National Grid Aerial Transmission Line Inepections Underway Helicopter surveys used to detect potential problems before outages occur

January 11, 206 — Waltham, Mass. – National Grid is beginning its semi-annual
aerial inspections of more than 2,900 miles of high-voltage transmission lines in
Massachusetts, Rhode Island, New Hampshire and Vermont. Starting this week (January
11, 2016), the helicopter flyovers will identify and address potential problems in
the transmission lines before they impact electric service for customers. These
aerial inspections complement the regularly conducted, ground-level inspections by
quickly and efficiently covering National Grid’s transmission system, even across
rugged and isolated terrain.

Transmission lines are generally defined as high-voltage lines carrying
electricity at or greater than 69,000 volts. They typically deliver
power from generating plants to local electric companies which in turn
serve their customers.
“At National Grid, we believe taking a proactive approach to reducing
outages and accelerating outage restorations is in the best interest of
our customers. Proper and regular inspections of our transmission system
are a critical component in providing safe and reliable power to our
more than 1.7 million electricity customers across New England,” said
Fred Raymond, vice president, Electric Project Management and Complex
Construction, National Grid. “Transmission lines can be damaged during
the winter months by severe weather, making now an ideal time to have an
up-close look and make sure customers have the reliable service they
deserve and expect.”
The helicopter inspections are conducted by experienced personnel using high-power
gyroscopic binoculars. They are particularly interested in signs of wear on power
line conductors and lightning protection devices; damaged or leaning transmission
structures; loose or broken guy wires; broken, chipped or cracked insulator
equipment; and trees leaning toward the lines or into the transmission corridors.
In addition to spotting damaged lines, towers or trees, the flights are conducted to
identify signs of waste disposal or unauthorized construction on the rights-of-way.
These could alter the clearance between the ground and the power lines and might
lead to human contact with the lines that could result in severe injuries or
vegetation interference that could lead to power outages. Of additional concern are
signs of erosion, which may cause the transmission structures to become unstable.
The inspections are expected to take approximately five weeks to complete, weather
permitting. Flight schedules and routes may be changed on short notice due to
regional weather conditions. Public safety officials in the communities over which
the flights pass are notified of flight patterns. Flights will also be conducted
during the summer months.
About National Grid
National Grid (LSE: NG; NYSE: NGG) is an electricity and natural gas delivery
company that connects nearly 7 million customers to vital energy sources through its
networks in New York, Massachusetts and Rhode Island. It is the largest distributor
of natural gas in the Northeast. National Grid also operates the systems that
deliver gas and electricity across Great Britain. Through its U.S. Connect21
strategy, National Grid is transforming its electricity and natural gas networks to
support the 21st century digital economy with smarter, cleaner, and more resilient
energy solutions. Connect21 is vital to our communities’ long-term economic and
environmental health and aligns with regulatory initiatives in New York (REV:
Reforming the Energy Vision) and Massachusetts (Grid Modernization). For more
information please visit our website: www.nationalgridus.com, or our Connecting
website. You can also follow us on Twitter, watch us on You Tube, Like us on
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