Bridge Moving
by Modern Methods
Six men moved the 120 tons of wood and iron contained in one span of the Wabasha street bridge, St. Paul, 50 feet Wednesday, and they didn't make much fuss about it as an expressman would in getting a trunk upstairs. The men were not unusually tired after their feat, for screws and compound levers accomplished what their hands could never have done and completed a task in which it would have been dangerous to have used machinery. By the aid of screws and rollers the men pulled the bridge the entire distance in eight hours. The lifting and trussing of the bridge requiring a week or more, and it will take almost that long for each of the other two spans that will have to be moved. After all this is done the approaches will have to be shaped up and the connection made with the permanent portion of the bridge. An attempt was made at first to move the bridge without the use of rollers, but it was found the friction was too great and that it could not be done. The rollers are simply iron bars cut in short sections, and as fast as they roll out from under the plate they are placed in front again. A screw mechanism is employed at each end of the span. In moving the bridge it is necessary to exercise the greatest care to avoid demolishing the old piers. The contract for moving the old bridge amounts to $7,500 and for building the approach $40,995.
A photo from the January 1900 issue of the Journal of the Association of Engineering Societies - thanks, Google Books -- shows a 120-ton section of St. Paul's Wabasha Street bridge being maneuvered into place.
The fourth Wabasha Street bridge, shown here in about 1900, was listed in the National Register of Historic Places in 1989. (Photo courtesy of Minnesota Historical Society)
