The Railway Conquest of the World

by Frederick Arthur Ambrose Talbot

One of the latest and most interesting, as well as largest undertakings of this class, is that in connection with the Curzon railway bridge over the Ganges at Allahabad, for the Allahabad-Fyzerbad railway. At this point the river flows between high banks of hard clay about 3 miles apart, and so resistant is this earth to scouring action that erosion has been brought to cessation practically. The width of the waterway, however, is about 1¼ miles, and when it was decided to span the river, a great length of steel appeared inevitable.

ERECTING THE PIERS FOR THE CURZON BRIDGE

The training-bund is to be seen in the background.

The engineer-in-chief for the work, Mr. Robert R. Gales, M.INST.C.E., however, decided to cut down the length of the bridge-work to 3000 feet. The project was examined at great length, owing to the fact that the difference in the level of the river during the dry and flood seasons is not less than 31 feet, as the Ganges receives the waters of the Jumna about 7 miles above the site selected for the crossing. Careful investigations, however, pointed to the fact that the accumulated waters could be directed safely through a channel some 3000 feet wide, and accordingly the erection of the training-bund was taken in hand on the left bank. It measures some 4000 feet in length from end to end, and the top is 5 feet above the flood-level of the river. The up-stream arm measures 3,300 feet in length, and the extremity ends in a sharp curve to mitigate the effects of scouring. Viewed from the bank, the work resembles a huge letter “L,” with the bottom arm pointing up-stream, and the tail overhanging for about 700 feet, while the upright member forms the embankment connecting the training-wall to the shore, and leads the railway track to the bridge.

The training-wall is built up of sandy soil, with stone pitched on the face exposed to the action of the river. At the top it is about 20 feet in width, and carries a wide-gauge railway track from end to end, so that should the floods tear a gap in the embankment, the injury can be repaired immediately by dumping spoil into the breach from railway wagons.

Erection had to be hurried forward, as the season available for operations was so short. In view of the fact that the erection of the wall entailed the handling of some 50,000,000 cubic yards of earth, some idea of the magnitude of the task may be gathered. It was split up into a number of contracts, and when the operations were in full swing no less than 7000 coolies found employment.

While this work was in progress the bridge itself was pushed forward. The length of metal is 3000 feet, divided into 15 spans, each of 200 feet, carried upon masonry piers. The bridge was called upon to meet requirements not only for railway traffic but for pedestrians and vehicles as well. A single line of 5 feet 6 inches gauge suffices for the former, which is carried upon the bottom deck, while the upper deck meets the second requisition, being 23 feet wide and about 60 feet above the level of the waterway when in flood.

The undertaking was pushed forward with such energy that it was completed in three seasons. The saving in outlay resulting from constricting the river channel, and thereby reducing the length of steel-work, represented no less than £100,000, or $500,000. This offers a convincing illustration as to the ingenious manner in which the bridge engineer in India has succeeded in reducing the costs of spanning the noble waterways of the country.

In a far-away corner of the same country, Upper Burma, may be seen another interesting example of the bridge-builder’s craft, carried out under particularly exacting conditions in a forbidding country. This is the Gokteik Viaduct, which carries the metre-gauge single track of the Burma Railway Company across the gorge of the same name. This structure was completed by the Pennsylvania Steel Company, of Steelton, Pennsylvania, and the award of the contract was criticised severely in Great Britain. But the Government wanted the valley spanned in the shortest possible space of time and at a moderate price. When the tenders invited from all parts of the world were opened, it was found that the British firms had been outclassed by their American rivals in both these essential factors.