Rural communities learn to live with a myriad of wires hanging from pole to pole along our roads, so much so that we hardly even notice them.  They carry services such as power, telephone, internet, and cable television.  Most of this involves so little in the way of electrical power that there is no real safety concern around them; fibre optic cable used in the transmission of cable television signals, telephone and internet traffic does not even carry electricity at all, just harmless pulses of light.  No matter what is being carried by them, all these wires are safely at or close to the top of very tall poles.  Only when the poles or the wires they carry come down do concerns, and dangers, arise.

SOMEWHERE IN SOUTH AMERICA.  WIRES ON POLES CAN BE A LOT MORE CONGESTED THAN HERE IN NOVA SCOTIA! PHOTO BY BERNIE SWAIN

In our area around the Medway River here in Nova Scotia, fallen wires are almost always caused by the weather, ice, wind and rain, often blowing trees down through a wire corridor, bringing the wires to the ground.  Less often wires can be brought down by vehicular collisions, themselves often the result of bad weather. If the wire involved is a power line, wet, windy conditions are among the most dangerous in which to have to deal with them.  The power carrying lines themselves carry varying amounts of power, up to some very high voltages indeed. High voltage wires, known as "primary electric power lines", carry an area's electric supply, and are generally located at the top of a pole and run parallel with the street.  Wires that carry electric current for domestic use, known as "secondary electric wires", run from a transformer fed by the primary electric power lines to the electric meter located at the building being served.

Fallen high voltage lines touching or connected to the ground may be feeding a lot of power into the ground itself.  As the distance from the wire increases, the voltage drops off, and this simple fact can cause a hidden, very real danger.  A person standing near a fallen wire might have both feet on the ground with one foot closer to the wire than the other.  This situation obviously occurs when the person is walking toward or away from the wire.  This different distance means that each foot would be subject to a different voltage, or potential, which may result in current flowing up one leg, through the body and down the other leg.  If the downed wire is carrying a high enough voltage, this flow of current through the body can be enough to kill.  For that reason, it is recommended that people, including fire fighters, keep a good distance away from downed wires, ideally as much as 33 metres (100 feet).  Again, always assume that a downed wire is carrying high voltage until confirmed otherwise.

PHOTO BY TIM NORMAN  http://www.timnormanphoto.com

The situation becomes more complicated when a wire falls onto or near an occupied vehicle, perhaps as the result of a collision. If there is no fire, the occupants should remain inside the vehicle until it is confirmed by power company officials that it is safe for them to get out.  If there is a fire in or near the vehicle such that they have to escape from it, they should jump (not step) as far as possible from the vehicle, refrain from touching their vehicle or the door for support, land with their feet together, and once they have jumped clear, hop or shuffle (feet touching together) until they are well clear (at least 20 metres) of  the hazard.

WORKING NEAR POWER LINES

The general guide lines for working near power lines are avaialble at:

http://www.nspower.ca/customer_service/safety/power_line_safety/index.shtml

Fire departments are not overly involved with power lines except when there is fire on a pole, power company equipment, a line is down or a building with electrical service is burning.  In all but the last instance, the fire department will only provide perimeter control until such time as the lines are de-energized.  In the last instance, house fires are often fought at potentially great personal risk under the assumption that the fire has caused the main breaker in the building to be tripped by fire caused shorts.

Typically the power company will send a worker to throw the breaker at the pole, but at a minimum that will involve a delay of more than an half hour after notification.  Until that has been done, at a minimum the building service line will be energized.  In some jurisdictions in the USA, a disconnecting switch at the transformer bearing pole is equipped with a padlock system for which fire departments have a key.  This permits a safe disconnect before the fire is atttacked by fire fighters.

Personnel should note the location of the power line and keep everyone well away from the area which will be covered by a circle of radius equal to the distance of the nearest power pole to the building .