. The street railway review . STREET RAILWAY REVIEW. (Vol. XIV. No. 9. decidcil tu tiiiiUI the girders citit of stock steel, and cuiistnict ilu-truss work nut of wood and iron rods. On May l8th all of ilic btrntswere capped and work was inina-diately begun to erect the lioistini;frame, which is (io ft. high and 61 ft. long. Most of the frame-work was done un the ground, so that as much of the labor as possible could be avoided after the trusses were got into the air. Verynearly all of the limber used was 8 x l2-in. slicks, except those useil Ihe longitudinal plate girders, 4K ft. ■ in. long an
. The street railway review . STREET RAILWAY REVIEW. (Vol. XIV. No. 9. decidcil tu tiiiiUI the girders citit of stock steel, and cuiistnict ilu-truss work nut of wood and iron rods. On May l8th all of ilic btrntswere capped and work was inina-diately begun to erect the lioistini;frame, which is (io ft. high and 61 ft. long. Most of the frame-work was done un the ground, so that as much of the labor as possible could be avoided after the trusses were got into the air. Verynearly all of the limber used was 8 x l2-in. slicks, except those useil Ihe longitudinal plate girders, 4K ft. ■ in. long and j ft. deep,arc on 6-ft. centers, anil weigh, complete with end girders and deadload of ties, rails, etc, 2i>.ioo lb. Each counter-weight is a specialcasting 4 ft. 6 in. by 23 in., weighing, stripped, 10,000 lb., and hasadditional weights so that it may be increased to 11,680 lb. It wasfound that 10,300 Ih. very nearly balanced the bridge when it was inany position. Flexible plow steel ^v. cables are fastened to end of. -l>K.\« IIUIDUE DlEN. on the curve, which were 4 x 16 cut down to 4X 12 to get the n-quired parabolic sweep. The entire framework consists of twopairs of 8xi2-in. twin trusses on 15-ft. 6-in. centers, each pair oftrusses lO-yg in. apart. In constructing the curves or runs, shortlengths of timber were taken advantage of to get the requiredcurvature. Bolting the 4x 12-in. pieces together and breaking jointsmade up the 8 x 12-in. finished run. In fastening the 4 x together, two rows of bolts were used, one each edgeon 2-in. centers and staggered. All the truss members were mortised and tenoiicil, using a 4 x and l^-in. oak pins. .y member subject to tensile strainwas paralleled with l-in. wrought iron rods. The erection of thehigh framing over the water was greatly facilitated by making useof a pile driver and its rigging. All lumber used throughout the bridge and run over cast-iron sheaves on top of the Irame to thecounter-
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Keywords: ., book, bookcentury1800, bookdecade1890, booksubjectstreetrailroads
