Due to limited space and excessive pick radii at the Dollarton Highway Bridge, North Vnacouver, BC, it was determined that a typical high tonnage crane would be too costly to erect these 36 precast box stringers, weighing 60T each. KWH designed, built and operated a custom gantry crane suited to the irregular layout of the piers.
The gantry used a trolley system to move the girders longitudinally. The entire gantry was mounted on rollers and runway beams in order to align the stringers laterally and to reposition itself for each stringer.
In order to keep the traffic flowing, half of the new bridge was constructed and opened, then the demolition of the old bridge and construction of the remainder of the new bridge followed.