Tunnel under the Elbe at Hamburg

Progress, Volume VI, Issue 12, 2 October 1911, Page 838

Tunnel under the Elbe at Hamburg

Our German Correspondent A tunnel under the Elbe at Hamburg became absolutely imperative owing to the immense expansion that Hamburg underwent in the last few years. it was impossible to replace it by a bridge, since that would have acted as a serious impediment to the marine traffic. Hence it was decided to begin the difficult work and to lay a double-tube tunnel. The two tubes are at a distance of two meters (6 from each other. In each tube the traffic is only in one direction. There is a passage in the middle for vehicles and a footpath on either side. .For a short distance in the middle of the river, the bottom is exactly horizontal. As the banks are approached it ascends imperceptibly. flic tubes are made of iron rings riveted to each other and reinforced with concrete on the inside and outside. The walls are covered with tile The successful completion of this tunnel in three years reminds one of the construction of the London Thames Tunnel by Isambert Brunei, which was built 70 years ago, only after surmounting the worst difficulties and after a loss of about seventeen years. A company was formed in 1824 to construct the tunnel, and began its work in 1825. The banks to bo joined were about 400 metres (1250 feet) from each other. The tunnel is composed of two vaults running beside and touching each other, and containing a passage for vehicles and a footpath. The work began with sinking a large shaft about to feet deep on one side of the river, at liotherhithe. Above this shaft was placed a steam engine for transporting Ihe earth removed. In 1820, they began to drive the tunnel, and on June 80 of the same year it had proceeded so far that they were under the bed of tin; stream. It was soon discovered, however, that between the upper edge of the tunnel and the bed of the river, there was a layer of earth only 9 feet thick. This was not strong enough to prevent the water of the river from coming through. The situation became critical. Brunei examined the bed of the river in a divingbell, and tried to stop the inpour of the water, which was becoming dangerous, by sinking layers of clay and loam into the Thames. A misfortune befell them, when some sailing boats cast anchor just above the tunnel and caused so much water to How into the tunnel that the steam pumps could not master it. On May 18, 1827, the tunnel was under water in 15 minutes, happily ■without any lives being lost. Brunei again examined the bed of the river and found that the tunnel was not damaged. The hole made by the inflow of the water was filled with earth, the tunnel pumped out. and work resumed. More inpourings of water, costing the lives of six workmen, repeatedly interrupted the work, but without diminishing the courage of Brunei. Then there was a want of funds, which stopped the work for seven years. Finally, the State placed the requisite sum at his disposal. On August 13, 1841, the tunnel was so far finished that it could be passed through. It required a year and eight months more for the building of the entrances.