The result of these investigations served to countercheck the surveys, which were found to be strikingly correct, and the design of the bridge was taken in hand immediately by Mr. G. A. Hobson.
Actual construction was commenced without delay, the task being undertaken by the Cleveland Engineering & Bridge Building Company of Darlington, who, by the successful completion of this task, once more emphasised the predominance of the British bridge-building engineer. The main span is a graceful curve of steel springing from the cliff-face on either side, the latter being excavated for the purpose of securing the foundations. As construction was possible only on the cantilever principle from either side, facilities had to be provided for the transportation of material as it was brought up by the railway, from the south to the opposite cliff, and for this purpose an overhead cableway was slung across the gorge. This vehicle of transport was employed not only for the building of the bridge, but also for the conveyance of other necessities for the railway, as the latter was pushed ahead from the north bank while the bridge was being erected. Workmen were also slung across the gorge by this means in a little cage, and occasionally visitors who were anxious to experience a new sensation made the trip at a cost of 10s., or $2.50 per head.
Photo by courtesy of Cleveland Engineering & Bridge-Building Co., Darlington]
THE GREATEST BRIDGE IN THE WORLD
The steel link springing in a single span of 500 feet from one cliff to the other over the Zambesi River just below the Victoria Falls. The trains pass across the gorge 420 feet above low water. Observe the net which was suspended below to catch falling tools and workmen.
One feature of the undertaking was the extreme care taken to protect the workmen from certain death in the river below if they slipped from their precarious perches in mid-air. A heavy, strong net was slung across the chasm beneath the actual working point to catch “boys and tools should they inadvertently drop.” The two ribs of steel were pushed outwards from either bank, and finally met in the centre, where the final bolts, securing first the two sections of the bottom members together, were slipped in without any untoward incident. At the point where the maze of steel springs from the cliff-face the bridge measures 105 feet from the bottom to the top member, while at the crown of the arch the depth is 15 feet. The width at the rail-level is 30 feet, while the bottom curved steel ribs, at the point where they are secured to the rock, are about 54 feet apart.
SETTING UP THE WORLD’S RAILWAY BUILDING RECORD IN AFRICA
Natives laying 5¾ miles of track in 10 hours, on the Cape to Cairo Railway.