Live line work

Live line work

Transpower temporarily suspended live line work on the National Grid in May 2017, while it assessed the practical implications of the new EEA Guide for the Assessment of Work Methods to Undertake High Voltage Overhead Line Work.

Following an investigation exploring the risk associated with different work activities, Transpower lifted the suspension in September 2018. Transpower has a series of live line techniques available for Service Providers, a full list is available below.

Contact us for further information.


Live line work techniques

The following work activities may be completed using live line work procedures.

Work activities

(110kV and 220kV only except where stated)

Live line helicopter conductor and joint testing:

  • Sub-conductor spacer replacement
  • Joint testing
  • Cormon conductor testing
  • Marker ball installation/replacement
  • Removing foreign objects
  • Conductor repairs (patch rod)
  • Minor conductor component maintenance and installation

Close approach:

  • Work between MAD and Live Line MAD
  • Bird deterrents / bolts and steel
  • CA within MAD (for e.g. assessing bolt and steel condition)
  • Non-load bearing general structure maintenance (e.g. pole cap, guys, lightning arresters, pole earthing)
Washing of insulators on energised lines by helicopter

Suspension pole replacement
Suspension pole X arm replacement (excludes the Gin Pole method)

Suspension re-insulation;

Horizontal post insulator replacement;

CA lifting inspection (suspension hot-end hardware); 

Armour rod replacement

Full tension splice rod installation (220kV only)

Non-load bearing hot stick or bare hand work, ladders/rope access:

  • Sub-conductor space installation/replacement;
  • Vibration damper installation/replacement;
  • Cormon conductor testing (locations not suitable for helicopter access);
  • Marker ball installation/replacement;
  • Removing foreign objects;
  • Conductor repairs (patch rod); and
  • Minor conductor component maintenance/installation