Pretty incredible

[Quickmarch 488]

See: https://www.cnn.com/2017/12/17/us/atlanta-airport-power-outage/index.html

 

This is pretty amazing that all of the power, including backups could be taken out. Appears it was a fire in a sub-station that started the mess. 

 

Cheers,

March

[allardjd 1,853]

That's a very interesting situation.  There is a lot not said in the article.  Raging electrical fires in areas of high cable concentration, e.g transformer, switchgear and cable vaults, can cause widespread, cascading failures taking out power to just about everything with a power or control cable passing nearby. 

 

I suspect that there existed some emergency power sources for some things.  Those sources might have included a) alternate connections to utility power, b) diesel or gas turbine generators and c) battery backups.  Those too can be vulnerable to a bad fire and to the extent they existed, some of them may have been affected too. 

 

Also, if a load (system or device or a group of them) is to be capable of being supplied by more than one source of power, those two sources of power must both be connected to a common device somewhere.  That device is what provides the ability to transfer from one source to another and to prevent backfeeding or simultaneous connections to different sources.  Without getting too technical, that's a necessity.  If one of those common devices or a downstream part of the circuit is fire-affected, the load fails despite the provisions for redundant power sources.

 

Though some of these alternate sources of power may have worked for some vital equipment, the article is pretty much silent on the ATC and operational side of things, which is where they were most likely to have been designed in.  For instance, did tower, ground, approach and departure radio communications (the latter the least vital of them) also fail?  It seems likely that some of these might have continued to function for a while, preventing an ATC catastrophe, but it really doesn't matter - ATC was not the main issue, if it was an issue at all. 

 

In any sizeable passenger airport, the loss of building lighting, AC and ventilation, internal ground transport (concourse trams, beltways, escalators, elevators, power-operated doors), airport security (video, door alarm systems, communications between security staff) and other internal communications (computer systems, phones, public address systems, lighted signs, intelligent display boards) is going to cripple any orderly flow of aircraft and passengers.  Add to that the loss of individual airlines ticketing, baggage handling and dispatch operations along with the TSA's security equipment going dark and the result is going to be pretty dire.  Apparently, all of that happened and most of those things probably had little or no designed-in capability for being powered by alternate sources except perhaps in large blocks close to the main sources.  That seems to be where the fire occurred.

 

It really doesn't matter to the stressed and stranded passengers whether ATC continued to function and redirect incoming flights, or if taxiway and runway lights, etc. remained functional - they may have but the article really doesn't say much about those things.  What was crippled was the people handling capability and that was enough of a mess.

 

Redundancy costs a lot of money in design, construction, operation and maintenance.  It's hard to fault the design of the airport electrical power system without knowing a lot more about the details.

 

Anyway, I'm pretty happy I wasn't there.

 

John