Pittsburgh Paper - A New Method of Laying Submarine Tunnels and Tubes

The device to which I desire to call the attention of the members of the Institute consists of a water-tight caisson, which is connected By a stuffing-box with the tube to be laid, and the caisson is pushed forward with hydraulic jacks set against the end of the tube. The tube is of hard white iron, cast in chills in segments. These segments are carried from shore through the tube itself, in which a track is laid as the work progresses, and the segments are bolted together in the caisson, where there is ample room to work and proper appliances for handling heavy weights. As each segment is bolted on, the jacks are set against its forward end, and when the whole ring is complete, the caisson is pushed forward by the jacks, a trench having been dredged out in front of it, or, in very loose ground, jets of water under a heavy pressure can be thrown out to loosen the ground in front of the caisson. The direction in which the caisson is pushed is completely under control, and both the caisson and the tube are loaded to the amount necessary to overcome their buoyancy. I understand that Mr. H. H. Hall, of New York, the inventor, is negotiating for the construction of a 16-foot tunnel of this kind across the Straits of' Northumberland, between Prince Edward Island and the main-land, and for tunnels in several other places. 4 One of the most interesting uses of this system is in laying water mains out into lakes. The work can be carried on without inter-