Ashcroft Bridge
Location: Ashcroft, BC Contract Value:
This five span bridge at Ashcroft, BC replaces a 60-year-old truss structure. The installation of the new bridge was 783 feet long and 280 feet wide. It posed an erection problem as the Thompson River becomes a torrent during run off. KWH chose to launch the steel trapezoidal bathtub girders from both sides, closing in the middle. The bridge was launched over a roller system that KWH/Somerset Engineering designed to minimize the critical web buckling stresses. The rollers were mounted on rocker beams which also simplified passage of plate thickness changes. Somerset designed a falsework bent, an expandable spreader bar lifting system and a launching nose. An innovative hydraulic push-grip mechanism was conceived to replace the pulling hoist and reeving operation which is conventionally used. Later a scheme to dismantle the old bridge was engineered. The 280-feet main span cantilever deck truss was removed from the center back, piece by piece.
