Heathrow power outage 1

[Hoxton123]

Heathrow Airport closed all day after nearby fire causes power outage - live updates

Flights are cancelled and diverted mid-air as Europe's busiest airport closes until midnight over a "significant power outage".

www.bbc.co.uk

i do now know what the substation voltages are, but one of the two transformers is completely burnt, and i guess they isolated the substation in order to fight the fire

 

[LittleInch]

The main site is 275kV incoming supply one side then what looks like 33kV the other.

A bit surprising there is only one main feed into such a critical bit of infrastructure.

 

[Alistair_Heaton]

There isn't, there are a few.

This is the power to the terminals not the infrastructure eg runway lighting, radar etc.

It's chaos it's going to take over a week to sort out the aircraft nevermind the rest of things out of place.

 

[Pud]

I'm surprised that transformer cooling oil is flammable.
Is this common practice worldwide?
There doesn't seem to be many re-routes to Newcastle (UK) airport. I would have expected more as there's a good(ish) rail link to London, and a rail link from the airport to train station every few minutes.

 

[oldrunner]

Initial question: How old was the transformer? Did the coil windings have a permanent compression system? A few years ago there was a 30 year old transformer that burned at a Houston substation. Transformers do not run forever and there should be a remove from service plan in place. These comments may not be relevant, but some of us remember the incident of a substation near San Jose.

 

[Alistair_Heaton]

There where to take pax on a diversion doesn't follow logic to anyone other than airline operation's.

 

[Bendolfc]

Not sure what the scope of works was but there was a load of work there a 4 years back https://www.ssen.co.uk/news-views/2...-upgrade-to-local-electricity-infrastructure/

 

[LittleInch]

I'm surprised that transformer cooling oil is flammable.
Is this common practice worldwide?
There doesn't seem to be many re-routes to Newcastle (UK) airport. I would have expected more as there's a good(ish) rail link to London, and a rail link from the airport to train station every few minutes.

Airlines prefer putting on coaches. Much cheaper.

Plus more links to other locations from Gatwick, Stansted and Manchester.

 

[thebard3]

I'm surprised that transformer cooling oil is flammable.
Is this common practice worldwide?
There doesn't seem to be many re-routes to Newcastle (UK) airport. I would have expected more as there's a good(ish) rail link to London, and a rail link from the airport to train station every few minutes.

It's not cooling oil. It is dielectric insulating oil that heats up during use and requires cooling.

 

[Alistair_Heaton]

Oh to note Heathrow won't pay for snow clearing equipment and say loosing a day of movements is more cost effective than investing in the gear and training

 

[Garbage1]

I am reading Heathrow got rid up emergency backup/standy generators, and switched to a biomass system that takes time to startup. Thus no emergency standby power that switches on quickly for critical systems.

Net Zero Wet Dreams?

 

[Alistair_Heaton]

They didn't loose any critical systems.

Those were off a different side.

The railway lost power as well.

 

[Garbage1]

Perhaps 'critical systems' was poor choice of wording. Maybe 'single point failure' is better term to describe functionally shutting down the whole airport, yet still having ability to communicate to redirect aircraft to other airports.

 

[LittleInch]

Lets not all jump on the zero emissions bandwagon.

Looks to me like there were two main TXs at the main substation, but the second one got wiped out by the intensity of the fire at the first one.

Heathrow is HUGE and there is no way any diesel standby system is going to allow anything other than minimal critical operation.

The biomass CHP plant would have tripped if they lost mains supply.

I suspect part of the airport could have operated, but the system has been built and expanded and interlinked so many times over the last 80 years I doubt everything would have worked.

 

[TugboatEng]

Looks like Heathrow uses up to 300GWh per year. I think a single GE LM2500 gas turbine could back that up. There is plenty of jet fuel around to fire it.

 

[oldrunner]

Initial question: How old was the transformer? Did the coil windings have a permanent compression system? A few years ago there was a 30 year old transformer that burned at a Houston substation. Transformers do not run forever and there should be a remove from service plan in place. These comments may not be relevant, but some of us remember the incident of a substation near San Jose.

Bingo. Old substation (transformer?) and 106.2 percent of capacity! That's a sign for extreme degradation of the coil winding insulation and is discussed (WARNED) in a number of IEEE Transformer publications. There may have been a short circuit that was the final straw.

 

[waross]

Heathrow is HUGE and there is no way any diesel standby system is going to allow anything other than minimal critical operation.

I worked on the battery bank for a 10,000 HP UPS that was intended for carryover until the diesel backup could come on-line.
This was for the feed water pump in a nuclear power plant.
There were four such systems in the plant.
eg: 40,000 HP on UPS and diesel. (Possibly an aero-derivative. I never got to see that part of the plant.)

 

[electricuwe]

Let me provide some background on disaster protection related to transformers.

- the usual liquid for cooling transformers is mineral oil as it provides excellent isolation and cooling - however this oil is flammable
- protection and regular maintenance, e.g. derived from regular oil analysis can minimize the risk of fire
- A Buchholz-Relay tripping the breaker in case of severe internal failure is usually used for protection
- Usually there are means provided that collect oil, minimize fire load and keep a faulty unit separated from the rest of the substation

In case of critical applications transformers can use non-flammable or less flammable cooling liquids like silicone oil or ester-based fluids.

 

[LittleInch]

Maybe some of the sparkies here can help, but it loks to me,from what I've been able to clean, is that these two TX are the A and B 275kV. The third on the right looks like an add on for local power distribution.

For street view it looks very much to me like there are no fire walls between these two. Is that normal? Bearing in mind this substation might be 50 years old.

Any other comments on spacing or design?

 

[thermionic1]

I'm surprised that transformer cooling oil is flammable.
Is this common practice worldwide?
There doesn't seem to be many re-routes to Newcastle (UK) airport. I would have expected more as there's a good(ish) rail link to London, and a rail link from the airport to train station every few minutes.

In the 1930's, a fluid called Askarel (PCB) was introduced as an alternate insulating fluid, as it had a higher flashpoint. It was outlawed in many countries in the late 1970's. That didn't stop cross contamination of oil processing equipment. To this day NON PCB stickers are required on all oil filled equipment in the US.

There are other alternatives, such as vegetable based insulating fluids, but they are generally not used on large power transformers. I've seen deenergized pad mount transformer in the winter where the "fluid" was a frozen solid.