The Canso Canal, which connects Chedabucto Bay and the Northumberland Strait, was opened to shipping traffic in 1955. The passage of vessels through Canso Canal is controlled by two pairs of sector gates, which are located at the northern and the southern entrance of the canal. While passing through the canal, each vessel is required to come to a complete stop at a predetermined location upstream from the sector gates. The gates are then opened to allow the vessel to exit the canal.

Each gate, weighing about 150 tons, is operated by a mechanism supported on a reinforced concrete recess cover slab. The slabs had deteriorated due to advanced age and to the severe climatic conditions prevailing in the Strait of Canso. A failure of the slab could potentially disrupt the canal operations.

SHM Canada was commissioned to carry out detailed structural investigation, to make recommendations, to design the replacement of the slabs at the north end of the canal, and to conduct construction reviews. The new design includes the use of high-performance concrete and incorporation of galvanized structural steel sections to transfer concentrated loads to the side walls.