London's Heathrow Airport announces complete shutdown due to power outage
cnn.com
cnn.com
> The power vulnerability for airports was never made more obvious and painful than in Atlanta seven years ago. An underground electrical system fire in late 2017 damaged two substations and caused a complete outage lasting nearly 12 hours at Hartsfield-Jackson International Airport
https://www.microgridknowledge.com/microgrids/article/551275...
To be fair, I'd probably be more interested to hear what major airports are doing to avoid a reoccurance of CrowdStrike-type scenarios. Which is perhaps a more likely re-occurence than loss of substation feeds.
1. UK’s has one major airport to get out of the country—Heathrow. Gatwick and that lot don’t carry the same weight. When Heathrow goes down, you’re proper stuck. Atlanta has DC, Miami right there.
2. UK allows transit visas, so half the people transiting can’t even step out the terminal, what do they do when the airport is closed?
The US doesn’t allow that, everyone clears customs/passport control, so no ‘no man’s land’ limbo for stranded passengers.
3. Heathrow's outage is going to take 24 hours as of right now. That's twice Atlanta
"right there"
It is a ten hour drive from Atlanta to DC. It is a nine hour drive from Atlanta to Miami.
It is a six hour drive from Heathrow to Paris.
Most importantly, you're in the same country whereas in the case of LHR closing the number of airports able to handle widebody long haulers...are essentially all in countries with different customs and visas.
But Dublin airport has about 1/2 the gates of Heathrow...
From which airport? The one that is closed because there's no power?
2: I don't know if they've done it, but the UK can grant entry for a few days to affected passengers. This will be part of a contingency plan.
3: The airport reopened for some flights already.
Both Gatwick [0] and Stansted are busier than either Washington airport [1], and if you're considering Miami as an alternative to Atlanta then why not similarly ridiculous options like Paris, Amsterdam, Dublin for passengers stuck in Heathrow?
Miami and DC aren't even close to the nearest major airport cities to Atlanta. Charlotte and Orlando are many hours closer and busier [1] in terms of commercial passengers (though still not as convenient as the UK's comparable airports).
Only about a quarter of Heathrow passengers are transiting [2] and a significant portion of those are citizens of the US, EU, UK and other countries who don't need a visa. Maybe 10% of passengers are stuck in limbo, not half of them.
[0] https://en.m.wikipedia.org/wiki/List_of_busiest_airports_in_...
[1] https://en.m.wikipedia.org/wiki/List_of_the_busiest_airports...
[2] https://www.statista.com/statistics/303939/flight-transfers-...
This is in the site guidelines: https://news.ycombinator.com/newsguidelines.html.
I’ve been using Edinburgh airport and Glasgow airport for 40 years to “get out of the country”.
Airside to airside bus shuttle?
> The US doesn’t allow that, everyone clears customs/passport control, so no ‘no man’s land’ limbo for stranded passengers.
Anchorage International Airport, amongst few (less than a handful really) other US airports, have separate international section with sterilised transit.
My second thought is, UK infra is crumbling so bad, this is really most likely just business as usual...
Also makes sense to pay for enough brainwashing to enable this.
The UK electricity grid is nationalised - it's run by the National Energy System Operator (NESO).
That is only a very recent change though, 1 October 2024[1].
Before that it was very much privatised, 1990–2024[2].
Technically in the background I suspect you will find very little has changed since October 2024 since (a) not enough time has passed (b) things like TUPE means you will end up with most of the same people doing the same things under a different logo, at least for a little while until changes get phased in.
[1] https://en.wikipedia.org/wiki/National_Energy_System_Operato...
[2] https://en.wikipedia.org/wiki/National_Grid_(Great_Britain)
And no, it is not a national security issue. There are three other airports in the London region, plus RAF Norholt and RAF Kenly inside the M25 ring.
I don't imagine an american being so dismissive about JFK being taken offline.
What will be telling here is how quickly things adapt to the disruption. I expect to feel more impact from the loss of power to businesses in the surrounding area that are involved in air shipment than in the flight disruptions (e.g. cold chain logistics and inventory management for just-in-time processes that warehouse near the airport.)
Most people won't have to. The substation area covers 62,000 properties, but only 4,800 are actually without power as a result of the incident. In addition they are expecting restoration of power by 15:00 same-day.[1]
It is.
If you read the text on the link it very much describes the situation, e.g. talking about the substation.
Second, the start time and other data (e.g. number of properties affected) correlates with that stated by the London Fire Brigade on their website[1]
[1] https://www.london-fire.gov.uk/incidents/2025/march/fire-at-...
Is it, really ?
From Heathrow's own website[1], so we can expect figures on the "generous" side:
"Heathrow Airport is expected to contribute approximately £4.7bn to the UK economy "
This incident started somewhere around midnight and is currently estimated to be resolved by 15:00. So let's round that up to "one day".
£4.7bn divided by 365 is £12.8m
Compared to say, the UK financial services sector which contributed £208.2bn to the UK economy in 2023[2] where an equivalent day out would cost £570m .... Heathrow's paltry £12m is equivalent to a 30 minute outage in the financial sector.
Also, to put it further into perspective - Tesco, the UK's biggest supermarket operator - had revenues of £68bn last year...[3]
[1]https://www.heathrow.com/content/dam/heathrow/web/common/doc... [2]https://commonslibrary.parliament.uk/research-briefings/sn06... [3] https://companiesmarketcap.com/gbp/tesco/revenue/
If we're going to be pedantic about fair comparisons, then really you would need to, for example:
Remove airport duty-free sales figures since that has a negligible effect on the UK economy, but does pad up their bottom line.
Remove leisure passenger derived numbers. Because "passenger tourism contributes to the UK economy" type data are very much finger in the air subjective estimates prone to bias and massaging. For example, common scenario is relatives coming to stay. They stay at your house, you feed them at your house, their net contribution to the UK economy is effectively naff all apart from maybe a couple of museum and transport tickets.
If money were no object even Amsterdam Schiphol or Brussels would make for a faster journey than Manchester!
Many flights have been diverted to Manchester, partly because airlines with flights to Heathrow also have flights from Manchester, but are less likely to have flights from the other London airports.
Manchester Airport railway station is 2 minutes walk from the airport's main entrance, I think using a covered walkway, or maybe it was underground. Going to London takes 2¾ hours with one change, trains run every 20 minutes.
It would be more convenient to be diverted somewhere a bit closer, but on the scale of an intercontinental flight it's not a big deal.
> Cardiff, Birmingham and Bristol as alternatives ... even Amsterdam Schiphol or Brussels would make for a faster journey than Manchester!
Cardiff Airport to London takes 3 hours by train, Bristol Airport about 2½ hours, both are less frequent. Amsterdam is four hours by train, Brussels is around 3 hours.
Birmingham (BHX) and East Midlands (EMA) are the only airports closer to London in travel time than Manchester.
0h 30m - Heathrow
1h 00m - Gatwick
1h 00m - Luton
1h 30m - Stansted
2h 30m - Manchester
3h 00m - Birmingham
3h 00m - Bristol
4h 00m - Cardiff
Plus Channel Tunnel trains:
2h 00m - Brussels
4h 00m - Amsterdam
Looks like I was wrong about Manchester being further than Cardiff though!!
Just to downplay the importance of Heathrow through numbers is a bit absurd.
It’s just delays, not destruction.
You'll need to back up that assertion.
I imagine any American who thought about it would have a similarly 'dismissive' attitude.
So basically this is what Putin is trying to do - find vulnerable points and attack them. For now, creating disruption without human casualties.
No. Its not.
Its the fact that the decades of under-investment in power distribution infrastructure is coming home to roost.
Its no secret there's little to no "fat" in the UK grid system. Hence it has difficulty coping with black-swan events such as this.
Anyone who buys datacentre space in London knows the reason prices have gone through the roof in recent years. Its becasue the grid simply cannot get the extra capacity to where it is needed. And this is before energy prices started rising due to the UK's electricity being mostly dependent on gas (previous governments having sold off gas-storage facilities to build houses on the land instead).
That's why its also a pain in the backside to build new banks of EV fast chargers anywhere in the UK. Getting the power there involves long, protracted, discussions with the grid followed by payments of large amounts of money and a written promise to the grid that you agree to load-shedding at any time if necessary.
I suspect you will find its not a single point of failure either. Its just that Hayes is a high-demand area, so see above for lack of excess capacity .... if one site goes boom, the other will struggle to take on 100% load.
What are you on about ?
Its not a national security issue. Full stop. There are many other airports in the London area and elesewhere in the UK. Heathrow is a civilian airport, not a military one. 99% of air cargo to the UK does NOT come to Heathrow.
Its not a single point of failure either. Sure, for those TEMPORARILY affected it might feel that way. But businesses with contingency plannign will simply invoke their DR plans and go elsewhere ... flights will divert, people will WFH instead of going the offices, people will have to travel to a supermarket a little bit further away.
Also, regarding "single point of failure", see this website[1]... 62,000 customers affected but only 4,800 without power[1]. Not quite a SPOF then is it !
Also, you want guaranteed N+1 resilience at grid level, who do you think is going to pay for that ?
Most people would be happy with the grid sorting out its capacity issues at N level, one thing at a time my friend.
Not even slightly true - Heathrow carries over 50% of air freight and is a major hub.
Not denying it, but it does depend on what you're sending.
For example, if you send something by DHL, it has a significantly greater chance of going through East Midlands Airport than it does Heathrow.
Same for UPS and others. The bulk of their recent investments have been away from Heathrow.
The non-Heathrow sites have better road connections, and more importantly for air cargo, the noise abatement rules at non-Heathrow sites are more relaxed.
The other problem with Heathrow is that BA have their finger in the pies and they have too many slots, so that limits any growth on the independent freight side.
Heathrow has effectively hit its capacity limit. That may or may not change if they ever build the third runway.
Your original post did though!
Heathrow undoubtedly does the most air cargo. Sure express often comes into EMA on dedicated flights, but lots of freight comes in the hold of passenger aircraft, and that’s where Heathrow is king. The lack of passenger traffic is undoubtedly a key reason why EMA only does 1/5th of Heathrow’s air cargo, as as you have noted it’s ideally located to serve a lot of the UK.
Not saying this incident is or isn't a national security issue, but this is not really pertinent to whether an incident is classified as a national security issue.
National security encompasses much more than just military-related stuff. The "security" part of "national security" is using a broad definition of security (like "food security" isn't strictly about physically protecting food from damage).
It means "critical infrastructure whose failure causes significant adverse effects."
The UK's main airport is absolutely that.
Your quote about 99% of air cargo not coming through Heathrow is made-up nonsense. The correct figure is closer to around 50% by volume and 70% by value.
https://www.heathrow.com/company/cargo
It's a major, major hub, not just for the UK but Europe, the US, and Rest of World.
The expense is unpleasant, but the money has to come from somewhere, and the user paying is easier to justify than all the other bill-payers collectively or the taxpayer.
So datacenters build in London as the connection/electricity price is same as building in rural areas and they'd obviously prefer being closer to users in London.
Most likely some combination of:
1. A chunk of the customer base (financial sector, hyperscalers etc.) that wants the low latency and who are price insensitive because of their deep pockets.
2. If peering matters to you, then you're limited to where the IXP is, which is usually only at the major London sites. LINX, for example, have LINX Wales, but that is not interconnected with LINX London, so you either need to get space in London or pay for fibre capacity back to London.
3. Fibre coverage outside large conurbations in the UK has traditionally been shit and to varying degrees still is.
4. The rural areas don't have substations ready-to-go and the NIMBY's come running if you propose building one or anything else in their backyards (see protests about new wind farms).
There are various locations outside of Central London but within the M25 boundary. But YMMV when it comes to being any less expensive. I suspect you will find the Outer London market has "hardened" over the last few years.
Verging into cynical territory, marketing might come into it a little bit. "Telehouse London" sounds cooler in the customer presentation "Telehouse near some village you've never heard of".
Here's one example map: https://www.colo-x.com/data-centre-database-map/
Hayes (North Hyde) is a few miles NE of Heathrow, but Laleham (similar sized) is only a few miles South - I’d would have assumed both served as fully redundant supplies for the airport, given it’s critical national infrastructure.
(The old BBC Television Centre in London had three independent supplies, I believe)
There's a story, possibly apocryphal, that the UK nuclear deterrent submarines used the continued broadcast of Radio 4 as a dead-man switch to determine if nuclear war had broken out and they needed to open the safe containing their orders.
Which is to say: What counts as "critical national infrastructure" can be surprising.
Wind was the dominant source of energy in the UK last year:
https://reports.electricinsights.co.uk/q4-2024/wind-becomes-...
https://www.thelocal.dk/20250321/sas-cancels-flights-from-no...
For national security London and UK can scramble several other airports for important flights.
If we mean that a long outage would have economic impact and is hard to find the capacity elsewhere, then yes. As per grandparent post "take down one of Europe’s largest airports and global air travel".
Always has been, always will be.
Grid power is hard. Even with local generation failovers for air and ground safety systems, Heathrow is massive and uses a lot of power (1-2MWh/day). It's hard to route around that sort of demand.
I don't disagree that this is something that shouldn't happen, but that's what we say for almost every preventable grid failure. I think this is a national inconvenience rather than a security issue though. There are short-term alternatives which will be used.
That number doesn't seem that high, compared to a single high-speed train running at about 300kph or above. Or lets say all of the London Tube/DLR.
Seems like nothing, actually.
[0] https://www.bloomberg.com/opinion/articles/2025-03-21/heathr...
[1] I know precisely nothing about power consumption of large systems but dividing the annual figure by 365 seems plausible.
The point I was stumbling to try and make was that Heathrow is dense. Just under a GWh a day delivered to a 1200ha site isn't going to get a natural diversity of supply, especially compared to a rail system does.
It's 3 orders of magnitude more: 1-2GWh/day.
https://www.heathrow.com/content/dam/heathrow/web/common/doc...
The 2022 version of that sustainability report puts their annual bought in electricity at 272,610 MWh, 747 MWh per day.
My wonky maths aside, it's amazing how much energy they've saved. In your link, the switch to LEDs alone saw a 20% total power reduction. I'm sure I've seen electric vehicles there so I'm surprised this number is still apparently in freefall. Perhaps they're doing more local generation (eg) PV
Military airports are working fine. National security doesn't rely on civilian airports. And communications networks aren't disrupted or anything. This isn't enabling terrorism.
It's absolutely a huge economic issue. Economic-political. But I'm not seeing a national security angle here.
https://en.wikipedia.org/wiki/National_security
Large-scale issues that impact the economy are typically under the "national security" umbrella. It's a term that uses the broad definition of "security".
Whether this incident qualifies, I don't know, but "national security" is definitely not just about military stuff. Just like how "food security" isn't about physically protecting food from damage.
I feel like this sort of "security reflex" only got worst after 9/11, it was already there before even before that point but starting with Bush jr. it cascading into lots and lots of non-military related areas.
The Russian war of aggression on Ukraine is a prime example: power infrastructure, transportation, communications, commercial hubs, healthcare, and general civilian targets of opportunity are all targeted with high frequency by Russian forces.
UK national security interests are spelled out in summary beginning on page 5 of this PDF, "Government Functional Standard: GovS 007: Security", notably
Each organisation’s governance and management framework shall cover physical, personnel, cyber, incident management, technical and industry security
<https://assets.publishing.service.gov.uk/media/613a195bd3bf7...> (PDF)
The US electric grid has also been of significant concern. Ted Koppel's book Lights Out (2015) addressed this specificly:
<https://news.wttw.com/2015/11/09/ted-koppel-americas-vulnera...>
As an example of non-military focus, the present US national security policy leads with ... tourist visas:
To protect Americans, the United States must be vigilant during the visa-issuance process to ensure that those aliens approved for admission into the United States do not intend to harm Americans or our national interests.
<https://www.whitehouse.gov/presidential-actions/2025/01/prot...> (20 Jan 2025)
An earlier document from the Bush II White House leads with:
People everywhere want to be able to speak freely; choose who will govern them; worship as they please; educate their children—male and female; own property; and enjoy the benefits of their labor.
<https://georgewbush-whitehouse.archives.gov/nsc/nssall.html> (2002)
Wikipedia's National Security article notes:
Originally conceived as protection against military attack, national security is widely understood to include also non-military dimensions, such as the security from terrorism, minimization of crime, economic security, energy security, environmental security, food security, and cyber-security.
Indeed. Large scale war is extremely expensive. Russia's government is spending about 40% of total tax revenue on invading Ukraine. So anything it can do to harm the economies of the people fighting it helps. Equally, this is why Ukraine has been putting so much effort into blowing up oil and gas infrastructure in Russia, their #1 source of tax revenue.
Economic and infrastructural sabotage isn't an unprecedented act in the last few years anyhow.
"Heathrow Doesn't Know When Power Will Be Back, Days of Disruption Expected" - https://www.newsweek.com/heathrow-airport-fire-counterterror...
If the entire transformer is lost, procuring replacement transformers for substations can take from several months to years. Insulation failures are relatively common in older power substations. It seems someone should have done a better job preparing disaster recovery scenarios for Heathrow.
Edit:
BBC reporting "some power" restored on a "interim basis" as the power company is now using a different substation. It would be curious if the increased effort on other substations would then cause further power failures...A bit like the postmortems of global cloud providers, where taking a node out, causes increased stress on other nodes...
(edit: and are back)
I doubt it's worth the additional expenses, though. Transformers exploding like this is extremely rare, and the main reason this one has such an impact is because the firefighting effort required the other two transformers to be shut down. Investing in better physical separation between the individual transformers is probably a way more effective investment.
"Power outage cancels, diverts flights at Kennedy Airport" - https://apnews.com/article/new-york-city-power-outages-eb883...
> https://thewest.com.au/travel/perth-to-london-flight-diverte...
> Perth Qantas customers who had their flights diverted from London to Paris after a massive power outage at Heathrow Airport will be put on buses to take them to take them to their final destination.
For anyone reading: it means "of course"
I may have put too much thought into this.
ofc
Insert that xkcd comic
If you happen to see that one, it stands for ‘laughing out loud’.
Sounds weird that one substation going down would close everything.
So perhaps the core issue isn't inability of the airport to operate, but of people to get in and out.
National Rail say [1] "An unadvertised shuttle service is running from Heathrow Terminals to London Paddington to ensure customers and colleagues can leave the airport" so trains can and are running, they just don't want flight passengers to go to the airport.
[1] https://www.nationalrail.co.uk/service-disruptions/heathrow-...
The substation on fire (North Hyde) is a 275kV major distribution substation.
That's a fairly significant distribution loss in itself (not just Heathrow but also 16,000 homes), and rebalancing the distribution will need careful coordination – flipping the switch on a load the size of Heathrow would then imbalance the network for the new distribution supply site.
You are off by a large number. More like 62,000 customers affected (although "only" 4,800 are actually without power right now)[1].
Also that area is more than just "homes". There is a lot of heavy elecrical load commercial stuff going on in that area too.
Could that explain it?
https://en.wikipedia.org/wiki/SS_Richard_Montgomery#/media/F...
Issue a Tsunami warning and get everyone off the beach for an hour Sunday at 3am.
(2) Right by a river leading directly into the capital. I don't know how far away a 2m tsunami would actually go, is it close enough to the river entrance to focus it? https://www.floodmap.net to play with what "2m" would mean to the local area.
[0] https://en.wikipedia.org/wiki/Berlin_Brandenburg_Airport
But what can the UK do about the likelihood of Floods?
The bird migration that constantly fly where the Estuary would be
Or an accident happening at the Grain LNG Natural Gas Storage plant, one of the largest in the world that’s right next to where the airport would be?
"How to Prevent Substation Fires": https://www.oilbarriers.com/blog/suppress-substation-fires/
What happened with Heathrows generators? Did they kick in? Do they have any?
Edits: yes they did kick in as normal https://www.standard.co.uk/news/uk/heathrow-ed-miliband-nati...
Note that usually backup generators are only for essentials like air traffic control, landing lights, and operating emergency stuff.
You are entitled to be re-booked on the next available flight or get a refund. If you take a refund the airline has no obligation to you anymore. You might find after taking a refund, the price of an equivalent flight is now much more.
https://electranet.com.au/wp-content/uploads/2025/01/15449-P...
This and quitting meat consumption (or significantly reducing either or both luxuries- I quit flying years ago, and I eat meat once a month or so as a delicous luxury) seem to be the two main ways we can reduce our individual carbon footprint, focus on which is a bit scammy by the industry heads who want to keep converting resources into money to swim in, so please also consider lobbying for stronger regulation of our collective carbon footprint.
Public luxury (libraries, health care, bike lanes, public transportation, education from birth onward that isn't about preparing obedient workers for the mill but reinforcing the benefits of mutual aid and participatory democracy), private sufficiency (I have enough. I actually have more than enough, and have spent about fifteen years getting rid of physical and digital baggage that gets in the way of good relationships, with an exponential increase in recent years, leveling out again as I scrape the barrel for more to let go of). There are so many of us on this planet- believing the lie that we can all be wealthy (in capitalist terms) will accelerate boom-bust-quit, and I don't see the Moon or Mars working out very well. We can be wealthy in social-animal terms, though, by being kind and loving and reciprocal. It's not that simple, nor will it ever not be a messy, dynamic situation, but there's a beauty to that.
Most people travel by plane because it's the only way to reach their destination in a reasonable amount of time.
Yesterday, if you'd have publicly shared this one substation is enough to take down Heathrow for an entire day, you'd have been disappeared by the British spooks for sharing extremely sensitive information threatening national security and you'd probably end up behind bars for over a decade.
Today, we all just know because it happened to catch fire, exposing the flaw.
I get it, all modern intelligence apparatus is draconian but this take doesn't really make sense IMO.
From an US perspective it'd be like taking out JFK, LAX and ATL at the same time. But even then, it doesn't really compare.
Same sort of logic that leads to people getting arrested for looking at HTML and reporting that it includes passwords.
Renaud discovered that Social Security numbers for teachers, administrators and counselors were visible in the HTML code of a public Missouri State Education website and reported it.
Governor Mike Parson tried to file charges against him and labelled him as a criminal for doing so.
I've been on the side of disclosing a handful of times and it's a gamble each time whether I'm going to get a CFAA threat (both implicit and explicit threats).
When did I ever say or imply that? I agree that intelligence agencies are draconian, but to imply that you'd be locked away (never to be heard from again) for pointing out that a substation could be bombed and cause power issues is ridiculous.
So, I guess I really don't understand your point. That being arrested for pointing these things out isn't bad because it's not being disappeared?
But for saying there is a single substation that, if taken out (by sabotage, terror attack, arson, or whatever), would cause great embarrassment and economic damage to the country by disabling THE British Airport? I think that’s a whole different matter.
With this kind of large-scale infrastructure it just isn't viable to rely on security through obscurity. If you want to protect against failure, invest in redundancy.
Don’t forget the BT Tower existing was technically classified under the official secrets act, even though it was extremely obviously there for everyone to see including on maps.
Not a conspiracy theorist here, but... there's been quite a few expensive things which caught fire in Europe in the past year and change and it turned out those things didn't catch it by accident.
There's also the "accident" that just happened to destroy a US military oil tanker. Sure enough, the captain of the ship was Russian: https://www.theguardian.com/business/2025/mar/12/captain-arr...
And it's very clear that multiple undersea cables have been intentionally cut by Russia-linked entities. You just don't drag anchors for hours over known cables by accident (the cables are on charts precisely to help captains avoid damaging them).
We're at war with Russia, and these kinds of attacks have both economic and psychological harms. They also allow Russia to practice techniques in case they need to ramp things up for a hotter conflict.
Its not highly classified. Its not even plain classified.
Its available on streetmap. The substation (like most are) is located on the edge of a residential area / industrial estate. People walk and drive past it every day.
Looking at streetmap, there's even a multiple big signs outside that says "North Hyde Substation". They don't even make any effort to hide it with obscured fencing, its all out in the open.
As others have also pointed out, its in open data downloads for ages.
Let me re-phrase that for you:
It only took down the airport because the airport clearly did insufficient capacity planning in terms of backup mechanisms.
How can I be so confident ?
Because that exact same substation serves a number of large datacentres in the vicinity.
Due to the grid constraints previously discussed here, many of those same datacentres take ALL their feeds (A,B,C etc.) off that one substation, the only difference is the cables are diversely routed. Not their choice, it was imposed on them by the grid.
They have ALL been without ANY electrical feeds all day. I know that for a fact.
HOWEVER, those same datacentres have been running non-stop like nothing happened. I know that for a fact.
Why, because they have N+1 generators (which are regularly tested) with at least 48 hours of fuel, which was topped up this morning as soon as it became clear it was a major incident and with multiple fuel deliveries already pre-scheduled from multiple independent suppliers. I know that for a fact.
The grid are of course very busy trying to work some magic to re-arrange things to get the datacentres back online. Meanwhile the datacentres are very happy to keep ticking away on generator power for as long as it takes, its not a problem for them, its an event they plan, prepare and practice for.
Heathrow could have done the same. They could have added generator plants here and there over the years when they re-built terminals and such like.
They didn't, or at least they didn't do so with sufficient capacity.
Maybe Heathrow also fell behind on their generator maintenance and testing regimes. Who knows...
There are people out there who say it is because their motto is "spend little, charge a lot", so they did de-minimis, prefering to focus on maximising revenue generating space. I could not possibly comment.
If it was considered a "threat to national security", that substation site would have been much better secured.
In addition, if it was a "threat to national security", the site location would not be on open public databases, it would be on List X.
As it stands, the substation site "security" consists of two low, easily scalable, fences. And probably some CCTV. That's about it.
Security by obscurity is not security. We are in 2025, you have streetview and satellite photos.
Anybody who knows anything about electricity distribution could look at that substation and tell you it was pretty important given the large size of transformers located there.
It also doesn't take a rocket scientist to see Heathrow is minutes away and put two and two together.
And if you think the bad guys don't have the ability to give some poorly paid maintenance guy at the electricity company some cash in relation for extra detail, I've got an igloo to sell you.
I wonder if they are looking for something or somebody and there is more to this story. (click on the helicopter icon to see previous runs): https://www.flightradar24.com/GINTV/3990e5fc