An old memory about High Voltage

[Metspitzer]

From another thread in another group reminded me of something that happened to us at Blue Ridge Mountain when I was around 10. (Some 45 years ago)

We were camping. We found a huge manhole cover so, being boys, we dug around it and opened it. One of the boys jumped in.

My memory is fuzzy, but I do remember a large flash and a yell. The boy was very shaken but alright. His thumbnail was cooked.

Now the fuzzy part. As I remember it, there was only one cable in the hole. The bottom of the hole was dirt. The man hole cover was metal and the ring around the opening was metal or at least pre cast, but no bottom. I never touched the cable, but it seemed to be very flexible and it had a Tee in the middle with a cap. I do seem to remember seeing the inside of the Tee and it looked like a stem.

The reason the boy gave for touching it was that he thought it was a water line and we was going to wet us. I don't really recall, but it seems like where we were camping didn't have any power and we were in a pretty remote area. There was a boat dock, but I don't remember anything around at all, much less anything that may have had electricity.

Without a doubt, what we discovered was a power line, but have never seen any high voltage line that would accept anything from a tee.

Does it sound like I am describing anything they may have used at Blue Ridge 45 years ago?

[bob haller]

the tee may be a place where vacuumn was applied to remove moisture, or inject inert gas....

[hrhofmann]

Exactly, the lines are usually pressurized to keep moisture/water out.

[Pete C.]

HV/MV underground distribution commonly uses connections that are basically big banana plugs, and have various terminations including "T" connections. They are usually manipulated live with hot line tools.

[trader4]

quoted text -

Perhaps the oddest part would be an underground HV line like that in the middle of the woods 45 years ago. I would think it might have been to support something very special with a need to keep hidden..... It wasn't near that resort/hotel that was secretly expanded in the 50s to house Congress in the case of the end of the world, was it?

[WW]

From another thread in another group reminded me of something that happened to us at Blue Ridge Mountain when I was around 10. (Some 45 years ago)

We were camping. We found a huge manhole cover so, being boys, we dug around it and opened it. One of the boys jumped in.

My memory is fuzzy, but I do remember a large flash and a yell. The boy was very shaken but alright. His thumbnail was cooked.

Metspitzer... This don't answer you question but reminds me of a time as a teenager. Was working on a piece of equipment that had a 1000 volt DC power supply. I unplugged it but neglected to discharge the supply capacitors. Was changing a part and took the 1000 volts from hand to hand. Blacked out for a moment but did not fall down. For several days afterward my elbows were very painful. A lesson will learned. WW

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[Metspitzer]

No, that place is in White Sulphur Springs, West Virginia. We were in the middle of nowhere. Unless you went by boat, no one would have made it to the shelter in time of attack.

They have done some very interesting shows on the place you are talking about. I am sure there are more.

Dick Cheney's neighbors complained about construction when he went into office. I wonder what he was doing?

[Metspitzer]

You are lucky. Some people that get into that stuff don't get another chance.

[DerbyDad03]

When I was in the USCG, we used to use a Hi-Pot and charge up huge oil- filled capacitors to 5KV or more and then discharge them with a dead man stick.

The purpose of the large CRACK and spark was to show the non-ET guys that the transmitter building was not a place to be without a one of us transmitter techs present. "This could happen to you!"

When we took the caps out of the transmitter, we attached grounding straps across the terminals so they wouldn'y charge up while sitting on the bench.

[micky]

I think I'm lucky too. I was measuring some vottage in a TV that was on. I knew what to touch and what not to touch, and had done this many many times over many years although this time I was crouching down instead of having the tv on my bench. I don't think I touched anything, yet a shock shot me back about 8 feet and I dislocated a shoulder which hadn't been out of the socket for 10 years. After that it was downhill for the shoulder until it came out

3 times in one week while I was barely using it, and I finally chose to have surgery, which did fix it.

It wasn't 110 or the high voltage so it must have been 2000 volts.

[jeff_wisnia]

I'll still always remember when (about 58 years ago) the professor teaching the "Rotating Machinery" course at MIT I was in told us, "You students will never get to be real engineers until you learn to take a shock."

We were working with motors and generators and the highest voltage on that equipment was 230 AC.

Thanks for the mammaries...

Jeff

[Robert]

Sixty years ago , back in high school, I was a clumsy teenage geek in the middle of the "tube" generation and got shocked just about every day in my little workshop.

The worst I got was when I bought a couple of pole pigs used from the power company and hooked them up backwards to get 1100 volts to power a quad of 811A's for a high powered ham rig. Now, THAT mistake, which I only made once, knocked me on my ass...... I was more careful, after that.. :>)))

I am thankful that transistors evolved and, while I have gotten occasional "mild" tickles , it's nothing I can't handle.......Otherwise, I'd probly be dead by now :>)))))

[jeff_wisnia]

We are obviously in the same generation Robert. I got my ham ticket at age 13 in San Francisco, W6KAH.

I'd built an "open chassis" 40 meter crystal controlled CW transmitter with a push-pull pair of 807s as the output power stage. I'd used one of those little multiplate plate air variable trimmer capacitors to tune the 807's grid driver tank. It was the kind which mounted under the chassis top with a hex/screw slot tuning stub sticking up a hole in chassis.

I was turning that capacitor with a screwdriver (power on of course) and my fingers were on the screwdriver shank when my knuckle swung around ant touched the naked plate cap connector on one of the 807s. My arm jerked up so fast that the screwdriver flew out of it and actually made a small mark on the plaster ceiling.

Funny how I've never forgotten that accident, and I've been triple carefull around anything higher than 24 volts since that day.

Thanks for the mammaries Robert.

Jeff

[DerbyDad03]

Electrocution stories? OK...

During the very first hands-on lab in my USCG electronics training, I got hung up on 400DC power supply and ended up not being able to let go of it. I was holding the 30 lb training device straight out in front of me and yelling "Turn it off! Turn it off!"

The guy next to me yanked on the plug but the power strip came up with it. The guy at the table in front of us reached over and slammed the power strip back down to the table, disconnecting the plug. I threw the power supply on the floor and was taken to the infirmary for a check-up. I had taken the current right across my chest, from hand to hand, but other than a couple of burnt fingers, I was alright.

When I came back to class the next day 3 things had changed:

1 - All of the power strips had been screwed down to the tables. 2 - The power supplied I destroyed was on display at the front of the room as a reminder to be careful. 3 - Two guys quit electronics training after seeing what happened to me. Wimps. They quit and I went on to work with mega-watt LORAN transmitters and 30KV power supplies.

[gregz]

I got it from my 60 watt transmitter. About 500 volts dc. I can feel it now. Only an instant. It helped me in my electronics career. I was a hand in pocket cautious person.

Greg

[Grumpy]

A yes but those radios still works new shit on market couple years then is no longer repairable that is called progress

[Grumpy]

I am working on 4-1000 linear but it looks like I will crock before it get finish and specially now since I got ready of power supply to heavy to transport just move from NJ to Tracy CA. KA2AYS "73"

[krw]

We called it "welding shop". No thanks! Avoided it like the plague.

I've been nailed many times by 120V and few by 750VDC (when I was a kid) but much prefer the stuff I work on now (nothing above 25V). ;-)

[krw]

Mine was a 6146. Ouch.

It taught me a lot (like unplugging equipment when working on it and never demonstrate how you got nailed - it still may be powered on).

Ditto, and ditto.