Why is the light rail using micro tunnelling in the CBD?
Micro tunnelling is being used to build drainage and stormwater capacity underneath Parramatta’s Church Street, including ‘Eat Street’. The use of micro-tunnelling machines will help minimise construction impacts in comparison to traditional pipeline construction at street level.
These will reduce the chances of impacting other pipes, electrical wires and utilities, and minimise noise, dust and vibration on Church Street. While micro-tunnelling work is underway, businesses and the community can continue to access public spaces such as Centenary Square.
What is micro tunnelling?
Micro tunnelling is an innovative method of construction used to create a tunnel under the ground. The machine is remotely operated and similar to a tunnel-boring machine but smaller in diameter (approx. 1.5 metres).
How will micro tunnelling work for the light rail?
One micro-tunnelling machine will dig six metres underneath Church Street, from Centenary Square to Lennox Bridge. Launched from a pit in Centenary Square, pipes of concrete will be pushed behind the machine to cut the tunnel. The machine will continue to a retrieval pit at Lennox Bridge.
A second, smaller micro-tunnel machine will drill across Centenary Square to a second pit outside Parramatta Town Hall, connecting to an existing pipe to extend stormwater capacity.
In total, nearly 600 metres of micro tunnelling will be undertaken on the Parramatta Light Rail project.
What are the benefits of micro tunnelling?
- Minimises the impact of construction through built-up environments like Parramatta’s Church Street.
- Reduces road and footpath excavations, as it is limited to a launch and retrieval pit.
- Smaller construction sites compared to trenching Church Street at street level then laying down a new pipe.
- Quicker and safer compared to traditional excavation methods.
- Work can be undertaken 24 hours a day with minimal impact on the community.
'Elizabeth' micro-tunnelling machine tracker