It's the time of year when thunderstorms are most common here. This has me wondering (actually, one specific flash of lightening the other day *really* got me wondering), about the risks involved with being on a piece of heavy equipment during a thunderstorm. Supposedly, one of the safest places you can be during a thunderstorm is in your car or truck. I think many people believe the reason for that is the fact that you're sitting on top of four rubber tires, and they are thought of as insulation. I can vouch for the fact that that's just not true. I've seen a triaxle dump truck blow all four tires across the back, and one of the front tires when the bed was raised into electrical wires. I've seen a parked tractor trailer that was struck by lightning. (The story there--It was at an airshow a few years ago, and a storm blew in right in the middle of the feature act. There was a beer truck parked nearby, and the lightning struck the CB antenna. Several people sheltering from the rain beneath the wing of a nearby plane were knocked down, but there were no serious injuries. The were little bits of fiberglass antenna scattered over a wide area, and of course the radio was fried. I've never been able to decide if the Lord was expressing his displeasure at CBs, or beer...) Anyway, that all indicates to me that the "rubber" theory is not valid. I've also heard that the reason it's safer in your vehicle is that you're surrounded by the metal of the vehicle, and that it will conduct the electricity, rather than *you* conducting it. If that's the case, it stands to reason that the same would be true for a large metal structure, like an excavator. The fact that you're sitting on metal tracks, and thus really well grounded, would seem to make it even better. The fact that you have a relatively higher profile than the average automobile would, however, be a disadvantage. A crane, with the boom elevated, would probably be really bad. Obviously, the *safest* practice would be to abandon the machine at the first sign of lightning, much the same as people are chased out of the swimming pool by the lifeguards. That's probably not practical for most of us. Certainly, you hear more stories on the news about boaters and golfers being struck by lightning than you do about heavy equipment operators. maybe that's just because operators are smarter about lightning than boaters and golfers (except for me of course). Do any of you know, authoritatively, what the real level of risk is?
Interesting i look forward to hearing what you guys have to say.
I watched a show last week on guys in helicopters that repair high tension wires and towers. What they explained was that wire, helicopter and occupants were all charged equally so there was no damage to any component. This scenario is a little different in that the machine is providing ground. If everything goes well, in that the operator is not the point of entry of the lightning, there should be no injury. As long as the body does not provide the path for the electricity to travel, there will be no injury. So if the machine takes the hit, and the operator is not halfway in or out (no contact to ground), he should be OK. He might get a tingling sensation or have his hair do something strange due to the magnetic field generated, but that's about it.
Steve's right, and I saw the same show this morning Steve. Those guys are insane, but it beats doing it from the ground. There was a story a few weeks ago about a guy from CT who was in RI fishing. A storm crept up on him and he tried to find shelter, but he was in a boat. He apparently found a little cove to pull in to, but was subsequently struck and killed by lightening. He was about 37 years old if I recall.
Yeah, I saw that same show. They wear those crazy suits that apparently route the electricity around them. That is absolutely nuts. Wonder what L&I per hour that is?!
I noy sure about a excavator ? but I would sit in them! I know a crane is grounded by driving a rod in the ground & hooking a cable from the boom on it!!
I posted the same question at one of the weather boards, and somebody was kind enough to give a pretty detailed reply. Here it is, cut and pasted directly: quote: -------------------------------------------------------------------------------- Originally posted by Digger242J Supposedly, one of the safest places you can be during a thunderstorm is in your car or truck. I think many people believe the reason for that is the fact that you're sitting on top of four rubber tires, and they are thought of as insulation. I can vouch for the fact that that's just not true. I've seen a triaxle dump truck blow all four tires across the back, and one of the front tires when the bed was raised into electrical wires. I've seen a parked tractor trailer that was struck by lightning. (The story there--It was at an airshow a few years ago, and a storm blew in right in the middle of the feature act. There was a beer truck parked nearby, and the lightning struck the CB antenna. Several people sheltering from the rain beneath the wing of a nearby plane were knocked down, but there were no serious injuries. The were little bits of fiberglass antenna scattered over a wide area, and of course the radio was fried. I've never been able to decide if the Lord was expressing his displeasure at CBs, or beer...) Anyway, that all indicates to me that the "rubber" theory is not valid. -------------------------------------------------------------------------------- Give that man an "A"! You are absolutely correct. When you deal with lightning, you have to remember that you are dealing with extremely concentrated amounts of electricity that are several orders of magnitude higher that what we deal with on a daily basis. The average lightning bolt: -has a charge of ~30,000 amps...most of your average electric appliances run on less than 10 amps. -carries ~100 million volts of electric potential...the average electric outlet in your home carries 110 volts. -has an internal temperature of 50,000F degrees...FIVE TIMES the surface of the sun. All this energy is concentrated in a channel no larger than a quarter. This energy density is sufficient to burn through any insulator...even the ceramic acordian-like insulators you see on power poles shatter like glass (ask any utility linesman...they'll confirm this). Furthermore, the average lightning channel usually has to arc through through at least five miles of air before it makes contact with the ground...and the nitrogen/oxygen compound of our atmosphere is a very good insulator. An inch or two of rubber may be sufficient to insulate you against the electricity we use on a daily basis, but when it comes to lightning, it's like putting gauze in front of a semi...just come on through! quote: -------------------------------------------------------------------------------- Originally posted by Digger242J I've also heard that the reason it's safer in your vehicle is that you're surrounded by the metal of the vehicle, and that it will conduct the electricity, rather than *you* conducting it. If that's the case, it stands to reason that the same would be true for a large metal structure, like an excavator. The fact that you're sitting on metal tracks, and thus really well grounded, would seem to make it even better. The fact that you have a relatively higher profile than the average automobile would, however, be a disadvantage. A crane, with the boom elevated, would probably be really bad. -------------------------------------------------------------------------------- Again, you are correct. The metal cage of the vehicle acts like a Faraday Cage and conducts the electricity around and away from you, but any elevated metal structure (such as a crane boom) increases you chances of being struck. There are additional caveats here as well: -Convertibles, cars with fiberglass or plastic shells, and open framed vehicles don't count as lightning shelters. -Open caged vehicles are not safe as they are vulnerable to "side flashes" or indirect strikes (e.g. lighting strikes a nearby tree and "bounces" into your cab). -You must avoid contact with conducting paths going outside. That means you must close all windows, lean away from the door, put your hands in your lap, don't touch the steering wheel, ignition, gear shifter, or radio. Given that last caveat, if you were to follow proper lightning safety procedures, you would be ineffective even if you were to stay in the cab. Best just to abandon the vehicle for a more substantial building. quote: -------------------------------------------------------------------------------- Originally posted by Digger242J Obviously, the *safest* practice would be to abandon the machine at the first sign of lightning, much the same as people are chased out of the swimming pool by the lifeguards. That's probably not practical for most of us. -------------------------------------------------------------------------------- Ultimately, it's your choice. Abandoning your equipment is the best course of action, especially in today's litigious society. And while most of the time civil courts will not fault the employer if the cause of injury is due to "an act of God", just dealing with a lawsuit to begin with is a costly endeavor in both time, money, and sanity. Why put yourself or your workers at risk when all it takes is a few minutes to evac everyone to a safe location? Few tstorms remain in one spot for more than an hour anyway. quote: -------------------------------------------------------------------------------- Originally posted by Digger242J Certainly, you hear more stories on the news about boaters and golfers being struck by lightning than you do about heavy equipment operators. maybe that's just because operators are smarter about lightning than boaters and golfers (except for me of course). Do any of you know, authoritatively, what the real level of risk is? -------------------------------------------------------------------------------- Actually, living here in Florida for the past seven years, I have heard numerous accounts of construction workers getting struck. Several have died or have suffered critical injuries. I have no hard stats to back it up, but my initial guess is that construction workers make up ~25% of strike victims here in the "Sunshine State". For more information: http://www.srh.noaa.gov/mlb/ltgcenter/ltgmain.html http://www.srh.noaa.gov/jetstream/l...tning_intro.htm http://www.lightningsafety.noaa.gov/ (be sure to check out the survivor stories to see what could happen if you were struck...not pretty ) ________________________________________________________________ One of the pages on one of the links provided contains this paragraph: "Convertible vehicles offer no safety from lightning, even if the top is "up". Other vehicles which are NOT SAFE during lightning storms are those which have open cabs, such as golf carts, tractors, and construction equipment." I really hate the idea of running for shelter at the first sign of a thunderstorm, but the idea of being struck by lightning doesn't hold much appeal either. The information provided above does nothing at all to promote my peace of mind. Well, nobody has ever accused me of being particularly effective even on the best of days, so I guess it kinda comes out even anyway...
I want to thank you Digger for giving me yet another thing to worry about in an already very dangerous job. you nknow the old saying ijnorance is bliss. well i was very blissful. no more thanks to you :bouncegri
Hey, I'm always happy to spread a little gloom and misery around in the world. BTW, you're not supposed to stand near trees in a thunderstorm either...
I have always considered being in an excavator as a good place to be for the prevailing reasons above there but the bottom line really is that my Lord knows where to find me when he comes calling and my time here is up. If I am running a dozer with an open cab I might look for a dryer place if I am getting wet but otherwise would continue working unless doing so would create more work later on by contaminating the soil. I worked through a tornado down in Branford ct in the late eighties and was amazed at the destruction I saw driving home at the end of the day. I happened to be carrying stone to fill in a footing for drainage in an old 215 Cat and was impressed with how dry it stayed in the cab,not a drop of water got in as I remember.A great topic!! Ron G
For years, when I was primarily running a rubber tired backhoe, I had the mindset that it was similar in saftey to being in a car or truck. I sat out a few strorms in the cab, but took the precaution of raising stabilizers and buckets off the ground so that I'd be on all rubber, just like cars and trucks. Once I'd seen a the incidents I described above, and gave the subject a little more thought, I realized the fallicy of the rubber being an effective insulator. As the fellow from the other site pointed out, that voltage is sufficient to pass through as much as five miles of air--a couple inches of rubber isn't going to make a difference. I do think the "side flash" that was mentioned is a legitimate concern. How often have you heard stories of people being hit because they were standing near something taller that attracted the lightning--something like a pole or a metal fence? I know I've heard of such cases. As far as the Lord knowing where to find you, I'm reminded of golfer Lee Trevino. He once said, "If you are caught on a golf course during a storm and are afraid of lightning, hold up a 1-iron. Not even God can hit a 1-iron." Sometime later, he was struck by lightning, although not fatally. The chance of being struck by lightning is often compared to the chance of winning the lottery. I guess staying on the machine during a thunderstorm is the equivalent of buying your ticket...
LOL! digger, I always get a chuckle from your sense of humor! :laugh
msha requires the operator to stay in the cab. during thunderstorms or in case of powerlines.. as long as your on the iron your suppose to be fine.. but once you dismount is when you become the ground point.. cause the body is easy for electricty to go thru its a better conducter then metal from what ive understood.. i know we were taught if we had to dismount due to lighting or powerwires.. we were told to jump from middle of machine.. not lowest point due to arching. nor the highest due to height/ fall injury.. but once we decided to jump .. we were to land on our feet and instantly go into a roll and roll at least 5 feet. before getting up.. payton
I'd never given this much thought till now, thanks for the lesson guys. now, if you'll excuse me, I gotta go out into a hurricane holding a 1 iron up lol.
TTT I know this is a old thread, but its that time of year for us again. Had a pretty good storm pass by today I shut the job down for a bit, but I'm still unsure at what point we should be callong it a day. I normally count Mississippi's after I see the lighting and if I don't get to 10 before the thunder we stop and get it 30mins to clear up. Doing demo we don't get rained out normally so we push through the bad weather.
i know of a guy that got hit standing next to a metal pole. the pole got hit and the bolt jumped into him. it screwed him up real bad. i would probly stay on the machine and ground it out as much as possible, the rest is up to GOD.
Not to be picky but I always felt I never wanted to be sitting in the seat of anything with steel tracks on it during a storm, never had the balls to find out just who was right on the subject so I opted for plan B, get the heck out of the seat and away from anything remotely grounded to anything and look for a safe dry place to sit it out that was lower to the ground than the machine I got out of. I've known a few that got killed by lightning and that was enough for me, if you think its safe, go for it and once the machine your sitting in is struck let me know how it turned out, I'll watch from a safer place and call for the ambulance to come get you, and unless your female and beautiful don't count of me doing mouth to mouth to revive you either, not until the storms over anyhow. I always shut down for storms not matter what and wait it out, no dirt is that important that it can't wait a few minutes or hours to move, that and from a distance I like rain and lightning, its nice and peaceful to watch a good storm from a dry safe place. Just my two cents worth though
Great subject! I went to high school with the guy who wound up being my best man. Then we kinda drifted apart cause I went and joined the Army. After I retired we got hooked back up. He was a deputy sheriff in our county. He was catching heck from his fellow cops because over a couple of years his patrol car was hit 3 times while he was on patrol. All 3 times while responding to reports of tornados on the ground ( we are in the county just west of Wadena MN that got hit so bad last summer). Twice the only effects were his radio and radar where fried, the other was a good hit that got the ignitions system too. He was not injured......except his pride at needing new shorts! While in the Army we never abandoned our tanks when the lightning was bad. Never saw any damage to em. Sat out one storm at Ft Know while an instructor inside the tanks with our students. A large tree was hit about 100 feet from where 8 tanks and 4 HMMV's were parked. About five miles from where we were a soldier was killed when he was struck.......he was in the NCO acadamy doing the dismounted land navigation course. Guess I never thought about it. Just just told us to stay in the tanks. Rick
I'm not sure where I would have liked to be when this one occured. Except a long long way away. I remember when it happened as we were issued the incident report. http://www.dpi.nsw.gov.au/__data/as...A08-03-Lightning-strikes-stationary-truck.pdf
Wow that was a hell of a strike
So if I were sitting in the truck at the time would the strike have killed me or the concussion of the tires exploding or metal parts flying around?
This back to the fore front because of an officer being struck while in Joplin Mo helping with the storm damage; http://www.policeone.com/health-fit...struck-by-the-Joplin-tornado/?fb_ref=homepage I'm not sure where the boss's heard or found this statement but at one time said we should wait 30 minutes after the last lightning strike before putting a boom in the air .
Our 110' logging tower got hit many times over the years. Often fried the electronics. We usually shut down as a storm approached and took the talkie tooter system out. Sometimes the storm came to quick. Saw my brother get knocked on his ass once when we were standing at the base of the tower when it was hit. He had a chainsaw in his hands. I think the end of the bar was touching the base of the tower. One time our rigging crew was standing in a creek while the rigging was being lowered when the tower was hit. Glad they didn't have a hold of those chokers. Another time the hook tender was laying out a new road. had the hindue of the haywire attached to the strap holding the haul back block. He got nailed, but I think much of the lightning was dissapated by the cable laying on the wet ground. Dangerous indeed.
I had a lightning bolt pass over top of the truck I was loading, between my 550 Barko and a Washington 108 and continue on over the hill we were on to strike a tree about half a mile away. The lightning was horizontal and right at my eye level on the Barko. That was 20 years ago and I can still see the flash. Why it didn't hit the loader or the 70' boom on the yarder, I'll never know.
At the landfill we work through the rain but sometimes We let lightning slip up on us. Especially if we are working a cell in the main pit its easy for it to get there. Sometimes I will not see a flash but see it. Ive had a spring storm blow up and be striking all around. That old open cab D5B seems mighty slow lol. Since we got the D4H with a cab Ill work in it more even real bad stuff the other day I had to move a surface water diversion berm. I know the cab should work like a Faraday Cage. Back when I was 21 I was running a 5299 and had 120 foot boom I was on the side of the Tennessee river. We were installing an intake tower for a treatment plant and I was runnin the crane some. I I coulnd boom down and a storm rolled down the the river. We had a really had packed clay road and the rain. Our trucks couldnt get out or up one hill as it was so slick. Most of the crew got in my crane, and some of the concrete workers got under a 30by30 Symon form. The ret got in the woods. The old crane actually got struck. I was in the seat and just felt a tingle. I had a flag on the stinger and it was singed pretty good. THe folks on the ground got a good jolt. At work we have a rul that 45 minutes after the last thunder before we can get back out. We noticed when its dry for a while and the and is blowing is the worst time for a lightning.
I work alot on draglines, almost every dragline now days has a lightening detector. When the alarm goes off, mining stops and you get out of the dragline, they shut it down and cut the pwoer. I dont know for sure what would happens when one gets hit, I think it would be different since a dragline runs off A/C. If anyone knows for sure please let me know.
We're in a major area here for thunderstorms, and they can strike at any time although they are more common in summer. 4 years ago a lightning strike from what was pretty much a cloudless sky killed a guy sitting under a tree having his lunch, so it focused peoples minds wonderfully. We have a system of detectors all round the perimeter of the site that can detect lightning discharges at a maximum of 50 miles distance. If a strike occurs at 30-50 miles we go on a low level (yellow) alert and work continues normally. If a strike occurs in the 10-30 mile range we go on a medium (orange) alert. Work continues but everyone working outside has to be aware of where their nearest lighning shelter is. If a strike occurs at less than 10 miles we go on high (red) alert and all outside work is stopped. On this highest level of alert all personnel must be either inside a building, in a vehicle with the windows rolled up, or in an approved lighning shelter. If we have a red alert then we must go at least 30 minutes with no strikes inside a 10-mile distance before the alert is lifted, even then it might only be lifted to orange level if we are still seeing strikes in the 10-30 mile range. However even during red alert the operation of all mining/earthmoving equipment continues as normal. That said we have no electrically-powered equipment like draglines or shovels, all our kit is diesel-powered. In the past I've seen us go on red alert around lunchtime and not go out of it until well into the evening. It plays havoc with construction, not so much with mining.
I just got in and saw this thread and wanted to make a comment about tires as an insulator. The last company I worked at used rough terrain cranes to set up drill rigs for geothermal wells. One rig move we were moving a rig on the site of a power plant. It was the middle of winter and there was snow on the ground. The crane operator was passing under the main power lines out of the powerplant and came in contact with them. The arc from the power lines killed the scale and burned dime sized holes in all four tires in the side walls about six inches up the side wall. I don't believe that tires will insulate well.
While this isn't about being on the ground. I've been hit several times in my years in an airplane. Never been electrocuted, but it depends on where it enters and exits the airplane, and the path it takes in between. Sometimes there has been no electronic damage to frying radios and other electronics. An inspection is always done to do a systems test plus find the burn marks where it entered and exited. Granted we don't fly through t-storms, but to avoid all weather out of the range of lightning isn't always possible or practicle. Just my 2c.
Lightning Strike Safety Facts • Lightning can strike from as far away as 10 Miles from the leading or trailing edge of a storm. • 30% of victims are struck under blue skies before storms arrive. • 60% of victims are struck under blue skies after storms have passed.
Safety Alert I got this this week. On July 15, 2012 at approximately 2300 hours driver of 777F haul truck was parked at the 1135 waste dump waiting out an electrical storm. Truck was struck by lightning causing significant damage to the rear of the truck. One left side outside duel was propelled away from the truck approximate 250 meters. The rim of this tire was another 50 meters further. All 4 rear tires were blown out and cab windows shattered. Driver exited the truck as quickly as he could and ran away to a safe distance from the truck.
I got an email with tons of pics from this strike. I couldnt figure out how to repost them here.
I'm glad that driver was okay, and I'll bet when he was running you couldn't have caught him w/ a top fuel dragster. This kinda proves the Faraday cage theory, seems he was safer in the cab.
If I was the operator I'd have sat tight in the cab. However it's alot easier to say that on here than to have to sit through it though. The temptation to run must be awful strong. Must resist ...............
I have always been told that you are safe in the cab of a crane if lightning strikes. I have also been told not to exit said crane until it is properly grounded because the machine (as well as the ground around it can store energy). I know the reason we drive rods into the ground and attach to our bigger cranes is not in case of lightning strike (lightning is completely unpredictable and will ground wherever it darn well pleases) rather to keep static electricity from building in the machine and popping people. Due to the high altitudes and surface areas in the air, moving wind and moisture is known to cause static electricity. I have heard tale of a person getting their car hit on a bridge while in motion and not being harmed but I cannot personally confirm...