Second Narrows Crossing project

We’re working to upgrade, replace, or relocate up to four transmission line structures that cross Burrard Inlet at Second Narrows near the Iron Workers Memorial Bridge so that they will continue to be able to operate in the event of an earthquake.

This upgrade will increase the reliability of the electrical system by upgrading or replacing infrastructure that does not meet seismic standards. It will contribute to the safe and efficient operation of the transmission lines that serve Vancouver and Burnaby.

The leading alternative involves:

• Reinforcing foundations, including ground improvements.
• Upgrading structures 687 and 688.
• Upgrading or relocating structure 689.
• Assessing structures 690 and 691 and completing seismic upgrades, if required.
• Painting structures 689 and 690.
• Constructing an access road to structure 689.

We're considering two design options for structure 689.

• Design option A – keep the tower in its current location.
  • Improve the ground around the existing foundation.
  • Upgrade the existing foundation.
  • Install a new steel tower at the same location.
• Design option B – relocate the tower north.
  • Improve the ground under the new foundation.
  • Build new foundation.
  • Install a new steel tower north of the existing tower.
    

We considered a variety of factors including First Nations interests, environmental and/or archaeological impacts, cost, system reliability, constructability, maintenance, property requirements, stakeholder interests and schedule. Alternative 1 performed best in the evaluation.

We considered five alternatives.

Two alternatives were advanced for further study in the alternatives assessment:

• Alternative 1 – Upgrade existing structures along the existing alignment (leading alternative).
• Alternative 2 – Build new transmission structures on a new alignment.

Three alternatives were determined to not be viable and did not advance to the alternatives assessment:

Do nothing.

• Does not address the issues with the existing structures.

Submarine cable.

• The south bank is too steep for cables.
• Much higher cost and longer schedule.
• New right-of-way likely needed on both sides of the crossing.

Installing a new cable on Iron Workers Memorial Bridge.

• The bridge can't carry the weight of the power cables.