Spacer Installation on 765,000 volt line

Matt Brink0 HN recommenders · 2018–2022
13.7M views · demo · evergreen · Uploaded 2013-02-21

Helmet-camera footage of linemen installing a spacer on an energized 765,000 volt transmission line, working from a helicopter. The crew bonds on and off the live wire as part of the job.

Cited as a striking example of live-line work and of potential equalization, with the air as the insulator.

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3 comments from Hacker News

@small_mind2018 · in “I Was a Cable Guy. I Saw the Worst of America”

Mmmm, but sometimes I've contemplated the hypothetical worst case scenarios for having to support a copper/fiber plant deployment, and what that might actually look like, once you get out into the residential field. I'm not saying I'm casting a sympathetic eye toward conglomerate post-monopoly abominations like Verizon & AT&T. Far from it. What I am saying is that as nerds, we really only want to think it looks like this: [VIDEO] [LINK] But actually, it's more often closer to waiting tables for no tips, in homes consumed by pet smells, infested by perverts, losers and arm chair quarterbacks, pissed off that they've elected to pay for systems that can still suffer outages, just like any vaguely fault-tolerant network. Sometimes, as a subscriber of such systems, the faults hit you. That's kind of what this article is drawing your eye toward. You wonder: "How the fuck can a business seemingly employ only monsters, operate policies concocted from purest evil, offer zero options, get propped up as a monopoly by the worst parts of government funding and compliance, and still turn a profit where so many other business would instantly implode and vaporize?" Part of the answer is that like airlines, they offer essential services to the general public, such that modern civilization may function, and enjoy utilities nearly as valuable as hot water, and they know it . But, the other part is that in order to interface with the gears of a transmission, contact must transmit the forces of t

@nosianu2019 · in “Why we ground electrical systems (2015)”

Yes. That's why this is possible, here the insulation is the air between helicopter and ground: [VIDEO] If that guy was connected to the earth he would get fried. Note that you still have to equalize whatever potential there is between you and the system, like they do in that video. Same reason why you should ground yourself and the hardware before working on your PC. Ever had a tiny spark hit you when you touched something (neither you or that "thing" being connected to the electrical grid, just static electricity e.g. from walking on the carpet)? But without connection to ground the only thing that happens is equalization of the potential between you and the target but no further flow. If you are connected to ground on one side and to a source that keeps creating an electrical potential, like the electrical grid with a power plant somewhere, there will be a continuing flow. If you are not connected to ground there won't be.

@ISL2022 · in “A helicopter will try to catch a rocket booster mid-air”

Power-line work on live transmission lines always seems incredibly bonkers. [VIDEO] [LINK] Let's fly a massive chainsaw beside a powerline. That'll be safe: [LINK]