National Grid has added the new Bell 429 to its helicopter fleet to inspect the electricity network in England and Wales - the first in the world to be equipped to work for a utility company. The Bell has begun work inspecting the 7,200 km of overhead lines and 21,000 pylons that make up the high voltage transmission system in England and Wales.
It has been fitted with a custom made internal workstation and a Westcam MX 10 high definition camera. This enables an observer to use both film and high definition photography to document the condition of the pylons, wires and insulators on the system. The helicopter will also be used for thermal imaging photography in colder weather to locate “hot joints” and to inspect electricity substations.
Michael Hannon, National Grid’s overhead lines field support manager, said, “Helicopters have proved their work in helping us to keep the electricity system safe and reliable. They have proved a cost effective way of keeping an accurate and documented record of the state of the network. We have all come to expect the 99.999% reliability of the electricity transmission network, but there’s a lot of work going on behind the scenes to maintain that record. This includes our use of a helicopter fleet”.
Michael Kane, National Grid’s chief pilot, said, “The new Bell helicopter looked like the best aircraft for the job both now and looking to the future. It is lightweight and provides good conditions for our observers who are working at a high level of concentration. It has lower maintenance costs and greater capabilities for the type of work we require”
National Grid has been using helicopters since the mid 1980s and they play an important role in enabling timely refurbishment of the system. Inspections from the air can be carried out much quicker than by linesmen climbing the towers. It takes three linesmen one day to inspect three pylons, while the airborne observer can inspect six pylons in one hour.
The new helicopter will also be used to carry out live line repairs to overhead lines. This work involved suspending engineers in a basket underneath the helicopter and placing them alongside lines carrying 400 kV. Live line work enables National Grid to carry out critical repairs without taking circuits out of service so that National Grid can maintain uninterrupted flow of electricity.