The wonderful tubular bridge, 6,592 feet long, built by Ross and Stephenson across the St. Lawrence River to carry the Grand Trunk Railway into Montreal.
THE BRIDGE AS RECONSTRUCTED
The continuous tube carrying a single track was converted into an open truss girder bridge to take two sets of metals, tramway line, road and pavement.
However, its construction constituted a vital part of the contract. Accordingly, the contractors lost no time in attacking the undertaking when they secured a foothold in the Dominion. The river was surveyed minutely up and down for a considerable distance, while detailed soundings were made to discover the extent and nature of the foundations requisite for the piers. After infinite labour a suitable site was discovered, and a great measure of credit for the location is due to Alexander M. Ross, who was one of the engineers to the undertaking, George Stephenson acting as consulting engineer. Ross carried carefully prepared and detailed plans of the structure he had formulated to his coadjutator in England, and Stephenson admitted, when first submitted to his notice, that “the idea was certainly startling.” However, he complimented Ross upon his daring, and as the latter engineer had won his spurs in England before he departed to Canada on behalf of the group of capitalists financing the Grand Trunk railway, his work received greater consideration from the eminent engineer than might have been the case otherwise. The result was that when Stephenson went to Canada to consider the subject on the spot he concurred with Ross in the general scheme, and the design was elaborated conjointly.
When the location was settled definitely, the project was assailed vigorously by bridge designers in America, but this animosity was inflamed from the fact that they had prepared alternative proposals for bridging the waterway at a different spot. The rival engineers emphasised the danger from ice, and commented strongly upon the risk, in fact serious danger, arising from this cause, to the full brunt of which Stephenson’s bridge would be submitted. Some critics even went so far as to state that the structure never would be completed, or if so, would come down under the first packing of the ice. Stephenson, however, treated his American detractors with contempt, and, to the mind of the latter worthies, appeared to fly deliberately in the face of Fate by concurring with Ross’s recommendations. That was nearly sixty years ago, but the piers have given no sign of collapsing yet.
The resident engineer and superintendent of the constructional work, Mr. James Hodges, realising the monumental character of the undertaking—for it was a larger bridge-building scheme than ever had been attempted up to this time—spent many hours together wrestling with difficulties as they developed, for the unexpected confronted them at every turn. The ice was one of their greatest perplexities, because during the winter the river is frozen so solidly that it will support the weight of a train, and, indeed, a track has been laid across the waterway in winter to maintain communication between the two banks. When the ice broke up, the floes became jammed and piled against the temporary works around the piers in an inextricable mass to such an extent that it demanded unremitting vigilance to guard against a collapse of the dams under the enormous pressure exerted upon them.
The depth of the river and the current were two other factors which had to be taken into serious consideration, for some of the piers are sunk in twenty-two feet of water, while the velocity of the current is about seven miles an hour. The working season was very short, averaging about twenty-six weeks during the year, and during this period every available man had to be crowded on to the work. When construction was in full swing, between 2000 and 3000 men found employment.
Photo by permission of the Pennsylvania Steel Co.]