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Heathrow airport ch...
 

Heathrow airport chaos.

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Well if terrorism is the cause then they have inconvenienced the wrong people 😆 

https://twitter.com/DavidWilding271/status/1902988770430869738

 

 


 
Posted : 21/03/2025 2:51 pm
Keando reacted
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I'm seeing more information on this now. Seems it's off site at Hayes, not actually at the airport. National Grid Transmission have made comment and the fire brigade have quoted 25000 litres of oil. All that suggests that it's a grid supply point at the root of this. Could still be "natural causes" and bad luck, but it's a much more substantial piece of infrastructure than I first thought.


 
Posted : 21/03/2025 2:54 pm
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I hadn't realised substations are full of oil.

Large transformers use it as an insulating media and it's circulated through large radiators for cooling. 

£534 + VAT for a 205 litre drum delivered. 😁


 
Posted : 21/03/2025 3:09 pm
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The reality is a peice of metal probably fell off a plane on final approach and shorted out some hv cables.

 

Or , the local yoof do what they do , or used to near Basingstoke. Whenever there was a big footy match they would launch iron bars at the local sub station and it would go bang.  Till they got caught 


 
Posted : 21/03/2025 3:25 pm
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The Russians! 

that is all.

 

known to be responsible for several warehouse fires across Europe and I believe may have been fingered as most likely suspects for a Uk one.

Tin hat on 

 


 
Posted : 21/03/2025 5:53 pm
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Posted by: tthew

Large transformers use it as an insulating media

Never mind the Russians, it sounds like the Decepticons did it!


 
Posted : 21/03/2025 5:57 pm
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Never mind the Russians, it sounds like the Decepticons did it!

I've worked in the industry almost 15 years now and still, to this day, when someone says "transformers" that little voice in my head sings "robots in disguise".


 
Posted : 21/03/2025 6:21 pm
ratherbeintobago, gringo, crazy-legs and 1 people reacted
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Posted by: tthew

Large transformers use it as an insulating media and it's circulated through large radiators for cooling. 

I learnt this quite a few years back when I got a day off due to it.

Someone spotted some scrap metal at the local substation and kindly removed it but unfortunately in the process managed to drain the oil resulting in a rather unhappy substation.


 
Posted : 21/03/2025 9:17 pm
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Posted by: crazy-legs

Posted by: ElShalimo

Hopefully be at Newhaven ferry by 7:30pm

On which day?

😉

 

Today!!

Got here okay, low traffic near Heathrow for a change. 

 


 
Posted : 21/03/2025 9:32 pm
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Posted by: tthew

I hadn't realised substations are full of oil.

Large transformers use it as an insulating media and it's circulated through large radiators for cooling. 

£534 + VAT for a 205 litre drum delivered. 😁

Is that for Midel? I'm sort of retired now but being 1 meter from a 2500Kva transformer when it went "BANG" does tend to focus your thoughts of mortality.

That was the second transformer that failed in a week after the first went "BANG" ejecting 3000 litres of hot oil into the building!

We ran the rest of the summer on 2 x 1750Kva generators that chewed through diesel at an alarming rate!!

 


 
Posted : 21/03/2025 11:36 pm
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Posted by: tthew

I hadn't realised substations are full of oil.

Large transformers use it as an insulating media and it's circulated through large radiators for cooling. 

£534 + VAT for a 205 litre drum delivered. 😁

 

Eh?, surely that doesn’t need explanation for folk, WTF did they think the radiator cooling framework around transformers was for? 

 


 
Posted : 22/03/2025 12:52 am
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Is that for Midel?

No, we use Mobilect mineral oil. The cost of swapping it out would be horrific.

Interesting transformer oil chat!


 
Posted : 22/03/2025 8:24 am
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Posted by: somafunk

Posted by: tthew

I hadn't realised substations are full of oil.

Large transformers use it as an insulating media and it's circulated through large radiators for cooling. 

£534 + VAT for a 205 litre drum delivered. 😁

 

Eh?, surely that doesn’t need explanation for folk, WTF did they think the radiator cooling framework around transformers was for? 

 

Most people don't know what a transformer does or looks like, let alone what the radiator cooling framework is or what medium it's filled.

Unless that's an electrical engineer joke that has gone over my head (unlike a plane to Heathrow).

 


 
Posted : 22/03/2025 9:21 am
 igm
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There’s a lot of nonsense flying around on the internet on this one - notably from some folk who should know better. 

All electrical kit fails eventually in this case it looks like it was a 275/66kV supergrid transformer belonging to NGET and feeding SSEN, who in turn supply Heathrow.

Customers like Heathrow get to specify the level of redundancy they want, and SSEN will have built this for them - but then charged Heathrow appropriately. Datacentres seem to be the customer class that clearly understands the reliability and resilience they need - other large customers less so.

That said the reliability of the electricity system is something like 99.9897% availablity and this connection will have been higher, so most customers rarely have to worry.

Beyond that, wait for the facts to emerge. Our forensic engineering capability in the power industry is pretty good - but it does take time. 


 
Posted : 22/03/2025 9:25 am
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Posted by: somafunk

Posted by: tthew

I hadn't realised substations are full of oil.

Large transformers use it as an insulating media and it's circulated through large radiators for cooling. 

£534 + VAT for a 205 litre drum delivered. 😁

 

 

Eh?, surely that doesn’t need explanation for folk, WTF did they think the radiator cooling framework around transformers was for? 

 

Apologies for my stupid ignorance. I just wasn't aware they used combustible oil for cooling something that makes sparks when it goes wrong. It's obvious when you think about it....

 


 
Posted : 22/03/2025 9:26 am
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With reference to potential terrorism or whatever, has anyone mentioned hanlons razor?


 
Posted : 22/03/2025 9:48 am
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Apologies for my stupid ignorance. I just wasn't aware they used combustible oil for cooling something that makes sparks when it goes wrong. It's obvious when you think about it....

Transformers don't really have any moving parts (tap changers aside) but the thing that will mess with your head is that the switchgear used for turning the transformer on/off might well have similar oil inside to quench the arc that forms inside when it's operated 


 
Posted : 22/03/2025 10:06 am
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£534 + VAT for a 205 litre drum delivered. 😁

£3.12/litre. About 1/5 price of Shimano mineral oil, some experimentation needed tthew, please 🙂

Heathrow Chief Executive Thomas Woldbye said he expected the airport to be back "in full operation" on Saturday.
Asked who would pay for the disruption, he said there were "procedures in place", adding "we don't have liabilities in place for incidents like this". https://www.reuters.com/world/uk/global-travel-chaos-has-airlines-scrambling-after-fire-forces-heathrow-shutdown-2025-03-22/
That's gonna cost, if they ever decide who is liable

 
Posted : 22/03/2025 10:07 am
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With reference to potential terrorism or whatever, has anyone mentioned hanlons razor?

About 40 posts down page 1


 
Posted : 22/03/2025 10:11 am
 igm
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Transformers don't really have any moving parts (tap changers aside) but the thing that will mess with your head is that the switchgear used for turning the transformer on/off might well have similar oil inside to quench the arc that forms inside when it's operated 

Ahh, the Caton Arc Trap, one of the finest pieces of intelligent engineering I’ve ever seen  

PS - not at 275 or 66 of course. 


 
Posted : 22/03/2025 10:31 am
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True, not at that particular voltage, but I thought it might amuse people to know that the vast majority of transformers contain flammable oil and so does a lot of the switchgear that controls them. They'd go bang an awful lot more often if they didn't though.


 
Posted : 22/03/2025 12:01 pm
 igm
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There’s still a load of OW410 bulk oil breakers kicking around at 132kV


 
Posted : 22/03/2025 2:22 pm
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I'm just listening to news reports that the government have ordered urgent investigations into the causes of the power failures. 

Which is helpful because I'm sure the DNO, National Grid and Heathrow airport are all thinking, "huh, I wonder what happened there? Guess we'll never know!" 🙄


 
Posted : 22/03/2025 8:35 pm
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The industry has seen similar before. Massive outages up north, you just have to suck it up. Powercuts anywhere near London and there's a national inquiry.


 
Posted : 22/03/2025 11:05 pm
 igm
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To be fair, it’s s national enquiry if someone just OK’ed a third Heathrow runway 


 
Posted : 23/03/2025 12:04 am
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Posted by: Onzadog

oil inside to quench the arc

I thought it was an inert gas like sulphur hexafluoride which was used to basically blow it out. At least I'm pretty sure that was the case for my first job, which was creating CFD software to simulate this event. However it was a few decades back and I didn't get very far.....LOL...I did solve one significant technical problem, my boss didn't believe me or like me, and I moved on to something else inside 6 months.

(Simulating a plasma arc in a domain with moving boundaries rather stretching the capability of commercially available CFD code at the time.)


 
Posted : 23/03/2025 8:59 am
 igm
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SF6 is being phased out (at least for the lower voltages) as it is a greenhouse gas. 

At lower voltages we’ve also used oil and we used used vacuum bottles. 

At higher voltages oil or air blast. Most of the air blast is gone now I think. 

We’re moving to dry air now. Slowly. 

Transformers are generally paper and oil, midel or occasionally cast resin. Big stuff is normally oil (unless someone knows better).

Cables paper/wax, paper/oil, gas pressure (which also uses paper/wax as I recall), or more recently various polymers with a special mention to XLPE (cross linked polythene) in that last category. Paper generally lasts longer than polymer.

Given decent quality switchgear and transformers should last 60 years plus, nothing changes particularly quickly. 


 
Posted : 23/03/2025 9:43 am
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