Pocketbook of Useful Formulæ and Memoranda
for Civil and Mechanical Engineers

Ib7 OF ENGINEERING FOKMUXÆ« RAILWAYS. Parliamentary Regulations fob Railways . Crossing Roads. Turnpike road. Public road. Occupation road. dear width of under bridge, or approach Clear height of un4er bridge for a width of 12 feet .. Ditto, for a width of 10 feet Ditto, ,, „ 9 „ Ditto, at springing .. ,. Over bridge. Height of parapets Approaches. Inclination . Ditto. Height of fencing . ft. in. j-35 0 j 16 0 12” 0 J- 4 0 1 in 30 3 0 it. in. 25 0 15 0 12” 0 4 0 1 in 20 3 0 ft. in. 12 0 14 0 4 0 1 in 16 3 0 LIMITS OF DEVIATION. In towns, 10 yards each side of centre line. In the country, 100 yards, or 5 chains nearly. DEVIATIONS OF LEVEL. In towns, 2 feet. In the country, 5 feet - •• ' DEVIATIONS OF GRADIENT. Gradients flatter than 1 in 100, deviation 10 feet per mile steeper. Ditto, steeper, 3 {pet per mile steeper. DEVIATIONS OF CÜRVE. Curves upwards of I a mile radius, may he sharpened to j mile radius. Curves of less than | mile radius may not be sharpened.