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Show Pneumatic Tires for British Railway Trains Although pneumatic tires are not unknown on American railways, in England the London, Midland & Scottish railway is experimenting with them with special cars to meet their conditions. These railcars have been turned out by the Armstrong, Arm-strong, Siddeley Motors, Ltd., at Coventry, and shipped to Rugby, where the experiments are taking place. They are made of the lightest possible pos-sible construction compatible with strength and the requirements necessary nec-essary to run at speeds of over 70 miles an hour. It has been found possible, by the extensive use of welding, to eliminate weight to such an extent that this latest type of railcar for 4 feet 8 inches gauge, which is 54 feet long and designed to carry 56 passengers and 15 hundredweight hun-dredweight of luggage, weighs only nine and one-half tons in running order. The car is carried on two eight-wheeled eight-wheeled bogies, one of which is driven. Each wheel is fitted with a gauge set at a predetermined ! pressure, and in the event of loss of pressure a plunger at the backet back-et the gauge is pressed out by a spring, closing an electric circuit which gives audible warning to the driver. A safety device within the tire allows the wheel to drop only one-half inch in the event of loss of pressure and enables the car to run on to the next convenient stopping stop-ping place before changing the defective de-fective wheel. The body of the railcar is built of 0.10 inch aluminum panels, bolted together. Complete rigidity is assured as-sured by this method of joining the sectional panels and the bodies are entirely free from vibration troubles. trou-bles. Full-drop windows mechanically mechani-cally operated are arranged beside the seats. The engine is an Armstrong Siddeley Sid-deley 12 cylinder "V" gasoline engine en-gine developing 275 b.h.p. at 3,000 r.p.m. The coefficient of adhesion between rubber tires and steel rails being several times greater than that between steel and steel, the railcar possesses extraordinary acceleration ac-celeration and braking properties. Under normml braking conditions the distance covered in coming to rest from 60 miles per hour is approximately ap-proximately 250 yards, and in emergency emer-gency the car can be stopped in approximately 85 yards from 60 miles per hour. |