The previously considered solution was based on crawler cranes travelling along the edge of a 200m x 30m cut-and-cover station box in order to complete the required lifts, but Marr’s heavy-lift, luffing jib crane solution centred on both cranes sitting alongside the box and provided lifting capacity across the entire site.

Marr MD, Simon Marr, said, “The site was congested and landlocked between two existing roads. The crawlers proposed would have placed a large surge load against the station box walls, which meant that the client would have to excavate around the box and fill in with groundworks to specific bearing pressures. The costs were excessive and would have had a major impact on the programme. Furthermore, using the crawlers would still have been a limited solution. Our solution facilitated lifting of loads from outside the project’s boundaries, which further de-cluttered the site and led to additional time and economic savings.”

Marr added, “Using fewer, higher capacity cranes also reduces the chances of collisions as multiple work fronts interact. The benefits of anti-collision technology are widely preached in our industry but it is often a ‘band-aid’ solution for poor crane selection.”

The cranes were designed by Marr and the manufacturer Favelle Favco. A 330t capacity M2480D with 90m boom and a 200t capacity M1680D with 62m boom. They lifted a variety of loads, including pre-cast beams, columns and panels weighing up to 60t in addition to site machinery, such as earth-moving equipment, mobile cranes, concrete, reinforcing steel, and general construction materials required for a tunnels project of such magnitude. The first crane was erected a year later and the job completed in October 2018.

This Sydney Metro brings the city an additional 31 metro stations and 66km of line, including 36km-long North West Rail Link and 30km metro extension from the end of Sydney Metro Northwest at Chatswood under Sydney Harbour. The Northwest Rapid Transit (NRT) consortium, comprising of Australia’s John Holland, CPB Contractors and UGL Rail, with MTR Corporation, was awarded the operations, trains, and systems contract.