Edward George reports on the increasing popularity of the steam wagon among model engineers.

A beautiful 4.5in scale Foden steam bus, based on the Foden works bus, built by Richard Pickles and Derek Bacon. All of the bus panels can be cleverly removed so the wagon can revert to the more usual flatbed lorry. ALL PHOTOS: EDWARD GEORGE

The model steam wagon, especially in the larger scales, seems to be the increasingly preferred choice for many builders. At the recent Harrogate Exhibition, I learnt not only that JRME (John Rex Model Engineers, a popular and highly respected purveyor of boilers, castings and, indeed, finished models) were working on a batch of no less than 10 4.5in scale steam wagon boilers, but also that Modelworks International will be shortly offering the 4.5in JRME Foden in kit form for self-assembly. My understanding is that Modelworks are planning a batch of 50 wagons with the option of either cast or pneumatic wheels.

The 4.5in scale JRME Foden wagon in tractor form at the Harrogate show. This, essentially, is the prototype of the Modelworks International model that they now plan to offer in kit form. The pneumatics at the front are small trailer wheels and those at the back from a domestic grass-cutting tractor.

The JRME Foden has certainly proved highly successful. It is offered either as a ‘duplex’ cylinder, ie it is twin high pressure, taking steam at 140psi or with compound cylinders working at 170psi. Both boiler designs are ‘Category 2’, which means they may be inspected under the auspices of a model engineering society. The duplex version, which has two 2in bore x 2 5/8in stroke cylinders is usually recommended by JRSM as it produce all the power the engine can use without the higher pressures required for successful compounding.

Model Foden wagons are also to be found in a variety of forms, including a bus version, articulated, with showman’s fittings and, in this example, as a six-wheeler.

So why is the steam wagon proving so popular? It is certainly true, being invariably of compound design, that the cylinders and motion of a wagon are much more demanding and time-consuming than a single-cylinder agricultural machine; however, there is a similar, if not greater, time-saving in the wheels, which are usually either a casting or a pneumatic extraction. The pneumatic wheel will almost certainly be based on a donor hub and tyre, usually from a light agricultural machine such as a Rotavator or a small car. Some builders will go to great lengths to source as near to scale a tyre as possible and will fit a dummy plate drilled for the correct wheel stud pattern so the finished wheel looks more realistic. In total it is still a great deal less work than the option of making all of the parts and spoking a traditional traction engine wheel.

Tony Webster’s superb 3in scale Fowler six-ton wagon. Apart from the boiler, a good deal of the model, including the wheels and chassis, is either aluminium or Dural, making a very light and manageable vehicle for its size.

Another bonus for steam wagon builders who own a platform back is that a driving trolley is not required – one less thing to be made and transported. Larger wagons have a big enough platform for several passengers, making them an ideal family vehicle. An increasingly popular feature at rallies is an evening road run to a local hostelry and the model wagon is, of course, perfect for the job as they are fast, give a beautifully smooth run on Tarmac roads and have an adequate capacity for passengers.
On the subject of speed, it is not unknown for a 4in model to travel at anything up to 25mph. To safely stop a model weighing some 500kg, decent brakes are essential. It is usual to use automotive brakes, which are more effective than ‘scale’ brakes taken from the prototype.

End of the On-line article.
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