Transpower technicians inspected power lines in Cromwell this week.
Transpower executive general manager grid delivery Mark Ryall said the workers were performing the inspections between Cromwell and Frankton as a part of work to boost the power supply to Queenstown and surrounding areas.
The technicians were safely suspended below a helicopter to take readings at different sections of the line.
"We’re using these readings to help us plan how much we can increase the amount of power that passes through the line."
Mr Ryall said the inspection and upgrade work was being done to get the most out of current systems until future investments were under way.
"Until then, we’re working to get the most out of our existing infrastructure through installing new transformers at our Frankton substation and upgrading the line that feeds it, which is why we’re carrying out these inspections now."
