Northern Tunnel Portal construction update - September & October 2022

The Northern Tunnel Portal structure will be fully enclosed following the installation of the final pre-cast roof components in September. Construction of the topping slab and backfill of the remaining roof area will then be completed.

Inside the structure, construction of the permanent internal walls and base slab is ongoing.


Northern Tunnel Portal construction

Within the rail corridor at Normanby

Works will take place during the standard construction hours of 6:30am to 6:30pm, Monday to Saturday.

Some activities will be completed out of normal construction hours, 6.30pm to 6.30am, due to traffic permits, safety requirements and construction methodology.

Excavation and construction of the tunnel portal structure

The works below will be ongoing until late 2022:

  • Transporting oversized plant and equipment.
  • Installing precast roof components and constructing the roof slab.
  • Waterproofing, pouring a concrete slab and backfilling the roof.
  • Constructing the base slab and inner walls beneath the roof.
  • Excavating, loading and removing excavated material with trucks.
  • Installing mechanical and electrical services.


Aerial view of the Northern Tunnel Portal – June 2022


What to expect

  • Construction activity with potential for an increase in noise, dust, vibration, truck movements and workers.
  • Construction impact mitigation activities such as street sweepers and water trucks.
  • Work is subject to relevant approvals and suitable weather conditions.

If you want to know more, all of this information is available in PDF form: