Seatoun Tunnel strengthening

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

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. 

What's going to happen?

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.

  • Building new buttress overlay beams in front of the existing ones of both sides of the tunnel
  • Constructing ground beams behind teh 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