Temporary cross passage 3B construction
Underground cross passage excavation will soon commence. These connection passages are being built to provide a critical safety feature for Cross River Rail.
Details of work
Cross passages are regularly spaced passages between tunnels to provide emergency access underground. The passages connect the two main tunnels and are generally located every 240 metres along the tunnel alignment. They will allow people to move from one tunnel to the other in the unlikely event of an emergency.
Cross passages are constructed after the roadheaders or tunnel boring machines have tunnelled through an area.
There are 16 permanent passages and one temporary cross passage being constructed as part of the project. Each cross passage is approximately 5.8 metres wide, 5.8 metres high and 6 metres long.
What to expect
Underground excavation work on temporary cross passage 3B, located approximately 30m undergorund (please see map below for location), is planned to start from mid-February 2021.
Work on the cross passage will be undertaken 24 hours, 7 days a week. It will take up to four weeks to complete.
Tunnelling is a safe construction technique and is unlikely to cause damage to property. Before excavation starts, property condition surveys are offered to property owners located along the tunnel alignment.
During this underground construction work, property owners above and close by the tunnel alignment may experience low-level noise and vibration.
Work will involve:
- Installing rock anchor supports on both sides of the two tunnels, including steel work, drilling and saw cutting
- Excavation of the cross passage using a rock hammer
- Installing steel mesh, concrete, and a waterproof concrete lining in the cross passages and surrounding area.
If you want to know more, all of this information is available in PDF form:
If you would like more information or have questions, you can contact our team using the details below: