Not since the turn of the century have any American-built locomotives been seen on the main lines of the railways of this country; so naturally great interest has been shown in the recent deliveries of so-called "Austerity" engines ordered from American locomotive building firms, to supplement the British built locomotives required by the Ministry of Supply for both ordinary and military needs. It is said that history repeats itself, and in this case it is so, although the reasons are somewhat different. Nearly fifty years ago, the locomotive-building firms of this country were so full up with orders that it was impossible to take any more; and so, when the Great Northern and Midland Railways were in urgent need of goods engines, orders were placed with the Baldwin Locomotive Works and other American concerns, for some suitable machines. The firms mentioned would not build to the British standard designs, and supplied typically American engines of the 2-6-0 type; but for various reasons, the engines proved unsuitable for the work, and after a short life, they all went to the scrap heap.
After forty years and more, there is an "emergency" of a different kind, and more engines are required than British firms can build. Once more America comes to the rescue; but this time, although the locomotives are typically American, they are built to a specified design. The British-built engines supplied to the order of the Ministry of Transport are very similar to class 8F of the L.M.S., being 2-8-0 type with plate frames; their cylinders, motion and other details are interchangeable with the engines mentioned. The chief differences are that the "Austerity" engines have parallel boilers with an ordinary narrow firebox going between the frames, and the tender has eight wheels set in rigid axleboxes, instead of having bogies.
The American-built engines are also of the 2-8-0 type, but they differ from their British sisters in having typically Transatlantic bar frames, a large parallel boiler with wide firebox, and a tender running on two diamond-framed four- wheeled bogies. They are furnished with British coupling gear, viz., side buffers and screw couplings, instead of the American central automatic couplers, and ordinary guard irons instead of a pilot, or "cowcatcher" as the daily press reporters love to call it. As I have not so far described an American type of engine in this series, I suggested to our worthy Editor that here was the opportunity, and he welcomed it.
In 2½-in. gauge size, the American version of the "Austerity" locomotive is superior to the British-built version, if it is to be operated by an inexperienced engineman, because the wide firebox does mot need such careful firing as the narrow one. Also, the heavy bar-type frames of this engine are not so liable to be damaged by collision or derailment as the usual plate-frames. The motion work is more accessible, as there are no frame-level running boards, merely a narrow gangway each side of the boiler; and the bogie tender makes the engine easy on curves. Please note, the engine is not an exact copy of the full-sized machine, for two reasons; first, I have introduced variations in the working parts, in accordance with my long personal experience of actual small locomotive building, in order that it will be a fully efficient little machine, able to haul a living load continuously, if built with average workmanship. Secondly, as material is difficult to obtain in certain sizes and quantities, and it is next to impossible to get special patterns made, I have arranged the general design to utilise castings and material already on the market. Despite these variations, the personal appearance of the little locomotive will be quite correct, as can be seen from the general arrangement drawing, which will appear in the next issue.
The engine has straight-topped bar frames, and a pony truck to match. Instead of the cylinders and smokebox saddle being cast together, ordinary separate stock pattern cylinders are utilised, but the smokebox saddle is so arranged that the "one-piece-look" is retained. These cylinders are of the ordinary slide-valve type, which are easiest for amateurs and inexperienced workers to make and fit; but the outward appearance of the full-sized piston-valve cylinders is achieved by using extra large gland and tail bosses on the steam chests, and covering the lot with a lagging sheet. The valve gear follows that of the big engine very closely, but is amended to suit the outside-admission slide valves. A little engine using superheated steam in bronze cylinders needs much more oil in proportion to size than its full-sized sister with cast-iron cylinders; so that the mechanical lubricator, though located in the correct position, is of necessity "outsize."
A boiler with parallel barrel and wide firebox is the easiest type of regular locomotive boiler to construct, and therefore beginners and other inexperienced workers will be "in clover" when it comes to the boilersmithing. One advantage of the shallow-depth bar frames, is that it allows the wide firebox to be raised entirely above them, and still keep well within the height allowed by the loading gauge. On the small engine, the height from rail to top of chimney is 7-in. exactly, equivalent to approximately 13-ft. in a 4-ft. 8½-in. gauge locomotive. I might here mention that a 2½-in. gauge engine is quite a size larger than the so-called "half-inch-scale," as an engine built to that "scale" would be 2½-in. gauge only. A 2½-in. gauger is approximately one-twenty-second of full size; and the maximum height permissible by the British load gauge from rail to top of chimney would be roughly 7_5/16-in., so our "austerity baby" is well within the limit.
The front end of the full-sized engine is decorated with a Westinghouse donkey- pump for the air brakes; and to make room for this, a miniature; smokebox door is placed slightly to one side of it. We don't need the air brake, and the smokebox door, if made to "scale" size, would be too small for our purposes; so, to keep these prominent characteristics of the big engine, yet give access to the interior of the smokebox for cleaning out ashes. sweeping tubes and so on, the whole smokebox front is arranged to pull out of the shell, like the lid of a press-top canister. This allows the front to be adorned with the before-mentioned Blobs and gadgets, which are dummy, and permanently fixed to it. The donkey pump makes a very useful handle! The boiler mountings include a squat stovepipe chimney, very "austere" but very realistic, a combined sandbox and dome cover, and a pair of pop safety valves. The backhead slopes, and has a pull-out regulator, or throttle, as our transatlantic cousins call it, and American-type fittings. The boiler is fed by an eccentric-driven pump and an injector.
The usual type of roomy American cab is provided, and this has a "well" deck; the roof can be made to slide off, if required. The tender is of the "dry- bottom" type; that is, the tank does not extend below the side sills. I have arranged this as a combination of British and American practice, for ease of construction. It has Andrews-type diamond frame bogies (our cousins call them "trucks") with disc wheels; the bogies are attached to the built-up bar frame by plate bolsters. On top of the frame is a British pattern soleplate, on which the tender body is built up in the usual way. There is ample space for coal and-water, and an emergency hand pump will be located in the tank, as usual.
Photocopies of the contstructional articles published in English Mechanics (12 Feb 1943 to 11 feb 1944) are available to members of the Association for £6.50 inclusive of postage.
All the necessary Castings to build the US Austerity are available from the Association as follows :-
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