The St. Clair tunnel.

The American Society of Civil Engineers met at Detroit, Mich., during the last week in July, & during the meeting paid a visit to the St. Clair Tunnel. The Grand Trunk provided a special train which took members to Port Huron, & there they were taken on a train of new gondola cars & pushed through the tunnel by one of the famous engines used for working the tunnel. Considering the stories that have recently gone about concerning the destructive action of engine gases, this visit to the tunnel was of special interest to some members of the party. It was learned from Chief Engineer Hobson, of the G.T.R., that the only corrosion that has been serious enough to be considered at all was that of the steel bolts through the flanges, of the cast iron segments making up the tube. The tube itself has not been appreciably affected. These bolts have been renewed where corroded & the bolt heads & nuts covered by concrete, which has been put in to fill the angle made by the flange with the cylindrical surface of the tube. It will be remembered, doubtless, that the lower half of the tube was bricked up at the outset & faced with concrete, flush with the flanges. The return trip through the tunnel was made within 5 minutes or less after the first trip, & there was very little gas or smoke in the tunnel; it could not have been disagreeable except to an unusually sensitive nose. The engines burn anthracite. The scheme of working requires a minimum interval of 10 minutes between the passage of engines. There is no doubt that the loss of the lives of 2 men a year ago or so, because of the breaking-in-two of a freight train in the tunnel, was due to the carelessness of the engineman & his disregard of the definite instructions for working in the tunnel. Nevertheless, the consequences of an accident of any sort which should keep a trainload of passengers & an engine or two in the tunnel would be so terrible that some other motive power will probably be adopted, if it can be done with reasonable cost & efficiency of working. The Co. is now considering compressed air motors. Obviously, the problem is novel in some particulars, as there is no precedent for motors of the powers which must be used in this tunnel.—Railroad Gazette.

Railways: G.T.Ry.

Results