Cherry Hill’s

ALLCHIN

ROYAL CHESTER

Cherry Hill’s model of the Allchin Traction Engine, Royal Chester, was only the second model she made. It was significant in many ways.

It was based on the Bill Hughes design in 1:8 scale published at that time in Model Engineer. Cherry thought that was too big, so she made hers in 1:16 scale.

That made it the first traction engine of many, the first use of her favourite scale, and it was constructed without the use of castings. It also started her researching her subjects and, after tracking down the original, she was able to measure all the small parts such as valves, handles, and fire irons.

When displayed at the Model Engineer Exhibition it made an impact. Cherry Hinds, as she was then, was a name to look out for, her model engineering career was underway.

While promoting the book Cherry’s Model Engines MEWS had temporary care of the Allchin between exhibitions, leading up to the London Model Engineering Exhibition at Alexandra Palace. That being the case, I thought MEWS readers might like to see a few ‘snaps’ of the 50 year-old model taken in the office. I mention them as ‘snaps’ as that is all they are compared with the professionally taken pictures of Cherry’s early models in the book, or those taken by Cherry herself of the later models that can be found in the book.

So here is it. If you want to challenge yourself to built something that can be compared with the best there is all you need are the Bill Hughes articles from Model Engineer (no doubt TEE Publishing will be able to provide back issues) or you might be lucky enough to find a copy of the out-of-print book. In addition, you will need some time with Royal Chester to measure up the bits and bobs, and to read the many MEWS articles dealing with fabrication to replace castings. Oh, and seven years of spare time. And the ability to do things like make the nameplates with sawn out brass letters soldered on.

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.

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 who 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.