On a level 980 gross tons. " 20 ft. grade 465 " " " 40 " 300 " " " 60 " 220 " " " 80 " 170 " " " 100 " 140 " " DIVISION VI. TANK SWITCHING ENGINES. CLASS 15-1/2 C. General Design Illustrated by Print on Page 114. CYLINDERS. Diameter of cylinders 15 inches. Length of stroke 22 " DRIVING-WHEELS. Diameter of drivers 48 to 54 inches. TRUCK. TWO-WHEELED, WITH SWING BOLSTER AND RADIUS-BAR. Diameter of wheels 24 inches. WHEEL-BASE. Total wheel-base 14 ft. 7-1/2 inches. Rigid " 7 ft. TANK. Capacity 700 gallons. WEIGHT OF ENGINE IN WORKING ORDER. On drivers 50,000 pounds. On truck 6,000 " ------ Total weight of engine, about 56,000 " LOAD. IN ADDITION TO WEIGHT OF ENGINE. On a level 1120 gross tons. " 20 ft. grade 535 " " " 40 " 345 " " " 60 " 255 " " " 80 " 195 " " " 100 " 160 " " [Illustration: Locomotive.] DIVISION VI. TANK SWITCHING ENGINES. CLASS 21 D. General Design Illustrated by Print on Page 120. CYLINDERS. Diameter of cylinders 15 inches. Length of stroke 22 " DRIVING-WHEELS. Diameter of drivers 44 inches. WHEEL-BASE. Total wheel-base 9 ft. 9 inches. Rigid " 9 ft. 9 inches. TANK. Capacity 750 gallons. WEIGHT OF ENGINE IN WORKING ORDER. Total weight of engine, about 60,000 pounds. LOAD. IN ADDITION TO WEIGHT OF ENGINE.