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We'll be using a Tunnel Boring Machine (TBM) at during this project. The tunneling process occurs underground using a tunnel boring machine (TBM); however, shafts are required at the start and end points. During tunneling, it may appear not much work is occurring; however, this is being done underground.​

​What is​ a TBM?

A machine used to excavate tunnels by breaking the surrounding soil/earth/rock to create a large diameter tunnel.

How big is the ​​TBM?

The TBM being used for this project is 4.5 metres in length, weighs approximately 30 tonnes and is 2.7 metres in diameter.

How fast does a TBM tunnel?

It is anticipated that the TBM will progress, on average, at a speed of about six metres per day in the expected conditions.

W​​hy does the TBM need to operate 24 hours a day?

The TBM operates under a pressure system to move forward. This is facilitated by the use of a slurry (water and material mixture) to lubricate the pipes a​nd reduce the friction. When tunneling stops, the slurry may harden and cause the pipes and TBM to be unable to be pushed forward.

Example of a micro-tunnel boring machine (TBM) used during tunneling

​What is a slur​ry separation machine? 

A slurry separation machine is a large piece of equipment (approximately two stories tall) used to manage soil removal. The machine separates the solids from slurry, so that the water can be recycled back to system. The machine operates 24 hours a day while the TBM is tunneling.  

Noise abatement panels will be used to dampen the noise generated by the machine.

Example of slurry separation machine used onsite during active tunneling