. Manual for railroad engineers and engineering students : containing the rules and tables needed for the location, construction, and equipment of railroads as built in the United States . he caisson and div-ing bell, has been very successfully employed, both in Europe andin America, for the putting down foundations in deep water. Itwas first used at the fine bridge built by the governments ofFrance and Baden across the Rhine at Kehl, opposite Stras-bourg. At this place the bed of the river is composed of an al-most indefinite depth of sand, gravel, and silt, which has beenknown to scour to a
. Manual for railroad engineers and engineering students : containing the rules and tables needed for the location, construction, and equipment of railroads as built in the United States . he caisson and div-ing bell, has been very successfully employed, both in Europe andin America, for the putting down foundations in deep water. Itwas first used at the fine bridge built by the governments ofFrance and Baden across the Rhine at Kehl, opposite Stras-bourg. At this place the bed of the river is composed of an al-most indefinite depth of sand, gravel, and silt, which has beenknown to scour to a depth of 55 feet below low water, and duringfreshets attains a velocity of from 9 to 11 miles an hour. Thearrangement adopted is sketched roughly in Fig. 137, in whichA A A A is a strong boiler plate box, open at the bottom, with * Kuiimis City Bridge, p. 99. FOUNDATIONS. 319 three holes in the top. Through the central hole a tube was in-serted, reaching downward a little below the bottom edge of thecaisson, and extended upwards, as the caisson sunk, so as to ter-minate at the height of the working platform. From the smallerholes ascended the pneumatic tubes, through which the com-. Fig- 137- pressed air was sent into the caisson, and the workmen ascendedand descended. Each air tube was used alternately, the air cham-ber being fastened to one while the other was being caisson being lowered to the river bed by screws, attached tothe platform, and the pier commenced upon the top of the in-verted box, or bell, compressed air is forced in through the tubes, 320 MANUAL FOR RAILROAD ENGINEERS. the water driven out, and the workmen commence to feed theearth under the edge of the central tube, through which it israised to the surface by a vertical dredge, consisting of a scries ofbuckets on an endless chain. These buckets, extending belowthe bottom of the central tube, made thus a hole into which thematerial was easily pushed. The pier was built of concrete,faced with ha
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Keywords: ., bookcentury1800, bookdecade1880, bookpublisherbosto, bookyear1883
