Woburn to Wakefield 345kV XLPE IG Transmission Line

Stoneham, Winchester, Woburn, MA

This project consisted of 26,100 LF of 8” PVC duct bank with associated conduits for grounding and communication fibers, 33 (5’x5’) communication manholes, and 17 (8’ x 30’) large transmission vaults. Many of the manhole installations proved to be challenging. Each proposed location had a unique configuration of existing utilities, which required McCourt to reroute or temporarily relocate them. Similarly, the duct bank path had numerous utility conflicts during excavation. These conflicts required McCourt to coordinate with Eversource and the local towns to revise the path to minimize the impacts and conflicts along the path. In most cases, McCourt was the lead party providing the proposed revisions.

A +/-500’ portion of duct bank along Lake Street required SOE that was 14’ deep so a drain line could be installed above it. Two sections along Cross Street in Winchester, each at least 500’ in length, needed a temporary water bypass to be designed and installed before excavation. This allowed us to remove the existing water line, install our ductbank at a depth of +/-14’, install & test a new water line, and remove the temporary bypass.

The Project also included six trenchless crossings, originally designed to be performed via jack and bore (J&B). The method involves excavating an entry and exit pit 20’-30’ deep and horizontally, augering a hole to push a pipe casing through. Of the six, only the first was completed using the J&B method. Differing site conditions, such as a ledge and a high-water table, prevented us from using the originally designed J&B method. The McCourt team led the Project to find alternate methods to complete the remaining Crossings.