Harry the Rocket is reputed to be Mamod's worst design ever; and Mamod don't deny it! They do admit that it was an experiment to see how cheaply they could produce a locomotive. As such, it could be described as a success :-)
Many components (boiler, engine frame, cylinder, crankshaft, flywheel and rail wheels) appear to be taken from the TE1A, some with minor modification. The boiler has a dummy smokebox door fitted in the front end and a dummy chimney mounted above. The wheels have flanges turned on them. Even the cardboard box is one from another model of loco, with a paper sheet pasted over the top. The boiler is 1 3/4" diameter x 5 1/2" long externally; probably about 5" internal. It is fired by a butane burner, which has a gas tank mounted at the rear. The boiler fittings consist of a standard Mamod safety valve and a standard Mamod type water level sight "glass". Steam is fed directly to the back of the port face of a single acting oscillating cylinder. The cylinder is 5/16" bore x 13/16" stroke (maybe intended to be a nominal 3/4"). This is connected to a crankshaft similar to that on the TE1A, with a crank at one end and a 2 1/2" diameter flywheel on the other. Final drive is from a 1/4" pulley incorporated in the flywheel, through a spring band to a 2 1/8" diameter pulley, attached to the front axle along with one of the front wheels. The wheels are at 45mm gauge (gauge 1). I have seen what is said to be the prototype for Harry the Rocket, and it has direct drive to the front wheels, as on the real Stephenson's Rocket (hence the name). However, that arrangement was abandoned, presumably because the engine lacked power with direct drive. The engine was bought as a non-runner because the gas pipe connection is missing. There is a dent in the gas tank but I don't think that will stop it working. There is extensive rust on the side panel on one side.| Make | Mamod |
| Model | 1355H Harry the Rocket |
| Made | 2006 |
| Description | 0-2-2 loco |
| Cylinders | 1 |
| Cylinder Type | single acting |
| Bore mm | 8 |
| Stroke mm | 21 |
| Valve Type | Oscillating cylinder |
| Boiler Type | Horizontal |
| Boiler Diam mm | 44 |
| Boiler length/height mm | 140 |
| Fuel | Butane |
| Mechanical Condition | Poor |
| Cosmetic Condition | Poor |
| Paintwork | Original |
| Packaging | Cardboard & polystyrene box |
| Purchased | 2 Oct 2019 |
| Purchase cost | £265 |
| Additional spend |