Wallis & Steevens Traction Engine – Authenticity
Introduction
Fortunately copies of most of the original drawings are available and with the help of current owners, it is considered most components are identical or very close to the original. As often seems to be the case though, none of the remaining engines appear to be absolutely identical! The Museum of English Rural Life was most helpful and provided approximately 50 drawings of the Wallis & Steevens 3 ton motor.
Essentially the tractor has been manufactured using techniques that were employed originally. Fabrication is often adopted in model making but it was realised fairly early in the piece that the best way to represent an original component that was cast is, not surprisingly, to produce a casting! Some components such as the wheel hubs and one of the brake bearings were fabricated but it is intended these will be cast for the next engine. Modern materials have been used in a few parts where there is advantage and it is not apparent. Bolts, rivets and screws appear like the original ones
Boiler
From the outset it was considered essential for the boiler to meet current design requirements and it was thought important for the boiler to have an external appearance close to that of the original. The production of the boiler was standard in that the original drawing was metricated with the inner firebox welded and fitted with solid crown stays, then the design was verified independently and finally the design was registered with WorkSafe. A graphic depicting the results of the finite element stress analysis is included and other than as mentioned the original design was essentially unchanged. The boiler was produced by Ainsworth Engineering, in Goulburn NSW which, rather strategically is on the main highway between Melbourne and Sydney.