Power Line Safety
Power Line Contact-What you’ll learn after you Die
In association with ConcretePumping.Com
Disclaimer This is a small portion of our information about power line contact, presented in a light and hopefully humorous format. Although we respect the seriousness of the issues, and the fact that good men, experienced men get killed everyday contacting power lines, this information is just a part, a very small part of the training that we put students through. For years we all were told to: “Just stay away”, “Look up and live”, this will help you understand why. It is not a safety guide nor is it a training guide; if you choose to use this information or a portion there of, you do so solely at your own risk.
It’s a nasty subject but after years of telling Operators to just stay away from the overhead lines, maybe it’s time to clear the air about what happens when you push the limit, play tag with God, maybe end up dead, maybe just get one of your arms or legs blown off, or maybe you’ll just walk away a little smarter.
The odds of surviving power line contact, not seriously injured or dead, is a bit less than being struck by lighting. We like to use that example because the two are very similar when it comes to what they do to your body. Basically, if you live, and some people do, it’s almost guaranteed you’ll be permanently injured; lose maybe a couple of legs or an arm. You will lose your ability to basically do anything in life and your going to suffer from the burns, which from what I have been told is the worst pain imaginable. If you die, your family or wife will probably get enough money to pay off your credit cards and pay for your funeral. It will be a closed casket funeral as your body will look like something no one will be able to stomach, let alone forget.
It happens all over the world everyday that concrete pump operators hit power lines. It’s just a fact. Will it change? Probably not. It happens when a combination of things take place. Usually bad judgment is the key. Lack of proper training and machine malfunction are also factors, but more than anything else one factor is the cause and one factor only - operator error. Its fatigue, bad visibility, bad advise, bad training, job security stress, bad setups that all play a part. For a lot of operators, it is the feeling they can’t refuse the job with the concrete already on site, the placers screaming to go, and the site super saying, “the last Guy pumped it from there”, “what are you a Rookie”, is not always clear or an option. Pushing the Operator Limits is what we term it as; and all these factors, and others affect your ability to make the right decision. That choice right or wrong may cost you your lively hood, your self respect. It may cost you the respect of your boss, your fellow operators. It will make the contractor eat the mud costs and the placers to loose thousands of dollars. What if your wrong, what if your right, who’s going to respect you for being wrong, and then what if you were right and in the end you just may have saved your life, maybe the placers life, the mixer drivers life. They have families, don’t they? It’s much more of an immediate stress than just telling an operator to stay away from power lines. It’s slightly more complex when your standing there looking up at the lines wondering if you can make it.
It’s always the same people onsite with great ideas and no experience trying to tell the operator what to do, putting pressure on an operator to do what they want because they really don’t know better. It’s a well known and documented fact that if you put ten people in a room and nine of them as a controlled test group intentionally answer a question wrong. Even though they all know it is wrong and the one person, number 10 person knows it is wrong, absolutely wrong, the number 10 person will almost every time, answer the same as the other nine, 100% wrong. It’s a fact.
It’s the same thing onsite, nine people, with their own agenda, all in a rush, all in the operators face, who don’t know the right way to safely do a pump job. They are all claiming this is the way to do it, and right or wrong, everyone including the operator agrees to follow the pack, agrees to have bad judgment and mostly always ends up paying the toll - the life or death price. Some times as Operators we do incredible and difficult things, seemingly impossible to some who do not realize the variables in pumping concrete. It can in fact be these successes, achievements that combined with the stress of what we do, and the pace that we are all required to move at that create a combination of errors and bad judgment. It’s the same reason that expert pilots will sometimes crash and burn. It’s not that one day they all of a sudden became bad pilots, it’s just one day they were too good at what they do. As a result of being accustomed to pushing the envelope, made only the slightest of mistakes. That’s all it took.
The best Operators are the best trained. That’s a fact. But it’s a lot harder to teach self confidence, to be able to control unruly site superintendents, and the placers, than it is to stand on your own in a group and be the one person that changes everyone’s plan.
This information may not teach you self confidence, but what it will teach you is what happens when the worst possible nightmare becomes the reality of where you are. You could be under a power line, touching a power line, feeling the surge of electricity flowing through your body like standing on a concrete vibrator. It will rattle your teeth, maybe it will permanently scar your heart muscles, your internal organs. Maybe it won’t because if you can still feel it, it’s means your not dead yet and maybe, just maybe, you might get out of this alive, maybe.
I can tell you what you’ll be thinking as the line is exploding and cracking around you, the ground and pump tires are on fire, oil everywhere is flashing. Boiling, exploding, that you’re thinking is that you wish you were the one in ten who did what you knew was right in the first place, and not play tag.
Understanding the Basics- Section One of Three
The Lineman’s Shuffle-How to Escape
A Lineman is one of those crazy guys that got talked into working for the Hydro Company on power lines all day. They make about the same money as us, and although they are the industry experts on playing with power lines, and they have far better safety training than we’ll ever come up with, they get killed all the time. What does that say? Well the fact is that there is no safe way to be 100% safe. There is no absolutely guaranteed way to be safe other than making sure that fully extended, your boom can’t reach any power lines. We know this is just not practical.
The Lineman’s Shuffle is a means of escape after the contact has occurred, and you are not grounding the machine. It should be something you practice without hurting yourself. You’ll know if you’re not grounding the machine because if you’re conscious and alive, you’re not grounded. The power that is hitting the machine is traveling down the point of least resistance. Where the machine touches the ground it is making contact. If there are mixers backed into the pump the contact circle, (LIKE A BIG POND OF WATER WITH RIPPLES FROM THE MIDDEL OUT), will include the mixers even if the chute is not contacting the grates. The contact to the mixers will be arching (jumping) back and forth from the chute and the back of the pump. Do not try to walk or shuffle between the pump and mixers or you will be killed. The main area of contact will be the outriggers, as they conduct the best. Secondary could be the tires or the lowest part of the truck, all of which will be on fire, unless you’re lucky.
Anything lying on or around the pump, including leaning against the pump will be energized. The placing system including the end of the boom will be energized, and the crew near the end of the hose may also be hurt or killed. The concrete will conduct electricity because it is wet. Adding in the rebar and the route to ground for the electricity gets easier. Almost all Placement Hoses have steel lining so it will conduct, just like a steel pipe. Again it will be wet inside so don’t think for a second because they are rubber, or even you are there with the rubber on your boots your going to be safe, because you won’t.
The idea behind the Lineman’s Shuffle is, without creating an alterative path for Electricity to Arc, that you shuffle away from your pump find a local store to buy a newspaper and a disposable camera. The cameras for the nifty pictures you’re going to get as the machines burns-melts into the ground, the newspaper is so you can start looking for a new career, and maybe a good lawyer. Chances are you may need both.
Does this sound easy? Don’t fool yourself, it’s not. Getting off the pump unhurt will be almost impossible. First, you have to get to a mid to high point on the pump that you can jump from. Try practice jumping from the lowest point on your pump and keeping both your feet perfect, same spacing, same height. Now look at your jump from the pump, did you get away from the unit with your feet together or did you not? The bigger the power, the longer the jump should be.
If you don’t get off clean, you won’t have to worry about the landing. Here’s another thought, when you hit the ground even if you stick the landing perfectly, depending on the amount of current still radiating out from the pump and mixers in a “CIRCULAR GROUND BORNE GRADIENT”, your legs may go in to an immediate series of uncontrollable muscle spasms just from the current in the ground. This will cause you to fall and at that point you will be killed, or badly burned. As you are now providing a different path for current to travel using your body water, that will be easier than the current flowing through the ground.
Find the right spot on the pump, no sense running to a spot you can’t jump away clean from because you have to stick the landing. The idea here is not to be picky as things can and will be changing around you fast. Second, you’ll also not be able to touch anything as you get to this “JUMP POINT”. Touch something, anything with your hands, your wet clothes, the remote, lift your feet, take a big step, panic, and your dead. One other thought as you are looking for a spot to jump, the arcing from the wires may temporarily blind you as it is much brighter than what your eyes can adapt to. Like looking at a weld being done except about 1000 times larger. If it blinds you even for a millisecond, again you’re probably going to die.
You can’t think of the pump, you may be able to save the crew, but chances are the boom is frozen against the power line and the fuses are blown. The machine is toast, scrap, and watching it burn is the only option. Don’t get a water line or hose and try to put out the fire. Don’t think there is anything you can do because there is not. Even the pros, the firemen when they get there will not put the fire out till they know the power is down. In one of the comments below an operator was killed as he tried to help put out another operator who was in fact on fire, and still contacting the machine. Operator number two, was also killed. According to eyewitnesses, the electricity arced through the fire extinguisher.
In some places the power will short out a couple of times and then be down. You can not rely on this. Beware of time-delayed relays. Even after line damage trips breakers, relays may still try to restore power. They may reset automatically two or three times. You may be unlucky enough to hit a line that refuses to recognize the power short or surge cause by the contact, and it will keep going at full power destroying everything and everyone till the hydro crews get it turned off.
In most areas, power is designed to keep going so don’t take the chance, stay away from the machine. Call 911 for help, and see if anyone else is hurt. Warn others to stay away from the machine, the general area. Do not panic, and do not make any more mistakes. Be thankful you’re not dead, just unemployed.
Just because you’re away from the machine doesn’t mean the danger is over. What is happening now is your outrigger dunnage is being melted at a heat that would weld steel. What does this mean? Well number one, the machine could become unstable and while people are standing there unable to see the outrigger pads melting, due to the blinding arc welding effect, the pump could in fact flip over and harm other people. There is no history that we can find about what takes place when you run extreme high voltage through holding valves, check valves and boom cylinders full of hydraulic oil so be careful to clear the area, to at least the length of sections in the air. Let’s not forget that your truck and its aluminum rims are all about to melt so no mater what, it is very likely that the machine will become less stable. We also know that when you super heat the structural steel it will likely fail. The pumps super structure and outriggers could also do the same. Although unlikely, it is still a risk. Do not assume anything. Watch the white hot steel of these outriggers as they and the truck explode and burn. Also note how hard it is to see the actual contact of the outriggers. Where is the Operator? Did he or she live?
Exploding Hydraulic Lines and Flashing Oil:
We all know that hydraulic oils like all oils will flash and burn with the right help. Regardless of the flash point which could be somewhere about 250 degrees Celsius, the heat from the contact could easily in milliseconds disintegrate and burn out hydraulic hoses, all long before the engine stalls. Sending out lit hydraulic oil burning all over the area and on you as the operator. Once on your clothes and lit, the hydraulic oils will be incredibly hard to put out and everything you do at that point will also effect whether or not your able to effectively get off the machine, or away from the machine, and ground radiant electricity with the electrical fires, the arcing of the flames and heat.
Take a couple of minutes and watch this short video of a transformer exploding. Transformers are everywhere and failure may or may not occur once your Concrete Boom contacts a line. On the other hand the contact may also cause wires to fall and to energize unsuspecting people on the ground or construction site. Regardless, the bottom line here is looking at this particular transformer failure you can see the possibilities if something like this were to explode near or overhead of you and the pump after the boom contacts a power line you would be burned severely. Just because it has not happened to a Pump Operator yet doesn’t mean it will not; have a look.
I asked some of the professionals to weigh in on Concrete Pumps and boom contact with power lines, and they did. Here are some quotes from professional lineman about boom contact and accidents. Pay attention. This may just teach you something; these comments and interviews were all gathered February 14TH – 17TH 2006.
“Tell them this is what you’ll hear, (referring to the transformer failure-fire and explosion), as the tires melt off your truck and everyone in contact with the truck becomes BBQ in a matter of micro seconds. If you’re lucky the breaker or reclosure will lock out. Or you'll blow a fuse down line. But don’t count on it. I’ve seen it sit there and burn till somebody trips it out. Maybe you’ll be lucky and blow a fuse and no one really gets hurt. Or maybe they will have to scrape your remains up with a snow shovel like they did 3 painters here. They weren’t really identifiable as people. All they did was push some scaffolding into some 20 KV and the breaker never saw enough of a fault to trip out. If you do live it will be maybe a month before they know the extent of your injuries, because electricity burns you from the inside out. At first the place on you might look red and swollen. A week later a small hole opens up. Then it gets bigger with time as the dead flesh and muscle rot off the bone. It isn’t fun and it isn’t pretty, but it’s a lot easier to warn your men, than it is to go out and watch the coroners office scrape them up with snow shovels, and dump your operators in little plastic bags”.
Senior Linemen Baton Rouge, La
“Usually you can identify the pile of ashes by the type of belt buckle the guy was wearing.”
There is only ONE, 1, way to handle this. Teach them that they can't come closer than 10 feet from an energized conductor no matter what (and there all energized unless the hydro personnel tell you the circuit has been isolated and grounded and shows you the grounds). Anyone who is seen closer goes down the road kicking stones. Or you'll be burying somebody. Zero tolerance. I think you should ask your company lawyer to explain Bill C-45., to your guys before they end up in jail.
In a nutshell if you don't absolutely keep your trucks away you can under Bill C-45 become a felon and spend years in the crowbar motel. This bill is a result of the Westray Mine disaster, take it seriously.
Senior lineman; AKA “The Old Lineman”
“We had an outside contractor contact a 138KV line with a digger derrick. The difference between to controls and the seat was enough to set the operator on fire. The other worker ran and got a fire extinguisher and tried to put his brother out. The current arced across on the spray and killed the brother. Both people died at the site. It was a horrid sight to see.”
Senior Lineman: Austin Texas Marcus;
Another hazard to be aware of; if the equipment the operator is on is set fire the operator needs to JUMP clear of the machine. If the operator steps off the machine and makes contact to both the ground and the machine they become a current path and will be hurt or killed. Once on the ground carefully shuffle away from the machine. I know of at least one operator who took a long stride away when an 115kv line was hit and the ground potential between his left and right foot conducted a current thru both legs. Since the path was not across the heart he lived but he lost meat on both legs.
Senior Lineman: Virginia, USA
Marcus If It Happens…..
It's maybe a good idea to consider the actual scenario if it actually happens.
When the boom makes contact significant current will most likely flow through the truck and into the adjacent ground, arcing over the surface of and ultimately igniting the tires. At this point there will be a high voltage potential between the truck chassis and ground, and also a voltage gradient across the ground as the current seeks a path to earth.
The best thing for the operator to do in these circumstances is probably boom away from the cable, as any attempt to climb from the vehicle may result in electrocution between chassis to ground or the unpleasant scenario where the ground borne gradient causes leg spasms that cause the operator to fall and make further contact with the live ground with his hands. That could ultimately lead to heart fibrillation by the current passing through his body.
By making an attempt to break the contact by swinging the boom (assuming the controls aren't carrying current to the operator), the operator may save the lives of himself and others in the vicinity and might even salvage the truck.
Senior Lineman Glasgow, Scotland
One of the best ways to avoid trouble is to contact the Utility Industry for an outage when you have to work in close proximity to power lines. I have seen two persons electrocuted. The truck boom made contact with the 13.8 KV primary line and two persons died. Nobody knew that two persons were electrocuted because they both fell in a canal and only one was found. Three days after the other body float up. If they had contacted us before they started to work the deaths could have been avoided.
Senior Lineman London, England
The distance electricity can arc to an initial contact is affected by ambient conditions like humidity, but in general is fairly low. However, once an arc has been established the air becomes ionized and forms a conductive path that can draw the arc out to a considerable length.
When shuffling; take very small steps and keep your feet as close together as possible. When a fault current is causing a voltage gradient on the ground, the distance between your feet will be directly related to the voltage between them. It's therefore very important to keep that to a minimum without putting yourself at risk of losing balance. If you fall and automatically put your hand out, then as soon as it hits the live ground the voltage differential between your hand/s and feet may be high enough to cause electrocution.
In the event of falling you would ideally curl up into a ball to minimize the area of ground contacted. If you do fall and pass modest current then you will probably do that automatically anyway.
I think the strongest message you can drive home is that nobody can force your guys to work closer to overhead lines than they deem safe. Beyond that they need to suggest that a representative from the electrical company is present and maybe get the person requiring the work to sign a formal declaration of responsibility. That should change their mind.
As far as a safe distance to cables goes, it's probably an easy rule of thumb that if the boom was fully extended then it wouldn't be any closer than about 20 feet at worst case to allow for the unexpected.
Senior Lineman, Glasgow, Scotland.
How to Shuffle:
Like everything, there are several ways to shuffle that differ depending on who you ask. Key points are very simple. Your feet are on the ground. Do not lift them for any reason. Do not move one foot any farther forward that ¾, (Three-Quarters), of the other foot, baby type steps, do not create a gap between your knees; don’t let your legs get apart. Whatever you do, do not fall, do not use your hands to touch anything. Do not put your hands together; do not rest them on the remote. Do not touch anyone ELSE. Do not panic. Try to imagine walking across a floor of solid concrete vibrators; this is exactly what it feels like. While this is happening, you will likely be having problems with your breathing, and uncontrolled adrenalin/fear. Again don’t panic. The fact that you are not unconscious and in cardiac arrest means that you might survive. If you fall you may black out, if falling ball up. Remember your legs may be having muscle spasms. Do not look back; looking over your shoulder as you move forward may cause you to loose balance. Get 30-50 feet away. Do not go back to fight the fire. Note Picture 1 of Failed Shuffle Attempt. Result: Time Off on a Stainless Steel Table- AKA Death. These are exit wounds. Most of the damage is internal.
The Hardwire Remote:
If you are running an older machine with a hard wire remote, you have to be standing on the machine. Again, the simple solution here is not to do the high risk job, line pump it, figure out a safer way. Having heard that before, and since you are now doing the job anyways, controlling the environment around the pump is critical. The hard wire could create a path for the current to flow around your body and it will. Be careful not to have it strapped to your body, if you can avoid it. You have to dump, “throw” the remote before you jump from the machine. Do not dump it on your feet or in your path. Do not throw it off the machine to the ground; someone else may try to pick it up and save the day. Do not have it close to your chest or heart area.
Using the Radio Remote –Standing Off the Machine:
If you are on the radio remote as most all of us are today, yes you are safe depending on where you are standing, but the mixer drivers and the crew may be killed. If you are able to get away safely yet cause your coworkers to be hurt or killed due to negligence, you will likely be sued and/or prosecuted for Involuntary Manslaughter. Although we have yet to see this as an industry, you could be the very first one the Attorney Generals office tries to make an example out of for the rest of the industry. Also, there are other issues with the remote as there is still ground radiance of the electricity depending on power level out to 35-50 feet. You may panic and instinctively move towards the machine. Regardless, the number one issue here is that if you are a decent operator you will immediately, without thinking of it, try to move the machine away from the power lines. As you have learned this through near contact misses on the job site with forms and rebar. Despite what is going on, the first order of business (if you are not electrocuted), is to attempt to free the machine only. If you still have radio control, you may not and at that point the machine may weld to the contact point and you will not be able to move it anyways. Again you should instinctively try to move the machine away up to 50 feet or more don’t waste time folding up or anything like that. CLEAR THE MACHINE FROM CONTACT AND CHECK FOR VICTIMS TO HELP. Remember this is only if during contact you have control and it is not about saving the machine. It is about having or creating safe access to the victims and not having further Hazards from the melting pump and certain full out fuel fire, and the power line breakers restoring power to the contacting pump boom.
Helping to Save the Lives of your Victims:
The rule of thumb for an electrical shock victim is:
Do not attempt to aid the victim until the source of the current is shut off, or the victim is no longer a path to ground. Touching a person who is in contact with a current source will not remove the path to ground. In fact, touching a person in this situation provides the current with another path to ground through the rescuer. Rescuers can provide no help to victims if they become victims themselves! Normal instincts to provide assistance must be checked long enough to analyze the situation. Despite your very strong desire to help, wait until the contact with the current source no longer exists or the current source is turned off. You need to think about what the term “Turned Off”, means in these contact scenarios. It’s not what we think. Picture 2: Arcing electrical burns through the shoe around the rubber sole. This was a High-voltage (7600 V) alternating current. Note the ID tag on the Toe. They don’t give you these if you’re in recovery.
The length of exposure to electric current, the path of current flow, and the size of surface area of electrical contact can affect the severity of the shock. Very small currents can cause spastic action, but recovery can be rapid. Slightly larger currents can cause muscle paralysis. In the event of paralysis, artificial respiration or massage must take place as quickly as possible to minimize damage to the brain from lack of oxygen. Ventricular fibrillation can occur with currents of 50 to 200 milliamps and will continue until something is done externally to restore regular heartbeat. Immediate first aid can save a victim whose heart has actually stopped beating and whose lungs have stopped pumping. Rapid action by knowledgeable persons can prevent body damage and save lives; however, heed the "rule of thumb".
Higher currents can result in electrical burns where tissue is destroyed. Even if burn injury is not visible, the current has traveled through the internals of the body so the burn effect may be beneath the skin. Knowledgeable medical practitioners will be needed to administer first aid to the victims of severe shock.
An electric shock results when an electric current flows through the human body as it seeks its path to ground. The body gives electricity a path to ground when it contacts conductor carrying electricity and, at the same time, it is contacting "ground," an object at zero voltage level.
The amount of current flowing through the body determines the extent of the injury. It is important to understand that the human body is a good conductor of electricity, primarily because of its water content.
Again if the power is not down, don’t touch the equipment and ground at the same time. In fact, touching anything in contact with the ground can be fatal. You must also remember that if the machine still has contact, and this is very critical, the power may reset its self as you rush to the aid of your co workers. This will kill you as the power comes back on and you will be in the zone and electrocuted. This is why, if possible, freeing the energized machine may be the best option.
Keep others away. Warn everyone not to touch the equipment or its load. That means outriggers, hoses, boom system anything contacting the machine or within 50 feet of the machine, including the pour area and forms.
Again you need to beware of time-delayed relays. Even after line damage trips breakers, relays may still try to restore power. They may reset automatically two or three times.
This is why “Breaking Contact”, If possible by moving the equipment clear of the wires is the best option in the first few seconds of power line contact. More serious damage is often inside the body where internal tissues may actually be cooked by being instantly heated to extremely high temperatures. Picture 3: This was the ground of an alternating current nominal circuit. Note this is an exit wound: Also note, lack of blood and the melting skin falling from the wound due to the cooking of internal organs; note below the left nipple you can see deformities in the skin as it was preparing to blow outwards with more exit wounds; also note the hard to see red and blue heat marks from the internal organ flash burning, showing around the outside shoulders and neck area. We have cropped the rest of the picture. This person is also dead.
Never attempt to rescue the victim of an electrical accident unless you have the appropriate skills and tools. Planning and training are integral to handling emergency situations where electrical shock has occurred. Workers are often injured because they are unprepared for an emergency. There are many tragic examples of workers, supervisors and even safety personnel who rushed in to save an injured fellow worker without thinking and were hurt themselves. A prime example is a worker on a site reaching for the first thing he can to help save a co worker, picking up a wood 2x4. He tries to help out and is killed as the power finds enough moisture in the wood to kill both him and his coworker. Again do not think you can save the pump if it doesn’t come free of the lines in a millisecond, this could get you and others killed. Concrete Pump fires can take the professionals 30-60 minuets to put out, so there is nothing that you can do with your $20.00 dollar fire extinguisher except get yourself and others killed by thinking you may be able to save the pump. You can not. There are far too many uncontrolled variables, including a couple of hundred gallons of flammable fuels and oils.
The “Bird on the Wire” Scenario:
If a person is completely on the unit he is in what is called the 'bird on the wire' and it is possible there may be no appreciable current flow over his body. Therefore no heat is generated and without the heat, no fire. The Operator is “The Bird on the Wire”, and the operator is in an equipotential zone. An Operator in an equipotential zone will become energized on his body, yet because there is no grounding or heat, no electrocution and again no fire. You will probably feel a sensation or think you do because of all the things going on around you. It may not be life threatening unless a transformer explodes and you get sprayed by flaming transformer oil, or get electrocuted getting off the machine. As for the boom, if it contacts a power line it will become energized and chances are it won't trip the system protection. Again you can not count on this scenario as it has variables that when it happens to line men they are prepared for and control. Our booms are not setup to have control over the same variables. But if an operator does get off a machine safely, after locked contact, it is because of the “Bird on the Wire” scenario.
Freeing the Energized Machine:
There is a chance that you may be able to move the boom, or contact point, off the lines. This normally happens when the contact is brief. For example, a swinging hose at the end of the boom tags the line and then drops off the contact. It does happen, and is common. If the hose is in the air the crew is safe. If the mixer drivers are standing on their trucks, (Safe) and the area around the pump is controlled, contact like this can take place and the only signs of it will be scorching from where the machine and/or the mixers grounded the power source. Owners or mechanics noticing this type of situation should pull the machine from service and interview the operator and the site superintendent. If you are the operator and this takes place, and the mixer drivers are not on their trucks, they will be hurt or killed. Concrete testers and others working around the pump may also be killed. Again controlling the environment is critical. Second, if the machine does make contact and if there are injuries and fire, explosions, stay calm as you will instinctually and instantly, try to move the boom of machine off the contact point. Be prepared for the power line surges as they may come in waves as the power source breaker shoots off and resets the power again. Also remember that the machine fuses could arc or short out and at that point there could be no control. There have been cases where the machine still maintains boom functions, relatively unharmed, while contacting the lines. Again this is only a possibility, it may not happen. Remember that as you pull away from the wire, you will be seeing an expanding and exploding Blue and White arc. Individuals around the machine including the crew on the site and even the mixer drivers will instantly run. They will think the boom is coming down upon them. As explained by one of the linemen, the air makeup around the contact point has changed and now will conduct electricity for extended lengths, how far exactly no one can say as it has yet to be tested.
Again it is important to stay calm. Check to make sure there are no injuries, make sure the mixer drivers are alright, stop pouring and call into the office for backup immediately. Apart from the pump being damaged, it may be on fire somewhere and just not obvious yet. Also your heart, which is being driven by adrenalin, may be experiencing irregular heart beat, arrhythmias, and you may not yet know or feel this. You could go into to full cardiac arrest within the next few minutes or even hours, or you may be alright. Arrhythmias are irregular heartbeats caused by a disturbance in the electrical activity that paces your heartbeat. The most serious arrhythmia is ventricular fibrillation, which is an uncontrolled, irregular beat. Instead of one misplaced beat from the ventricles, you may have several impulses that begin at the same time from different locations—all telling the heart to beat. The result is a much faster, chaotic heartbeat that sometimes reaches 300 beats a minute. This chaotic heartbeat means very little blood is pumped from the heart to the brain and body. Medical attention is needed right away, go to the hospital.
UPDATES: The United Kingdom Changes its Safe Distance to Power Line Laws: February 18th 2006
I was at a course updating my IPAF card today. IPAF is the International Powered Access Federation and a card is required to operate aerial access units. The distances they specify for power and transmission (in the UK) with boom fully extended are:-
9m (30') to wooden distribution poles.
15m (50') to metal pylons.
All measurements are to the closest wires, somewhat more generous than the American allowances.
Senior Lineman: Glasgow, Scotland.
Understanding the Safe Distance Zone:
The first thing you have to learn is that there is no real safe zone. We heard from a senior lineman that after contact occurs that the air molecules become ionized and that the electrical current can then travel on those molecules. What does than mean? Take two minutes and watch this video on an actual line break. Looking at the electricity traveling through the air possibly 40-50 or more feet really makes you see what kind of problem getting too close can cause for you. This is an extreme video but it does show the possibilities of the Contact Problem. You have to remember as an operator just because something has not happened or has not been documented, doesn’t mean it can’t happen. Here is a good example of what we think we know, verses reality. Recently a large helicopter carrying men from an offshore oil platform crashed after being hit by lighting. On average, helicopters in this work get lightning strikes nine plus times per year. Jets on average get one strike per year. In this scenario the helicopter received tail rotor damage 300% more severe than anyone had ever thought could in fact be possible. Remember just because you haven’t seen it, doesn’t mean it can’t happen.
“Once an arc has been established the air becomes ionized and forms a conductive path that can draw the arc out to a considerable length”.
There are always the variables. We all know and are taught that the safe distances are somewhere between 10-20 feet. The ACPA says 17 feet. We say, simply put, more is better. Big lines require big clearances.
The issue here is the what if factor, and there are just too many to even go through, but let’s talk about the basics. First let’s look at different situations. With so many sources of information from all parts of the world everyone has somewhat of a different view. We know that electricity can arc. We know there have been cases whereas electrical currents have jumped from one point to another. It’s the distance of these arcs that are very hard to pin down, like describing the fish that got away. To everyone it looks different maybe larger, maybe smaller. A good example would be a wet hose coming out of a jobsite attached to the end of the boom gets drawn to the power source and then arcs. Is there draw, is there static, magnetism, could this happen, why take the chance? Of course these types of things do take place. A theory is that large overhead lines running the biggest currents can form an invisible circular barrier. Like a vertical tornado only on its side, lying horizontal, these currents can travel along the line base. Setting up your machine under the lines, in line with the power lines, even if the clearance is good, could still create an arc. Setting up not inline with the flowing current may in fact be much safer. If you want to be smarter about power lines the first thing you need to know is how to spot the voltage of the lines based upon how the poles carry the wires. Have a look on the web and see what the average lines look like and get familiar with them. If we owned the power company we would spend everyday trying to figure out how to carry more juice in smaller lines. So looking at and tracking the industry information sites might just make a difference for you.
Again more than anything stay away and don’t think you know everything. None of us do and this industry is changing and different in every part of the world. So be safe, ask yourself every time you get near a power line. What’s my life worth to me today, to the people that need me? What would they do without me? What if I killed someone? Would I go to jail for manslaughter? What am I doing this for? Look up, look around, stay safe, stay away, stay alive because once your dead, there’s no coming back. Remember that you’ll never learn anything after you die.
Closing Note: For those of you who still think you can push the limits, one final thought, here it is. It is a definition of pure stupidity. If you can’t think about yourself, think about the guy on the end of the hose and the mixer drivers. Here’s exactly why if you hurt anyone out of negligence you may end up in jail and don’t say you didn’t know, because now you do.
In order for a person to be found guilty of involuntary manslaughter the government must prove that someone was killed as a result of an act by the person;
Second, in the circumstances existing at the time, the person's act either was by its nature dangerous to human life or was done with reckless disregard for human life; and
Third, the person either knew that such conduct was a threat to the lives of others or knew of circumstances that would reasonably cause the person to foresee that such conduct might be a threat to the lives of others. Department of The Attorney Generals Office
Involuntary Manslaughter Sentencing Ranges
1 Years Alabama, Connecticut, Utah, West Virginia, Wyoming 2 Years Iowa and Texas Colorado, New Mexico 3 Years Arizona 4 Years California, Missouri, Nevada, New York, Oklahoma 5 Years Delaware, Kentucky, Louisiana, North Dakota, Oregon 6 Years Tennessee 7 Years New Hampshire 8 Years Indiana 10 Years Alaska, Arkansas, Georgia, Idaho, Illinois, Maryland , South Dakota, Washington Minnesota, Ohio 15 Years Florida, Michigan, Vermont 20 Years Hawaii, Kansas, Massachusetts, Mississippi, Montana 30 Years Rhode Island, District of Columbia
This information is to provide some of the considerations with respect to power lines and their inherent danger.
The International Operator Training Center adheres to the principle that, “The very best Operators within the industry are those who started with Comprehensive Training.”
We believe, “Advancements within this industry consistently lay demands on individuals operating equipment to understand both the capabilities and limitations of new technology.”
In brief, “We strive to create knowledge and understanding of the best methods and operations for some of the most technologically advanced equipment within the modern construction industry, and to pass that knowledge on to individuals striving for better opportunities, better careers and greater income.”
“The International Operator Training Center encourages its students to respect and understand, the abilities and limitations of the modern concrete pumping machinery, and to use that understanding, training and knowledge to perform their jobs with the utmost professionalism and safety.”
Take your time, think about your pour options and always make the right choices! These are the safe choices- Because there are no others!
OTC- Be Safe Not Stupid!
Published by www.concretepumping.com