"Northern Pass" Transmission Line (Tamworth: home, purchase, luxury)

[NHForester]

It looks like a metal item was placed under the lines and the person waited to film what was going to happen.

[NrthernNewEnglandVillages]

Mac_Muz, I'm not an expert on electrical transmission by any means, but it seemed someone was filming what they claimed to be a short-circuit in a transmission line. When I saw it I could only imagine a snowmobiler going under the Northern Pass lines when such a streak of electricity zapped the ground (assuming such an event would/could actually happen).

My point for putting up that video was also to make the broader point that these are industrial-grade lines running through people's backyards. What dangers--real or perceived--lie in wait?

[NHForester]

I used to work for a company that had a power company as a client. We were always warned not to get our equipment too close to the lines as they will arc if too close and the distance varied by the volts in the line and the humidity in the air.

[Mac_Muz]

Thanks NNEV. Who ever took the video seems to have some understanding that there was a flaw??? there?

He was able to place a metalic object on the ground and then wait a while for his arc, it seems ....

I see that sort of thing as a freak accident, and can't figure out how he was able to predict this action.

It happens, I know it happens, there was a news story a few years ago about a like arc, on a wet school sports field, and cars were invovled if I recall correctly.

Like NH Forester says there were other criteria involved, as humidity in the air, the metalic cars acting as a path to ground, and etc, but I can't figure how you can place a metal object out and wait around for what seemed a short time and just get an arc.

The current can charge a body, human or other harmlessly, UNTIL the rest of the connection is completed. Birds land on high tenstion lines all the time, and are not often killed. But it does depend on what the bird does next sometimes.

I don't know enough about the project to say one thing or another about this particular project, other than I would prefer to see the lines buried for less ugly.

I am of the opinion that in most cases a buried line is less expensive over all. The fast and dirty towers method is more costly over time, and at more risk to any kinds of storms.

The ice storms in the mid 90's in NE, Ny, and eastern Canada cost more I think, than it would have to bury most lines, where nothing would have happened to them at all, where they were buried.

I am personally not fond of 'ugly' sticking up all over the place, as towers and wind mills. I just think these are ugly. There may be no getting around wind mills, but there is another way to do towers and run wire.

This includes cell towers and other communication towers as well. There is no getting around some of these, but man, some of the places these end up is a sin for ugly.

There is some sort of tower near me in the town of Moultonboro, and while it towers over everything else at least it was made to resemble a tree. Still it is a eye sore, but not as bad as others.

Another advantage to 'buried' is it takes more learning for a terrorist to attack, not that it can't be done.

The towers and line method is easy to attack, It may as well have a target you can see from space.

In some cases, all a terrorist needs to take out communications is a common pin.

Is there a proposed map? I didn't see one.

[flyonpa]

3-9 meter from each wire is the ARC hazard area.

The problem with putting them underground is the cooling of the wire, In the air the 'air' cools them. If you put them underground you need to cool the wire, Oil is put around them in a Pipe common way of cooling them under ground. Problem is if the oil coolers lose power, they have to power then up and cooling before they can run power thru the lines. Thats way it takes so long to re-power a city with underground lines after a major power outage, they have to restart each under ground line but have to wait for the power from section to section to get the cooler running.

[Burgermeister]

Don't ask me how I know, but that was probably a picture of a test they do just after putting a new transmission line into service (or vandalism). In order to certify that the relays work, they attach a wire to a weight and launch it over the transmisson line (much like a kite string would do), the resulting flash and arc is "sensed" by a relay at the Switching Stations and the circut breakers are opened automatically. The circut is normally re-energized once for test and if it trips again, the location of the short-circut is calculated by a computer chip and a crew is sent out to repair any damage. Normally, it is very difficult to cause an arc just by being in the area (such as driving underneath the lines), however, smoke from wildfires often will create a path to ground causing a short circut. So, do not build a fire under a hot line. Might get the wrong kind of flash

[darylyh]

If transmission lines were likely to arc like this, seems to me we'd not have hiking paths beneath them, animals grazing beneath them, etc.

[Mac_Muz]

Burg, I sure don't know, but I think you are on to it. Maybe that thing on the ground I can't see well is a mortar and launces a wire just to create the arc testing as you say.

Fly, I didn't know there was oil cooling, but if that works other places it can work here. The time issue is moot to me since the power goes out all the time around here anyway for a tree limb falling on the wires.

That can happen on a day so fair it makes you wonder if postal mail missed getting the bill paid on time.

Maybe the oil cooling needs bigger chillers, so the temp never gets close to critical, I don't know.

To me the typical user, I just hate seeing the towers and the wires wrecking scenic places.

I live in the boonies and because i like scenic places. When I go hiking now I see towers all over the mountain ridge lines, and I just don't like it. Then the storms we get each decade slam the wires and crush the towers. After the last biggie ice strom there were 56 poles down between me and the state highway. I didn't have power for 3 weeks, and I didn't really care about the loss.

Later that summer after I was in Montreal and saw the crushed high tension towers, not my dinkweed poles. The towers were laying crushed for so far as the eye could see. They looked like toys in a field for a child to re-assemble.

Had these been under ground, where ever they had been, there would have been no power outage in the first place. The oil would never have been overly heated and life for most people would have been at reduced power outage risks. No???

I got water from the same brook I always got water from, but with a bucket, instead of the fawcett, I heated with wood, so I just tossed on another log.. normal I had a spare car radio and battery and hooked that up for news and music. It was a ice storm and so I dumped out 2 metal file cabinets and filled them with ice from the trees and put my foods stuffs in them on the nawth porch

it wasn't any problem to me. But ugly is......

[Burgermeister]

The main reason they will not use an underground cable is cost (and it is substantial). As one poster already mentioned, power flowing through a conductor creates heat and that heat has to be disbursed. One way to overcome this is by using HVDC instead of HVAC, but again you have to have an AC/DC converter station on each end which unfortunately drives the cost back up. Too bad Tesla died before perfecting his power transfer through the air theory

I have mixed feelings about this project since it appears to go right through my parent's neighborhood in Lancaster (my future retirement home), yet I understand the need for affordable electrical power. Guess that makes me a NIMBY

[Mac_Muz]

I still am un-aware of any map plan. That could make me a NIMBY. I can go wild of taking of the wild left, and thar ain't much left.

And then 1 ice storm can cost as much as to build the system once...... plus inflation. Fast and dirty is no answer.