Lockhart's Book of Instructions for Locomotive Firemen (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 edition. Excerpt: ...port "P," allowing the pressure in the brake cylinder to exhaust to the-atmosphere. Emergency Position-The sudden reduction of train line pressure causes the triple valve piston to move out so quickly that the graduating spring cannot withstand the impact of the extension on the triple valve piston, but springs back, allowing the piston to travel its full stroke. The slide valve now uncovers port "T" in its seat, admitting air from the slide valve chamber and auxiliary reservoir into the chamber above emergency piston, forcing it down, unseating the emergency valve. The air pressure in cavity "Y" above check valve now flows to the brake cylinder. Train line pressure now raises the eheck valve, allowing the train line pressure to flow to the brake cylinder, until the auxiliary reservoir and train line pressure have equalized in the brake cylinder when the check valve recloses. The effect of uniting the auxiliary and train line pressures in the brake cylinder in the emergency application of the brake is that on account of the large volume of air in the train line the pressure will equalize at a higher pressure than could be obtained by the auxiliary or train line pressures alone. The "K-2" Triple Valve. The distinguishing feature of this valve is its retarded exhaust. The exhaust ports are constructed in the shape of a triangle. When the valve is in running or service position the sides of the triangular ports are toward each other. When release takes place the large volume of air rushing into the train line through the brake valve forces the valve to the full limit of its stroke, bringing the points of the triangular ports together, retarding the exhaust. As the air flows toward the rear of the train...