Handbook of construction plant, its cost and efficiency (1914)
Dana, Richard Turner, 1876-1928 · Chicago, The M. C. Clark Publishing Co. · leaf 639
of a bottomless box. It isoperated as follows: When near grade the shield is set on thetrench bottom in the position illustrated, with its open endstraddling the end of the completed pipe. Hay is then stuffedinto the spaces between the sides of the pipe and the sides of theshield to keep the mud… … TRENCHING MACHINES 635 and jointed inside the shield, which meanwhile acts as a tempo-rary cofferdam. Only general figures are available on the cost of this work.Mr. Hall states that for depths of 10 ft. and less the cost has
Contractors' operations · Building
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