Page:The Working and Management of an English Railway.djvu/128

 same weight one mile at a speed increased to forty-four miles an hour required 2.06 oz. of fuel—a striking testimony to the great increase in expenses which railway companies have had to incur to keep up the high rates of speed now demanded in railway travelling. The economy of fuel effected by these engines is very considerable, and the fact is not without importance to a Company whose engines consume in the aggregate an average of 3,000 tons of coal per day, or upwards of a million tons in a year.

The compound engines are fitted with "Webb's radial axle-box," which is described as follows:—The axle-box consists of a single casting, with brasses fitted in each end for the journals, and which works between two curved guides formed of flanged plates stretching from frame to frame, thus allowing a lateral motion of inch to the axle on either side of the centre line of the engine. Underneath the axle, and within the box, are placed two horizontal helical springs, coiled right-hand and left-hand, and working one within the other, so that when the engine enters a curve the springs are compressed to one side against cross pieces connecting the axle-box guide-plates, and the shock transmitted from the rails through the wheels is minimised, while, as soon as the engine gets on the straight line again, the springs resume their normal position, and the engine is kept central. The axle-box, as originally designed, had two sets of controlled springs placed laterally on each side of the centre line of the engine, but as it was found that there was a tendency, in the case of a broken spring, or of one set being stronger than the other, for the wheels to be forced out of the centre line when running on the straight, the present arrangement was designed to