Connecticut Light & Power Co. (CL&P; Hartford, Connecticut, U.S.), a Northeast Utilities subsidiary, has completed approximately 8.6 miles (13.8 km) of the overhead portion of 345-kV electric transmission line from Bethel to Norwalk in southwestern Connecticut. The line was placed in service in October 2006.
CL&P contracted InfraSource Services Inc. (Media, Pennsylvania, U.S.), a specialty contractor servicing utility transmission and distribution infrastructure in the United States, to construct the lines through its business units M. J. Electric and InfraSource Transmission Services.
The project entailed new 345-kV and reconstructed 115-kV transmission line installations, including surveying, right-of-way clearing/access, road construction, foundation installation and removals. InfraSource installed 8.6 miles of a new 345-kV transmission line, a combination of laminated wood H-frames (26 structures) and steel monopoles (58 structures) with new bundled conductor throughout, and removed a portion of the existing 115-kV line, which was replaced with an underground cable system.
InfraSource worked side by side with CL&P on a portion of the work where the existing 115-kV line was replaced with a 115-kV/345-kV composite line for about 1.3 miles (2 km).