ERECTION 0¥ THE GOKTEIK BRIDGE. 



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and weighing SO tons. Its maximum lifting capacity is 30 tons. 

 It consists of 3 trusses, two of which are connected by transverse 

 bracing, built on the cantilever plan, each being 219 feet in length, 

 ■10 feet in height, and separated by a width of 24^ feet. The lower 

 chords of the traveler supported four trolle}^s, each provided with 

 a chain hoist having a lifting capacity of 16 tons. Powerful clamps 

 were especially designed for holding the rear end of the traveler 

 to the girders of the viaduct, and it was supported on a series of 

 wheels enabling it to be easily moved as the work progressed. 

 Most of the material was lowered from above by the traveler. In 



Gorge ami main towers with bridge under construction. 



erecting the towers crossing the deepest portion of the gorge a tem- 

 porary track was built on a wooden trestle at an elevation of about 

 100 feet above the base, and material for the lower parts of the towers 

 hauled to the spot and transferred to their positions by special derrieks. 

 An idea of the quantity of material placed in position can be gained 

 when it is stated that it comprised most of the cargoes of three steam- 

 ships, and when loaded on the cars at Steelton, Pennsylvania, repre- 

 sented a solid train li miles long. The erection plant alone weighed 

 250 tons, and. in addition to the traveler, included three hoisting 

 engines, a series of air compressors, a telephone system for communi- 

 cation between the gangs working at each end of the viaduct, and the 



