Runway melts at London Luton airport as temperatures in UK near 40°C | Hacker News Reader

Runway melts at London Luton airport as temperatures in UK near 40°C

dailytelegraph.com.au

257 pointsrussfink363 comments

Even more unusual are the grass fires so close to London.

Seeing people's homes destroyed is so tragic, particularly as I bet they would never have thought this would be an issue here in the UK.

Sky News have some astounding[0] footage[1]:

[0]: https://www.youtube.com/watch?v=7NP7GF8xS5g

[1]: https://www.youtube.com/watch?v=TjBV4R18ICY

...and before the rest of you jump in saying this is regular in your country, please note that it is NOT regular here in the UK. Today, the UK has seen the highest temperature in ITS recorded history.

I saw the second video yesterday, but I found it interesting when watching it, because I also was looking at Google Maps to see where it was.

https://youtu.be/TjBV4R18ICY?t=255 (4m15 on your [1]) shows a lot of destroyed buildings and we're left to imagine that these are houses as it later cuts to images of houses and fire engines. But actually, if you look on Google Maps, you can see that it's actually a fireworks factory, a fairly important detail that was missed out.

You can see it yourself at: https://www.google.com/maps/@51.4680241,0.2185786,453m/data=... the same layout of buildings and the label "Wells Fireworks Factory" in the centre of it.

I found it interesting when reading your post, because I was also looking at Google to learn more about the factory.

You can see it yourself[0] the fireworks factory was closed and abandoned in the 70s. A fairly important detail that was missed out!

Not sure what the motive behind your message was, but peoples' homes were indeed destroyed in these fires[1]!

[0]: https://www.remotelondon.com/wells-fireworks-factory-dartfor...

[1]: https://www.itv.com/news/london/2022-07-19/major-incident-de...

Oh good find. I know nothing about the history of the fireworks factory, but assumed it was still in use if it's labelled on Google Maps. It seemed likely that with such a use, this area would in fact be at higher risk than the surrounding grassland, and I wondered if maybe that was the source of the initial fire.

And yes, I had seen later footage of actual houses destroyed, and it wasn't my intention to take away from that, I just saw something that seemed interesting and overlooked. But, if the site has been abandoned for half a century, that is unlikely, so my speculation is moot.

But a lawn fire is not directly temperature related, is it? I suspect the grass has dried from lack of rain, such that some small spark that would ordinarily have fizzled has taken hold.

As a former wildland fire fighter, I can assure you that temperature (and wind and relative humidity) have a HUGE effect on fire behavior. Furthermore temperature and relative humidity (not so much wind) have a huge impact on ignition. My training emphasized this quite heavily, but I thought the effect was exaggerated until I experienced it first hand.

In the Western US, construction, mining, forestry, etc. industries are well aware of the fire risk from routine work (construction equipment, off road vehicle traffic, chain saw work, etc.). In "red flag" conditions, there are fire watch policies. For example in forestry work, my crew would have to cease chain saw work late in the morning and stand a fire watch for 30 minutes before leaving the work site.

So as I watch the news about these fires, my first thought is ignitions: routine activities (parking a vehicle on grass, driving construction equipment, discarding a cigarette) that would be unlikely to cause a fire in normal (backward looking) UK weather conditions. My next thought is that once a fire has started, it is likely to burn hot and fast. Hotter and faster than I suspect fire fighters in London are accustomed to.

As an aside, I have been trying to figure out a good source for weather data. I see plenty of sources for temperature, but I am curious about the wind speeds and relative humidity. From the photos I am seeing, it looks like wind speeds are over 10 mph.

^ this is why we come to hacker news. Deep contextual comments from knowledgeable professionals. Thank you.

In Australia during droughts there are reminders to not throw cigarette butts out the window of cars. Lightning also plays a large role in starting fires, but I also recall, as a child, being told that rubbish (litter) such as bottles and cans can reflect the harsh sunlight in a focused way and cause an ember.

I recall not buying a diesel mazda car because it had a disclaimer about not parking on long grass because of the danger of starting a fire. Apparently, mazda finally made it to recall status:

https://www.abc.net.au/news/rural/2017-12-29/ford-rangers-ma...

From the owner's manual⋮

> Parking over or near anything flammable, such as dry grass, is dangerous.

https://owners-manual.mazda.com/gen/en/cx-5/cx-5_8gj1ee18b/c...

You could try the Met Office website. This is a station in North West London

https://www.metoffice.gov.uk/weather/observations/gcpvj0v07

Humidity was about 15-20% during the afternoon, winds 13 gusting 26mph.

> But a lawn fire is not directly temperature related, is it?

The rate of evaporation is directly related to the temperature. Even ignoring additional factors affecting evaporation like wind and topographic variance in dryness, the vapor pressure of water (the biggest contributor to evaporation rate) at 40C is an order of magnitude higher than it is at 20C:

https://en.wikipedia.org/wiki/Evaporation#/media/File:Water_...

Sufficient subsequent days of high heat and low humidity will dry out a lawn very quickly, as grass is a plant that is not adapted to retain moisture very well.

With hot/dry enough conditions for a sufficient period of time and a bit of kinetic energy in the form of wind, grass that isn't watered quickly becomes flammable, which is why it is usually where large fires first take hold.

The lack of rain comes from the same climate emergency though, this has been confirmed scientifically as well.

Not sure why you’re being downvoted. Weather patterns like droughts are exacerbated by climate change. Heat waves are known to make it easier for fires to catch and spread. Heat waves are more common now due to climate change. Thus climate change makes fires more likely/common. It’s pretty straightforward.

The ‘lawn fire’ that burned a village today started in a compost heap. Heat was categorically a factor.

Together with the heat the compost pile spontaneously ignited. They went to get a hose to douse the smolder, but by the time they got back wind blew embers into dry grass, and woosh.

A rare combination of events can cause a compost pile to catch fire. These all must be met before the occasion arises.

- The first is dry, unattended material with pockets of debris mixed throughout that aren’t uniform.

- Next, the pile must be large and insulated with limited airflow.

- And, finally, improper moisture distribution throughout the pile.

Key to preventing any issues is proper maintenance of your organic matter to prevent hot compost bins or piles.

https://www.gardeningknowhow.com/composting/basics/overheate...

If one pours gasoline all over the floor, yes, a match needs to be lit. But the gasoline all over the floor raises the risk of a disaster.

It’s not like it would dry out quicker

While the right wing media in the UK ignored the climate crisis in their coverage and instead focused on the “positive” side with front pages full of children eating ice cream and people at the beach.

Weather is not climate though.

It really isn’t. People commonly think that the climate warming by a degree means that the weather warms up by a degree.

However, there’s a good 100 miles of air above us, and that mass of air warming by a degree means that it can now retain a LOT more humidity before it starts precipitating as rain.

This means coastal areas get drier and hotter, while mountaineous areas get much more rainfall (and more of it as water instead of snow), as well as flooding, mudslides, etc.

Yes, but do you think many parts of the world setting new heat records year after year is just weather, or climate-related?

The point is moot,because the right wing channels are downplaying[1] the current extreme weather like it's no big deal - not just climate-change

1. https://twitter.com/MrMatthewTodd/status/1548353724086530049

The automated weather broadcast at Yuma airport in Arizona reports the runway temperature. Yuma is a joint civilian/military use airport and some fast jets have a surface temperature limit for their tires. I was there doing some flight test work once and it was reporting 160F, it wasn't even a super hot day.

In case anyone is curious why tarmac gets so hot:

> The rate at which an object can reflect solar radiation is called its albedo [source: Budikova]. The bigger the albedo something has, the better it reflects radiation. Traditional asphalt has a low albedo, which means it reflects radiation poorly and instead absorbs it.

Asphalt has an albedo of ~0.05 - which means it absorbs ~95% of solar radiation. Tarmac is ~0.1 - which means ~90%.

I didn't know there was a difference between the two!

> Asphalt is a mixture of aggregates and bitumen that needs up to two days before it completely cures. Whereas, Tarmac is a combination of crushed stone and tar that cures quickly.

https://tarmacdriveways.ie/key-differences-tarmac-vs-asphalt...

From your link I learned that tarmac is short for tarmacadam, named after John Macadam, who is also the name-origin for macadamia nuts.

https://en.m.wikipedia.org/wiki/John_Macadam

That is incorrect. John McAdam[0] has the name for tarmac, while John Macadam[1] has the name for macadamia nuts.

0: https://en.wikipedia.org/wiki/John_Loudon_McAdam

1: https://en.m.wikipedia.org/wiki/John_Macadam

And there's a name that became a French word there: macadam https://fr.m.wikipedia.org/wiki/Macadam_(route). Thank you both parent and GP for the history/etymology lesson.

Interesting! I often wondered while sitting on a runway, if tarmac was so good, why don't we get any? It's just at airports!

Strangely, you don't sit on Tarmac, even on a runway. Airport ramps, aprons and most busier runways are paved with high strength concrete.

And then you have other factors impacting a surface temperature including:

rainfall (you could probably spray the runway and it will cool down and be dry quickly…)

Length of day (we’re about 1 month past the summer solstice in the N. Hemisphere, and days are long in the northern latitudes)

Shade (unlikely on runways, they’re in the sun all day)

Wind (probably best anywhere on a runway unless it’s in a valley)

Cloud cover during the night: can’t radiate to the universe where it’s about -273C if clouds are in the way.

Can you clarify how night cloud cover factors in? Do clouds really substantially reduce the radiative cooling capacity? Is that by functionally reflecting radiation back at the source (the earth)?

Broadly yes. It's why deserts have such extreme temperature fluctuations between day and night. No clouds are part of the reason, as well as very little humidity to serve the same heat-retaining/heat-reflecting role.

On my first time in the Nevada desert I was astonished to find that I needed a jacket at dawn to stay warm, after all kinds of daytime heat. Looking at Elko NV's weather this week, it's got highs of 99F/37C and overnight lows of 61F/16C

Radiation is a function of the temperature delta between two points.

The sky around where clouds are might be around -20C, while outer space is at -273C or so, so you get much more radiative heat loss in the latter state (clear sky).

(This is also why you’ll see gardeners try to cover their plants when there’s a “frost warning” even though the temperatures won’t be going below freezing).

And from the opposite perspective, the sun is really far away but incredibly hot, so it transfers heat to us, and more as you get closer (and less as you get further away).

Anyone out there trying to figure out white tarmac/asphalt?

Probably not the wisest idea to have a highly reflective material as the landing surface for planes humans are flying.

You can make runways out of concrete.

Probably absorbing heat quickly is good for cold climates, to keep warm on cold days. It might prevent ice buildup on days near freezing.

Surely there must be a way to cover tarmac and asphalt with a specially developed white paint to raise albedo to prevent melting.

How much would putting mirrors on the earth affect climate change? How large a mirror would you need to make a difference?

The most cost effective mirrors to cover a large fraction of the Earth and reflect back the sun's heat are... the polar ice caps. Which we are melting because of climate change.

This is one of the main reasons people are so worried about it being "too late" to fix climate change. There are positive feedback loops like this where a little increased heat causes even more rise in temperature.

Practically, high albedo materials (essentially they reflect a lot of light but aren't necessarily mirrors because they do scatter the direction of that light) can reduce building's HVAC energy consumption. They can also effect city level microclimate (mitigating the heat island effect).

It takes a lot of high albedo area to effect the overall climate. For example, melting ice caps do decrease the albedo of parts of the Earth, accelerating climate change. Large scale increases to Earth's albedo in the form of space mirrors were seriously considered as options for global warming mitigation as late as the Obama administration. However, the risks of unintended modifications to the environment (e.g. crop failures, unpredictable weather) are generally considered too great. At present, space mirrors, with an estimated lifetime cost of $5 trillion for 50 years of cooling, could be a decent "last resort" option compared to the possibility of spending hundreds of trillions upfront to permanently solve the problem with carbon capture (although cost estimates vary widely based on the amount of CO2 that needs to be captured).

Other options include stratospheric aerosol injection (https://en.wikipedia.org/wiki/Stratospheric_aerosol_injectio...) which could minimize the effects of climate change for as little as $55 billion/year, and marine cloud brightening (https://en.wikipedia.org/wiki/Marine_cloud_brightening), which could cost as little as $5 billion/year. Possible side effects might include ozone depletion and acid rain for aerosols. Marine cloud brightening could cause weather changes.

So yes, you could manipulate albedo but it will always come with side effects and costs.

Yes, in other words: the darker a thing is, the darker it is. Is someone here actually suprised by the everyday phenomenon that dark objects get hotter than light-colored ones?

(Edit: I apologize for the uncalled for smugness. But "albedo" is not some special physical quantity, it's literally a measure of how light/dark colored a material is. "Alba" is Latin for "white". Although granted, albedo is usually measured across the whole spectrum, not only the visible part.)

Not necessarily true. It depends on the object's optical properties.

I well remember working on my parents' car in Phoenix summers. The chromed wrenches on our driveway surface got to instant-blister temperatures. Tools with black surfaces were uncomfortable to pick up, but were usable.

The chromed tools had a lower absorption of sunlight than the black tools, but their IR radiation coefficient was even lower. So equilibrium temperature (at which radiated energy = incident energy) was much higher for the chromed tools.

No need to be an asshole about it. Some folks probably don't know the relative darkness of asphalt and tarmac.

Snow can have an albedo lower than 50% - and non-white sand can have an albedo higher than that.

It's not as simple as color.

In particular, there are dark things that have an albedo higher than asphalt's 0.05...

Dark will get hotter in sunlight but can be cooler at night if the sky is unobstructed.

The difference between "not surprised" and "understand why" is vast. For example we (humanity) still don't understand _why_ gravity works despite not being surprised by its existence.

And don't forget the 10,000 rule: https://xkcd.com/1053/

https://xkcd.com/1053/

They probably use a different ~~tarmac~~ material composition for the runway.

Luton is all asphalt. The long runway at Yuma is concrete and the shorter ones are part asphalt part concrete. And they likely chose the asphalt formulation appropriately given that they’re in the middle of a desert.

I would expect their asphalt being a lot harder and more heat resistant than the one that let my motorcycle fall multiple times in the past years because it melt during summer heat. I clearly wouldn't expect airplanes wheels to "sink" into asphalt like my bike stand, but they need a strong grip when braking during landings which I doubt a much softer surface would offer. Not an expert though, just speculating.

A softer surface would give more grip, not less. In fact it would give so much grip that it starts to adhere to the tires.

Have Yuma temperatures actually changed that much? A quick check suggests that the level of change is much smaller than that in the UK. Climate change has increased the extremes in the UK quite significantly in the last 40 years. It's a case that the changes in extremes are not accounted for in UK planning whereas Yuma is known to be consistently very hot.

I buy the 71 C ground temperature; ground temperatures can be 25-35 C hotter than the ambient air temperature, which is what gets recorded. This is also why rails buckle more than you'd expect: on a 40 C day, you're likely to see the rails heating up to 60-65 (as in, if you touch them, your finger will burn).

> ground temperatures can be 25-35 C hotter than the ambient air temperature, which is what gets recorded

Ground temperatures are almost entirely responsible for the majority of the thermal energy/temperature put into the air, down at the surface.

Also I'm sorry but the UK bloody loves a bit of weather melodrama. Climate change is a big problem but the specific effect of it on the UK in particular has honestly not been very bad at all yet. Tarmac has been melting in the heat here longer than I've been alive, which makes me suspect we use weak, crappy British tarmac. This was a little bit hotter than previous heatwaves, which is bad, but felt about the same and has also been really short - not sure what to make of that. However we scarcely get a weekend here without some "most (x) ever in (y)" fuss and haven't in 40 years which is really getting quite tiresome and making it harder to respect the real problems. I'll worry about it when I'm done drinking gin in the rain.

Not just the UK. It's been over 100º a lot of days here in Texas, and people from other places in the U.S. keep asking me how it feels, like it's a brand new and shocking experience. But from a perceptual perspective, it's normal. My perceiving brain doesn't do sophisticated statistics. It isn't a scientist. My brain's reaction to 100º+ weather is, well, this sucks but it's a familiar, age-old kind of suck. I spent time outdoors in 100+º weather every summer growing up, so I just don't make a gut connection between a string of hot days and my sense of fear and urgency about global warming.

> really getting quite tiresome and making it harder to respect the real problems

I agree that it trivializes and undermines the real problem of global warming. People have this false implicit assumption that if global warming is real it must be possible to immediately perceive it, and instead of challenging that, we keep trying to inject drama and danger into familiar experiences, and it just rings false. On a subconscious level, I suspect we all know it's silly. Also, what happens if it's not this hot next year? After spending 2022 essentially telling people that they can directly perceive global climate trends by walking outside, what will they think if the summer of 2023 is relatively cool?

I'm probably wrong, I'm not an expert in public opinion, it just feels false.

>most (x) ever in (y)

The hottest temperature ever recorded here isn't some niche thing like most rainy April for 5 years. Also maybe the fact that there's constantly new unusual weather should tell us something.

yeah lol not surprised. im in texas, not even as hot as arizona, and friends motorcycle kickstands have lowkey melted into ashpalt a few times.

I've been at Phoenix airport on a hot, but not crazy hot, day where the parking lot asphalt was tacky and stuck to your shoes.

Latitude of Yuma, US: 32.6° N

Latitude of London, UK: 51.5° N

To be clear they are talking about the air temperature rather than runway temperature and I've added the latitude so you can understand why it's a big deal that London has hit 40 degrees.

While we're picking random data points - Malillia (Sweden), at 57° N, set a record temperature of 38°C in 1947.

They are not random. Those are the two locations being discussed in the thread you replied to :)

Oh wow, that’s really interesting, was it just a freak event or part of a trend?

-> Hard to Say

That’s weird, some cursory searches show a definite upward trend for quite some time, i do find these weird sites where they consistently pick outliers in a dishonest manner. It really wouldn’t be worth engaging with them though

The Phoenix airport has to close down during peak temperatures on summer days because it exceeds the maximum operating temperature of the airplanes. Pretty cool.

Any reason that airports in super-hot places like that, don't run heat-transfer coils under their runways, to cool them down with a heat pump like a skating rink does? Runways aren't an order-of-magnitude larger in surface area than skating rinks, so it's not cost. And they wouldn't even need to turn on the heat pump for 3/4ths of the year. Do we just not know how to create heat-transfer coils that wouldn't break from the stress of planes landing "on" them?

Your comment fascinates me. A normal ice hockey rink is 1,800 square meters. The biggest indoor ice rink in the US is the Schwan Super Rink = 28,000 sqm which consists of 8 separate rinks.

Yuma's 4 runways total 543,000 sqm. At midday those runways are absorbing 543MW of energy from the Sun. So that might require 100-200KW of electricity to run the heat pumps. And then you still need somewhere to dump the heat.

In short, I think the reason they don't cool runways is due to the cost.

There's a ton of comments on HN like this. A quick brainstormed "why don't they just.." as if cooling a runway, building a subway, conducting space travel or doing anything else bound by physics is as trivial just because it is conceptually simple. Might as well ask why you can't ski in your backyard in London because after all it is trivial to add some pipes to your refrigerator.

Also I don't know of any skating rinks that operate outdoors in summer, or to use a more favourable example, something like lowering a surface temperature from 20C to -5C (an ice rink, indoors) vs lowering a surface temperature from 80C to 55C (an assumption for a runway, outdoors). Even Dubai, a major transport hub, much hotter than UK even this week, with cheapish energy costs, little public debate uses other mitigations such as runway materials and scheduling many takeoffs for 2-5AM (there are many costs due to high temperature besides runway degradation).

Then we wonder why when it's hot, it's really bloody hot at airports. Is that sum really right? that an airportsworth of tarmac is like a whole power station pumping its entire output into ground heat? because it looks right to me and it seems like the easy, sensible option is just to rip up the airport...

Isn't a large part of electricity production around making things hot to drive turbines?

Airplanes are very heavy so this may not be physically possible, but if you could run coolant pipes under runways, couldn't that captured heat be used in energy production elsewhere?

I’d just douse them with water. It’s not like UK airports and pilots can’t handle wet runway landings.

Hm. An Olympic ice rink is 30mx60m, or 1800m^2. The "largest ice arena complex in the world" (https://en.wikipedia.org/wiki/Schwan_Super_Rink) is 28,000m^2 but has 8 Olympic ice rink, sort of.

Yuma International/MCAS has roughly 540,000m^2 of runway (plus taxiways).

I imagine skating rinks in temperate/hot places are indoors and well insulated. Your solution would work well for an indoor runway.

> Runways aren't an order-of-magnitude larger in surface area than skating rinks,

International hockey rinks are 30m by 60m. My local airport, which isn't that big as far as these things go, has two runways each of size 45m by 2200m. That's 55x larger per runway.

They either use concrete or have different asphalt blends that handle higher temperatures.

Did it melt or did it buckle because of expansion?

Title says "melt" but the only quoted source in the article says "defect".

They found a defect, it has not melted. Another source:

> The RAF didn’t specify why it suspended flights, but a spokesperson said “the runway has not melted” as early media reports indicated.

https://www.cnbc.com/2022/07/18/london-flights-suspended-aft...

Yeah, the "melted" might be incorrect, however the quote from the Royal Air Force is about another (military) airport.

That quote is about Brize Norton Royal Air Force base in Oxfordshire, not Luton.

@dang could we have the link updated to a better source?

Yeah, The Sun isn't a great source. Reuters' title on this is "Flights briefly disrupted at UK's Luton airport as heat damages runway"

Huh? The Sun is clearly a great source of radiant heat.

Reuters headline yesterday had the “melted” language.

My adblocker is blocking the link got some reason.

Based on my experience with how airport operations work I suspect they noticed a defect on lesser pavement or a service vehicle with higher ground pressure than an aircraft left a dent somewhere on the runway and they then concluded that they should stop bouncing object that weigh tens of thousands of pounds off of the runway until it hardens back up lest ruts form there.

> The runway also “melted” at the RAF Brize Norton, military air base in Oxfordshire, west of London, on Monday as the UK struggled to cope with the weather.

That word "melted" seems unjustified. CNBC reports:

> The RAF didn’t specify why it suspended flights, but a spokesperson said “the runway has not melted” as early media reports indicated.

https://www.cnbc.com/2022/07/18/london-flights-suspended-aft...

Totally unjustified, sensational nonsense.

> The UK’s highest of 38.7C was recorded in Cambridge in July 2019.

This isn't remarkable.

>the record temperature of 100 degrees was reached at Greenwich on August 9

This was in 1911, from: https://trove.nla.gov.au/newspaper/article/115352761/9911357

> Totally unjustified, sensational nonsense.

I wish we had a pithy term for people underplaying exceptional events (complacency-mongering?) to show off how unflappable they are, because it would be nice to use it in this case.

Temperature records being broken are, by definition, exceptional events. In this case, the UK's temperature record was broken by 1.5C, which is a huge increase.

> This was in 1911

Cherry-picking a data point. There's a very significant trend of hotter days and record breaking occurring in the past few years. One outlier in a century of data doesn't mean very much (and your source of a paragraph from an Australian newspaper in 1911 seems to get the value wrong).

Sorry you can't think of a name to call me.

This is as much cherry-picking as the linked article is. It's one measurement.

> source of a paragraph from an Australian newspaper

The link is an Australian paper, too.

Are you, perhaps, unaware that these are in different units? 38.7C is 102F. The UK switched in the 60s to centigrade[0]. I'd also be suspicious of the accuracy and method of temperature collection in 1911.. the Met Office didn't start collecting data until 1914, and of the source accuracy.. Wikipedia[1] seems to suggest 98F (36.7C) and in another town. It certainly was extremely hot that August in 1911... especially without modern conveniences.

[0]: https://en.wikipedia.org/wiki/Metrication_in_the_United_King... [1]: https://en.wikipedia.org/wiki/1911_in_the_United_Kingdom

What's your point? That this is unreliable reporting?

I'll take your word for it that the met office didn't start collecting temperature data until 1914. Countless other entities didn't either, and none of them were cited either. In what year did Wikipedia start collecting temperature data?

https://digital.nmla.metoffice.gov.uk/digitalFile_1f3ce836-7...

>Monthly Weather Report 1911

Last page (140):

>In England 90° was exceeded on several days, the hottest being AUGUST 9th, 97° at Camden Square, London, Wokingham and Hillington, 98° at Raunds, and 100° at Greenwich (in the Glaisher screen; the value recorded in the Stevenson screen was 97°), the highest ever recorded in this country.

AFAIK Stevenson screens are now the standard, and Glaisher stands tend to record higher maximums, so the 100 isn't directly comparable.

You mean it wasn't liquified?!

> "following today’s high temperatures, a surface defect was identified on the runway" https://twitter.com/LDNLutonAirport/status/15490520549365719...

> "high surface temperatures caused a small section to lift" https://twitter.com/LDNLutonAirport/status/15490713790095114...

My question - how does the composition of the surface compare with that in other parts of the world that are hotter - Dubai, Saudi Arabia, Australia, the American southwest? Is there some code or regulation that helps these hotter places avoid this problem, and if so, should the UK government adopt them?

"the American southwest"

Here in Denver, at least, our runways are all made of cement instead of tarmac. I knew one of the civil engineers who worked on the special blend of cement the used, and from what I remember of what he told me, it is much thicker than I expected, and has other stuff in it compared even to highway-grade cement to make it more durable. The freeze-thaw cycle is still rough on the cement, in 2007 $11 million of cement slabs had to be replaced due to that. The airport as a whole has 15,000 20-square-foot slabs across its multiple runways.

Of course, one could still have buckling with cement if the expansion joints are too close together for the expansion of adjoining slabs over a certain temperature. Perhaps this is what actually happened here?

> Here in Denver, at least, our runways are all made of cement instead of tarmac. [...] has other stuff in it compared even to highway-grade cement

That's something that looks so different about (some/many?) American roads that I never twigged about until you said that. Roads are tarmac here too, not just runways. For some reason it didn't occur to me reading other comments about hotter places not using tarmac that it'd effect roads for cars too.

I am from the Denver region and from personal experience I know the area has a lot of Bentonite clays [0] which can expand as water is absorbed and contract as it dries. My neighborhood was built on land with a lot of this clay and our streets are wavy and our driveways are cracked to hell. I imagine they deal with similar issues at DIA.

[0]: https://en.wikipedia.org/wiki/Bentonite

My neighborhood is the same. The ground and site prep out at DIA the Civil Engineer friend told me about took things like that into account.

I for one have had much of the cement replaced around my house (some more than once) and when I had the driveway redone, explicitly asked them to mitigate against the clay with whatever they had that made sense. I forget what all they had extra in the proposal that I approved (it was 10+ yrs ago) but my new driveway isn't having any issue while some neighbor's new ones are already cracked again.

I'm guessing the composition is dictated by local average conditions. It rains a lot in the UK and freezing ground temperatures are common in the winter too.

I lived in Spain for a while and non-average weather such as a day of heavy rainfall can result in disaster movie-style scenarios. It's all relative.

I would have guessed local outlier conditions with a bit of padding rather than averages, but I suppose those latent optimizations get progressively more expensive.

Which part of Spain? On the Atlantic Spain, heavy rainfall can just be "Thursday".

Alicante/Valencia mainly but, yeah, I lived in Galicia for a while also. Two different worlds in many ways.

The article mentioned a section "buckled" - this is the more likely outcome. When designing roads/runways, engineers design for the most likely thermal range. This is then used to determine how much expansion to account for. You'll see this most commonly on bridges, with sections of "teeth" that allow for large expansion/contraction ranges, since the bridge can't expand in the same way a ground road can.

In this case, its likely more a matter of runways needing more precision, and therefore the design allowance on the range of extreme temps being much lower. I'm sure a civil engineer could explain better.

Aha, so perhaps the press got it wrong by saying it "melted" - maybe it actually buckled. They might have it confused with common roads that are actually softening and "melting" rather than buckling.

Growing up in a very country part of Texas, the road in front of my house changed over the years as the county would upgrade it. One upgrade in the 80s was a tar base with gravel rocks. During the summer when it would get 100+, the tar would melt and get stuck to everything. It is the primary reason I quit running around barefoot as a kid. I ran along the road with the melted tar, and learned a life lesson. Not only was the hot tar painful, it was extremely unpleasant to remove.

Maybe in the 40 years since, people have figured things out like don't pour gravel covered tar roads in the heat?

Chip seal is still very common. I suspect that the reason you may have seen it evolve at a particular location is that the usage pattern of the road changed. Everything from gravel to asphalt to tarmac to concrete makes sense depending on what kind (and volume) of traffic a particular road sees.

This is exactly what happened. When my parents built the house and moved in, there were only a handful of houses. As more houses built and more traffic came from that, the county went through the upgrade process much like in Sims games.

That tar was often waste product, perhaps for processes that aren’t happening.

Not sure about your area, but in mine GE “donated” waste oil to counties for use on roads. Much of it was contaminated with nasty stuff and there are cancer clusters along these roads as the crushed stone and dust would get ground down and become airborne.

Thaks for that. Now that's a thought that's going to fester. None of the neighbors that I knew from back then nor anyone in my family got cancer, so probably shouldn't let it fester too long though. Phew

Pouring them in the heat is the best time because it's easier to melt the tar.

I didn't mean the physical act of pouring hot tar when making the road. I meany don't pour as in don't use that material in places where it regularly, almost set a calendar to it, getting hot enough to melt the material.

Nope!

It's still the cheapest way to resurface a road.

As well as making concrete runways the best thing the UK government could do is adopt a "war footing" where it comes to climate change.

I use the term war footing because the impact of climate change is going to be on the order of a major war. And also because the response required for the decarbonisation required is going to be a significant portion of GDP.

Or they could keep their heads in the sand.

The whole world needs to.

I've flown through Dubai a few times, and I think most of their flights are early in the morning or at night. I don't know if that's for the runway or for the tires (or just heat in general), but I wonder if those factors played into things in the UK?

It's for air temperature. Warm air is considerably less dense, which raises the takeoff and landing speed of planes (for a given weight), up to unsafe levels, in addition to requiring a longer runway.

Mmm, density altitude... (https://www.faasafety.gov/files/gslac/library/documents/2011...)

Or requiring weight reductions on the aircraft itself (fewer pax, lower fuel, less cargo).

This definitely isn’t the case, flights go all day at DXB.

I don't know if that's for the runway or for the tires (or just heat in general), but I wonder if those factors played into things in the UK?

Some afternoon and evening flights are sometimes cancelled at LAS if it's over 110°. Something to do with the expansion of the fuel due to the heat, and long-distance jets can't get enough on board.

It's in the local newspaper there occasionally, and should be Googleable.

Not takeoff needing longer runways at higher temp due to less engine power?

And the runway is packed away into a hangar rest of the times?

If you use a cold weather composition in hot weather, you get melting asphault like this. If you use a warm weather composition in cold weather, you get cracks and potholes earlier than normal. Your composition is typically defined by climate conditions, not weather extremes.

Thank you - good explanation - the problem, then, is that there is no "one <type> fits all" solution for tarmac. It's just a case of the runway being built for different conditions. In other words, mother nature (global warming) violated the design requirements.

American highways use a PG rating system for the bitumen in the asphalt. You can read about it here: https://ftp.dot.state.tx.us/pub/txdot-info/cst/tips/faq_pg.p.... Short story is yes, places where it is expected to become very hot do use asphalt that doesn't rut under higher temperatures. The only exception I know of it Death Valley, which technically requires PG 76-10, but uses 70-10 just because California deemed it wouldn't be worth it to manufacture the extra grade just for one place that doesn't see much traffic. So I guess the highways just sometimes melt in Death Valley, too.

I do recall being a kid going on road trips through these deserts and noticing some of the highways were red and seemed to be made of something different. This was before the switch to the PG rating system. My dad claimed it had something to do with not melting the tire rubber of the vehicles on those roads, but I have no clue what his source was and I can't find any information about these highways, if they even still exist.

Its about building a surface that will also survive the winter and the summer. Its a tricky problem to solve. We could probably replace this with tarmac that could survive much hotter temps, but would just crack and break in the winter when its gets too cold.

Thank you - good explanation. There is no "one <type> fits all," then, for tarmac.

There's a similar story happening with our rail lines. The story seems to be that the materials we used in the UK are not stressed to deal with 40 degree heat. They never thought it would be an issue in the UK. Whereas many European railway lines were made to deal with 40-45 degree heat. I'm guessing it's the same for runway tarmac or whatever it is ...

Climate change is here ...

It's not so much the materials - modern rail, especially for high speed trains is laid in long continuously welded sections. The track is pre-tensioned so that at cold temperatures as it tries to shrink it is under significant tension and as it warms it becomes less tensioned. The question is what temperature to tension it to - at some temperature it is no longer under tension and above that it becomes in compression and then you have risk of the rails buckling. If I recall correctly, in England the track is tensioned for 27C (a typical hot summers day temperatures). They could tension for a higher temperature, but then you risk rails cracking in very cold weather. So in the end it's a compromise, but one that was made without expecting the current 40C temperatures.

> at some temperature it is no longer under tension and above that it becomes in compression and then you have risk of the rails buckling. If I recall correctly, in England the track is tensioned for 27C (a typical hot summers day temperatures)

While the basic gist is correct, a certain amount of compression is fine, too, because the trackbed can resist a certain amount of sideways buckling force, especially once the track has settled in a bit. It's only when the buckling forces caused by the temperature expansion and resultant compression exceed the sideways resistance of the trackbed that you get buckling.

Besides, rail temperatures on a hot summer day in the sun will definitively be higher than 27 °C – that value just happens to be the neutral temperature between maximum allowable compression and maximum allowable tension, whatever those temperatures exactly are.

The relevant HN thread, a few days ago:

https://news.ycombinator.com/item?id=32118818

> There's a similar story happening with our rail lines

No, there's a similar story happening with everyone's rail lines. There's a curious thing bout Britain where the British press love a hysterical "here's an example of Broken Britain!" headline, and Europe and America quite enjoy seeing the UK getting any sort of comeuppance (and normally I wouldn't begrudge them this, there have been a lot of insane goings on in the UK of late).

But the only instance I've seen of this - not announcements of restricted services or reduced speeds as a precaution or due to reduce damage in overhead lines, actual buckling - today has been in Spain:

- https://twitter.com/rail_arri/status/1549039421525458945

- https://twitter.com/rail_arri/status/1549034924010655745

edit: and just minutes after I post this, I spot an instance in England from the weekend! https://twitter.com/networkrail/status/1548760985246261249/p...

Britain is broken.

This isn't the place to debate it, but we're currently a rudderless, borderline second world country.

It's going to take a generation to recover (let alone thrive) from what the last decade of flagshagging idiots have done to this once great country.

They put more gravel inside the tarmac or use concrete.

Adding alternative links since site is down

https://www.cbsnews.com/news/extreme-heat-in-uk-disrupts-air...

https://www.theguardian.com/uk-news/2022/jul/18/uk-transport...

They could have planned for upgrading infrastructure to cope with expected warming trends beginning 35 years ago or so, but that would have entailed admitting that the science of atmospheric CO2's effect on climate had essentially been settled since 1980.

Send BP and Shell the bill for the infrastructure upgrade, since they spent so much time and effort on science denialism in the 1980s and 1990s and 2000s.

The great irony is that BP and Shell did plan for global warming and did upgrade their infrastructure accordingly. Even back in the 80s, they build their ocean drilling rigs to be high above the water knowing full well that they were causing the icebergs to melt and the water level to rise. They just kind of forgot to let us rubes know about it.

Are you sure about the oil rigs? The thing with ocean is that there tend to be waves. They are designed to survive once-in-1.000-year storms or worse, especially since the Draupner E platform got hit by a huge rogue wave in 1995.

Sea level rise is measured in millimeters per year. When a platform is already 20-30 meters above the sea, the handful of centimeters of sea level rise over its lifespan is completely insignificant.

There were plenty of scientists letting the public know about the global warming in the 80s. The public didn't want to know about it.

Don't blame "the public". This wasn't some conscious informed choice by millions of people. The public sucks the glass teat of mass media, and the interests controlling it did not want to present global warming as a problem.

In fact, this state of affairs has not even changed that significantly.

As you were writing this post, did you have a source for this, or was this hearsay? Not asking you to look for a source now, just curious about the quality of information in HN.

There is this article from ArsTechnica talking about a lawsuit from the city of New York against chevron which describes the issue described by the OP https://arstechnica.com/tech-policy/2018/07/judge-dismisses-...

The direct quote from the complaint (found here on page 5: https://cdn.arstechnica.net/wp-content/uploads/2018/07/show_...) would be: Meanwhile, beginning in the mid-1980s, Exxon and other major oil and gas companies, including Mobil and Shell, took actions to protect their own business assets from the impacts of climate change, including raising the decks of offshore platforms, protecting pipelines from coastal erosion, and designing helipads, pipelines, and roads in the warming Arctic)

I don't know about BP, but this internal memo from 1988 is what people are referring to when they say shell knew about climate change in the 80s: https://biotech.law.lsu.edu/blog/Shell_Climate_1988.pdf

Source here: https://graphics.latimes.com/oil-operations/

The investigative research that brought this up was a big development in proving that they knew on an institutional level that the science was real.

https://graphics.latimes.com/oil-operations/

Global warming is caused by burning fuel, not by extracting it. To say Shell and BP caused the icebergs to melt is ridiculous.

Gunshot wounds are caused by the impact of the bullet, not the pulling of the trigger. To say I killed that guy is ridiculous.

edit: at least someone who sells bullets or guns has the excuse that they can be used for sports or entertainment. If you pull oil out of the ground, it's meant to be burned, made into plastic, or put outside to roast in the sun.

They suppressed the information that global warming was happening.

Sadly to this day there are people who have been politicized into disbelieving the science, which has been very clear for a long time.

I fear for our ability to deal with the problems of humanity when so much of our politics is easily fooled people fighting ideological wars for the benefit of others.

Don't Look Up ;)

There are also some that think that only God can control the weather, so if the world is warming that is His will; and that the end of the world is imminent, and will be the greatest moment in the history of the universe for the faithful.

I'd bet that probably 20% of the voter base believes exactly that, and that 10% think that not believing that should be grounds for deportation or imprisonment.

If by infrastructure, you mean trains, then the UK, like every other country uses rails appropriate to the average temperature.

"Network Rail said that its rails have a "stress-free" temperature of 27 degrees."

https://www.bbc.co.uk/news/business-62182880

Why would all countries not just use rails that can tolerate all possible temperatures.

'All possible'? What are all possible temperatures? I think you've answered your own question, if you think about it: a line has to be drawn somewhere, you have to do some sort of statistical analysis, chance of circumstances occuring which this would not cope with <x%, yeah ok good enough, that sort of thing. That's engineering.

That's not the way metal works.

I'm pretty sure it comes down to cost. Steel rail has to meet certain wear and strength requirements as well as be reasonably inexpensive to manufacture. And there is not likely an alloy that will accomplish that and not expand in the heat.

In the US, the typical construction method is welded rail. AFAIK there is no allowance for expansion, at least on straight sections. Perhaps curved sections can move a bit to allow for expansion but move too much and the train goes off the tracks.

Because that's not possible without a lot of expense. Metal expands thats just basic physics. Its hard to stop that.

Not sure why you’re getting downvoted. This seems like an earnest question.

I fully agree. In addition charge back all dividends paid as global warming was long a scientific fact. Profits always must come with responsibilities. Time that people who profited are paying their bills.

1955 opening day of Disneyland.

In temperatures that reached 100 degrees, the fresh asphalt on Main Street, USA melted into a sticky tar that ensnared the high heels of some women

https://www.history.com/.amp/news/disneylands-disastrous-ope...

The main reason for this was that they just laid the asphalt too late and it didn’t set in time.

Disneyland was built with remarkable pace, with some of the original rides being closer to ‘industrial machinery with chairs attached’ than you might imagine!

That’s only 37 degrees in normal people temp.

That's too expensive. The sheikhs would no longer be able to build their ski resorts in the desert.

Much of the London tube doesn't have AC. Talk about lack of planning. Pretty sure all lines of the NYC Subway had ac 25+ years ago and they're notorious for drawing out project timelines.

Little consolation when you're waiting 15 minutes for the R train on the sweltering platform, ugh.

But yeah – sadly London's system used to be pretty cool, but the clay interior has acted like a battery, slowly absorbing the heat, and it simply can't absorb any more. It's a massive engineering problem (and oversight).

Great article on the why here: https://www.ianvisits.co.uk/articles/cooling-the-tube-engine...

To be fair, that’s been a work in progress for years, and some lines do have AC. It’s not like they haven’t been planning for it at all.

IIRC a big difficulty is that the tunnels are extremely narrow, so it’s just difficult to get any extra equipment in there. (I wouldn’t have thought that’s insurmountable, though, so there’s probably more to it than that.)

The lines without AC were constructed (mostly) in the 19th century. It's not possible to fit AC.

Alternative ways to cool the trains have been under investigation for decades, but there isn't an obvious solution.

They didn’t need AC in 19h century. The ground itself was cool and kept people comfortable.

200 years of constant usage has heated up the surrounding bedrock.

Space in the deep tube tunnels is really tight[0] (making it tricky to fit on-train air con radiators) and there's insufficient air circulation in the to clear the extra heat emissions in any case. They're working on both, but (unlike the shallower cut-and-cover lines and the NY Subway, both of which have saner tunnel sizes) it's decidedly non-trivial.

[0]: https://commons.m.wikimedia.org/wiki/File:Why_London_Undergr...

but many trains without lack if space, like DLR, are also without AC

Thankfully the Elizabeth line, opened this year, has AC. Both in trains and stations (at least the new build ones).

Small steps…

There was a competition to see if anyone could solve the problem

http://news.bbc.co.uk/1/hi/magazine/3069037.stm

Its much harder on the tube, as where do you dump the hot air? Back into the tunnel? London's clay has basically baked around the tube and is a really good insulator. Its not a particularly easy problem to solve.

You vent it to the surface, at least that's what NYC does.

NYC is also a much warmer summer city than London.

The tube is for the dirty working class, AC is for the elite. A few weak people dying in London is no big deal - that's how life in London always worked.

Everyone in London uses the Tube. What are you on about?

> Send BP and Shell the bill for the infrastructure upgrade

Should they also get credits for all the progress oil has allowed us to make?

Have they not already been financially compensated for this?

No, they extract and sell oil and they happen to do it at a profit. This is not the same as being compensated or billed for things that resulted from the use of that oil.

That's called _money_.

I expect that much infrastructure designed for a previous set of worst case scenarios is going to experience failures, especially older and poorly maintained infrastructure.

Hopefully many of them can be managed like when the event occurs. However, some of them like seawalls may fail during single catastrophic weather events.

I live in the southern part of India and a city by the sea. Summer temps here routinely cross 40°C each year for several days or weeks. There are other parts of India that get 1-1.5°C higher temps. I am surprised by the destruction caused by the high temps and the fires in and around London.

What seems to be the driving factor for this apart from the obvious record-setting high temp?

Usually, when infrastructure is built without extremes in mind, it won't withstand them. Where I live, it's an annual joke that during the heavy rain of the year, a lot of things break, flooding occurs, etc. That's because heavy rain is relatively rare, so most infrastructure isn't really built to handle the peaks very well.

I assume it's the same story.

Same occurance on the M25 in 2003.

https://en.m.wikipedia.org/wiki/2003_European_heat_wave#Unit...

Wow if you block cookies on this site it 100% blocks you and kicks you out.

Does the title have a typo and it should be as instead of has or is this correct?

The headline is correct as written. There is an abbreviated grammar common in English newspaper headlines (at least in UK and seemingly Australia). "($thing_x occurs) as ($thing_y occurs)" means "$thing_x occurs, because of or related to $thing_y occurring".

So you might also see a headline like "Dortmund's title hopes fade as Lewandowski scores hat-trick" => "Dortmund's chances of winning the Bundesliga became narrower, after Bayern won and Robert Lewandowski scored three goals (possibly against Dortmund)"

It's something native speakers often don't realise, but there's a lot of really specific stuff for healdines

X as Y is perfectly fine, but the article headline still and the HN title previously read X has Y. That is what I was wondering about, whether this is some strange headline shortcut.

OH sorry! I must have I read your comment exactly backwards because the headline had already been corrected :D

That's just the regional accent.

Either one is correct. Meaning is subtly different, but not much.

"has" is not correct it should be "as".

A later sentence in the article is formed similarly and correctly uses "as" - "The runway also 'melted' at the RAF Brize Norton, military air base in Oxfordshire, west of London, on Monday as the UK struggled to cope with the weather."

But the airport can have temperatures. With some additional punctuation, has could be read more clearly.

As in, "melted runway at London Luton airport has gained sentience, named itself The Global Warming, and is holding the rest of the UK as hostage with its super-area-heating power; negotiations are ongoing"?

Spray it with water?

Back of the envelope calculation:

Yuma International (discussed above) has 540,000m^2 of runways. Assume a depth of 0.1m of cooling, that is 54,000m^3. The density of asphalt is 2322kg/m^3, so we have 310^9kg. The specific heat of asphalt is 900 J/kgK, so that'd be 310^12J to get rid of 1 K degree. The specific heat of water is 4184J/kgC. If I assume the water goes from nearly freezing to nearly boiling and have my algebra right, that's about 6,000,000kg of water or about 6000m^3 of water, all to lower the asphalt by 1 degree. That's about 2.5 standard bulk units of water (Olympic swimming pools).

By comparison, 2.5cm of rain on the same runway area is about 13,500m^3 (?) of water.

I think it's doable. Anybody got some spare garden hoses? :-)

Formatting. Sigh.

flooding the runway would temporarily deal with the heat but also render it unusable for a different reason.

Why? Airplanes are able to land in the rain.

You'd need to design a system and make it pass all sort of tests and specifications.

It's not as easy as bringing two firetrucks and spraying for 10 minutes. When mistakes end in potential dead people they don't DIY solutions

Cools the runway but can make the local atmosphere more dangerous for humans.

Yeah we're not really equipped for this...

I don’t understand this. Do they use different asphalt up there?

I wouldn't be surprised, there are a lot of different asphalt mixes out there for different scenario. Idk specifically about temperature, but would't be surprised.

I had a local HVAC guy once tell me that the next Elon Musk type is going to be whomever owns the largest HVAC company in the UK and Europe.

We already have mature HVAC companies. They’re just going to expand their operations in Europe.

ITT: Americans not understanding that London is at the same latitude as Calgary, and Houston is located around Kuwait's.

"Please don't sneer, including at the rest of the community." It's reliably a marker of bad comments and worse threads.

Also, please don't post nationalistic flamebait—it leads to nationalistic flamewars, which are the last thing we need here.

https://news.ycombinator.com/newsguidelines.html

Edit: it looks like you've been posting quite a few flamewar comments, unfortunately. Can you please not do that? It's not what this site is for, and it destroys what it is for, so we end up having to ban such accounts.

The runway melts at 40C? Call me skeptical.

Melted presumably doesn't mean "liquified," it means "the heat was sufficient to push the integrity of the runway beyond its safe operating parameters."

And it probably wasn't just 40C; it was probably much hotter, since it's black tarmac.

"Tarmac", the stuff we coat roads on here gets very soft in the summer.

When I was a child (90s), my dad lost a finger when we were replacing the alloys on his VW Corrado and the jack sank into the tarmac and collapsed dropping the car, he pulled his arm out just quick enough to _only_ lose a finger.

I'll never forget how dismissive my mum was when I said "mum, come quick, dad's cut his finger off, it's on the floor".

Fun story aside, the tarmac / road covering we use here do "melt" at relatively low temperatures.

Did they reattach the finger? Does he still have feeling in it and can move it?

It was crushed and not a clean cut so they couldn't reattach it.

Is it still embedded i the tarmac?

It's worded that way for shock value:

1) 40C is the air temperature, the surface temperature of something exposed to the sun is much higher

2) It's not like it's a big hilarious, swirling sea of tarmac. Part of the runway will be a bit softer than they deem safe.

The UK heatwave is still extraordinary, but you need to take tabloid headlines with a generous pinch of salt.

3 ) there are parts of the world where runways built decades ago were built with 40C (expected air temperature) in mind.

Luton, UK is not one of them.

Also true!

It’s quite believable that the tarmac wouldn’t have been specced for 40C in England. Especially when the airport opened in 1938.

> The runway melts at 40C?

No, the runway melts at a much higher temperature, but as it turns out pavement gets much hotter than air temperature on hot days; various sites I can find siting a very rough guide as 35°C air temperature to 65°C pavement temperature.

You appear to be correct:

> The RAF didn’t specify why it suspended flights, but a spokesperson said “the runway has not melted” as early media reports indicated.

https://www.cnbc.com/2022/07/18/london-flights-suspended-aft...

It is more likely the black tarmac used to fill in cracks in said runways, and I’m almost certain you’ve stepped in that on a hot day at some point in your life and know that it gets soft. No reason to be skeptical based on a hot headline take.

More like runnyway. This is bad engineering

Failure or going temporarily out of use does not necessarily imply bad engineering. Engineering also has to assess the cost of a solution and weigh this against the risk and impact of any failures. In this case the prior on risk of a ‘melting event’ may have gone up since the runway was designed. The impact of closing for one day in x years may also have been explicitly deemed acceptable.

Illustrating that design isn't always 7-sigma availability, There's a shopping mall parking garage near here that is essentially the river bank. When the river runs a high flood, the waters are intended to inundate a lot of parking spaces, to avoid overly-confining those waters. And it's deep enough that some of the parked cars float. Also this parking garage replaced a surface parking lot that was doing the same thing. The second level of the parking garage is not supposed to be inundated, so the garage is a lot taller than it would have been for the same capacity. One can see flood stains on the walls of the first level.

The alternative would have been to build levees to confine the waters to a channel, and hope the channel was deep enough.

Right. Just like homes in the southern US would stand up to 36" of snow load without issue.....

Yep and not just homes, power grid, roads ... everything. People joke that the south of England "shuts down" when there's snow, and while there are services that suffer it's never quite like how badly Texas collapsed during their big storm.

When there are extreme weather events that you've not planned, designed and built your infrastructure for, you're basically at the mercy of mother nature. In the UK's case that's extremely hot weather, in Texas' case that was extreme cold

Essential service melts at 40°C..... well, that wasn't designed very well, was it?

It's one of London's six airports, primarily used for discount holiday flights. Hardly safety-critical.

Besides, this is literally the first time ever it has reached temperatures this high - and it has been open for 84 years. I bet they also "failed to design" for hurricanes, cataclysmic floods, and volcanoes!

Two out of those three are a real possibility though.

Now they are

That still sounds like really, really, really bad design. 40C is not a hurricane, flood, or volcano. It's a mildly hot day. Engineering fail.

As I understand you are engineering for a range of temperatures with problems to be found outside either end of the range (though I imagine it’s also possible to engineer for wider or narrower ranges to some extent, with appropriate cost implications).

Coping with higher maximum temperatures means more cracking and damage at very low temperatures, so it is not necessarily a case of just building in more buffer at the top end but a trade off between the cost and frequency of events like this and the cost of dealing with the effects of winter.

Given that this had literally never happened before and the frequency of similarly hot events was also lower in the past, it’s perhaps unsurprising that the trade-off landed where it did, even if it may well be in for a rethink now.

When these designs were made, 40 °C in the UK was a once-in-5,000-years event. Now, it seems to be about 1 in 30 years (we don't have enough data to be sure).

Also, the problem usually isn't the 40-degree air temperature itself, because that's usually in the operating range--it's the rails and machinery and confined spaces hitting 60+ that fucks everything up.

New York considered shutting down its subways in July 2011 when it was "only" 40.5. Why? Because the underground stations were hitting 50, which (esp. in New York humidity) is dangerous for the most heat-sensitive people.

I'm sorry, but that's a whackadoodle approach to engineering. 40C is well within the range of expected temperatures, and the men who designed it failed epically. There have been heatwaves in the UK since 1911 where the temp approaches 40C.

https://www.theguardian.com/uk-news/from-the-archive-blog/20...

All of those temperatures are multiple degrees below 40.

I doubt it's a once every few decades event anymore. It got to 38 in several places in the country a few years ago. It seems to get up to the mid 30s every year now.

The problem is these temperatures are quite a bit higher than ever previously recorded, and go beyond the reasonable scenarios for which they were built. I’m sure sure newer UK infra is designed for higher temperatures but this is new territory and unfortunately probably just a taste of what’s coming.

Worth also adding this wasn’t as bad as it sounds- only a small patch was faulty and fixed within a few hours. For bigger problems see the various wildfires and also widespread breakdowns in chilled food storages. I also hate to think how barn animals are faring.

> The problem is these temperatures are quite a bit higher than ever previously recorded, and go beyond the reasonable scenarios for which they were built.

Exactly. I remember talk in the press about the default asphalt composition for the roads where I am (Romania) being changed to handle higher temperatures like 15 years ago. We're a lot more to the south and got warmer faster than the UK.

It's just the UK's turn now.

It was designed for conditions known to exist in the area. Then conditions changed due to climate change.

Luton is not that important. If Heathrow or Gatwick melted, there'd be riots.

Wait till you learn about the Texas electric grid.

Toronto has certainly had 40° days and there were no concerns at the time with the runways melting.

Great, sounds like you engineered things for your expected temperature ranges.

Story here is a major piece of infrastructure is experiencing temperatures outside of its designed-for temperature range.

Toronto is interesting in that it has to deal with a fairly extreme range of temperatures between summer and winter, in the UK the spread is much more narrow (or at least, it was).

As someone who lives in the GTA...

Your post doesn't make sense for two reasons.

1) Toronto airport was built to withstand these temperatures as we have reached them before. Basically it is within the expected design parameters. UK's airport is experiencing temperatures outside its normal range.

Building infra is a lot of cost/benefit analysis. Building runways to experience the wide temperature range Toronto faces is very costly.

2) A lot of our infrastructure has been impacted by "extreme heat" as well.

How many times has GO transit issued "reduced speed" notifications due to track temperatures?

> UK's airport is experiencing temperatures outside its normal range

This certainly seems like a case of infra debt catching up.

How is it debt to not massively overengineer?

They're concern would have been handling rainfall within nominal temperature ranges, not building it to handle every possible scenario?

Would you consider it tech debt if the runway structure failed when a UFO landed due to its exhaust causing resonance?

Or the classic "penny wise and pound foolish" which is fitting as the saying originated in the UK.

Perhaps they opted to error on the side of "lets be really optimistic on temperature ranges and save a lot of money on materials"?

The roads on the other hand…

Why would concrete melt, ever? Someone used the wrong words, or didn't understand what they were told.

[Edit] Ok, so they made poor choices in runway materials. O'Hare and other airports near me are all steel reinforced concrete.

> Why would concrete melt, ever?

The runway is made from asphalt concrete, in which the bitumen binder starts to melt in the temperatures being experienced.

> Someone used the wrong words, or didn't understand what they were told.

That someone is you.

> Why would concrete melt, ever?

The components of concrete melt, and they melt not long after steel does. You’d have entirely melted concrete before 2,000 deg C, depending on what’s in it. When rock melts, it becomes a material quite familiar to you. Cement melts sooner, and those are the two main components.

We’re not talking about that, though, as the issue at this airport is squishiness of tarmac.

It's tarmac, not concrete.

Not only that, but forget concrete: think asphalt. Having lived in Texas with countless 100+ F days, I can confidently say the asphalt never melted.

What are they paving runways with in Luton, anyway?

> “I can’t believe how those southerners can’t handle 1 below freezing and half an inch of snow, it’s not even that cold”…

> Because infrastructure is built in a local context, where materials, designs et cetera are chosen on what is/was normal. I’m genuinely curious: do you really not understand this?

https://news.ycombinator.com/item?id=32154999

Seems many people in this thread have trouble understanding that most of the infrastructure we build is built for the people living there under the conditions they normally experience, not for "freak" outliers like this.

Similar to how if there is snow in southern Europe, most infrastructure shuts down while in Russia they run trains through snowstorms. But if it gets tiny bit too hot in Siberia, the trains shut down while in southern Europe they survive no matter how hot it gets.

So many crazy posts like yours...

As others have said, why did Texas have so many problems when it got cold?

Taking our infra, designed for your temps and stating "others should have this too" doesn't make sense.

I live just outside Toronto (Ontario). When you were struggling with a brief cold snap which cost 246 lives because it was -19C, large and heavily populated parts of Canada faced -40C and no one died?

"Texas was not winterized, leaving it vulnerable to extended periods of cold weather, leading to widespread power outages"

why wasn't it winterized?

Because statistics show it was a controlled gamble NOT do to this. UK airport is the same deal.

They could use different (and more expensive) materials, but they gambled it wouldn't be needed, much as why Texas didn't winterize the equipment.

Remember that time in Texas all our infrastructure shutdown because it got cold here?

Next, you seem to be completely clueless on aggregate mixes, your mix will be a balance of rock and tar meant to survive a temperature range. Texas mixes will be more aggregate. The problem is this make it less flexible in cold weather and it would degrade far faster. So great you'd design a runway to survive Texas heat that occurs once every few decades versus the cold winters that happen every year.

How is the infrastructure in Texas generally? Roads? Bridges? Power grid?

More likely, someone decided to amp up the drama trying to get more clicks.

The media coverage of the heatwave has veered between upbeat excitement and scaremongering - but never about the real issue of climate change. Just about a runway with a bit of a chip in it

This does appear to be the case:

> The RAF didn’t specify why it suspended flights, but a spokesperson said “the runway has not melted” as early media reports indicated.

https://www.cnbc.com/2022/07/18/london-flights-suspended-aft...

I don’t understand, sure it’s hot for London, but not that hot (100F). Not even close to as hot as it gets frequently in the deserts (Vegas, AZ) and south here in America. Yet, runways are melting and the media is absolutely freaking out. It’s 100 degrees, not that big of a deal.

“I can’t believe how those southerners can’t handle 1 below freezing and half an inch of snow, it’s not even that cold”…

Because infrastructure is built in a local context, where materials, designs et cetera are chosen on what is/was normal. I’m genuinely curious: do you really not understand this?

Let me guess this is you last year:

I don't understand, sure it's cold for Texas, but not that cold (0F). Not even as close to as cold it gets frequently in the tundra (Winnipeg, Saskatoon) and north there in Canada. Yet pipes are freezing and the media is absolutely freaking out. It's 0 degrees, not that big a deal.

Point being, a place has all it's infrastructure designed for the climate it's in, not a different place's climate.

It is literally the hottest that the UK has ever been in recorded history. It is roughly the same temperature as the high in Tucson today. It is very hot.

You can build infrastructure for this heat. The UK does not have that. This is why runways are melting and the media is freaking out.

Also the media don’t generally need much of an excuse to freak out.

Sadly there isn't a functioning government in the UK that can freak out and do something about it.

Not a civil engineer, but everywhere uses different materials spec'ed to withstand the environmental factors that occur there. You live in Arizona which uses asphalt that should tolerate expected weather conditions in Arizona. It si probably a different asphalt than what gets used in Maine and a different asphalt that gets used in Florida because all three of those place need infrastructure that accounts for different weather conditions.

There isn't really a one size fits all answer, each material has its pros and cons that works best for different conditions.

Interestingly boring. Idaho has a podcast about their roadway system. If you listen to enough episodes, one thing you learn is Idaho uses different kind of asphalt in different areas of the state. Why is that? Some part of the state have the high desert climate and other parts of the state have a more colder and mountainous climate.

its about temperature difference relative to geographic norms. this is the hottest recorded temperature in UK history.

Stuff gets made out of different things in different climates. In Arizona it's not a big deal because the engineers expected 40 celsius as a regular occurrence and chose material compositions to withstand it. In the UK, they didn't, and we're seeing the consequences. 40 celsius has never happened in recorded British history. The previous record was 37.something.

I imagine Arizona infrastructure would fail pretty rapidly if temperatures somehow dropped to -30 celsius, and there would be Novosibirskians wondering what the big deal was.

It's a big deal because people don't have A/C.

The runway is outside though. I've never heard of runway melting in the hottest and most humid parts of the US.

You've also never heard of the runways frost heaving in the hottest and most humid parts of the US. Things tend to be engineered for the climate they experience the vast majority of the time.

The parts where its been hot and humid since the turn of the century? Where they knew back in the 30s and 40s and used the appropriate additives in the asphalt/concrete to handle those temperature ranges?

We can't change this infrastructure immediately, it was built for English summers which used to mean 30 in the air, 50-60 ground temp. Now we're pushing 40 air and 80 ground...

Maybe I'm nitpicking, but to say it was nearly 40 Celsius when the recorded temp was 38 C is an exaggeration. When I lived in New Mexico, it would hit 40 C for a couple days at a time in the summer. That sucked. Where I'm at in the Midwest, the temp hits 38 C for a couple of days at a time in the summer. It's a big difference in what kind of precautions you need to take.

I realize they don't have the infrastructure to deal with the heat the way we do, but tell me that and then tell me the actual temperature reading. Don't round up 2 degrees C like it doesn't matter.

It has hit 40 in a bunch of places in the UK today https://www.bbc.co.uk/news/uk-62217282.amp

That changes things. I was just going by the article.

Be thankful they're giving out a temperature within 10 F of the actual observation. Where I live the TV news has stopped giving out temperature at all and just reports the "feels like" humidex index, a made-up number that makes everyone feel smug about how well they're bearing the load of global warming.

The humidex is more important for people.

100F with 10% humidity is hot.

100F with 90% humidity is deadly.

I've never heard it called a humidex index, just heat index. It's pretty invaluable here where the humidity gets high enough that your sweat doesn't evaporate. In the desert, I just had to wear sunscreen and keep drinking water. In the Midwest, it can be 10 degrees cooler and you have to stop and find somewhere to cool down regularly. Your body just can't dump heat with that much moisture in the air.

Typical hot daytime temperature at this time of year is 22 to 25. It could easily be 17 or 18. For us 38 is almost 40.

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