The Locomotive Of Today

176 The Tender, Brakes, etc. : Condensing Arrangements. tank to allow for the expansion of the pipe when it is heated by the exhaust steam. Inside the tank a pipe takes the steam down to the bottom of the water, where any not condensed escapes into the water and is finally disposed of. To allow for the escape of the air, etc., displaced by the entering steam, another pipe is fitted to the top of the tank, standing vertically just in front of the cab. Inside the tank, below this escape pipe, a box with large perforations in the bottom of it is fitted in the tank. This prevents the water being thrown out of the tank when the condenser is being employed. The escape pipe is placed at the side of the cab window so as not to obstruct the drivers view. When most of the running is made with the ordinary biast pipe, and the condenser is only occasionally used, the water in the side tanks does not get too hot for the injector feed, but when running on services which require almost con- tinual use of the condenser, as on underground lines, the water gets too hot and injectors would not take it. Pumps worked from the crosshead or other moving part of the engine are, therefore, fitted for maintaining the proper water level in the boiler. The water must, however, be frequently changed, or the steam will not be condensed, and a large valve is usually placed in the bottom of the tank, operated by means of levers in the cab, for emptying the water expeclitiously ready for the tanks being refilled with cold water. The lever in the cab for moving the flap valves in the blast chamber is provided with a binding screw so that the valves may be firmly held in the required position. When running and using the condensing apparatus, no effect from the biast being obtained on the fire it is necessary to keep the blower on in order that the steam pressure may be maintained. For fuel, smokeless Welsh steam coal, or a similar product must be used on underground service. Recently oil fuel has been burned with considerable success, and as it possesses many advantages in firing, it should be largely adopted. At D a section of the valve chamber is drawn to a larger scale to show the arrangement of the flap valves, etc. The body, which is of gun-metal, has open sides, to which covers with flat faces are fitted; bosses upon these covers have holes through them for the rods upon which the flap valves inside the chamber and levers outside are fitted. The flap valves are also of gun-metal, and have grooves machined at each side, about an inch wide by % of an inch deep, into which strips are fitted. These are forced outwards by flat springs to form a steam tight joint against the covers. The faces of the valves are also seated fairly upon the faces of the holes to