in the firebox to a compression fitting on the valve chest. The valve is a standard slide valve. It is controlled by a fixed crank on the crankshaft. The engine is not reversible.
The cylinder is a mazac casting with brass end caps, mounted on a substantial cast frame. It is double acting. It's difficult to measure the cylinder bore without dismantling, but it appears to be about 8mm. Stroke is 20mm. There is a plugged hole directly above the valve which, I assume, is for oiling. Exhaust is piped to the bottom of the chimney, which is mounted on the base.
The end of the piston rod is connected to a built-up crank at the centre of the crankshaft. The crankshaft has the valve return crank at one end and a 51mm diameter flywheel at the other. Also at the flywheel end is a small pinion meshing with a larger gear wheel mounted on a bracket cast in with the engine frame, giving a slightly more than 2:1 speed reduction. The second shaft has a small pulley attached.
When purchased by me, the paintwork was in generally poor condition, flaking in most areas. This seems to be a common problem when painting on aluminium. Most of the remaining paint disappeared after a simple cleaning operation so I had to do a full restoration.
The bottom photo on the left shows the engine in as-found condition.