overhead power lines – agricultural risks
According to the Health and Safety Executive guidance document
on safe working near overhead power lines in agriculture, each year
on average two agricultural workers are killed from electric shocks
and more are injured, suffering serious burns, when they come into
contact with overhead power lines (OHPLs) at work.
As the agricultural machinery being used, such as combine
harvesters, tipping trailers and irrigators becomes increasingly
large, the risk of contact or near contact becomes greater.
Electricity can ‘arc’ across gaps, which means that workers may
still be at risk if their equipment is too close to the OHPLs, even
if it is not touching. Not only agricultural equipment and
machinery present a danger, jets of water or liquid slurry, coming
into contact or near contact with an OHPL can also cause a
discharge of electricity and a high risk of fatal or severe
shock.
The recent prosecution of a farm management company highlights
the issues associated with such accidents. Following the death of a
casual farm worker who was electrocuted when the extended grain
chute of a combine harvester he was operating touched an 11,000
volt overhead power line, the company was fined £120,000 and
ordered to pay costs of £45,000 for breaching health and safety
legislation.
The farm management company was responsible for the hiring of
casual farm workers, including the worker who was killed, and for
managing health and safety on the site. They had failed to inspect,
monitor, supervise or audit adequately health and safety management
on the farm. In addition they had failed to ensure that the farm
manager had received adequate health and safety training.
Consequently, risk assessments for working in fields with OHPLs had
not been carried out and the farm workers had not been adequately
trained on safe working practices.
The worker who was electrocuted had been driving one of the
largest and tallest machines on the market and as there was a
problem with the grain discharge spout, this had been left extended
while cropping the field. The combine's height with the chute
extended was 5.7 metres. This was therefore in excess of the legal
minimum height for overhead lines in fields, which is 5.2 metres,
and the actual height of the lines involved in the accident, which
were 5.6 metres. No consideration had been given to these
facts.
The HSE guidance provides practical advice on how to avoid
danger when working near overhead power lines. Suggested measures
that should be implemented include:
- determining the routes and operating voltages of OHPLs running
across the farm land or near the boundaries and map them
- know the safe operating distances
- ascertain the maximum height and vertical reach of all farm
machinery and equipment with all parts raised to their full
extent
- check the heights against the line heights marked on the OHPL
map
- identify any areas of high risk
- plan work to avoid high-risk areas
- use alternative access points and routes which avoid OHPLs
- train all staff to be aware of the risks associated with
OHPLs
- ensure contractors are aware of the location of OHPLs before
they come onto your land. Give them the clearances. Ascertain
whether their machinery and equipment is safe to use near
lines.
