Pocketbook of Useful Formulæ and Memoranda
for Civil and Mechanical Engineers

Forfatter: Guilford L. Molesworth

Sider: 744

UDK: 600 (093)

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Side af 764 Forrige Næste
242 MOLESWOBTH'ö POCKET-BOOK Roads. Ordinary English turnpike-roads, 30 feet wide, the centre 6 inches higher than the sides. 4 leet from the centre, J inch, below the centre. 9 feet from the centre, 2 inches „ ,, 15 feet from the centre, 6 ,, Footpaths 6 feet wide, inclined 1 iuch towards the road. Side drains, 3 feet below the surface of the road. Road material: bottom layer, gravel, burnt clay, or chalk, 8 inches deep. Top layer, broken granite not larger than inch cube, 6 inches deep. Some use a 2J-inch ring to clear all angles of the cubes for bottom metal, and a 2-inch ring for top metal. Footpaths: fine gravel, or aifted quarry chip- pings, 3 inches thick. Gauging Road-metalling. Heaped on the side oi the road ready for laying. L = Length of aide of gauge in inches. B = Number of Bushels re- quired per lin jard of road. L = 12| V B. The heaped bushel being reckoned at 2700 c. ins. L =s 17 kJ C when C = the number of ‘‘cubes” per “ line.” A “cube” being = 100 cubic feet. A “line” „ = 100 lineal feet. . Wear of Roads in India is reckoned at 1 cubic yard of metal per mile for each cart that passed as a daily average over the road.