Slipping of Eccentrics.—Place the reverse lever in the forward notch of the sector. Place the crank on its forward dead centre, as near as can be judged by the eye, and loosen the set screw of the forward eccentric, that is to say, the eccentric which connects to the upper end of the link. Move that eccentric round upon the axle until the slide valve leaves the steam port at the front end of the cylinder open to the amount of required valve lead. In moving the eccentric round upon the shaft, move it in the direction in which it will rotate when the engine is running forward, so as to allow for and take up any lost motion there may be in the eccentric straps, in the eccentric rod eyes and bolts, and in the other working parts of the valve gear; for if the eccentric was moved backward, all such lost motion would operate to vitiate the set of the valve. The eccentric being placed as directed fastens its set screw securely.
If the backward eccentric is the loose one, throw the reverse lever to the backward notch of the sector, lifting the link up so that the eccentric connected to the lower end of the link may be approximately adjusted by moving it around upon the axle in the direction in which it will rotate when the engine is running backward, until the back cylinder port is open to the amount of the valve lead. Another very ready plan of temporarily adjusting the eccentrics is as follows: Place the reverse lever in the end notch forward, and place the engine crank or driving crank pin as near on a dead centre as the eye will direct, and open both the cylinder waste water cocks. Then disconnect the slide valve spindle from the rocker arm, and move the slide valve spindle until the opening of the cylinder steam port corresponding to the end of the cylinder at which the piston stands will be shown by steam blowing through the waste water cock at that end of the cylinder; the throttle valve being opened but a trifle, to allow a small steam supply to enter the steam chest and cylinder, for if much steam is admitted, it may pass through a leak in the piston and blow through both the waste water cylinder cocks.
The position of the valve being thus determined, the eccentric must be moved upon the driving axle until the valve spindle will connect with the rocker arm without being moved, or moving the valve at all.
Hot Axle Boxes.—If not convenient to reduce the speed of the engine, or if that and free lubrication do not cool the box, a plentiful supply of cold water should be administered, it being well to have at hand a small hose pipe, by means of which water from the tender tank can be used. If the brasses have Babbitt metal in them and it should melt, it is better, if possible, to cool the axle box while the engine is moving, which will injure the journal less than if the journal is stopped to cool the box, because in the latter case the brass or box is apt to become soldered to the journal of the axle, and when the engine is again started, the cutting or abrasion will recommence with extreme violence.
Breaking a Lifting Link Or the Saddle Pin That Connects The Slot Link To the Reverse Shaft.—Cut a piece of wood and tie it into the slot of the link, over the link block or die, making it of a length to keep the link in the position for hauling the train. Then fasten another piece of wood in the link slot beneath the sliding block or die, thus securing that die in the proper position for the engine to go ahead. In this case, the engineer must be careful in stopping, as he cannot reverse the engine on the crippled side.
Secondary accidents are almost sure to occur if a disconnected piston is not securely blocked in the cylinder, or from blocking the piston aright and attempting to let the slide valve run, or from attempting to run with the parallel rods on one side only disconnected. There are numerous accidents, which only common sense and a familiarity with the locomotive can provide a temporary remedy for, but those here enumerated are by far the most common.
ADJUSTING THE PARTS OF A LOCOMOTIVE.
When the wedges of the axle boxes are to be adjusted for fit to the pedestal shoes, the engine should be moved until the coupling rods on one side of the engine are in line with the piston rod, because in this position the rod will, to a certain extent, act as a guide in keeping the axles parallel to each other, and at a right angle to the line of engine centres.
Bear in mind that the distance from the centre to centre of axle boxes must be the same as the distance from centre to centre of the crank pins, and that when the coupling or side rods are in line with the piston rod, they act to resist the axle boxes from being set up too close together.