Two machines each weighing as much as four Being 747s have arrived in Queensland ready to be fitted out and deployed on that state’s biggest ever rail tunneling project.

Parts in respect of two tunnel boring machines which will be used on the $5.7 Cross River Rail Project have arrived at the Brisbane headquarters of German construction equipment manufacturer Herrenknecht.

Set to weigh around 1,350 tonnes once assembled, each machine will be 165 metres long and  will contain a 7.2 meter diameter ‘cutterhead’ which acts as a drill and can tunnel through rock which is harder than concrete.

Previously used on the Sydney Metro Project, the machines will be refitted and refurbished for Cross River Rail.

Once assembled, they will be launched in early 2021 from the Woolloongabba Station site and will each dig a tunnel under the Brisbane River to the Albert Street Station.

They will then continue to the new Roma Street Station before emerging at the project’s northern portal at Normanby.

The machines will work at a rate of 30 metres per day and will line each tunnel with curved concrete segments as they go.

All up, they will generate 290,000 cubic metres of spoil.

Currently, 16 people have started work on the machine’s retrofit including 14 locals and two specialists from Germany.

Over the next nine months, an additional 15 to 20 workers will be joining them.

Aiming to relieve congestion and enable trains to run more frequently by creating a second river crossing, Cross River Rail will deliver a new 10.2 kilometre rail line from Dutton Part to Bowen Hills including 5.9 kilometres of twin tunnels under the Brisbane River and the CBD.

The project will deliver new underground stations at Boggo Road, Woolloongabba, Albert Street and Roma Street, upgrades to stations at Dutton Park and Exhibition, six upgraded stations from Salisbury to Fairfield on Brisbane’s Southside and development of three new Gold Coast stations.

Underground metro tunnel. An engineer is staring at the level of rails looking towards the end of line.

Queensland Premier Annastacia Palaszczuk welcomed the arrival of the machines.

“We know that to continue rebuilding Queensland’s economy, we must forge ahead with job-creating infrastructure like Cross River Rail,” Palaszczuk said.

State Development Minister Kate Jones said Cross River Rail would transform the way Queenslanders travel and leave behind a legacy of skilled workers trained by world-leaders in specialist trades.