Situation:
The Worcester 115 kV Underground Project spans 3.4 miles across Worcester, Massachusetts providing a reliable electric power source to meet the needs of the surrounding communities. To ensure the delivery of this transmission project, BOND was chosen to install 2.5-miles of 115kV UG transmission line, from National Grid’s Vernon Hill Substation, to Bloomingdale Substation. In addition to executing the trenching operation safely along a densely populated business and residential area route, an extensive amount of ledge removal was undertaken to attain proper depth. Other major work included a 42-inch pipe jacking under the active CSX / MBTA railroad spur line, as well as sidewalk and pavement restoration. Existing spare ducts were utilized for the first 1-mile of the project with the remaining 2-miles requiring a new 6-way concrete encased duct bank and splicing vaults.
Challenges:
- Densely populated business and residential area route
- Extensive amount of ledge
- Work performed underneath an active CSX / MBTA railroad line
- Extremely fast-track schedule
Solutions:
- Close coordination with National Grid to coordinate scheduling and production that would cause least impact to neighborhood and traveling public
- Brought in additional forces to work ahead of the mainline excavation and crews to remove the excess rock and ledge
- Close collaboration with CSX and MBTA officials to modify original trenchless method from jack and bore to a pipe jacking; this eliminated any risk of underground obstruction
Results:
- Successfully increased reliability of electric power supply throughout Worcester communities
- No unscheduled disruptions of service
- Delivered to National Grid on time and placed in service as scheduled