digger242j
Administrator
We've had some discussion here recently about calling for utility locates before digging. I read a thread on Pop's crane accident site last night by a guy who raised a crane's boom into some 14 kv wires, and it got me to thinking about a couple of incidents I've been..uh...associated with.
The first one was a loong time ago. It was in my first year as an operator, and I was on a 580 backhoe. I was dressing up an area near a tall pole. I was backdragging with the front bucket, and watching only that. I got too close to a guy wire--the kind that comes off the side of the pole and goes to an anchor in the ground--and my stabilizer (in the fully raised position), caught the wire. It rode along the edge of the stabilizer pad til it snapped free, but in the process it pulled hard enough that it gave the whole pole a pretty good *twang!*. Nothing happened for a few seconds, but the wires at the top of the pole, and for a couple hundred feet either direction, were swinging back and forth like crazy. All of a sudden, there was a big bang, like lightening striking. Two of the wires had come close enough that they arced between them. Fortunatley, we never heard any more about it. Apparently, there was no power outage or anything, but it sure woke me up.
The other occasion was a whole lot uglier. It's fortunate that nobody was hurt. I was operating a highlift when a tri-axle dumptruck showed up with a load of stone. He started to raise the bed to dump, but nowhere near where the material was needed. I stopped him, and pointed to a spot near the bottom of a wooden pedestrian ramp that had been built, and said, "Put it over by the bottom of the ramp."
Now, this was at the edge of about 2 acres of parking lot, and the only pole within 150 feet was next to where I'd told him to dump. I go back to work, and he lines up right under the wires and dumps. I just happened to turn toward the truck and saw this bright flashing going on back by the rear of the truck. "What the heck is going on there?" I wondered.
As it turns out, there was a guy wire running from the one pole to the next one. When he raised the bed, it pushed up on that guy wire, which pulled the poles closer together. As they got closer, the 30,000 volt lines at the top of the poles sagged downward. Once the middle wire touched that guy wire, the circuit was completed, right through the aluminum bed, to the frame, and the axles, to the ground. I'd have thought that all that rubber would have made for better insulation, but it doesn't. He blew all four tires across the back of the truck, and the passenger side front.
About that time, the conductor finally burned through and fell across the top of the truck. By that time it had tripped out the transformer feeding the line, and it was dead. *That* also happened to knock out the power to a 9 story office building at the other end of the parking lot.
And of course, the first words out of the driver's mouth were, "HE told me where to dump!" And my answer to that is, "The very first thing they teach you about driving a dump truck is to look for wires before you raise the bed." (I still wonder if his inattention had anything to do with the fact the the guy had his girlfriend riding with him.)
Everybody in the office building got the rest of the day off. The Fire Department got to take their trucks out of the garage and blow the sirens, and the electric company guys got to do something that wasn't on their schedule. Other than having to make a statement to the general contractor's insurance company, I never heard any more about it.
The first one was a loong time ago. It was in my first year as an operator, and I was on a 580 backhoe. I was dressing up an area near a tall pole. I was backdragging with the front bucket, and watching only that. I got too close to a guy wire--the kind that comes off the side of the pole and goes to an anchor in the ground--and my stabilizer (in the fully raised position), caught the wire. It rode along the edge of the stabilizer pad til it snapped free, but in the process it pulled hard enough that it gave the whole pole a pretty good *twang!*. Nothing happened for a few seconds, but the wires at the top of the pole, and for a couple hundred feet either direction, were swinging back and forth like crazy. All of a sudden, there was a big bang, like lightening striking. Two of the wires had come close enough that they arced between them. Fortunatley, we never heard any more about it. Apparently, there was no power outage or anything, but it sure woke me up.
The other occasion was a whole lot uglier. It's fortunate that nobody was hurt. I was operating a highlift when a tri-axle dumptruck showed up with a load of stone. He started to raise the bed to dump, but nowhere near where the material was needed. I stopped him, and pointed to a spot near the bottom of a wooden pedestrian ramp that had been built, and said, "Put it over by the bottom of the ramp."
Now, this was at the edge of about 2 acres of parking lot, and the only pole within 150 feet was next to where I'd told him to dump. I go back to work, and he lines up right under the wires and dumps. I just happened to turn toward the truck and saw this bright flashing going on back by the rear of the truck. "What the heck is going on there?" I wondered.
As it turns out, there was a guy wire running from the one pole to the next one. When he raised the bed, it pushed up on that guy wire, which pulled the poles closer together. As they got closer, the 30,000 volt lines at the top of the poles sagged downward. Once the middle wire touched that guy wire, the circuit was completed, right through the aluminum bed, to the frame, and the axles, to the ground. I'd have thought that all that rubber would have made for better insulation, but it doesn't. He blew all four tires across the back of the truck, and the passenger side front.
About that time, the conductor finally burned through and fell across the top of the truck. By that time it had tripped out the transformer feeding the line, and it was dead. *That* also happened to knock out the power to a 9 story office building at the other end of the parking lot.
And of course, the first words out of the driver's mouth were, "HE told me where to dump!" And my answer to that is, "The very first thing they teach you about driving a dump truck is to look for wires before you raise the bed." (I still wonder if his inattention had anything to do with the fact the the guy had his girlfriend riding with him.)
Everybody in the office building got the rest of the day off. The Fire Department got to take their trucks out of the garage and blow the sirens, and the electric company guys got to do something that wasn't on their schedule. Other than having to make a statement to the general contractor's insurance company, I never heard any more about it.
ointhead 
