Hi ! I'm a neewbie on this forum as well as in the trade , I would like to know what are the protection we have in excavator against lightning ??? some people are saying that the cab is insulated !!! which I'm not sure that I would trust !!! what you guy's think and know ??? regards
I think you are asking about the risk as an operator in being injured if the machine is struck by lightning while you are operating. You are safe. The machine is providing the path to ground, not you. The only time you might be hurt is if you were outside in contact with both the machine and the ground at the same time, I'm not sure you'd be at much risk there either since the tracks would provide a far better ground than a person in shoes would.
lightning dosent strike yellow paint that is why CaT uses it. Pj
I just send the laborer out with a 10' piece of copper pipe. He acts as the litghning rod, while we keep working. Works every time.
maybe that's our problem.....we have been using PVC pipe all this time, come to think of it copper tube would work better on a more serious note though, has anyone here ever lost a peice do to lightening? I cant say that I have ever heard of it. Pj
Many years ago a guy running a loader doing a job for me told me that he and his buddy were sitting under a machine (I didn't get the type or if it was tracked or wheeled) when lightening hit the machine. His buddy was touching the machine and was killed. He was deafened and had trouble seeing for about 3 days.
That part, I'll disagree with. Lightning is pretty funny stuff, and it will sometimes follow other paths in addition to the best ground. You need not be touching the machine. Just being close is risky. Think of the advice to not seek shelter under a tree, for instance. It's because the tree is tall, but one would expect that the current would follow the tree, but it can also travel through you, if you're close enough. A number of years ago, I was at an airshow, with the Civil Air Patrol. A thunderstorm swept in (ended the Blue Angels performace at about mid-show ), and during the storm, lightning struck a beer truck parked near the edge of the display area. It reportedly struck the fiberglass CB antenna, mounted to the driver's side mirror. There were tiny bits of fiberglass spread over about a 50 foot diameter circle. The CAP airplane was parked nearby, and several people who had taken shelter beneath the wings were shocked as well. The people weren't in contact with either the plane or the truck, and obviously the truck wasn't in contact with the plane either. I googled around a little for more information, and came across the National Lightning Safety Institute (NLSI). There's lots of good lightning info there. (More than I had time to read.) Cut and pasted from their site. (I bolded the part that seems to apply most.):
Wouldn't a lightning strike be almost the same if a part of the machine came into contact with a high voltage line? Best place is in the machine, as standing near the machine without even touching it could be fatal.
I would think it would be similar. Another misconception that people have, is that you're safe in a car or truck because it's on rubber tires, which will act as an insulator. The reason you're safe is that the metal of the vehicle is a much better conductor than you are, so the current follows the metal to the ground, and doesn't need to travel through you. I probably should have noted above that moving some distance away from the machine might protect you if the machine did happen to get struck, but if you were still in an open area, the lightning might just prefer to strike you directly, and spare the machine. I was on the job once when a truck driver raised his bed into contact with a 28,000 volt line. It blew all four tires across the rear axle, and one of the front ones. If they were such a good insulator, you'd expect the truck to have been unaffected by the voltage. The way I always looked at it, if that current can arc through the space of several miles of air (the distance between the clouds and the ground), then it really isn't going to have much trouble arcing several feet or yards further.
protection for lightning: I think you've pretty well nailed'er, digger242j... :thumbsup Excellent fact about the tires, too... spot on!!! OCR
I saw a rubber tired crane hit a high voltage line 30 years ago. The tires did nothing to stop the current flow. The crane and the tires and the operator burned and melted in a few minutes. Made me always aware of power lines when operating near them. Hitting a primary underground you may get off with just burning up the bucket and boom but overhead is not pretty. Have seen what a dump looks like after hitting a power line and it is not pretty either.
protection for lightning: Bill, I think there's a picture, or video, of that floating around some where on this site... I know I've seen a picture of a crane on fire, some where on the Net... I'll do some looking.... This might be it: http://205.243.100.155/frames/longarc.htm#Crane Or, go here and scroll down to Link Belt crane.... http://205.243.100.155/frames/longarc.htm Might not be the same one, quote from site.... OCR
Hi ! Thank you to all of you who shed light on this topics , very informative , regards
There was A guy in Bradford,pa that had his brand new linkbelt 160 struck by lightning while it was parked over night. When he showed up in the morning he noticed the machine smelled of burnt plastic. When he tried to unlock the door the key would not work. He called the dealer and they sent a mechanic out. after inspecting the machine they found that it had indeed been struck by lightning and everything electrical including computer was fried. A big insurance claim later that was all fixed and then a little while later several different barings started failing throughout the machine. After a few months the insurance co finally just scrapped the machine and got him a new one.
:jawdrop Notice that it didn't happen until a few minutes later.
I remember my physics professor talking about the different planes of travel electricity takes once its on the ground. So like Digger's story at the air show, some people standing right next to the beer truck could be fine(actually that sounds like a really good spot to be). And then say 50yds away someone had one foot in one plane of current and the other in a different one and thus be a conduit for the electricity and die. it was an interesting concept. The teacher used a real example of a baseball diamond and the strike was in the infield, the pitcher was fine and two outfielders perished....
Last summer we had an especially violent thunderstorm in the afternoon and our fire department got several calls for houses struck by lightning. On the one that I went to, the brick chimney was struck, exploding the top of the chimney. The house was on a culdesac and we parked the trucks there. As the firefighters were investigating the strike, I noticed brick debris in the roadway where I had parked the truck over 1/4 mile away. There's some amount of power in lightning!
Ok random question on the topic. New to the forum by the way. So in say a John Deere 544J wheel loader would placing your bucket on the ground give the lightning a means of travel to ground to maybe bypass the occupant? Possibly try electronics and blow fuses...but maybe save a life?
Sitting in the metal cab is the safest place to be in a lightening strike. Google "Faraday cage" the electricity flows around the cab instead of through it.
Friends of ours lost a son to lightning strike when he jumped off a dozer and was running to his work truck. I’ve been in the same situation myself... in the heat of the moment, it doesn’t make sense to remain sitting in an all metal machine when the relative safety of a vehicle is just there.
We would have intense storms several times a year in the mine. I concur with Queenslander that it is counterintuitive to remain sitting in a 75 ton wet block of iron... we were instructed that when the storm was popping close to make sure the windows and doors were closed, come to a stop and sit with your hands in your lap. After the main body of the storm had passed... back to work. Staying in the machine worked at our place.
I should also mention that in both the cases that I mentioned, we were on open canopy tractors with rain blowing in, windows probably down in the truck, so the urge to make a bolt for it is overwhelming.
On a rubber-tyred machine placing the bucket on the ground would give the energy a clear path to ground instead of it having to find its way through tyres (think steel cords) and/or jump to ground from the machine frame For machines with no cab or an open ROPS all bets are off, but our machines were all equipped with cabs & aircons, so the SOP was always - stop work, ground the work tool or equipment, close all windows, leave the engine running for the aircon, and sit tight until the all clear sounds (if your work site has a lightning alert system) or until the storm has moved away (if it doesn't) ........... As someone else pointed out earlier, Google "Faraday Cage" because that's exactly what the cab of a machine is. So in that respect remaining inside the machine cab is safe, being inside the work truck cab is safe, but it's the bit in between that'll get you every time. I understand Queenslander's point that it appears counter-intuitive to sit tight inside tons of metal as opposed to jump and run, but lightning travels at (unsurprisingly) the speed of light and there ain't no human being born yet that can move that fast......... In mining work simply continued as normal during thunderstorms, the only time it stopped was if the rain got so heavy that roads or haul truck operator visibility became compromised.
Was working a farm a few years back and had a brand new I mean less than 500 hours on it 8 series deere tractor get struck on the GPS globe fried every harness and circuit board in it even blew the top of one battery insurance fixed it tractor is still running
Way back in the day, we waited out storms sitting or standing under aircraft. I can also remember just keeping on working through it—it rains a lot on Guam and in the Philippines. In ‘96, a lightening strike at Hurlburt Field, FL killed a guy standing under the wing of an AC-130H. Ever since, the lines are cleared if lightening is declared w/in 5 mi. Kinda makes me cringe to think back on all the time I spent as a potential lightening rod.
Had a friend send me this a few years ago. Would not have wanted to be the operator of that truck
But note that the document clearly states "Extensive equipment damage. No injuries to driver". That's as good a recommendation as you'll ever see to stay in the machine during a lightning storm. Even with a direct strike to the truck the operator got out without a scratch. The reason it blew out the tyres is because there was no metal path through the machine to ground and the energy grounded through the steel cords in the tyres.
Yes, safe inside the truck. I can't imagine what it was like, must have been like sitting on a bomb when it went off. I like: "Driver exited the truck as quickly as he could and ran away to a safe distance from the truck" I think that if I was the driver they could also add "to change his pants" at the end of that sentence.
While I can sympathise with the feelings of the operator after having had his machine blasted how on Earth was he to know what a "safe distance from the truck" was..? The old adage "lightning never strikes twice" is BS, if a second strike had come down anywhere near the truck while he was running away he'd have been a crispy critter in a heartbeat. Again I know it seems counter-intuitive but provided the truck didn't go on fire he'd have been safer to stay in it while lightning was continuing to come down. TBH all it did was blow the rear tyres, then the cab windows from the shockwave, maybe a few hydraulic lines as well. I had a 7-year period of up close and personal experiences with electric storms. Right back in the early days of my last job, and before we had a lightning warning system, we lost a guy through a lightning strike as he was eating lunch under a tree. We were mining on top of a mountain consisting mostly of iron so as you can imagine it made one hell of a lightning rod. Being right in the path of the Atlantic hurricanes was just another complication. I have never seen strikes like it, coming down in big thick blue bolts that you could feel long before the noise blasted your eardrums. It kinda focused the mind wonderfully.