As part of its national Visual Impact Provision programme, National Grid is seeking to remove some of the most visually impactful of its existing overhead lines in Areas of Outstanding Natural Beauty and National Parks. At the ICE event on January 24 National Grid senior project manager Steve Ellison will outline the tunnelling work under the Dwyryd Estuary in Eryri National Park (formerly known as Snowdonia).

In the Eryri National Park, the only solution to enable the removal of 10 pylons and 3.4km of overhead line that spans the estuary near Portmeirion, is to place the 400kV replacement cables in a tunnel under the estuary.

The team is operating in a highly built-up and populated area, very popular with tourists. The geology and associated groundworks are extremely challenging and the team will need all its experience gained from the Feeder 9 gas pipeline under the Humber to deliver the project.

Ellison’s talk will explore technical aspects of the work including the tunnel design and the TBM; safety and risk management; geology and groundworks; the stages of project delivery; crossing under roads and railways and the estuary; collaborative working with main contractor Hochtief UK; and environmental mitigation.

It will also reference lessons learned and applied to the project and how the team has worked to support the community along the way.

The free online event will be held on January 24 from 13:00-14:00 (GMT). To register click here  or for more information contact Sara Horrell at  wales.temp@ice.org.uk