A contractor struck an 11kva cable with a mechanical auger whilst digging holes for fence posts around one of our sites. A pre-task meeting had been held and the positions of the holes and a low voltage cable on the site marked on the ground after scanning; unfortunately the contractor decided it would be easier to dig the holes further back from the agreed route, which took them into a neighbouring property and in close proximity to the high voltage cable.

KEY FINDINGS:

The contractors were shown the line of the new fence by a Supervisor.

A method of work had been agreed and Permit to Work and Worksafe completed. - Unknown to the site staff, the contractor decided it would be easier to dig the holes further back from the original fence line, to avoid an existing tree root, which took them into a neighbouring property.

The area they dug into had not been scanned because they were not supposed to be digging there

HOW THIS INCIDENT COULD HAVE BEEN AVOIDED:

The contractors should have followed the instruction in the Permit to Work and method statement, digging in the prescribed locations.

Scanning of the adjacent land and access to the site plans of the neighbouring property may have increased awareness of the dangers of not following the agreed procedure.

KEY REVIEW POINTS:

- Ensure contractors understand that deviation from agreed Permits and methods of work is forbidden without prior approval from an authorised company Supervisor.

- Provide sufficient Supervision of contractors during these sort of tasks.

- Prior to excavating on site boundaries, consult neighbours in respect of buried service plans and scan for cables as appropriate.