Spencer roped in for Canadian bridge inspection system

The existing Pattullo Bridge, centre, is being replaced

The old Pattullo Bridge, which crosses the Fraser River near Vancouver, British Columbia, connects the municipalities of Surrey and New Westminster. It opened in 1937 but no longer meets modern design standards.

The Pattullo Bridge replacement is being built by Fraser Crossing Partners (FCP), a 50/50 joint venture between Acciona and Aecon, and is expected to open in 2024. Once the new bridge is open, the old one will be removed.

Working on behalf of FCP, Hull-based Spencer Group is designing, manufacturing, testing and commissioning a semi-permanent access system to enable maintenance engineers to inspect all elements of the bridge’s stay cables.

The cradle element, which transports personnel to the desired inspection location, operates similarly to a cable car, moving up and down a track rope on the four-lane bridge.

The cradle will be electrically hoisted up and down the main track rope and will vertically move up and down to enable personnel to inspect the stay cable wires throughout the lifespan of the bridge.

Spencer’s bespoke access system for inspecting stay cables on the new Pattullo Bridge

Spencer Group principal engineer Gordon Neilson, considered an industry expert in bridge gantry design, is behind the design for the Pattullo Bridge cable fan access system.

Manufacturing and testing will take place in the UK before the whole access system is shipped to Canada for installation.

FCP is designing the bridge to interface with the stay cable access system before it is tested and commissioned by Spencer Group.

Spencer Group project director Steven Bunting is leading the project and coordinating the various stages of the design and build. He said: “Our unique design on this project will be transferable to other cable stay bridges all over the world. It addresses challenges faced with the need to carry out tactile inspections of cables from a dedicated work platform, at difficult to reach locations at significant elevations.”

The semi-permanent access system will enable maintenance engineers to inspect all elements of the stay cables