We had a good thunderstorm yesterday arvo with a lot of good ground strikes of lightening, I was on the d4 pushing up some piles to burn and decide it was wise to get off the machine. I was wondering if these big lumps of steel well earthed to the ground are big magnets for the lightening. What sort of damage do they receive if they get a direct strike? Has anyone been hit with lightening when operating or do you know of anyone that has been hit and what was the human damage. I have known of people fishing from alloy boats that have been hit and they survived OK a bit shaken but the boat grounded out to the ocean. Secondly, O rings used in hydraulic fittings, are they special O rings or can you use normal ones purchased auto parts stores. Looking forward to your answers. Ken
Run for cover while you can. Best get the proper orings unless you know what the aftermarket are made from. There are a few different types. Later Bob
What Bob/Ont said ... Or follow the dog in a bad storm if possible as they generally run for cover . Buddy of mine got hit by lightning inside a barn during a storm , he had an aluminum shovel in his hand at the time . Knocked him to the ground & shook him up a bit . As for sitting on a piece of equipment during a bad storm I've heard it both ways . Some say stay on it & others say get off .
Yair . . . wbvs58 . I have never seen a machine struck by lightning. Like you I used to wonder though, I could not help but think that lightning may have been attracted to five or six hundred feet of bright shiny scrub chain flicking around behind. Like bolts there used to be only two sorts of "O" rings . . . Caterpillar and all the others. Things change but, given the relatively small cost involved and the inconvenience and awkwidity of changing out some "O" rings I would forgo the Auto Supply shop and go with genuine parts or at least "O" rings from a reputable hydraulic supply business. Cheers.
My dad ran a crane with clamshell off the sixty foot boom for years. He said it had been either close or had been hit but the flash and boom were so intense he didn't know one way or the other. He apparently didn't suffer any ill affects of it but they generally would shut jobs down in the woods when they saw the flashes getting close. As far as the O rings go if they are black colored I've used any I could find that fit the particular groove that was needed. Where is gets touchy is for high heat applications like transmissions or special fluids. Don't put a black O ring in for a yellow or orange one. Go to the dealer and get the right one.
My take on the lightening is that a piece of tracked machinery is well earthed so the current would go straight to earth and not through you. It would be a different matter if you were standing beside it hanging onto some part of it, some current would ground through you. There is also the question does the machine get a higher incidence of strikes than the rock of similar size sitting beside it? One thing for sure you would have to have your ticker in good shape it would give you one hell of a fright. For the sake of settling this question I am not going to volunteer to do a scientific trial on the matter. With regard to the O rings it is not about the cost of things I have found Caterpillar parts to be very reasonable and the parts guys very good to get on with over the phone but it is more about the convenience of being able to get them when I need them and being able to eyeball them and match up a size. I might just get Hastings Deering to send out a half dozen of each of the common sizes. Ken
John, you would think that any close strike would have gone through that boom and grounded harmlessly just like through a lightening rod on a building but like I said I amnot going to volunteer my services, I don't think I would survive the boom. Ken
Where we are there are heavy lightning storms very frequently. Our policy is that in case the cab has windows you stay in the cab with the windows rolled up. We've had machines struck by lightning and the operator was unscathed every time. In the case of machines with an open ROPS the operators are told to bail out and seek shelter as soon as the electric storm alert sounds.
We recently had a roller struck. Blew every ecm and controller out of the machine, Harness were fine but, all other parts had to be replaced. I would assume a pad foot would be properly grounded but I guess not.
Well that is what I was hoping to hear thanks Nige. Caterpillarmech was the wiring and those units badly charcoaled or was it just the electronics taken out without obvious signs from outside. Electronics don't need much stray current to blow them. I have had experience with that with inverters and lightening in my standalone power system that run my house, always seems to be that bluddy mother board. Ken
On the o-rings get yourself a copy of Cat's "One Safe Source" catalog. It lists all the o-rings, what they are made of and dash number equivalents. Might go cross-eyed reading it but the information is there.
It happens occasionally that cranes get hit. We had a American Crane with a pile driver attachment that got hit a number of years ago in N.D. while building the power plants. It took 20 ft of paint off the boom near the tip but no damage to the operator other than buzzing ears. We changed the pile hoist line as it was also blackened for a stretch. It was connected to to a partially driven pile and the thought was it carried the current to the ground through the pile. In our tower cranes if the operators have time they climb down. If sudden they stay in the cab. The spot you do not want to be is on the ground touching the machine or rigging when the lighting hits, no different than a down power line.
The wiring and controllers had no visible damage. Hooked up et and it showed a bunch of blank modules. My guy tried to reflash them and they did not take the file. This was the only problem. The great thing is the call came in for a non starting machine two hours away of course.
It's called a Farradays cage, after the guy who discovered it. So long as you stay in the machine, you're safe. Note the IN, hanging on the outside, or in close proximity to it, is the danger zone. It's why ships at sea, or aircraft, manage to survive storms unscathed. A metal "cage" will shield what's inside it from current. O rings are o rings, provided the chemical composition is correct for the material it's in contact with.