Each year contact with overhead power lines causes death and major injuries to workers in the construction
industry, in fact about one third of inadvertent line contacts prove fatal.
Due to the nature of their work, scaffolders in particular need to consider carefully any work that will be carried
out in the vicinity of overhead power lines, as contact with overhead power lines is not the only consideration.
If a scaffold pole approaches the line conductors may allow a ʻflashoverʼ or arc to take place and this risk of
flashover increases as the line voltage increases.
Work under overhead electric power lines should not be carried out without consultation with the owners of
the lines and wherever possible the lines should be diverted or made dead before work begins.
Scaffolding structures should not be erected within six metres of an overhead power electric line, the owner
of the line may advise a greater distance for some lines. This distance should be marked by coloured bunting
mounted at a height of 3-6 metres above ground, immediately over barriers erected on the ground to prevent
lengths of tube accidentally encroaching on this safe distance.
Where work is to be carried out under overhead electric power lines and the lines cannot be made dead the
following precautions are recommended:
a) The owner of the line should be consulted about proposed working methods.
b) The work should be supervised by a competent person.
c) Scaffolding tubes of a length likely to reach high enough to touch the overhead line, or get close enough
to cause flashover or arcing to take place should, be avoided.
d) A horizontal barrier of timber or other insulating material should be erected to form a roof over the
construction area.
The use of insulating guards to protect conductors from being contacted by scaffold tubes and / or proximity
warning devices without other safety devices are not accepted.
The arrangements made and management of work under or in the proximity will usually be under the control
of the main or principal contractor on site however the scaffolding contractor has a duty to ensure that his
employees are not exposed to an uncontrolled hazard or risk.
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NASC
NATIONAL ACCESS &
SG5:02
OVERHEAD POWER LINES
1.0 INTRODUCTION
NASC
2.0 PLANNING THE WORK
3.0 WORKING UNDER OVERHEAD POWER LINES
If it is necessary for plant to travel under overhead lines, the area where they may pass should be as small
as possible and not more than 10m wide. This passageway should be clearly defined by the use of fencing
barriers, and goalposts should be in position across the width of the passageway. The goalposts should be
of rigid construction and of a non-conducting material, distinctly marked in order that they may be clearly
identified.
Warning notices should be provided on each side of the passageway advising people of the hazard and giving
the cross bar clearance in order that drivers realise that they must lower their jibs, etc. To give crane drivers
sufficient time to lower the jib before reaching the goalposts, it is advisable to position advance warning
notices as far from the goalposts as is required by the length of jib on the machine.
Where it is not possible to limit the passage of plant to a given point, goalposts may consist of tensioned steel
plastic-covered rope, and should be erected on both sides of the line at a distance of not less than 12m from
the conductor. The increased distance allows for the possibility of ropes being stretched by cranes. Where
steel ropes are used, they must be effectively earthed and should be fitted with coloured bunting.
Some basic ʻʼRules of thumbʼʼ which may assist in ensuring the safety of those who work in the vicinity of
overhead powerlines.
DO carefully note the position of all overhead lines before commencing work.
DO co-operate during planning and site work with the owners of overhead lines.
DO ensure that the main contractor has sited barriers, goalposts, bunting etc. in accordance with
the advice given in HSE Guidance Note GS 6.
DO keep overhead lines in view when moving scaffolding or machinery and take special care
when felling or lopping trees.
DO remember that the raising or slewing of a scaffold pole may cause danger when operating near
an overhead line.
DO avoid any machinery that is in contact with an overhead line until the Electricity Company
confirms that conditions are safe.
DO warn others to keep well clear.
DONʼT drive a high vehicle below an overhead line when an alternative route is available.
DONʼT raise the bed of a tipper lorry beneath an overhead line or drive under the line with the body
of the vehicle raised.
DONʼT steady any suspended load unless you are satisfied that there is no danger from overhead
lines.
DONʼT handle or use scaffold platforms, poles, pipes or ladders unless they are at a safe distance
from overhead lines.
DONʼT transport long objects beneath overhead lines, unless they are carried in a horizontal
position.
DONʼT approach or touch any broken or fallen overhead lines.
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4.0 PLANT PASSING UNDER OVERHEAD POWER LINES
5.0 DOʼS AND DONʼTS
NASC
Whilst every effort has been made to provide reliable and accurate information, we would welcome any corrections to information provided by the Writer which
may not be entirely accurate, therefore and for this reason, the NASC or indeed the Writer, cannot accept responsibility for any misinformation posted.
NASC, 4TH FLOOR, 12 BRIDEWELL PLACE, LONDON EC4V 6AP
TEL: 020 7822 7400 FAX: 020 7822 7401
enquiries@nasc.org.uk NASC - National Access and Scaffolding Confederation
The only way I knew how to do it, sorry.
