Seatoun tunnel strengthening

Wellington City Council plans to undertake earthquake strengthening work on the Seatoun Tunnel in 2019.

Seatoun tunnel entrance.

This is part of an ongoing programme to improve the safety and accessibility of Wellington’s earthquake prone structures. 

Alongside the essential strengthening work, there are plans in place to extend the existing pedestrian handrail on both sides of the tunnel and to replace the sodium lights with new more efficient LED fixtures.

The 112-year-old tunnel is a heritage structure so it will be a priority to ensure it maintains its current charm. However, the inside will be painted to make it brighter and safer for residents to walk to through.

Updates

May 2019

From Monday 6 May contractors will begin work to install traffic signals at both entrances to the Seatoun tunnel.

Installing the signals will take approximately four to six weeks, with crews working between 9am and 4pm. In the latter half of the project there will be approximately one week of night works, with any noisy work finishing by 10.30pm. During night works traffic will be controlled by stop/go paddles while the tunnel is reduced to one lane. 

Once operational, the signals will be used to manage traffic during earthquake strengthening work, scheduled to start in August. Beyond this the signals will remain in place to manage traffic during any future maintenance or upgrade works, or in the event of a major incident, as happens with the Karori tunnel.

When there are no works taking place in or near the tunnel the signals will be turned off.

Contractor contact: HTS Group, 027 432 1059

About the project

The project includes:

  • building new buttress overlay beams in front of the existing ones of both sides of the tunnel
  • constructing ground beams behind the parapets of both portal walls
  • installing 20 rock anchors (10 either side of tunnel)
  • repairing defective areas of portal and painting both walls
  • constructing new ground beam in front of retaining wall - held in place with four rock anchors
  • extending the pedestrian handrail along the ramp on both sides of the tunnel
  • replacing lighting in the tunnel with LED lights.

Vehicle and pedestrian access to the tunnel will be affected at times while the work is underway, and diversions will be in place. More information will be available nearer the time.

Background

Originally constructed in 1907, the tunnel comprises of an arched brick liner with concrete portal walls. It is 2.5 m in height, 8.1m wide at road level and has a 6.2m wide carriageway. There is a 1.2m wide footpath with a steel handrail that sits approximately 0.6m above the carriageway surface.

More information

Faiz Tawfeek, Team Leader Structures
Phone: 04 499 4444