
Anne Gunning
R2111 Danger Danger High Voltage!!!
Updated: May 3, 2021
R2111 The site survey.
Syllabus learning Outcomes
1.1 Describe how to identify potential hazards and risks on a site, including overhead and underground hazards (eg electric cables)
1.4 State why it is necessary to identify the existence of overhead and underground services.
Introduction
There is a big focus on risk assessment in the syllabus and rightly so. Our eyes glaze over when the term risk assessment is mentioned but not doing this correctly may mean someone dies or lives are changed forever due to injury or financial loss.
This blog focuses on overhead and underground services, why it is necessary to locate their exact position (map them) and the potential risks associated with them.
What is risk assessment?
This is a process where you identify hazards that have the potential to cause harm to humans together with assessing the likelihood of this harm happening and the possible consequences. The final stage is to set out a plan of action to reduce, control or eliminate the risk.
Types of overhead and underground cables
Overhead cables
These include telephone wires and electricity power cables. Do not mistake overhead power lines on wooden poles for telephone wires. You do not have to touch power lines for the electricity to arc downwards so it is not just about touching cables – there is also a recommended distance between power lines and any objects. I worked with a community group who looked after planters on a railway station and they were not allowed to take water to the platforms because if sprayed upwards, electricity could arc downwards from the power lines. In a domestic garden outdoor electrical sockets need to be included in the risk assessment.

Overhead cables : Telephone cables

Wooden poles carrying electricity cables
Underground services
These can include electricity cables, water mains, gas supply pipes, sewage/waste water pipes, oil pipes, cables for phone / TV and other gases or substances (if near a factory/hospital)

Oil pipeline

Outdoor sockets or powered equipment such as a water fountain indicate there must be services supplying the electricity below ground.

Signage may indicate presence of underground services

The pipes go somewhere but where and what are they carrying?