Maintaining live power lines As part of its ongoing commitment to asset management, National Grid is re-establishing live-line working.

Working on live cables from a trolley placed by helicopter allows the National Grid Maintenance Delivery team to achieve significant efficiency savings.

OCC, with its long relationship with National Grid Asset Engineering, was chosen to develop a desktop application to model live-line working. In addition to designing and prototyping the application, OCC worked with National Grid to identify testing and acceptance criteria for this safety-critical software.


The resulting application, LiveLoad, models the effect of a helicopter placing a trolley containing a maintenance engineer on a high-voltage cable. The application manages model parameters such as transmission line geometry, ground geometry, wind speed, conductor and insulator properties, trolley position and trolley weight and displays the results for consecutive sections of the line.

Armed with LiveLoad reports, National Grid engineers can make informed decisions about programmes of live-line work.

National Grid

National Grid is the largest privately-owned, independent transmission company in the world and one of the top 100 companies in the UK. It owns and operates the high-voltage electricity transmission system that carries power from generators to suppliers across England and Wales. It also owns and operates transmission links to Scotland and France and plays a vital role in enabling the wholesale marketing of electricity.