Marr Contracting has completed what it claimed as the world’s heaviest tower crane lift during the boring of a new subway tunnel in Australia.
The specialist in large tower cranes used a Favco M2480D tower crane to lift a 225 tonne section of a tunnel boring machine (TBM) from an exit point along the subway tunnel. The TBM, named ‘Mum Shirl’, was one of two machines being used to drill tunnels for Barangaroo Station as part of the Sydney Metro City & Southwest public transport project.
The 330 tonne capacity luffing jib tower crane was used to lift the front shield section of the TBM out of the ground in a single section.
Marr Contracting said it made the enormous lift using the M2480D crane with a 55 metre boom and a six fall 330 tonne hook block. The crane was operated from inside a station box measuring 4 x 4 metres, that was located next to the TBM’s retrieval point.
Simon Marr, managing director at Marr Contracting, said, “Tunnel boring machines are often used in urban settings with limited space and are traditionally installed and retrieved by crawler cranes and gantry set-ups which can take up a lot of room, are costly, and provide additional issues around ground preparation next to the excavation from which the TBM is to be installed or retrieved.”
He added, “Our uniquely designed M2480D crane is a simple solution in many situations. It doesn’t require an expansive set up and because it can be assembled in the existing excavation, it doesn’t take up valuable room on an already congested work site.”
According to Marr, once the remaining sections of the TBM will also be removed from the tunnel, the machine will be reconfigured to continue work on the Barangaroo Station.
While Marr and its M2480D tower crane were already working on the construction of one of Sydney Metro’s stations, the lifting of ‘Mum Shirl’ was not originally part of the company’s scope of works. The company said the lift, plus addition tasks, were added duties assigned to it by the Northwest Rapid Transit (NRT) consortium – comprising John Holland, CPB Contractors and UGL Rail – later on in the construction.
Marr was contracted to work on the Sydney Metro project’s Barangaroo Station and Martin Place in October 2018. The company had previously completed works to Sydney Metro’s Castle Hill Station in 2016.