An electric transmission line that runs 25 miles from Franklin, N.H., to Sunapee is getting a series of support braces, upgrades that Eversource says are part of a system of “hardening” lines to better withstand storms.
The $600,000 project involves cross-braces put on some 212 towers in the right-of-way, which cuts across country between substations in Franklin and Sunapee. Fourteen of the towers will be replaced.
The line runs between Salisbury, N.H., and Andover, N.H., and crosses Interstate 89 near Exit 12. Built in 1967, it carries electricity at 115 kilovolts. The voltage is reduced at the substations so that it can travel on distribution lines along the street.
“(The line was) designed years ago without the benefit of computer programs and modern transmission line design software,” Eversource spokesman Martin Murray wrote in an email. “Our use of that technology now, as part of our reliability-enhancement program, has helped determine that additional strengthening is required.”
Murray said Eversource has completed similar work on its bigger transmission lines, which carry electricity at 345 kilovolts, and is now analyzing and working on its 115 kV lines.
Eversource said that in New Hampshire, it invested approximately $325 million in 2015 on improvements to transmission and distribution systems.
The utility said that since 2012, the frequency of outages across Eversource’s service area “has decreased by 18 percent and the amount of time it takes to restore power when it does go out has decreased by 26 percent.”