Power Failure at Atlanta Airport 1

[EEJaime]

Hello all,

Just wondering if anyone had heard anything regarding the cause of the complete power failure at the Atlanta Airport, (Hartsfield-Jackson Atlanta International Airport). It is astounding to me that such a complete failure could occur. I have designed power and backup power systems for major airport facilities. With the redundant utility incoming connections, redundant isolated feeders, emergency power systems which feed both ends of a service-tie-service medium Voltage service and isolated feeder routing, it is impossible for me to understand how a fire "in an underground structure..." could cause such a complete interruption. The incoming utility lines and the on-site power generation should not share any facilities with the exception of transfer switches. LADWP,(Utility) and LAWA, (Airport Authority), here in Los Angeles would have our collective hides if we designed something with such a catastrophic single point of failure.

I was just curious if anyone had any real information. I doubt those reporting have any idea of what really occurred. Thank you in advance for your time.

EEJaime
Los Angeles, CA

 

[EdStainless]

The article in the WSJ has a little information in it.
Sounds like switchgear for both primary and backup were in the same installation.

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P.E. Metallurgy, Plymouth Tube

 

[Hoxton]

I'm not red posting, but should this be in the' engineering disasters' forum?

 

[dpc]

What little I've been able to determine, it was a major fire in the electrical distribution facility, taking out both services. This facility belonged to the utility, not the airport, per the news story I read. My first impression is that this is a classic "common mode" failure where a single event takes down the entire system. I've had some experience working with utilities when primary and backup sources are necessary. The distribution engineers often don't get it. Their proposals generally involved running two circuits on the same poles or through the same manholes. Speculation on my part, but I have a lot of scar tissue on this issue when dealing with utilities. Not sure if there was local generation, but also read that a transfer switch was destroyed in the fire. Low probability event but created a significant hazard.

It's unlikely we'll ever get the full story, to be honest.

 

[Mbrooke]

Thank you for starting this thread- I am also mystified how this could happen- but then again I know nothing of the power system in that particular airport.



Posted at another EE site:

http://www.ajc.com/business/georgia...d-airport-fire-outage/LmQ9sG6pj8HnwP8nuUAlEJ/

http://www.ajc.com/news/live-update...ights-canceled-monday/62XmUU7EEZrEfaynZuy4yI/

BTW- from various videos of the incident it looks like not only the main power supplies failed- but also the life safety branch. There are no emergency lights anywhere. Something is very wrong with the picture.

 

[Mbrooke]

What little I've been able to determine, it was a major fire in the electrical distribution facility, taking out both services. This facility belonged to the utility, not the airport, per the news story I read. My first impression is that this is a classic "common mode" failure where a single event takes down the entire system. I've had some experience working with utilities when primary and backup sources are necessary. The distribution engineers often don't get it. Their proposals generally involved running two circuits on the same poles or through the same manholes. Speculation on my part, but I have a lot of scar tissue on this issue when dealing with utilities. Not sure if there was local generation, but also read that a transfer switch was destroyed in the fire. Low probability event but created a significant hazard.

I agree 100% on the utility side of things. For some POCOs a backup is simply another circuit in the same conduit or pole- and I do not blame them all that much to be honest as for them its very common to feed entire towns or even small cities via double circuit single tower transmission lines, and more often then not it does the job really well. But what I do not understand is how a failed transfer switch in a utility vault would remove ememrgency power at the airport- I would think the ATS would be customer owned completlety separate from the POCO.

It's unlikely we'll ever get the full story, to be honest.

Sadly, that is my feeling as well.

I'm not red posting, but should this be in the' engineering disasters' forum?

A lot can be learned and exchanged from this discussion. Some engineers deal soley with reliability and redundancy as a living. I myself have extensively designed and drawn up re-closer loop schemes (including the cost vs benenfits), service continuity is an entire science all onto itself.

 

[crshears]

Toronto's [actually Mississauga's, but lots of people don't like being reminded of that!] Pearson International Airport is, depending on utility configuration, fed by a minimum of four feeders from four different busses located at a minimum of three separate transformer stations on different high-voltage circuit corridors. There is also an associated combined-cycle power plant capable of carrying the entire site in an electrical island in the event of complete grid collapse.

Common mode failures there are very, very unlikely.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[dpc]

Regarding emergency lighting - many facilities go with wall packs with self-contained batteries because they are the cheapest solution. NEC requirement is that these operate for 90 minutes. That's when the batteries are new. I'm not surprised that lighting was soon non-existent.

Sadly, the electrical design of major "people" facilities such as airports, arenas, museums, etc, is generally an afterthought, both in terms of design criteria and budgeting. It's common for the owner to be happy to turn over the design and provision of the main incoming power system to the local utility. After all they are the "experts". Also, many of the local consultants who get hired for this type of work have little or no experience with systems above 600 V.

Because electrical systems are generally much more reliable than any other part of the facility, the equipment is often neglected and seldom thought about.

 

[Mbrooke]

I agree- however I would be surprised if an airport of this size does not have at least several 200kw diesel gen sets for bare minimum emergency lighting, fire pumps, electric door locks, ect, ect.

 

[Overvoltage]

Don't forget that the utility also has to pay to construct the additional redundancy requested by the designer. Incoming revenues can pay for some utility costs, but backup facilities tend to have little usage, therefore little revenue, so often require up-front subsidies by the owner during construction. Often times the owner would much rather have fancy art than pay for the redundant facility costs (beyond those required by code of course). The utility is often in the same boat as the designer. U:"We can give you this great system that is fully redundant." O:"For free?" U:"Well, no..." O:"Ok, nevermind..." O:*goes to look at shiny thing*

 

[racookpe1978]

The Atlanta airport is owned by the "city" of Atlanta as a jobs source and income source, and tax source, and is notoriously corrupt.

Nope, no emergency lights, door lock, bathroom lights, bathroom paper towel dispensers, toilets ...
Fire protection and alarms still up during the power outage? Nobody is saying.
Announcement system? Was Dead.

Yes, there is a thread in the Disaster's section.

 

[dpc]

I agree- however I would be surprised if an airport of this size does not have at least several 200kw diesel gen sets for bare minimum emergency lighting, fire pumps, electric door locks, ect, ect.

if they felt they had two independent utility sources, maybe not. Also, one account I read mentioned that the "switch" that should have transferred to an alternate source was in the same electrical room as the switchgear and was also damaged in the fire.

 

[Mbrooke]

Wait, we have a disaster's section?


@dpc: Even then their should be Bodines or bug eyes- which I saw none running- unless the vids were shot after the 90 minutes of (sometimes wishful) run time. As for the generator ATS, I highly doubt it would in a utility vault if that is what is being said.


Not trying to discredit you- just intensely curious about how things got the way they did. And a bit angry (not at you) that such a critical facility is so fragile.

 

[dpc]

I'm avoiding the disasters forum. Dead wall-packs are extremely common, especially if not periodically tested. Battery life is maybe five years. I don't see why the generator ATS would not be near the main electrical room. Obviously, a lot of things went wrong. Most likely poor design coupled with poor maintenance practices and lack of operational understanding of the system.

The most surprising thing to me was the reported lack of first responders and airport staff. Saw a photo of TSA agents taking people in wheelchairs up a stairway. To me, the most striking aspect of the Atlanta airport has always been the huge number of airport personnel standing around doing nothing.

 

[Mbrooke]

Again- Atlanta power said this was on there end- not the customer owned equipment. Yes there are countless installations where an ATS for a backup generator is in the main electrical room- but I have yet to see or hear in a utility vault.

 

[Mbrooke]

BTW, anyone have a link to the disasters forum? I can not find it.

 

[davidbeach]

forum815

 

[waross]

Don't forget that the utility also has to pay to construct the additional redundancy requested by the designer. Incoming revenues can pay for some utility costs, but backup facilities tend to have little usage, therefore little revenue

Energy cost is the sum of the bare cost of the energy and the cost of delivery.
Hence, KWHr charges for the energy and
Demand charges to cover the cost of delivery.
Many utilities will charge a demand tariff for a back-up line.
If the utility is charging the same the same amount for a backup line they may be overcharging as the cost of installing a second circuit is much less than the cost of a second line in a second location.
However, that said, it may be that the customer was faced with paying the construction costs up front and made the MBA choice.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[Overvoltage]

Completely correct. I just didn't want to get into a treatise on rate-making so I greatly over-simplified it.