Engineering Wonders of the World
Volume I

390 ENGINEERING WONDERS OF THE WORLD. rig. 5.—THE DELTA BARRAGE, FROM UP-STREAM. however, this scheme was abandoned ; the impetuous ruler of Egypt had lost interest in it. Seven years later Mougel Bey proposed the erection of a barrage in the position of the present structure. His designs were com- pleted in 1843, and in that year work was begun upon the barrage now standing. From the first the undertaking was unfor- tunate. The engineers were hustled over their work, and the foundations, in consequence, . _ proved defective when first A Failure. put to the test. Abbas Pasha, who succeeded Mohammed Ali in 1849, had no faith in the barrage ; and Said Pasha, his suc- cessor in 1854, thought as little of the barrage as a barrage. But he entertained the com- forting idea that by a timely manipulation of the dam sluices he could so flood the whole of the Delta provinces as to sweep away any enemy advancing from that direction. Said Pasha also believed that, by making the bar- rage into a fortress, he could deal destruction to any fleet that might chance to sail down- stream on the alluvial flood. The fortifica- tions were begun in 1856, and, with the super- structure of the dam, finished in 1863. At this date sluice gates were fitted on the Rosetta branch only, and when they were used serious signs of weakness showed in the barrage. Water passed underneath, and welled up on the down- stream side. Further defects appeared in 1867, and from that date until 1884 the barrage remained idle. Then, under the direction of British engineers, the Damietta branch was provided with gates which, were used with some effect during that and the following year. But the whole structure was now ex- hibiting signs of instability. In 1890, after the old floor had been strengthened with a thick layer of masonry and extended up- stream and down-stream, the dam was rend- ered capable of holding up a head of thirteen feet of water. As a result, it is claimed, the record of the heaviest cotton crop—3,275,000 cwt.—before that undertaking, was raised to 3,640,000 cwt. the year following its com- pletion. The foundations of both branches were further consolidated in and about 1898 ; 6-inch boreholes,aggregating miles in length, were drilled through the piers to the founda- tions, and filled with cement grout, and sub- sidiary weirs were added down-stream. With the work thus strengthened, a further seven feet of water could be held up. This com- pleted the building of the first barrage. The Rosetta and Damietta branches of the barrage are respectively 1,525 and 1,765 feet long. Each, branch, has sixty-one arched sluice openings, 16'4 feet wide, separated by piers 6'6 feet wide, and 52 feet f^om back to front over the cutwaters. The cutwaters, ends of arches, copings, etc., are constructed of ashlar, the remainder of the superstructure of brick- work, and the foundations of concrete. Each sluice opening is provided with, two wrought- iron sluice gates sliding in cast-iron grooves fixed in the piers. The upper sluices are 8 feet 4 inches high, and the lower 3 feet to 8 feet high, according to the varying levels of the floor. They are furnished with friction wheels, and can be raised clear of the water level at flood time by means of hand wind- lasses. In connection with both branches locks have been placed for the accommodation of boats passing up and down the river. It may interest th© reader to describe here two methods used in 1843 for establishing the