Since Bill Hughes first described his Allchin traction engine in 1 1/2 inches to the foot scale in 1957, it has been modelled many times in many scales including 15mm, 2in. 2 1/4in. 3in. and 4 1/2in. and possibly more. Here Julius has the equivalent of a 3in. scale version (but in metric). Builders will be interested that John Rex can supply castings and parts for a 3in. version - see: no doubt he will be happy to build you one, too.

Royal Chester, no 3251, was the last traction engine built by Allchin in 1925, intended for the Royal Show at Chester. Actually it never carried the Royal Chester nameplate - that was a Bill Hughes addition.

Bill first saw the engine while out “engine hunting” in North-east Derbyshire in 1948 in the company of two other Allchins nos 1257 and 1407 and Marshall no 69256. Owners, the Earnshaw brothers, let Bill make many visits (cross country walks from Sheffield) to measure 3251 “which took my fancy”. The other three engines were cut up for scrap, as most were in those days, but Bill won the interest of pioneer preservationist, Chris Lambert and he bought her. In those days they went for £25 each! Royal Chester was sold in 2011 for £114,000.

The Earnshaw brothers were agricultural contractors who, in 1948, found it easier to run a Fordson than a traction engine. Of the three Earnshaw Allchins, Royal Chester, differed in several particulars - notably in that both axles are sprung (the other engines being unsprung), while the, boiler was 2in. less in diameter, and the smokebox 4 in. longer. In addition, the driving position is at the near side on Royal Chester instead of the  offside.

Dimensions recorded by Bill Hughes:

Rear Wheels:  6 ft. diameter, 8.5in. wide, two driving-pins.

Front Wheels:  3 ft 10in 9 in. wide 10 spokes.

Flywheel: 4 ft. 6 in. diameter, rim 6 in. wide by 1.75 in. thick, 6 spokes. 

Single Cylinder: 10 in. bore by 12 in. stroke.

Connecting-rod centres: 3 ft. 3 in.

Eccentric-rod centres: 2 ft. 8.5in. Eccentric-sheave diameter: 7 in.

Crankshaft as forged: 4 in. diameter. (All journals turned to 3.5in. diameter.)

Steering-wheel: 17 in. diameter, 5 spokes.

Brake operating wheel: 13 in. diameter, 6 spokes.

Hornplates  0.625 in. thick, and distance between them is 32.5 In. thus firebox is also 32.5 in. wide and boiler ditto diameter, with lagging 1.5in thick.

Bolting flange at chimney foot  13 in. diameter.

Width of engine over hind wheels: 7 ft. 7 in.

Width over tender: 2 ft. 10.5 in.

Thickness of plating of tender: 0.75 in.

Distance between tender side and nearside hind wheel: 13 in.

Distance between tender side and offside hind wheel: 10.5in.

Steering at offside nearside. 0Pump in cab, at offside, driven by eccentric between crank and crankshaft bearing.

Click on drawings to download - for personal use only. Although drawings reproduce well on this website, they are even better if downloaded.

Click on drawings to download - for personal use only.

Although drawings reproduce well on this website, they are even better if downloaded.


Part one by Julius de Waal