Author Topic: Would you drive under this plyon?  (Read 2094 times)

0 Members and 1 Guest are viewing this topic.

Offline Avacee

  • Supporter
  • ****
  • Posts: 300
  • Country: gb
Would you drive under this plyon?
« on: April 19, 2017, 04:14:46 pm »
http://www.bbc.co.uk/news/world-asia-39645534
Go on, dare you! - your vehicle is a Faraday Cage :)

What goes poof just after it starts to fall? .. Is that part of the design in case of a failure?


 

Offline Tom45

  • Frequent Contributor
  • **
  • Posts: 426
  • Country: us
Re: Would you drive under this plyon?
« Reply #1 on: April 19, 2017, 05:15:12 pm »
What the brave soul (idiot?) that was spraying water on the fire?
 

Offline bsudbrink

  • Frequent Contributor
  • **
  • Posts: 406
  • Country: us
Re: Would you drive under this plyon?
« Reply #2 on: April 19, 2017, 06:26:50 pm »
Sort of like a scene from an old Godzilla movie.
 

Offline Red Squirrel

  • Super Contributor
  • ***
  • Posts: 2452
  • Country: ca
Re: Would you drive under this plyon?
« Reply #3 on: April 20, 2017, 04:41:58 am »
We must construct additional pylons!
 
The following users thanked this post: IdahoMan

Offline Vgkid

  • Super Contributor
  • ***
  • Posts: 2570
  • Country: us
Re: Would you drive under this plyon?
« Reply #4 on: April 20, 2017, 06:05:28 am »
We must construct additional pylons!
I'm surprised this comment didn't happen sooner.  ;D
If you own any North Hills Electronics gear, message me. L&N Fan
 

Offline R005T3r

  • Frequent Contributor
  • **
  • Posts: 387
  • Country: it
Re: Would you drive under this plyon?
« Reply #5 on: April 20, 2017, 09:24:29 am »
Never heard about crane-truck contact?
 

Offline jm_araujo

  • Regular Contributor
  • *
  • Posts: 62
  • Country: pt
Re: Would you drive under this plyon?
« Reply #6 on: April 20, 2017, 10:53:47 am »
I'm waiting for the conspiracy theorists to say that it must have been an inside job, open air flames (like fuel) can't melt steel beams   |O
 
The following users thanked this post: boffin, tooki

Offline jeroen79

  • Frequent Contributor
  • **
  • Posts: 515
Re: Would you drive under this plyon?
« Reply #7 on: April 20, 2017, 11:18:49 am »
 it must have been an inside job, open air flames (like fuel) can't melt steel beams
 
The following users thanked this post: tooki

Offline TerraHertz

  • Super Contributor
  • ***
  • Posts: 3684
  • Country: au
  • Why shouldn't we question everything?
    • It's not really a Blog
Re: Would you drive under this plyon?
« Reply #8 on: April 20, 2017, 01:24:54 pm »
The transmission line circuit breakers trip just as it's starting to tilt, with those arc-overs as the cables get too close to the pylon. So after that point it's all mechanical. Thin sheet metal Faraday cages are moot, when it comes to tons of falling steel girders.

That said, after it gets hung up by cable tension, I would drive under it - for enough money.

As for building (slum) fire 'melting' steel - no, but it can get thin steel girders hot enough to go soft. And those pylon girders are thin.  The important point being that their thinness prevents much heat loss by conduction from the section within flames, along the girder to cooler areas. Also the absence of fire insulation on the pylon girders, unlike the very good fire protection all steel frame skyscrapers have around the pillars

For what fire does to thin, unprotected, low thermal mass steel girders, I'm sure everyone has seen the twisted tangles of collapsed steel roof girders after fires in small factories.

Otoh, building fires cannot heat steel up enough to form rivers of bright yellow molten steel flowing out the window openings of a skyscraper. And yet there are multiple clear videos of this happening in a specific case.
Collecting old scopes, logic analyzers, and unfinished projects. http://everist.org
 

Offline zl2wrw

  • Regular Contributor
  • *
  • Posts: 57
  • Country: nz
Re: Would you drive under this plyon?
« Reply #9 on: April 21, 2017, 06:39:14 am »
[SNIP]
Otoh, building fires cannot heat steel up enough to form rivers of bright yellow molten steel flowing out the window openings of a skyscraper. And yet there are multiple clear videos of this happening in a specific case.

If you are talking about the skyscrapers that I think you are, "ordinary" building fires do not involve the high speed injection of tens of tons of aluminium (plus the chemical oxygen generators and portable oxygen cylinders which are typically carried with said mass of aluminium).
I understand that the oxidation of aluminium is so exothermic that it can rip oxygen atoms off of iron oxide, resulting in bright yellow molten iron (thermite reaction). Aluminium is also capable of stealing oxygen atoms from H2O, resulting in aluminium oxide, hydrogen gas and a whole lot of heat! (ask the British navy about the Falklands war...) - a broken water pipe (toilets on each floor in those skyscrapers?) and or fire sprinklers would be a source of oxidiser for an established aluminium fire :wtf:
Yes, it is hard to ignite aluminium, but a bit of oxygen enrichment (see above) will fix that...
 

Offline German_EE

  • Super Contributor
  • ***
  • Posts: 2400
  • Country: de
Re: Would you drive under this plyon?
« Reply #10 on: April 21, 2017, 02:54:36 pm »
No way would I drive under that pylon if I knew that there was a fire at its base, I would park 100m away and watch what happens though. The big surprise is that the authorities didn't stop the traffic once the fire had started!
Should you find yourself in a chronically leaking boat, energy devoted to changing vessels is likely to be more productive than energy devoted to patching leaks.

Warren Buffett
 

Offline chris_leyson

  • Super Contributor
  • ***
  • Posts: 1400
  • Country: wales
Re: Would you drive under this plyon?
« Reply #11 on: April 21, 2017, 05:03:02 pm »
Hot rolled steel starts to loose its strength at around 300C and at 500C it's down to half strength so I'm not surprised the legs failed. Static load on the structure is maybe around 40 to 50 tonnes.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf