Canadian engineer . f the bridge, but only for a width of 7 feet overeach track. It was, therefore, possible, by arranging thefloor-beams to come between the tracks of the CanadianNorthern, to allow their bottom flanges to be about 2 feetlower than the bottom of the stringers and main side girders are 31 feet apart and the bending momentOn the floor beams consequently large, so that the extradepth thus obtained for them was most desirable. Thecross section of this span is typically the same as thatshown for Thistle Lane on Plate No. i, but the outer railhas no superelevation as at
Canadian engineer . f the bridge, but only for a width of 7 feet overeach track. It was, therefore, possible, by arranging thefloor-beams to come between the tracks of the CanadianNorthern, to allow their bottom flanges to be about 2 feetlower than the bottom of the stringers and main side girders are 31 feet apart and the bending momentOn the floor beams consequently large, so that the extradepth thus obtained for them was most desirable. Thecross section of this span is typically the same as thatshown for Thistle Lane on Plate No. i, but the outer railhas no superelevation as at Thistle Lane, and there are buttwo lines of stringers under each track instead of span is divided by the two floor beams into threepine!s. The stringers—two under each rail—are built gid-ders, 30K in. deep. The floor beams have 60x34 in. websand a flange composed of two 8x8x^ in. angles, one 17X 11/16 in. plate and one 17x54 in. plate. The bottomflange is curved up at the ends to meet the bottom of the. Fig. 3.—Curved Western Approach, Looking From the East. main girders. The girders are 8 ft. deep, 3 ft. 3 in. belowthe rail and 4 ft. 9 in. above, and consist each of a yO x Hin. web and flanges of two 8x8xM in. angles, one 17x5^in. cover plate and two 17 x % in. cover plates. The material and general dimensions of the four truss spans over the river are indicated on PlateNo. 2, and Photo No. i gives an idea of the appearance ofthe completed bridge. The spans have 6 panels of 25 and are 32 ft. o in. deep, centre to centre of chords and31 ft. 3 in. wide centre to centre of trusses. The maindiagonals in the two centre panels were reversed from thecustomary direction, making them compression memberswhen there is a symmetrical arrangement of the live adds to the appearance of the truss, and it was alsofound to be economical on account of the reversal of stressin these members. The trusses are cambered iH in. atthe centre. Longitudinal
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishertoron, bookyear1893
