Annual report of the Boston Transit Commission, for the year ending .. . First Annual Report. 51 this the inbursts so frequently occurred that finally, in 1809,after many trials and large expenditure of money, the workwas abandoned. The well-known tunnel of the elder Bruneiwas begun in nearly the same locality in 1825, and com-pleted 17 years later, after encountering many dangers anddifficulties. Its cross-section is a double arch 38 feet wideand 22^ feet high, both of these dimensions being portion of this tunnel under the river is said to havecost about $2,800 per linear foot. B
Annual report of the Boston Transit Commission, for the year ending .. . First Annual Report. 51 this the inbursts so frequently occurred that finally, in 1809,after many trials and large expenditure of money, the workwas abandoned. The well-known tunnel of the elder Bruneiwas begun in nearly the same locality in 1825, and com-pleted 17 years later, after encountering many dangers anddifficulties. Its cross-section is a double arch 38 feet wideand 22^ feet high, both of these dimensions being portion of this tunnel under the river is said to havecost about $2,800 per linear foot. Brunei invented and used a complicated shield, which wasa most important factor in his work. Most or all of thesub-aqueous tunnels that have since been driven in softground have been of independent circular tubes of com-paratively small diameter. Shields for such cylindricaltunnels, the art of using them, and the art of quickly build-ing the walls of the tunnels themselves, have been greatlyimproved during the last 25 years. The use of compressedair for horizontal tunn
Size: 1318px × 1897px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbostonma, bookcentury1800, bookdecade1890, bookyear1895
