Locomotive Engine Running and Management

by Angus Sinclair

POSITION OF BOXES WHILE SETTING UP WEDGES.

With the wedges in a proper condition when the locomotive enters service, we yet must care for them and adjust them from time to time, when it is necessary to take up the lost motion between the pedestals and boxes. When doing this work, it is important that the position and condition of the driving-box should be considered. The position of the box should be such that the wedge may be set up to the proper degree of tightness with certainty and without much labor. It is important that a wheel position be found where the box would not be moved by the wedge when the latter is being adjusted. This position will be found where the box is up against the dead wedge, since the lost motion will then be between the box and the wedge to be moved. To get all the driving-boxes in that position at one time is a difficult matter, if it is to be done by pinching the wheels. The position of the rods decides the direction of their action on the wheel by the thrust or pull upon the crank-pin. If the rod is above the wheel center, pinching behind the back wheel will force both the wheels and boxes on that side up against the dead wedge; but, should the rod be below the wheel center, similar work with the pinch-bar will draw the forward box away from the dead wedge, the side rod doing this by pulling on the crank-pin,—this is always supposing the dead wedge to be in the front pedestals. The best position, therefore, to get an engine into for setting up all the wedges, is, with the side rods on the upper eighths; for then pinching behind the back wheels will push all the boxes up to the dead wedges. The work can then be done without putting unnecessary strain upon the wedge-bolts, which are often found with the corners of the heads rounded off, and the thread injured to such an extent that it will not screw through the binder-brace,—a condition of matters nearly always caused by trying to force up wedges without putting the engine in the proper position. If the wedge-bolt, from faulty construction, or through injury, is unable to move up the wedge, driving is resorted to, by which means it is battered on the end; and the jarring of each blow causes the ashes and dirt on top to fall behind the wedge, throwing it out of parallel, and introducing material that will cause the wedge to cut. The ashes and dirt that accumulate so readily on the top of wedges and boxes cause no end of trouble, although the fact is not generally recognized; and it will generally be fruitful labor to have these parts well cleaned off before beginning to set up wedges. Many complaints that are made, of wedges not being properly adjusted, proceed from the disturbance that follows grit introduced between the wedge and box.