angles between the top flanges of the contiguous girders for each track.

In half-through spans the girders are to be divided up into panels generally not exceeding fifteen (15) feet in length. If a steel floor system be used, there are to be brackets of web-plates and angles at the ends of the cross-girders extending to the top flanges of the longitudinal girders, so as to stay the latter effectively; while, if a wooden floor system of ties resting on shelves or on the bottom flanges be used, there are to be steel cross frames with solid webs, of the greatest depth obtainable, with similar brackets at their ends for the same purpose. Half-through plate-girder spans are to have a rigid, double-intersection, lower lateral system of angles riveted together by plates and angles at their intersections and to the bottom flanges of the steel stringers, if the latter be employed.

Web-stiffeners shall be placed at the ends of plate-girder spans, also at all points of concentrated loading and at intermediate points at distances not exceeding either the depth of the girder or five (5) feet, except in the case of shallow girders where the shear, including impact, does not exceed five thousand (5000) pounds per square inch of web section. Under such circumstances the spacing of intermediate stiffeners may be made as great as three (3) feet six (6) inches.

All stiffeners must bear tightly at top and bottom against the flange angles. Under end stiffeners there must be fillers flush with the flange angles, but intermediate stiffeners shall, preferably, be crimped. All stiffeners must be in pairs.

End stiffening angles shall in no case be less than 3 1/2" X 3 1/2" X 3/8", net, and must have sufficient area to carry the entire end shear, including impact, with the specified intensity of working-stress, no reliance being placed on the fillers.

The sections of intermediate stiffening angles shall not be less than those given in the following table.