We widened the Narrows

Construction of a duplicate bridge alongside the existing Narrows Bridge in Perth was required to match the profile of the existing structure. The structure is comprised of four “I” beams and was constructed in two halves. Both halves were concurrently incrementally launched from the south abutment and then an in-fill strip was poured between the two halves to form one bridge.

The structure was launched across twelve temporary piers and then lowered onto four permanent piers following completion of the launching process. The launching equipment was designed to allow for lifting and pushing the bridge, then raining hydraulic rams to serve as a braking system to prevent the bridge from sliding backwards between launching cycles.