Engineering Wonders of the World
Volume III

284 ENGINEERING WONDERS OF THE WORLD. 8, 10, 12, and a main line of bars to panel point 14. With the exception of the last, these bars had a screw adjustment at their lower ends. That running to panel point 14 was of exactly the length calculated to be sufficient. After the closing of the arch all these bars were, of course, removed. Work on the foundations began on Sep- anchor bars. Then the toggle joints were opened to pull the first bent back slightly, and give the cantilever such an upward inclination that the sagging caused by the gradual addition of weight should bring the extremity of the cantilever into the exact vertical position for closure with the end of tho other cantilever. ALL STEELWORK ERECTED, JULY 31, 1897. Foundations built. to be brought tember 9, 1895, and was completed on the first day of the following June. The heaviest items to be handled were the pedestals of the arch, weigh- ing 16 tons each, which had to the edge of the gorge on both sides of the river and lowered into place by means of tackle attached to the cables of Cantilevers commenced. the suspension bridge. When the hinges were in place, the arch was built out to panel point 2 on timber falsework, and attached at that point to the first of the secondary Handling- Material. Owing to the non-coincidence of the centre lines of the old and new bridges, the handling of material could not be effected as conven- iently as in the case of the railway arch, and the stiffen- ing trusses of the suspension bridge had to be employed to support for cranes with jibs swinging out laterally. To avoid undue twisting and straining of the trusses, loads had to be lowered from both sides of the cranes simultaneously, and the weight of a single load had to be restricted to 6 tons. Interference of the truss suspenders