The Locomotive Of Today

THE LOCOMOTIVE OF TO-DAY. 119 Section III.—THE FRAMING, WHEELS, etc. HAVING described the engine itself, we have next to con- sider the carriage and running gear. The engine and boiler are arranged and carried on a framing supported bv the wheels and axles. The frames are in Europe invariably built up of plates, usually four in number, the two inner being the main frames, whilst the two outer are for supporting the footplates, splashers, etc./ and in addition take the bearings in cases where they are outside. The main frames are inside the wheels, and extend the whole length of the engine—from the back of the front buffer plate to the back plate in tender engines, or to the trailing buffer plate in tank engines. They are strongly stayed across from one to the other at suitable positions in their length, the contour depending upon the class of engine, arrangement of wheels, etc. The outside frames are usually thinner, and when not used for carrying bearings are frequently of angle iron some 6-in deep by 3-in. on top flange to support the footplatings. It was formerly the custom to make “ sandwich ” frames, which were built up of two thin plates of iron boltecl on either side of a piank of oak ; this practice has now become obsolete and plate frames are general. In America the practice has always been to build up the framing of bars some 3 or 4 inches square in section. The main frame plates being arranged vertically and inside the wheels, the space to be obtained between them is limited, for as the distance between the tyres (upon the standard 4-ft. 8|-in. gauge) is 4-ft. 5|-in., the greatest width over the frames must not exceed 4-ft. 4-in. outside, this giving f-in. between the frames and tyres, less than which it is not advisable to allow. The frames are now invariably of Steel plate, rolied to the thickness required, from i-in. to i|-in. Fig. 24 shows a set of frames suitable for an express engine having a leading bogie, single driving wheels, and trailing carrying wheels, with inside cylinders and inside- bearings only to all the wheels. The depth varies to suit the- different attachments, at the leading end it is equal to that. of the front buffer plate, then opens out to take the cylinder,, and below it the bogie centre pin casting, then is reduced* again swelling to take the driving axle box guides or horn- block, being stayed across the bottom of the gap so made by the hornstays. Then for some distance at the top it is hori-