. The Street railway journal . orms beingsupported at one end on the skew-back and at the other endattached to a set of steel rods suspended from an A-frame atthe end of the arch. One of these A-frames was set at theabutment and anchored back to the piers of the trestle ap-proach to the bridge; the other A-frame for the first archwas set on the pier at the other end of that arch and an-chored back to the second pier. The anchors for each A-frame, consisting of i^-in. round steel rods, which were ini6-ft. lengths, connected by sleeve nuts. Turnbuckles werealso provided on these rods so that the
. The Street railway journal . orms beingsupported at one end on the skew-back and at the other endattached to a set of steel rods suspended from an A-frame atthe end of the arch. One of these A-frames was set at theabutment and anchored back to the piers of the trestle ap-proach to the bridge; the other A-frame for the first archwas set on the pier at the other end of that arch and an-chored back to the second pier. The anchors for each A-frame, consisting of i^-in. round steel rods, which were ini6-ft. lengths, connected by sleeve nuts. Turnbuckles werealso provided on these rods so that the length of the anchorscould be adjusted. A series of eight ij^-in. round steelrods, each provided with a turnbuckle, radiated from the topof each A-frame. These rods each supported two shorteri-in rods diverging to the sectional rib forms. These shorterrods were connected to U-bolts on the lifting frame carryingthe assembled pairs of sectional rib forms, and supportedthe latter until the rib forms for one arch had been PLACING KEYSTONE IN ARCH In addition to the 4-in. x 6-in. timbers of the carrying framein which the pairs of rib forms were assembled, two lightwooden frames on each pair of forms were used to bracethe latter. The second sectional pairs of forms were broughtinto position after the first had been placed, and the twosections of that pair supported at one end on the two sections 1 SEPtEMBER I, 1906.] STREET RAILWAY JOURNAL 345 of the first pair and at the outer end by the second set ofrods attached to the A-frame. The connection between thesectional form was made by steel dowels placed in gas pipesbuilt into the inside lower corners of the sections as thelatter were cast, and in some cases by wooden blocks fittedto the inside of the section. In this manner the remainderof the sectional forms were placed in position and supported. The keystone of each set of arch rib forms required nosupport other than that supplied by the two sectional formsadjacent to it.
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
