Beware electrical hazards
If a conductor is down and the squadman knows that it is deenergized, he should respect the wire just as much as he would if he knew the line were hot. All primary circuits are supposed to have oil circuit breakers on them that automatically open or deenergize the circuit if there is trouble on it.
When a line crew goes to work on a damaged circuit they take two precautionary steps: First they “put air in the line.” That is, they open a switch other than the oil circuit breaker so that as much as 3 feet of air is between the line and load side of the switch depending on the voltages involved. A cardinal rule for linemen is: “Never work behind an oil circuit breaker.” An oil breaker is a spring-loaded automatic switch, and even though it is supposed to “lock out,” malfunctions can and do occur and the switch just might reclose itself.
Secondly, the line crew will ground all the circuits on the line side of the break. A fireman cannot “put air into a line,” neither does he have the equipment to ground a line, so these two items alone are enough to make him stay clear of conductors on the ground.
It is necessary to know a little about power company procedures in locating and clearing a “locked out” circuit to understand the most important reason to stay clear of broken primary lines. If a lineman knows where and what the trouble is he will open air break switches and ground the lines immediately.
However, in about 95 per cent of his trouble calls, the only information he receives is that a certain substation or circuit is out. The first thing he does is to go to the oil circuit breaker, reset the switch and close the breaker. He is supposed to switch the breaker to manual operation which only allows the breaker to relay one time. There are indicators on the larger breakers which will show him what to look for, if there is still trouble on the line.
In about 25 per cent of the arses the breaker will hold, because some line trouble will clear itself, such as a limb falling across the line, or perhaps a fused tap line that has grounded or shorted conductors. If the oil circuit breaker is not set on “manual” and left on “automatic,” when a lineman trips it on, the breaker will relay or turn itself on three times before it locks out. The first relay will be instantaneous, the second in about a minute, the third in about two minutes later. Either one of these “shots” of electric current is enough to be fatal. Just remember that even though a conductor is deenergized when you arrive on the scene, there is a very strong possibility that it will not stay deenergized.
Another important factor to remember is that every conductive object that a live wire touches becomes a hot conductor. This could be an automobile, a fence, wet ground or pavement, guy wires, telephone lines, poles themselves and probably most important to us as rescue workers—people or animals. We have to disengage people from live conductors, but in far more instances we will need to recognize foreign conductors, or conductors other than the actual wires, and take the necessary precautions to keep ourselves and others away from these seemingly innocent hazards.
Emergencies involving vehicles
If live conductors touch a vehicle, the vehicle becomes a conductor. If the vehicle is upright the rubber tires act as an insulator, energizing the vehicle. Any person coming in contact with the vehicle while standing on the ground will, with his body, give the current a path from the energized vehicle to ground. This flow of electric current through the body can and often does prove fatal.
If the occupants of the vehicle remain inside, they are relatively safe from electric shock. When the victims are rational, and conditions permit, tell them to stay in the car. If, because of fire or injury, it is imperative to remove them at once, remember that as long as a person does not come in contact with both the conductor and the ground at the same time he is relatively safe.
If people inside of the vehicle can understand and carry out instructions, tell them to jump off, not step off. By the same principal, if squadmen get into a similar situation, they, too, should jump off, making sure that both hands and feet are clear of the vehicle before coming into contact with the ground.
It is impossible to give a set rule on how to approach an energized vehicle or conductor. The ground around a conductor is also energized. The amount of current and the size of the area are dependent upon the conductivity of the earth or pavement, which is determined by moisture and chemical content.
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It is possible to receive a good shock by walking up to a grounded conductor. This happens when the legs and hips give the electric current a path of less resistance to pass through, than does the ground over which the person is walking. The wetness of the earth or pavement would probably be the more important factor in determining how close you can approach a grounded conductor. Always approach slowly with short step. Usually you will feel a small stinging or shocking sensation on the soles of your feet before you get close enough to get into serious difficulty.
Handling energized wires
When all other means of saving life have been expended, and it is necessary to move a person from a conductor of electricity, a fireman should have some idea about how to protect himself and others involved in the rescue. The handling of any conductor is a last resort. The term “any” is used because you should assume that “all” conductors are energized.
There are many instances when the risks involved in rescue are not justifiable. For example, if a person is in contact with a transmission or distribution conductor and is burned severely and quite obviously beyond help, it would be a foolhardy gesture on the part of a squadman to risk his life to save a body. One victim for a coroner is far more desirable than two or more. If high voltages are involved, 13,000 volts and up, the risks involved in moving a line are terrific. Rope should not be used on high-voltage lines unless it is dielectric rope and is absolutely dry. Even hot sticks that linemen use are kept in heated dehumidified trailers, and are tested regularly. Stay clear of extremely highvoltage lines regardless of the circumstances.
Moving lower-voltage lines
There are several methods of moving lower-voltage primary lines. One of these methods is to use a dry rope. Each end of a ¼-inch rope, 100 feet long, should be weighted with ½pound weights. Put one end of the rope on the ground about 30 feet from the conductor. Throw the other end of the rope under the conductor so that it will be at least 30 feet from the conductor itself. Then toss the end that is on the ground near you over the conductor. You now have the rope looped around the conductor. Go around the broken conductor to both ends of the rope and pull the conductor away from the object or area that you want to clear, being careful not to let the wire touch objects that would endanger the safety of yourself and others.
Dry boards can be used to move a conductor, but the board should be dry and clean and at least 12 feet long. Regular linemen’s rubber gloves are good to use if you happen to have them, but they should not be depended on when handling conductors carrying more than 5,000 volts.
“A slow hurry”
In rescue work every second counts. A good squadman will proceed in a slow hurry, evaluating the risks involved against the possible good he could do by taking these risks.
When a person has been lying on a conductor for only a matter of minutes, perhaps only three minutes will make the difference between life and death. The victim can be rolled off the conductor with hot sticks or dry boards, or he can be pulled off with a dry rope. If the conductor is grounded, care should be taken to keep it grounded, because the more current that flows into the ground the less current will flow through the victim’s body. Bystanders should be kept at least 100 feet back for their own safety and so that rescuers will have sufficient space in which to work. When a victim is removed from a conductor more burns may result, but the burns are not of primary importance at this time. Air exchange and blood circulation must be started immediately. Do not touch the victim or any part of his clothing with your hands or feet until he is clear of the conductor.
First-aid treatment of electric shock
Two immediate possibilities in electric shock cases make fast and precise first-aid treatment a vital necessity. When there is a possibility of saving the life of an electrocution victim two factors have to be determined almost immediately: Does the victim have a pulse? Is the victim breathing? Other complications such as burns and traumatic shock will have to be considered and are important, but the first and immediate problem is to restore blood circulation and put oxygen into the victim’s lungs so that the blood can carry oxygen to the brain and other vital organs. A knowledge of closed chest cardiac massage and mouth-tomouth resuscitation is a must at such time.