Transpower is replacing the near 40-year-old conductors (the wires) that run between Wilton substation and Makara Peak, and Makara Peak and Tower 26 on Polhill near Durham Street, just before Central Park substation.
The work will begin in December and continue until late April 2019 - with some further work expected next season (ie summer 2019/20) between Wilton substation and tower 14.
The line crosses mainly Wellington City Council land (including Polhill Reserve, Zealandia and Makara Peak Mountain Bike Park) and a small number of private landowners.
Why is this work being done?
The existing conductor is showing signs of corrosion and other wear and tear. It is near the end of its life and we need to replace it to ensure this line continues to provide a reliable supply of power to the Wellington region.
The duplex (double strung) conductors will be replaced with a slightly thicker simplex (single) conductor, so you may notice the lines look a little different and less intrusive.
This is one in 40-50 year work and the first time on this line since it was built in 1978. We appreciate your patience to enable this work to be completed.
What is being done?
Reconductoring works are done by pulling the replacement conductors through running blocks (or pulleys) placed on each tower and then clamped into place.
We initially set up ‘pulling sites’ at the Wilton substation, tower 14 via Makara Peak mountain bike park and at tower 26 which is accessed from Durham Street. However, a technical issue regarding clearances between old and new conductor during pulling has recently (late March 2019) led us to establish another wiring site at tower 21. The effect of this change in programme will see us out of Polhill slightly earlier than planned, but impacting Makara Peak over April.
The old conductor is pulled from the line and the new conductor is attached to the steel cables and pulled into position between the pulling sites. At each tower in between the conductor is tensioned or sagged to the correct position and clamped into place.
The project will take around twelve weeks, from February through to late April. There will be little impact to the public during most of this time, except during the days when the conductors are actually being pulled or moving in the air.
When the conductor is being pulled, our contractors will monitor the area to ensure there is no access under the line. While there is very little risk of a conductor falling, no one should be underneath while it’s being pulled.
Most tracks in Polhill are underneath the lines at some point, therefore, after consultation with WCC and community groups, it was agreed all tracks at Polhill will be closed during pulling days. As a large pulling site is to be established next to tower 26 at Polhill access past tower 26 will be shut from early February until around 8-9 April 2019.
Makara Peak, being larger, means that some tracks will need to be closed during these days, but not the entire park.
The planned pulling days are below. Depending on weather and other events outside of the workers’ control, these days may change. Please keep an eye on Transpower’s social media updates for daily updates during the work.
- Polhill closed 1st-4th
- Bottom of Transient track closed 1 February – 9 April
- some Makara Peak tracks closed from 9th-18th, 23rd-30th
- These dates are subject to change.
- Transient track will be closed between tower 26 and Karepa Street until 9 April. There will be a large amount of pulling equipment around Tower 26 and the area will be securely fenced off. Access must be restricted because of the hazards.
- Once we have vacated our tower site at 26 (on Transient) on 9 April our work in Polhill will be complete and the park completely available