Heathrow - Page 1
Forum section: electronics / general

author: IanB
author_rank: Super Contributor
timestamp: March 21, 2025, 05:12:44 pm
content: Situation: "Transformers are filled with cooling oil, and unfortunately this caught fire"Question from member of public: "Why not fill the transformers with water instead, since water doesn't burn?"

author: factory
author_rank: Super Contributor
timestamp: March 21, 2025, 05:24:55 pm
content: What temperature does it take to cause the oil to burn? Water apart from having obvious electrical problems, would boil away* leaving the rest to melt/burn and then there is the corrosion issues.*we had a sub-station building at work turn into a sub-sauna, because of damaged cables that were under water.David

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 21, 2025, 05:40:33 pm
content: With a building full of high voltage and oil, you'd think that some sort of automatic fire suppression system would be an idea...

author: floobydust
author_rank: Super Contributor
timestamp: March 21, 2025, 05:51:40 pm
content: It looks like many failures, just in the substation alone.I worked in the utility industry SCADA and transformers have many sensors. Sudden pressure sensor (SPR), Buchholz relay, pressure relief valve switch contact etc.There are other sensors, typically: oil temperature 26T, winding temperature 49T, low oil level main tank 71T and conservator 71A, cooling fan fail etc.There can also be a differential protection relay 87T which monitors current (power) in and out. If an internal arc occurs there is a big difference which means trouble, they trip in 30msec.The protection relays are supposed to trip breakers and disconnect power fast to prevent such a big fire in the first place.You can see in Hayes pics there is also the fire suppression system that missed the boat. Red piping and sprayers surrounding each transformer.These systems can get old and rarely tested.The oil is typically mineral oil but less flammable silicon-based synthetics are used.Nevermind the airport's new Net Zero emergency generators using woodchips and requiring mains? I wonder if this is true, seems ridiculous.

author: themadhippy
author_rank: Super Contributor
timestamp: March 21, 2025, 06:17:34 pm
content: QuoteWith the added bonus of hot water for a nice cup of tea whilst fighting the fire

author: Xena E
author_rank: Frequent Contributor
timestamp: March 21, 2025, 07:00:30 pm
content: Polychlorinated biphenyl oil wouldn't have caused all this disruption.X

author: tom66
author_rank: Super Contributor
timestamp: March 21, 2025, 07:00:48 pm
content: What's crazy is that critical British infrastructure depended upon a single substation, a disaster waiting to happen - wait, no, that's par for the course really for this country.I am sure a certain V. Putin is looking at how vulnerable our infrastructure actually is and hybrid warfare remains on the table here. It really wouldn't take much to cripple the UK for days at a time.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 21, 2025, 07:22:51 pm
content: Yeah, fire water burn!

author: NE666
author_rank: Frequent Contributor
timestamp: March 21, 2025, 08:43:56 pm
content: Quote from: tom66 on March 21, 2025, 07:00:48 pmThe truth will come out in the wash, however, I have seen it reported that there is alleged to have been a pre-existing fault with a transformer in their alternate supply, rendering it inoperable as a backup. Still a sh1tshow, but at least if true that would at least mean that redundancy had been designed in.This incident couldn't have come at a better time, a time when the current government is again considering the option of allowing a third runway. I can't think of a clearer example why we should not continue to place all our eggs in one basket, rather than distribute capacity across the country.

author: floobydust
author_rank: Super Contributor
timestamp: March 21, 2025, 09:47:57 pm
content: There are two transformers, so that one can be taken out of service for maintenance, redundancy etc. - standard practice for the bus architecture there.But... it's right next to the one that blew up and it shows some dents and dings. Certainly the heat would damage control panels nearby.Also, smoke has a much lower breakdown voltage than air, dense smoke will easily arc.You would not switchover/energize the second transformer without more trouble.What's with the 133 brush fires in Wales? Space lasers are real! lol.

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: March 22, 2025, 12:06:02 pm
content: Quote from: IanB on March 21, 2025, 05:12:44 pmTheZ-machinedoes use deionized water, but that picture should scare off any concerned members of the public.

author: Nominal Animal
author_rank: Super Contributor
timestamp: March 22, 2025, 02:58:32 pm
content: Quote from: radar_macgyver on March 22, 2025, 12:06:02 pmAs I understand it, the water needs to be continuously deionized and filtered. Not exactly a suitable option for transformers, especially since the failure of deionizing and filtering the coolant water would be basically just as catastrophic. Better KISS.

author: UnijunctionTransistor
author_rank: Frequent Contributor
timestamp: March 22, 2025, 04:28:02 pm
content: Quote from: tom66 on March 21, 2025, 07:00:48 pmThis exact theory has been put forward;https://youtu.be/ZuN8Fi1Kv0A?si=zU6RJaAUNObnU1lz

author: themadhippy
author_rank: Super Contributor
timestamp: March 22, 2025, 04:45:00 pm
content: QuoteNope,seems theres at least 3,bit more info here.https://www.telegraph.co.uk/news/2025/03/21/heathrow-electricity-substation-fire-north-hyde-hayes/Having worked in place with 3 HV grid supplies it sounds a fairly accurate description,it took us around 12 hours to get fully back to 100% mains power when one of the HV feeds was lost and that was on a site much smaller than heathrow

author: 5U4GB
author_rank: Super Contributor
timestamp: March 23, 2025, 11:16:23 am
content: Quote from: themadhippy on March 21, 2025, 06:17:34 pmFeck off, cup!

author: tggzzz
author_rank: Super Contributor
timestamp: March 23, 2025, 11:35:40 am
content: Quote from: themadhippy on March 22, 2025, 04:45:00 pmTo my surprise, that articledoescontain useful information.One point that deserves expansion is that the power grid across west London is creaking. A couple of years ago National Grid state they would not be connecting any new housing blocks to the grid. That was politically unacceptable, so some compromising (in both senses) wording was issued.Not a good starting point when considering the future extra load as electric vehicles become more common.

author: tggzzz
author_rank: Super Contributor
timestamp: March 23, 2025, 11:39:58 am
content: Quote from: tggzzz on March 23, 2025, 11:35:40 amTo my surprise, that articledoescontain useful information.One point that deserves expansion is that the power grid across west London (i.e. Hillingdon, Ealing, and Hounslow including Heathrow) is creaking. A couple of years ago National Grid state they would not be connecting any new housing blocks to the grid.https://www.bbc.co.uk/news/uk-england-london-62346322https://www.datacenterdynamics.com/en/news/report-home-building-to-halt-in-west-london-due-to-data-center-power-demands/That was politically unacceptable, so some compromising (in both senses) wording was issued.Not a good starting point when considering the future extra load as electric vehicles become more common.

author: tom66
author_rank: Super Contributor
timestamp: March 23, 2025, 01:10:18 pm
content: Grid connectivity (not just in London) has been an issue for some time for EV infrastructure, it took Tesla 6 years and 1 day to get power to their Fleet Supercharger because of connectivity delays. It is the reason the government has missed their target of 6 rapid chargers at every motorway service area. This is also why the supermarkets are getting into installing chargers, with Asda and Morrisons just starting and Sainsburys with 50 x 6 station stalls already installed - they often have existing connectivity to the grid at their supermarkets, so putting in chargers is not as difficult as MSAs where they often only had 50kVA service and gas heating.I don't think it's as much of a problem for home charging since we're talking 3.6kW or 7kW intermittently switched on and off and for the average UK mileage it's equivalent to a few long electric showers running now and then which the grid manages fine already. But it's definitely a big problem for rapid charging.Might be more of an issue for heat pumps though as that's roughly 2-3kW winter load continuously for every house on the street on top of anything else, with current capacity sized for around 1kW per home (averaged over 24 hours).

author: tggzzz
author_rank: Super Contributor
timestamp: March 23, 2025, 01:56:55 pm
content: Quote from: tom66 on March 23, 2025, 01:10:18 pmAgreed.There was a minor scandal about a large hub, possibly near Birmingham. It was built but not connected to the grid due to grid capacity limitations. IIRC, it has finally been connected.

author: floobydust
author_rank: Super Contributor
timestamp: March 23, 2025, 06:43:03 pm
content: Critical infrastructure, utilities being sold off to private companies, is a basic disaster recipe.Of course you'd run the assets into the ground, to provide maximum return to shareholders.No penalties for running antique transformers, rated 76MVA and running max was 80.6MVA so 6% over design. No penalties for not keeping up with upgrades.The Hayes substation, it's got empty land, two plots next to the exploded transformer for expansion. North Hyde Electricity- they got room for more or bigger/newer transformers. Better get on it lol.National Grid publicly traded, just disgusting because that profit comes out of ordinary folk's pockets and they can charge for any shortcomings that occur.

author: TimFox
author_rank: Super Contributor
timestamp: March 23, 2025, 06:51:51 pm
content: A problem with unregulated privately-owned infrastructure:If the only penalty to the infrastructure owner from failure-induced interruptions of service is lost revenue from the consumers, then the external costs to those consumers from an interruption can be much larger than the lost revenue, while the required investment to achieve higher reliability may not be covered by the elimination of that lost revenue.

author: Zero999
author_rank: Super Contributor
timestamp: March 23, 2025, 08:41:01 pm
content: Quote from: TimFox on March 23, 2025, 06:51:51 pmI believe in the UK the regulator Ofgem forces them to pay compensation to their customers for lack of service. I wouldn't be surprised if in other countries they can be sued.

author: UnijunctionTransistor
author_rank: Frequent Contributor
timestamp: March 23, 2025, 08:49:40 pm
content: Quote from: TimFox on March 23, 2025, 06:51:51 pmThat is exactly what has happened to the Texas grid, and one of the reasons ERCOT hasn’t interconnected to either the Eastern or Western grids.After the disastrous 2021 near-total blackout, what was the Texas government’s response? Instead of passing legislation to require that the utilities have plans for those contingencies, it gave a tax-holiday to encourage the consumer to purchase emergency generators.In other words, place the burden of investment on reliability on the consumer, not the utilities. Typical Texas solution.

author: Stray Electron
author_rank: Super Contributor
timestamp: March 23, 2025, 09:07:04 pm
content: Quote from: UnijunctionTransistor on March 23, 2025, 08:49:40 pmCorrections added but yeah, otherwise I agree completely.

author: TimFox
author_rank: Super Contributor
timestamp: March 23, 2025, 09:08:17 pm
content: UJT: precisely.It is still true that there are three main power grids in the US: eastern, western, and Texas.Without connections across State borders, Texas avoids Federal regulations.(There are corners of Texas, for example El Paso, that for geographical reasons are part of interstate grids, and therefore avoided the big problems of 2021.)Stray Electron: In many ways, including ones that it is proud of, Texas is not typical of the US.

author: Analog Kid
author_rank: Super Contributor
timestamp: March 23, 2025, 09:09:43 pm
content: Quote from: UnijunctionTransistor on March 23, 2025, 08:49:40 pmHmm; reminds me very much of Enron some decades back ... and we know how well that ended up.

author: floobydust
author_rank: Super Contributor
timestamp: March 23, 2025, 09:44:49 pm
content: Where this all ends up I think is forecast by UK water companies:Maximize return to investors, sewage dumping is fine, max. out loans, and um er sorry the infrastructure has not been maintained and too bad we're broke. We just have to increase rates!MBA: Literally run everything into the ground, suck all the cash out and cry for more loans, bailouts etc.This is all fine as a business greed strategy but the infrastructure repair bill left behind... goes entirely to consumers in a bad way.Thames Water Co. - They just secured $3.9B to prevent financial collapse. Even if it gets (re?) nationalized that massive debt in the form of non-maintained infrastructure only goes to consumers.National Grid own infrastructure in the UK and USA (20M customers NY and MA)? Who's paying for that nice shiny new transformer? Their stock looks fine lol.

author: TimFox
author_rank: Super Contributor
timestamp: March 23, 2025, 10:38:35 pm
content: Quote from: Analog Kid on March 23, 2025, 09:09:43 pmSome day, someone will explain to me what Enron was purportedly doing while they perpetrated the fraud that finally brought them down.(They were up-to-date on their payments for naming rights on the baseball stadium for the Houston Astros, when the team cancelled them.It was suggested to rename it after someone less hated, such as Osama bin Laden, but they switched to Minute Maid, the orange juice owned by Coca-Cola, thereafter changed to Daikin, the air-conditioner manufacturer.)

author: UnijunctionTransistor
author_rank: Frequent Contributor
timestamp: March 23, 2025, 11:31:01 pm
content: Something less hated

author: TimFox
author_rank: Super Contributor
timestamp: March 23, 2025, 11:55:15 pm
content: An interesting precedent for the Enron scandal was Equity Funding Corporation, which collapsed in 1973.Starting in 1964, they had been seriously inflating their portfolio of outstanding insurance policies, using computer fraud.Apparently, when they started the creation of fictitious policies, the usual auditors were not good at detecting problems on the computer system, as opposed to hardcopies.The fictitious policies were sold to reinsurers, and the premiums were paid by issuing more fraudulent policies, up to maybe $500 million.(Bin Laden was a "someone".)

author: floobydust
author_rank: Super Contributor
timestamp: March 24, 2025, 12:17:37 am
content: Elizabeth Holmes' father worked for Enron as VP, for a while...Another group of parasites are energy traders. They can buy/sell electricity in the future- but I can't as a consumer.Electricity price here goes up 10x during high grid load (hot/cold weather) or supply shortages (generator offline for maintenance, no wind, no solar at night etc.) to $1/kWh.For the life of me I can't figure out why so many leeches are involved in the electricity industry, we allow it, we pay for it, grid continues to decline - when it's an essential service to a nation.

author: Gyro
author_rank: Super Contributor
timestamp: March 24, 2025, 10:31:59 am
content: Apparently Heathrow did have sufficient power available on Friday via two other substations (so it is supplied by three in total, which seems like reasonable power network redundancy). The issue seems to be more about how Heathrow's systems are able to deal with loss of one of its feeds - changeover, loss of systems, bringing them back up, safety verification etc.Quotehttps://www.bbc.co.uk/news/articles/cdjy4m0n1exoOh dear, that damning 'full confidence' phrase, that never ends well.

author: tom66
author_rank: Super Contributor
timestamp: March 24, 2025, 11:30:59 am
content: Pretty bad that they couldn't get the incoming feeds swapped over in time to keep critical systems going. I know someone who works at a critical infrastructure datacentre and they have this sort of thing nailed down, their UPSes give them about 5-10 minutes, enough time to get the diesel generators going, they have fuel on site for 48 hours off grid, once the outage is more than four hours long an automatic order for new diesel goes in and a tanker arrives the next day. It pays to do this because they had workmen up the road cut into the ring accidentally and it took the DNO more than eight hours to get power restored to the area. They were the only building with power still on for that whole site, a warehouse up the road with frozen food in it had to dispose of tonnes of product as it had defrosted.I would have expected somewhere like Heathrow would have sufficient generators scattered around the site to keep everything bar perhaps non-critical lighting and air conditioning going during an outage. And they should have drills to simulate what happens when feed X, Y, Z goes off, how well does the site respond to that, what mitigations are required?

author: Jeroen3
author_rank: Super Contributor
timestamp: March 24, 2025, 11:48:14 am
content: It looks like this specific substation, North Hide, is not part of a ring.https://webkaart.hoogspanningsnet.com/index2.php#12/51.4881/-0.3938

author: themadhippy
author_rank: Super Contributor
timestamp: March 24, 2025, 12:09:45 pm
content: QuoteHave you read any of the reports? if you had you'd realise they did have generators and ups to keep critical infrastructure going,the problem seems to be bringing the lost transformers load onto the remaing 2 supplys.

author: tom66
author_rank: Super Contributor
timestamp: March 24, 2025, 01:30:04 pm
content: Quote from: themadhippy on March 24, 2025, 12:09:45 pmThat's not what has been reported though is it? It was stated that they didn't have enough backup capacityfull stopto keep infrastructure going, other than the most critical infrastructure like runway lights:Quote from: the BeebLater, the Heathrow boss stated it is impractical to have such backups (which is really not true: 10MW+ backup solutions do exist for hospitals and the like.) I'm not sure why, but it seems they assumed that they'd be able to fail over to the other supplies and for some reason that didn't work, perhaps their automatic changeover gear was faulted or perhaps they'd never tested it. It seems once power actually switched off it broke a lot of infrastructure, which itself is bad (a facility -should- be able to cold start pretty quickly; yeah, there will be downtime, but 18 hours is pants.)

author: Monkeh
author_rank: Super Contributor
timestamp: March 24, 2025, 01:57:39 pm
content: Quote from: tom66 on March 24, 2025, 11:30:59 amThey did. Critical systems are air and ground traffic control, runway lighting, security controls. Not baggage handling, terminal main lighting, air conditioning, escalators, lifts..Heathrow would need something on the order of 240MWh of battery storage, capable of putting out upwards of 60MW. This would then need to be distributed across the site. Cost? Hell, I don't work in this industry, but it's at an airport and in the UK, so high. More than a once in 50 years outage?What happens if one of those several fairly large battery banks suffers a fault and fire within the perimeter? Is that more likely or less than a transformer fire?The real question is why did the entire airport need shutting down, not just affected terminals? Is the power setup that mixed for some reason, were they overcautious, do they have perhaps computing infrastructure which is centralized and not suitably supported?E: Embarrassing typo..

author: tom66
author_rank: Super Contributor
timestamp: March 24, 2025, 02:52:49 pm
content: Quote from: Monkeh on March 24, 2025, 01:57:39 pmThere's a difference between life safety (if this goes down planes will crash) and critical (if this goes down we can't do airport stuff) though. WHSmiths going dark isn't a big deal, people will just have to buy even more overpriced sweets on the plane. Baggage conveyors and check-in desks going offline is a big problem because then planes can't depart.It would be pretty normal for non-essential lighting and air conditioning to be on a non-backed up supply, so the terminals might lose some amenities, but it wouldn't put everything out of service, and crucially even if it did mean they had to halt movements through the airport temporarily for passenger safety, they could get up and running a lot quicker than 18 hours.They'd probably need somewhere around 10MWh of battery storage to provide 'critical' backup power before conventional generators took over based on a 3C discharge rate for a typical UPS. A Tesla Megapack is about the size of a 40ft shipping container and stores 3.5MWh and can output 7MW peak. So they'd need 4-5 shipping containers worth of battery storage, distributed around the site. Generator wise, a 10MW diesel generator can also fit within a shipping container. They also had on-site CHP which can power and heat Terminal 2 entirely, apparently, but that did them no good during this outage.Having this backup power does not sound impractical for a major airport. Expensive? No doubt. But when the airport is so very critical for the transit of a quarter-million passengers every day, it's something you want to be as robust as possible.Quote from: Monkeh on March 24, 2025, 01:57:39 pmProbably very unlikely if LFP packs are used, which is where grid storage is going nowadays. With NCA it's a higher risk, but an airport would be experienced with putting out jet fuel fires from plane crashes.Quote from: Monkeh on March 24, 2025, 01:57:39 pmIndeed, although it's unclear whether each terminal gets its own feed from the grid or if Heathrow is effectively its own private DNO. Gatwick owns its own 11kV network (it's subcontracted out to a DNO for maintenance, but they own and are fully responsible for it.) I couldn't find out information on how Heathrow manage theirs, but it's possible that there is only one point at which grid power is connected into this local network and therefore a failure of grid supply takes all terminals out, as appears to have happened in this case. If the facility was truly independently fed from the grid in three locations, you'd expect, say, Terminal 4 and 5 to remain operational whilst 1/2/3 are offline, but that didn't happen.

author: fourtytwo42
author_rank: Super Contributor
timestamp: March 24, 2025, 03:56:54 pm
content: In a nutshell no foresight, no planning, no practice and when the chips are down they just panicked as they had no idea what to do! Now we are just getting the rearguard PR stuff excusing themselves apparently by stating that anybody else would be just as bad........really!!I was involved in various non-stop systems and we never had a problem making such things work, it is common known technology.Obviously Heathrow has a serious management problem, maybe they could get some cheaper competent individuals.

author: floobydust
author_rank: Super Contributor
timestamp: March 24, 2025, 04:50:48 pm
content: National Grid exec saying there is "enough power" but there ain't no brain powerIt takes minutes to redistribute load on the grid. Our one control room is an entire wall that is multiple huge screens, and computer software easily looks at the mesh and move load around without causing grid collapse. It's not like a gnome has to ponder over it for a day.Two other substations with capacity? What about Heathrow's feeder... was it only going to the Hayes sub, you know the one with the fire...It's massive CYA with these execs (who command multi million$ paycheques) and nobody wants to be the fall guy for this.Nevermind Heathrow having emergency generators but they didn't land a single plane? What's the point of them?In facilities with UPS or emergency generators, mains wiring gets complicated because you have multiple power systems. For example the plant UPS should only power safety-critical loads, not the lunchroom kettles and microwaves. Over the years electricians don't care and will just run outlet feeds from anywhere.A huge problem is testing any of this. Nobody wants to switch off the breaker, turn on the fire suppression system etc. it's just too high risk.One power plant here I worked in 2x430MW there was switchgear explosion in the substation and the plant lost incoming mains. Then the big UPS did not start up, it was dead, didn't work. This thing the size of an office building a few floors and the battery room too. UPS was never tested beyond the day it was commissioned.The power plant needed station power to start up. So they were out of power for days which was really bad as the DCS controllers required batteries for their DRAM, only a few hours life. This same controller used in nuke plants as well.So the PLC's, DCS etc had no emergency power, batteries went dead erasing their S/W. Power plants can't start/run without grid power from somewhere else.

author: IanB
author_rank: Super Contributor
timestamp: March 24, 2025, 05:11:05 pm
content: So let's suppose the airport has independent power feeds from different substations. Can all feeds be energized at the same time, or would that result in back-feeding one substation from another? And if only one feed is active, switching over to another would require first isolating one feed and then activating the other. And if you wanted to test that this works, you would need to do a switchover drill from time to time? And such a drill would be disruptive to operations? Unless you did it during off hours in the middle of night, which I suppose is possible.

author: AVGresponding
author_rank: Super Contributor
timestamp: March 24, 2025, 06:05:42 pm
content: Quote from: IanB on March 24, 2025, 05:11:05 pmYes, they can, and should, be energised at the same time, but the two alternative supplies should be behind time-delay changeover contactors (big, orverybig, relays), that are set up to switch only when the mains drops out for more than a set time.The important IT stuff should all be behind UPS's capable of supporting the load while changeover happens. The unimportant stuff (normal lighting, kettles in staff canteens etc) just has to deal with having no power for a few seconds, maybe up to 30 seconds or so, depending on the timings. Generators normally are only used when the mains drops out for a sustained period (30 seconds, 2 minutes, or whatever, it varies), as you don't want them firing up and switching off a lot if you've got a supply that drops out for a couple of seconds regularly (like when major grid works might be underway and they are switching betweeen supplies upstream).They should be testing pretty regularly; em lighting regs say you have to do a functional test weekly, and a duration test yearly. I would expect a responsible PPM regime to have similar requirements for mission critical stuff, though I don't know the regs, if any, on this particular case.It's common to test emergency systems during night time, for buildings/complexes that run seven days a week.

author: floobydust
author_rank: Super Contributor
timestamp: March 24, 2025, 06:11:29 pm
content: "As you know", there is a shortage of brains including the guy who coined that phrase...In substations, it is routine to switch to the alternate feeder/breaker/transformer etc. for repairs and maintenance. Their component/bus structure has redundancy - but not in the middle of a massive fire. Then they must isolate the nearby buses but the "shut everything off" approach is what they went with. (It was strange press said the Hayes substation still had some power present. I feel for the firefighters who must have been terrified.)Any (facility level) testing is very risky as any mistake or unexpected outcome will cause lights out and some poor schmuck gets thrown under the bus for it.The money flow must not be interrupted. Down time is never is allocated for these kinds of big tests. The result is nobody willingly does these tests live, end-to-end, ever. They are avoided in critical facilities such as airports, hospitals, power plants etc. They will test only bits and pieces.Dual feeders to a facility I don't remember seeing. It's one line and then backup generators to give coverage for the line failing, as I've seen with hospitals.How was substation 2 or 3 to feed Heathrow when substation 1 is on fire? Where are the feeders/breakers for this? Located in sub 1 on fire? they aren't usable. These must be another switchyard or else this entire design is bullshit out of the mouth of National Grid CEO.A redundant feeder/substation system fails if the facility can't properly isolate.With dual feeders to a facility, there is a bus-tie breaker that is typically open. Otherwise you can get reverse power flow unexpectedly if there are grid problems somewhere else and the feeder from one sub becomes a load. This usually causes an overload of sub 2 and it trips and lights out. I don't know if phase difference between subs is an issue as well.We haven't seen the other end of this debacle, I'm not sure how many transformers/feeders Heathrow has in it's distribution electrical scheme.

author: Monkeh
author_rank: Super Contributor
timestamp: March 24, 2025, 07:02:12 pm
content: Quote from: tom66 on March 24, 2025, 02:52:49 pmTo be fair, as far as I'm aware this is the only time this has occured in the near 80 year operational history of the airport. Is it reasonable to spend that sort of money, which ultimately comes at the cost of every passenger and every recipient of cargo, to cover a one in what, 20,000 chance? What's the installation and maintenance cost over the next, say, 25 years vs the loss of one day of service? They're a business, remember, and one with an effective monopoly - they care not how it affects you, only the profit margins in the end.You're right, though, I was considering battery backup only while they did changeover, in practice you only need to cover long enough for generators to warm up to take the load, so I probably overestimated the storage (but not the AC generation, obviously) by an order of magnitude or so. My bad.QuoteI recall, but I'm not in the mood to source specifics, that at least one terminal was still powered. I've also heard vague mentionings of one of their own transformers being out of service at the time, so perhaps they were configured with less optimal distribution than normal (and North Hyde was operating past normal capacity at the time..).Somehow, I doubt we'll ever get any specifics, just vague mumblings about improving training and redundancy and how expensive that is, while all the ticket prices go up a bit more.

author: TimFox
author_rank: Super Contributor
timestamp: March 24, 2025, 07:05:00 pm
content: This is an example of the economic calculation (including probability of failure per time) that determines the rational level of investment in redundancy for a given level of penalty.

author: NE666
author_rank: Frequent Contributor
timestamp: July 02, 2025, 09:01:11 am
content: "Issues at an electrical substation which caused a fire that resulted in Heathrow Airport closing were first detected seven years ago but not fixed, a report has found.The National Energy System Operator (NESO) said moisture entering electrical components at the North Hyde substation caused the blaze at the site that supplies the UK's biggest airport with power.It revealed an elevated moisture reading had been first detected in July 2018, but the issue went "unaddressed" for years, with basic maintenance by National Grid cancelled."- BBC News, June 2nd. (emphasis mine)NESO Final Report:https://www.neso.energy/document/363891/download

author: NE666
author_rank: Frequent Contributor
timestamp: July 02, 2025, 09:21:12 am
content: TL;DR- "A catastrophic failure on one of SGT3’s high voltage bushings caused a fire to ignite on SGT3.This was most likely caused by electrical arcing as a result of moisture ingress in the bushing."- "SGT3 had been automatically disconnected from the network by its protection systems. These protection systems operated as expected, isolating the power supply in approximately 110 milliseconds to prevent further electrical hazards."- "fire on SGT3 resulted in damage to one of SGT1’s high voltage bushings and marshalling kiosk. Its protection systems operated 28 minutes after SGT3 tripped. This automatically switched SGT1 and SGT2 out of service; SGT2 was connected to the same high voltage circuit supplying SGT1. This resulted in the loss of all supplies at North Hyde 275kV and 66kV substations."- "North Hyde 275kV substation was built in 1968, by the Central Electricity Generating Board, with limited physical distance and no fire barrier in place between SGT1 and SGT3."- "The July 2024 fire risk assessment stated that if a fire started on any of the three supergrid transformers, ‘it would not be suitably suppressed’. As a result, a high priority action was created on the pump of the water mist system to be appropriately serviced and maintained. That action remained outstanding at the time of the incident, in March 2025. National Grid Electricity Transmission stated that it was planning a combination of replacements and refurbishments of the fire suppression system by October 2025"

author: NE666
author_rank: Frequent Contributor
timestamp: July 02, 2025, 09:22:58 am
content: (TL;DR)2"Coulda, woulda, shoulda"

author: Jeroen3
author_rank: Super Contributor
timestamp: July 02, 2025, 10:42:11 am
content: Component was failed in 2018 lol, this smells like it's soaked in incompetence.Was is also never checked again since then?QuoteThis is also do not understand. Even if some tie-breaks require to be manually operated, assuming qualified people are on call, can be done in a few hours tops, right?I mean, when you design your network to havethreesources, you must have redundancy as a priority, otherwise you'd just have one or two.But did it just stop there? Why, how... Questions...

author: SteveThackery
author_rank: Super Contributor
timestamp: July 02, 2025, 11:05:32 am
content: Quote from: NE666 on July 02, 2025, 09:21:12 amThis is a perfect example of a "common mode failure" - the type of thing we Reliability Engineers get overexcited about. Fire is a very common mechanism for cascading failures across all the elements of a redundant system, which is why the need for mitigation (ie fire suppression) is well understood. Obviously not considered important enough, in this case.

author: themadhippy
author_rank: Super Contributor
timestamp: July 02, 2025, 11:07:29 am
content: Yet another example of a public service diverting the money we pay to supposedly maintain the infrastructure into shareholders pockets,our water industry has been getting away with it for years,

author: tggzzz
author_rank: Super Contributor
timestamp: July 02, 2025, 04:54:20 pm
content: Quote from: SteveThackery on July 02, 2025, 11:05:32 amI remember the Browns Ferry Nuke Plant incident that very nearly became a Fukushima. Everybody remembers that the incident was caused by acandle, of all things. Few people remember how the control cables were (mis) routed...What will the fire mean for other nuclear plants? That depends on whether the NRC carries out the recommendation made by the Factory Mutual Engineering Association of Norwood, Massachusetts, the fire underwriters the NRC engaged as consultants:Quote from:http://www.ccnr.org/browns_ferry.html#leTranslation: don't route redundant cables in the same tray; try to use separate conduits!

author: floobydust
author_rank: Super Contributor
timestamp: July 02, 2025, 08:11:06 pm
content: It's best to run an asset right into the ground. This keeps repair costs low and ensures your executive bonus is secure. Maximum profit is essential.Transformer blows, oh well we'll review our oil testing. Thanks. We got an extra 7 years out of it. National Grid.Transformer fails, it should have tripped the breaker but no- the protection gear must also be old. It's usually as old as the transformer (57 years) because upgrades are expensive and make the scorecard look bad.Moderntransformer protection relays would not have let it arc long, to this scale of fire. BUT they need PT's and CT's and installation, commissioning etc. which is costly- so it will get deferred until the transformer is replaced at EOL which is usually because its capacity is too low due to grid load growth.I'm saying they'll only replace the transformer as a big project to upsize it as well. There is room right next to it in the substation pics.Then the project costs are considered a grid upgrade and passed onto the rate payers. Free transformers!

author: Terry Bites
author_rank: Super Contributor
timestamp: July 04, 2025, 02:33:37 pm
content: I was brought up in the shadow of a substation. I think it peaked my interest in all things leccy and pushed me into my first Bond villian project. (Very sexiful)When I was a kid I woke up in the night thinking that the aliens were landing in the allotments. Bright blue and purple light, sizzling, ozone, dogs howling, women screaming the works.It was chilling. I got ready to greet them, I was ready for something wonderful to happen.Infact a post insulator had worked its way loose letting a 132kV cable flap around in the breeze. The fire brigade turned up and said sod that for a game of soldiers.It was two hours before an LEB bloke showed up in a morris minor and said sod that as well.More recently (for me) the same place blew up even more spectacularly> news.bbc.co.uk/1/hi/england/london/7443326.stmA would be terorist cell could bring this country to is knees by attacking a few strategic utility nodes.To prevent this the national grid have a high security top secret control room located at:Warwick Technology Park, Gallows Hill, Warwick, CV34 6DA tel. 0800 096 3080.As you can see, they've well hidden it in those bushes. The armed guards are on a break watching tellitubbies.I'd cut of their power for starters.https://www.google.com/maps/@52.2735411,-1.5649634,3a,88.3y,311.37h,89.62t/data=!3m7!1e1!3m5!1s3FRaDxljL2wbq6Aqlzkeuw!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D0.38130114550882865%26panoid%3D3FRaDxljL2wbq6Aqlzkeuw%26yaw%3D311.36968063346325!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI1MDYzMC4wIKXMDSoASAFQAw%3D%3D

author: MrMobodies
author_rank: Super Contributor
timestamp: July 09, 2025, 08:34:45 pm
content: https://www.bbc.co.uk/news/articles/ce8ze69ye4poQuoteWhen passengers become irate due to overcrowding and delays lets calm them down with some music.. NO!Douse out their noise and frustration to hide the extent of future failures and make the airport sound more pleasant.The passengers may just want to check their ticket out and board not be bombarded with false illusions in the form of audio like when they walk in some nature reserve park or building with speakers everywhere trying to imitate things they don't have.At a busy airport where it is crammed I don't think they'd be wanting to listen and pay attention to sounds in over crowded conditions especially with delays when they are waiting for their fight to be called.What about those it annoys by hearing the sounds closer than what the machinery makes?Do you think this could be an insult on the passengers?Shouldn't they be investing in backup systems and staff to help in emergenciees than hire someone to showcase these false audible illusions.What if the planes were all suspended and the passengers hear what they think are planes taking off how would that sound and if they challenged the airport staff?Sounds very stupid to me, waste of money and out of touch.The music maybe in a smaller airport that does not experience much delays or failures might be soothing where the customers do not get irate as a result.What do you think?