Engineering and Contracting . ets, ofwhich there were appro.\imately 60,000, ^in. diameter, were driven by means ofpneumatic riveting hammers, a compressedair plant having been installed for the pur-pose. center to center, under the end floor beam,which had been designed with a specialview to such use. This arrangement of thecastings left a clear space under the trussbearings for landing of the span on oakblocking over the bridge seats preparatoryto its being jacked down to its oak blocking was required for thetemporary support of the span at an eleva-tion about 8 ft. 514 ins. hig
Engineering and Contracting . ets, ofwhich there were appro.\imately 60,000, ^in. diameter, were driven by means ofpneumatic riveting hammers, a compressedair plant having been installed for the pur-pose. center to center, under the end floor beam,which had been designed with a specialview to such use. This arrangement of thecastings left a clear space under the trussbearings for landing of the span on oakblocking over the bridge seats preparatoryto its being jacked down to its oak blocking was required for thetemporary support of the span at an eleva-tion about 8 ft. 514 ins. higher than its fi-nal position, this height being necessary topermit the skidway to pass over the para-pet wall of the abutment. Before the afore-mentioned cast iron shoes and the skidwayrails was placed a ^-in. steel plate, largeenough to include both castings, with stripsriveted to its under side to form guides toengage the rails on the skidway. When the scow was in position under theoverhanging end of the main span, in front. Before faWng Before Clearirq Sponreaoyfor Fwea&ainLoad on Scow, oway fracK Jocx-ct Dc^^ Fnal Position Enq-Contr Plan, Elevation and End Views of Skidding Track and Jacking Operations. about 4 ft. by pumping in water. As thiswater ballast would render the scow un-stable transversely until it took a bearingunder the 415-ft. span, it was necessary touse a small balancing scow, which wasplaced at the north side of the large scowand secured to the latter and the stiffeningspan, by means of diagonal and horizontalstruts, and was equipped with counter-weight and adjusting screws to provide forany raising or lowering of the large general dimensions of the large scowreferred to, which was buih at the site,were: Length, 155 ft.; 33-ft. beam and 12ft. deep; made in two sections for con-venience in launching. It was built of I2x12 timbers for the ends; bulkheads and in-termediate frames, 6x12; sheeting on thesides, 4x12 for the bottom, with
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Keywords: ., bookcentury1900, bookdecade1900, bookpublisherchicago, bookyear19
