The Locomotive Of Today

The Boiler: Ashpan, Smokebox. 25 engines that run mostly in one direction, as main line, express and goods engines (see B), but at both front and back ends for engines that are designed to run either way as tank engines (see A). The use of the ash-pan, as its name implies, is to catch the ashes that fali through the fire-bars, and also to pro- vide a means of preventing entry of air through the bars when desired. 1 he dampers regulate the quantity of air admitted to the lire, and are under the Control of the enginemen ; they are opened and closed by means of suitable levers and catches on the foot plate, easily accessible, and through them the ashes can be removed at the completion of the day’s work. 3 he ash-pan is attached to the foundation ring by means of pins screwed into the under-side of the ring, projecting sufficiently far to pass through the angle-irons on the ash-pan, and having split cotters driven through the holes in them. It is advisable to make the bottom of the ash-pan with a slight inclination upwards at the ends, so as to prevent the small dirt accumu- lating there being blown out whilst running on to the motion and moving parts of the engine. I he smokebox, at the front end of the boiler, is in inside cylinder engines built up directly from the upper face of the cylinder castings, but in outside cylinder engines is formed above a box-like stay placed between the frames at this point; the wrapper is made up of two pieces of plate J-in. thick, rolied to required shape, and jointed at the top. The front plate which has the door hole in it, is either flanged to shape by hydraulic pressure, or the joints between it and the wrapper are made with angle-irons, the flanged plate making the neater and cheaper job. The door is provided for getting at the tubes for cleaning or repairs, and also for washing out the boiler. It is generally circular in form, and dished to give it greater strength; on the inside, about i^-in. from it, a second plate is fixed for protecting the outer door from the heat. This form of door is hinged at the side, and .has at its centre a fastener usually called a “ dart,” which has a flattened end with shoulders. This is passed with the head in a horizontal position between two bars of iron, about 2-in. apart, which extend across the front, inside the smokebox, and then turned so that the shoulders catch on the inside, the door being then screwed tightly on to its face by the outer handle or wheel. Another common form of smokebox door folds in the centre, and is hinged on either side; this form has been frequently adopted where some obstruction may prevent the opening and shutting of a round door. A third form hinged at the top and opening from below is often met with on engines with lovv boiler centres.