The Locomotive Of Today

120 The Framing, Wheels, etc. : Hornblocks, Stays.. zontal; upon this portion the expansion brackets ot the- bøiler slide. Below the frames are shaped out to take the- trailing axle box guides, being stayecl as before by the homstays, the- end being of a depth suitable for taking the footplate and trailing buffer plate. The plates after marking are roughly punched out to shape, and are afterwards slotted or otherwise machined to the exact dimensions, then levelied by hammering or rolling, and finally drilled, the holes which are to have cold rivets inserted being made y^-in. less than the finished size. The hornblocks, spring brackets, etc., are carefally fitted in their appointed places by chipping and filing, and the holes are reamered out to exact size, the bolts or rivets being- turned a tight driving tit in them. If the latter are hammered down cold the holes are better iilled then than would be the case with hot rivets. The hornstays are fitted and secured across the openings cut to receive the axle box guides. The frames are next placed upright at the proper distance apart; the cylinders, bogie casting, motion plate and frame stays are put between and temporarily held by bolts, and the frames squared by having lines of fine twine stretched on each side outside them, and set equally distant. Two other lines are passed through the cylinders from a straight-edge fixed across the front of the frames, at the proper height, to another straight-edge placed across through the driving hornblocks, and fixed so that the centre line of the driving axle may be represented by its edge. The centre line of the cylinders, shown by the twine, will now intersect the centre line of the axle when the cylinders are set. To be more nearly correct this imaginary centre of the driving axle is assumed by some builders to be from one to rtwo inches above the actual centre, to allow for the depression ,of the springs due to the weight of the engine. The lines are all pulled as tightly as possible, and the distances between them taken carefully in all ways, so that the frames may be free from all cross-windings or other inaccuracies. All the holes are next opened out to finished sizes in the cylinders, bogie centre, frame stays, etc., and the rivets or bolts turned to fit tightly in them and secured. In the plan at B the various stays, etc., are shown in position. The frames are set in at the leading end in order to increase the side play of the bogie wheels, and are supported by a strong stay of angle iron rivetted to them and the buffer plate. Next there are the cylinders, then the slide bar bracket ji.nd the frame stay fixed just behind the driving wheels and.