NY Queens Sidewalk Explosion 1

[Mbrooke]

Queens New York showing a vent explode spewing fire. The man survives but with burns.

Any ideas on what might have caused this?

https://www.nbcnewyork.com/news/loc...survive-sidewalk-explosion-in-queens/3177378/

 

[MacGyverS2000]

Likely a gas main broke and leaked into the support tunnels...

Dan - Owner

http://www.Hi-TecDesigns.com

 

[MintJulep]

Looks more like a transformer vault to me.

 

[1503-44]

That's why one should never use underground vaults for gas pipeline systems.

I will never be able to walk across one of those again.

I'm very glad the guy wasn't killed.

 

[TugboatEng]

I was driving and had something like this happen in front of me. It lifted the manhole cover about 3 feet in the air, flipped it, and it landed right back in the hole. I don't think anybody would have believed me if I didn't have a passenger. It was also one of the very rare instances I borrow someone else's vehicle.

 

[LittleInch]

They are usually large / high voltage electrical cable faults. If you look closely there is some steam or white smoke coming out already. The flames come from burning insualtion.

NYC i'm pretty sure still has a lot of steam piping hence all those shots you see of steam drifting out so no one probably thought any thing was up.
but if it was gas you would have a constant jet fire and maybe a large bang.

This was one in London a little while ago

https://www.standard.co.uk/news/lon...ase-in-pavement-blasts-in-london-9734894.html

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[FacEngrPE]

thread184-119479 discussed the problems related to arc flash in manholes. This is a location where a LV grid distribution system exists. Grid distribution systems are known to have particularly high arc flash energies.

2.4 Secondary Grid Network Cable Protection
Underground cables connect secondary buses, moles, and crabs in the grid network system to one another. The number of cables per phase and cable size depend on the maximum possible load flow. The number of cables can range from one to dozens per phase.
Cable-to-cable limiters protect these cables. Limiters are designed for 4/0-, 250-, 300-, 350-, 400-, 500-, and 750-kcmil cables. Limiters are also available for connecting cable to bus and
cable to moles. Limiters are also included in “fusible crabs.” These limiters should coordinate with the network protector fuses and the insulation damage characteristics of the cable.
Some utilities do not use limiters for cables 4/0 and smaller because they assume that cables are small enough to burn clear.

 

[1503-44]

Two per week in London 2013! That's getting pretty dangerous. Made my "Do not cross" list.

 

[cranky108]

Maybe look into a short chain welded to the manhole cover, and just inside the manhole.

Also prevents theft.

 

[TugboatEng]

We tend to be late to the show in the marine industry but perhaps we finally have something to teach everybody else.

https://www.bicera.com/