The Locomotive Of Today

The Framing, Wheels, etc. : Bissel Truck. 147 side of the centre are lugs, through which pins pass, carrying the upper ends of the swing links, and a large centre casting is held in a socket fixed to the main engine frame, with pro- jections to which the lovver ends of the links are coupled, so that the frame can freely move laterally without affecting the centre line of the engine; the frame and with it the axles, etc., all swinging upon the links. To the back of the above mentioned frame is fixed another one well stayed and V shaped, pivotted at its apex by a pin to a frame-stay between the main frames of the engine. This Controls the movement of the truck, and prevents the wheels and frame from turning upon the centre piece, and taking up a position at right angles to their proper centre line, as they might do when the engine moved, and they were not held by the pivot. The axle boxes slide in the pedestals, and upon the top and at each side of the boxes beams bear, which reach down and carry at their ends bearers for the springs, which are of the coiled type, and are compressed by the weight between the bearers and the bogie frame. The weight is transmitted through a compensating lever coupled at its one end to the leading coupled wheels of the engine, and bearing upon a point in the centre casting of the bogie at the other, being pivotted at, or near its centre to a frame stay. When more or less weight has to be carried upon these different pairs of wheels so connected, this pivot has, of course, to be nearest to that pair which carries most weight. B is a plan of the arrangement, C is a half cross section through the centre, showing the swing links clearly, and D a half end elevation. The weight placecl upon this bogie centres it as in the four wheels bogie with similar swing links. When the swing links are arranged as shown, with their bottom pin-holes doser to the vertical centre of the engine than the top ones, they have the advantage over those placed exactly above each other, for when the engine goes round a curve it swings over and the outer wheels are made to take the greater weig'ht, which allows the inner wheels greater freedom to do the inevitable slipping upon the shorter rail length inside the curve. Links arranged exactly vertically will simply swing over and approximately the same weight will still be carried upon each side of the bogie. Another method of obtaining a flexible wheel-base is by means of a radial axle box, which allows a movement similar to the above, but in a different way. Instead of the movement being controlled by a centre pin about which the wheels radiate; the axles are fitted with boxes which are of a form such that