“The Standardizing of Working Loads and Working Stresses for Eailway Bridges.”

THE INSTITUTION OF CIVIL ENGINEERS.

ENGINEERING CONFERENCE.

Section I.—RAILWAYS.

27 May, 1897. (No. 1.)

Considering the importance of the subjects of this Paper, it is surprising that there has been so little reference to them in the Proceedings of the Institution.

Working Loads.—The question of loads to be taken in designing railway bridges had received considerable attention in America, but no general effort has been made in this country to arrive at anything like a uniform system of loads for general use. In America, bridges are generally designed to carry alternative train-loads of two or more types, and the stresses in their structures are taken out on a more rigid basis than obtains in England; but at the present time there appears to be a tendency towards the adoption of a system of uniform loads, or of uniform loads together with one or more concentrated loads, computed so as to produce bending moments and shears approximately equivalent to those obtained from the typical train-loads.