Boston, MA
McCourt Construction installed two new turnkey 115kV lines and two new fiber optic lines for Belmont Light in 2017. These lines connected BMLD’s new substation to the transmission grid via an Eversource substation in Cambridge. McCourt’s work occurred entirely along an active MBTA Right of Way in Belmont and Cambridge, MA.
For this project, McCourt installed 8,200 circuit feet of new 115kV Pipe Type Cable lines and two miles of underground fiber installation including six communication handholes. Portions of this infrastructure (~370 LF) required digging within the MBTA Zone of Influence, so McCourt designed and installed a permanent steel sheeting system along the ROW to mitigate track settlement.
Additionally, this project required five deep trenchless crossings (one is pictured above). McCourt utilized Pilot-Bore Micro tunneling to complete these crossings. Each of these crossings required extensive dewatering systems which McCourt designed and executed using a combination of sheeting, well points, and deep sumps.
Due to soil conditions, approximately 1,000 LF of new lines required a pile-supported concrete mat. McCourt designed a helical pile system to support this vulnerable segment of the project.
Project Overview
Owner: Belmont Municipal Light Department
Completion Date: November 2017
Unique Project Features
- Work alongside active railroad ROW
- Work within the “zone of influence” of active railways
- 5 trenchless crossings utilizing pilot-bore micro tunneling
- Electric/fiber lines supported on helical piles
- New permanent steel sheeting to mitigate against potential track settlement
- Thermal concrete encasement
- Work within active electric substations
- Extensively contaminated soils
- Stringent vacuum excavation requirements
- Extensive dewatering
- Installation of a turnkey cathodic protection system
- Thermal grouting of HOBAS casings
- Work adjacent to wetlands and environmentally sensitive areas