Engineering Wonders of the World
Volume I

434 ENGINEERING WONDERS OF THE WORLD. that their former “ Sahib ” is starting a new job, for a general concentration to take place. Blacksmiths, masons, carpen- Native , , , Workmen ters, masonry inspectors, etc., come from the Punjab ; Path- ans, for digging heavy cuttings, from across the North-West Frontier, and even from Afghan- istan ; Bombay Khallassies or bridge-builders from Bombay ; petty contractors from all parts. Of course these form a nucleus only of the vast army that is required. Arrange- ments have to be made for subordinate en- gineers, clerks, large contractors, Chinese carpenters, etc. Formerly the native of India could not be persuaded easily to face the three days’ sea journey between India and Burma, but now thousands of natives under- take the journey annually, and find employ- ment on the rice fields, public works, and the railway. In the divisional office at Sittang there were so many races of clerks, draughtsmen, etc., that English was the only common language amongst them. For such work as the Sittang Bridge the men chiefly required were Bombay Khallassies. These men belong to a race of hereditary sailors, and are very smart at all work in which the handling of heavy pieces of iron- work is required. The leading men amongst them have usually had great experience, and are very keen on their work. They are just as ready to work in water as on the top of a girder—in fact, they swim like fish and climb like monkeys. Of the ten pairs of cylinders for the piers, six pairs were completed in the first season s work (1905 to 1906). In October 1906, as soon as the rainy season was over, girder erection was started from one end of the bridge on wooden stagings on piles driven Later, when more cylinders First Season’s Work. into the river. had been completed, this work was carried on at both ends of the bridge simultaneously. The steel and cast-iron work for the bridge, amounting to about 2,600 tons, was all made in England and dispatched to Rangoon. Thence it was brought in barges towed by launches, specially purchased for this bridge, through a system of canals which connects the Sittang River with Rangoon. It was decided that the bridge must bo completed as early as possible in 1907, and that therefore everything must be made secure before the rains began. The rainy season generally opened about the middle of May, but the heavy floods did not usually appear till the middle of June. After that date stag- ings were likely to be not only dangerous in themselves, but, if carried right across the river, so serious an obstruction to the river, heavily charged as it always is in the first flood with débris, logs, etc., as inevitably to lead to disaster. Of course, as soon as a span was sufficiently complete the stagings were removed and used for another span. This was comparatively easy, but to draw 40-foot piles that have been driven 10 feet or more into the ground takes time. More- over, the maximum depth of .low water had by this time been increased, by scouring of the bed, from 24 feet to nearly 30 feet. In the circumstances, as it was very neces- sary that the whole railway from Pegu to Moulmein should be opened for traffic before the following dry season (1907 to 1908), it was decided that for the two centre spans, A Novel Scheme. where th© water was deepest, some other method than staging must be employed. The scheme adopted was to float out the girders. The simplest way of floating out is to work at a low level—as was done in the case of the Britannia Bridge—and then to raise the girders by mechanical means to the correct height. In the case under consideration the system of jacking up the girders and building the piers at the same time was not possible with piers composed of cast-iron cylinders made up of