Measuring some 4 km in length, the Champlain Bridge has six lanes with a total width of 24 metres. It was the first Canadian infrastructure to use prestressed concrete, with metal rods to reinforce it. Altogether, 476 girders were constructed in a special yard set up on Nuns' Island. Two overhead travelling cranes carried the girders along 2.5 km of track to their installation site.
The steel superstructure of the elevated portion of the bridge (49 metres high) was built by Dominion Bridge. Since scaffolding and floating cranes were not permitted in the Seaway channel, the engineers cantilevered the central span. This technique implies a greater risk of imbalance or failure during construction should there be an excess load, because the span is unsupported.
Assembled right in the river, at an average depth of 12 metres, the four slender piers were designed to withstand the pressure of the heavy ice flows in this turbulent stretch of the St. Lawrence.
The project engineers in Montreal had to devise specialized, innovative and efficient equipment to deal with various constraints, such as the length and weight of the structure, a climate that slowed work during the winter months, and a critical construction schedule.