Hacker News new | past | comments | ask | show | jobs | submit login
How Amsterdam’s Airport Is Fighting Noise Pollution with Land Art (amusingplanet.com)
147 points by jath2 8 months ago | hide | past | web | favorite | 62 comments

There are a lot of opportunities to make functional structures attractive (even attractions in themselves) but this approach seems to have fallen into abeyance, in particular in the USA and the UK, for some reasons over the past 50 years.

For example instead of brutalist bollards and jersey barriers, pedestrian ways could be set aside via grade elevation or attractive, gapped structures that invite walking instead of looking threatening. Water plants could have "water temples" again.

It seems like some theory that doing anything beyond the functional minimum is a waste of the taxpayer's money. But isn't a crude structure also a tax on the psyche?

I think in US culture there isn't generally much regard for taste or aesthetics for some reason. You can see in cities, public places, transport, offices, people's homes, clothing, packaging. Aesthetics or function is either not considered at all, or done with a horrible taste (think most airports, government offices).

In general, at least in Northern Europe, we have beautiful well kept and functioning cities, libraries and I think it's some kind pride or attitude in the culture, that while things are necessary, they can be also be beautiful, it doesn't necessarily have to cost more.

I'm not American (and don't live in the US), but this is a ridiculous over-generalisation. The US is a massive country of over 320 million. It attracts architects and designers from around the world, as well as producing many influential and world-leading figures of it's own. The country is so vast, that making such sweeping generalisations like this can never capture the enormous quality and scope of design (good and bad) that must stretch from one side of the country to another.

>> You can see in cities, public places, transport, offices, people's homes, clothing, packaging.

Yes. Art and beauty happen where private money is funding the construction. There are some great corporate buildings, private houses and churches. But public structures, things funded by governments spending tax dollars, lack heart. Compare US manhole covers to those in Japan, or even Germany. The cost difference is negligible, but US cities just lack the whimsy. Or compare US coinage to Canadian. American money is covered in symbols, crests and dead guys. Canada went with polar bears, beavers and loons.

This is so wrong. America is full of beauty, and many have great taste.

Maybe America is not to your taste.

There is something to be said about beauty being exclusively secondary to a place’s purpose in the US though. This is evidenced by the fact that when American cities champion creative efforts, it’s seen as special. For example, street art in Chicago is seen as something positive but different. All of America’s buildings aren’t brutalist and ugly, but clearly aren’t looking at aesthetics as a primary concern.

Many are. Frank Lloyd Wright was an American designer who embraced beauty. There have been many others.

American architecture is certainly not the center of brutalism.

I have no idea what you are alluding to. Can you name a city you would consider aesthetically bankrupt so I can understand what you’re refer maxing?

brutalist != ugly

At least not necessarily.

I've yet to find any street art in Chicago that is beautiful. This is obviously subjective, but I just think it looks trashy.

Of the three explanations:

1) you’re in the wrong neighborhoods

2) you have bad taste

3) there is no good street art in Chicago

... I don’t think #3 is the most likely.

He didn’t say that America wasn’t beautiful, he was talking specifically about American cities. There are some beautiful parts of some American cities, but I think the general criticism is fair. I think it just so happens that the same is true of most cities around the world too. There are beautiful parts of Paris, London, Athens, St. Petersburg etc, but also large gray, dirty, ugly parts. It’s right to point out that large parts of many cities are dirty and ugly, but unfair to single out America as being uniquely culpable in creating such spaces.

It’s also unfair to compare the the nicest parts of Amsterdam with the worst parts of SF, just as it’s unfair to compare the nicest parts of Boston with the worst of Mumbai. What America is full of is natural beauty, but generally outside of the cities. From sweeping desserts to warm beaches and deep forests, they have it all, and it really is beautiful. Northern Europe is lovely too, but it’s also small, far from densely populated, and homogenous. America is vast and varied, and if we’re talking about the whole continent it has everything from glaciers to rainforests.

I don't think it's America specifically, I think it's just all newer parts of cities. Old parts of cities are nice because the ugly parts have been torn down and only the nice buildings remain. The ugly parts of otherwise nice cities tend to be the stuff from the past century that hasn't died off yet.

America is pretty young and grew a ton in the past century, so there's still a ton of 50's era mass-produced architecture and car-centric civic designs. They're not old enough to need replacing yet. I don't think those will stand the test of time, but there's still some gems in there that I hope to see persist. I think we just need more time for the cities to evolve.

Only thanks to the taste of pre-XX architecture. For anything built since the 50s, it's another matter.

> It seems like some theory that doing anything beyond the functional minimum is a waste of the taxpayer's money

No, I don’t think that’s the cause.

The cause is that we are in a period of financial intermediation. Every sip of coffee, every home construction, every dentists office needs to be a financial instrument, easily tracked so that the markets can be made.

Essentially: as long as every endeavor is a private money-making endeavor, we can only do one thing at a time.

How would you even do the accounting on some sort of pedestrian walkway that both covered your liability and provided a public right of way? That’s some sort of public/private partnership... how would you short something like that?

Integrated systems are not amenable to finance so we have to wait.

In a few years we might have software that could efficiently underwrite multi-purpose projects like that, but it’s just not possible on today’s markets.

Agreed, it's not as impressive as in person but I've always liked seeing the Cushman Powerhouse #2[1] when I drive 101. I feel like we should take pride in our infrastructure and making them architecturally attractive is a great way to do that.

[1] https://olympicaerialsolutions.com/cms/wp-content/uploads/20...

The link isn’t working for me—I get a Cloudflare error saying the site doesn’t allow hotlinking

Copy the URL and paste into a new empty tab.

I opened in incognito and then it worked

Remember that barriers to protect pedestrians work two ways: to protect them from cars, but also to restrain them from getting into car territory. Gapped barriers have a place but do not stop drunks from wandering into traffic. Some gaps, if they obstruct sight lines for either car or pedestrian, can be worse than having no barrier.

Bollards (wide gap structures) are not for protecting pedestrians. They are very dangerous for fast-moving vehicles. Bollards are to stop slow stuff like cars trying to park. They are for keeping drivers from driving into defined areas, not for shielding pedestrians from car accidents. Bollards are placed to stop cars entering city parks, not between a sidewalk and the highway.

Source? Bollards are used extensively in the US to protect from either ram-raiding burglaries or car-ramming terrorist attacks.

For example, bollards stopped the vehicle from the 2007 Glasgow Airport attack from entering the terminal: https://en.wikipedia.org/wiki/2007_Glasgow_Airport_attack

Glasgow is in Scotland, not the USA.

An example in New York: https://www.usatoday.com/story/news/2017/05/18/what-stopped-...

The point is that if people are going to insinuate that bollards are not intended for protecting pedestrians, there had better be some evidence to the contrary. (They may not actually do so in the same way that guardrails don't actually help, but the road to hell is paved with good intentions: https://www.nytimes.com/2014/10/13/business/highway-guardrai...)

> not for shielding pedestrians from car accidents

I think you're making two separate distinctions here. Bollards are not appropriate as a first defense on motorways because they present a great risk to motorists. Bollards are however often built to shield pedestrians from car accidents (and other situations where cars enter pedestrian space inappropriately, like ram raids and vehicular terror attacks), they're just not good for protecting motorists when they do so. The most common bollards in major American and Canadian cities are explicitly specified and built to protect against fast-moving vehicles of a certain weight and center of gravity).

A truck crashing into a series of bollards (a glancing blow, not a direct terror attack) turns into a meat grinder. The first bollard impact, say to the right of the front bumper, initiates a rotation. The vehicle then turns sideways to its direction of travel, becomes unstable, rolls, then impacts the next bollard. Anyone inside or anywhere near this chaos is injured. The bulk of the vehicle will eventually stop beyond the line of bollards, in pedestrian territory. This never happens, and there are no videos, because no idiot builds roads this way. The closest we have to bollards beside roads are telephone poles and trees. See this vid at 2m15s. Watch the car rotate, roll, become airborne and land on the sidewalk.


More rotation after impact: https://www.youtube.com/watch?v=R3DC-Ryx7RA And more rotation->roll->stop off the road: https://www.youtube.com/watch?v=pY7xo61drg4

At the 2010 winter olympics a luge slider also illustrated this as he left the track and hit a series of uprights/bollards. He died, his body landing outside the track. Anyone standing there could have also been killed.

Modern traffic safety is about keeping cars away from pedestrians during a crash. Smooth barriers without gaps keep the crashing vehicle on the road. Many are designed to redirect front wheels, literally stearing the vehicle back into the road and away from people. The goal is to slow everything gradually while keeping the crashing vehicle away from pedestrians. Barriers are even tied together in a big chain so that they can gain strength from each other, allowing very small/low barriers to redirect enormous vehicles. They might not look pretty, but they work.

https://www.youtube.com/watch?v=22mzoAkJJBQ https://www.youtube.com/watch?v=j-HevN1bzbA

But you can't use ungapped barriers in town centres or other areas of arbitrary pedestrian flows. Hence, bollards will always have a niche.

I'd really like to see a technical analysis of this project - I've checked the usual spots (JASA, INCE Journal, Journal of Sound & Vibration, etc) and couldn't find anything. Google searches just lead to Paul De Kort's writeup, and similar articles.

A little background about issues involved: if you have a noise source on (or just above) the ground, and a receiver on (or just above) the ground with line-of-sight to one another, there are three paths that noise can take from the source to the receiver:

1. The source can emit sound that goes up into the atmosphere, but under certain atmospheric conditions, that sound can be reflected back down to the receiver.

2. The sound travels directly, in straight line, between the source and receiver.

3. The source emits sound that travels downward at a shallow angle into the ground, and is reflected up to the receiver.

For path #3, if the ground is acoustically "hard" (generally meaning non-porous), the reflected ground path adds to the noise heard at the receiver. If the sound is acoustically "soft", generally porous, the sound is absorbed [0] so the reflected sound does not add to the direct sound, and the resulting total noise is quieter compared to the situation with hard ground. This explains the reduction in sound level when the land was plowed - the hard ground (dense, packed soil) was transformed into soft ground (loose, tilled soil). This also explains why background noise levels drop when snow is on the ground.

It looks like the Schiphol landscaping addresses mostly #3, possibly #2 (by blocking direct LOS between the source and receiver). This is interesting, but the same can also be achieved by a noise wall at the airport taxi and run-up areas (which is the typical solution), or creating a wide, dense tree belt. The claim is that spacing the berms by the wavelength of the (presumably dominant) airport frequency creates greater reduction, but I'd really like to view technical data to see how well that works.

The articles claims the berms have "reduced noise levels by more than half" - is that in terms of sound pressure, sound power, or sound perception?

If sound perception, that's ~10 dB and that's really impressive.

If sound power, that's around 6 dB, which is decent.

If sound pressure, that's 3 dB, which is strictly in the "meh" category.

[0] Technically the sound isn't absorbed, it goes through a phase change so that the reflected sound cancels out part of the direct sound.

My thinking is this is strongly influenced by the polder landscape. Polders are how the Dutch reclaimed so much land from areas that should be under water.

So, it is basically a lake bed that was drained and then stuff built on it. This means it lacks a lot of the usual natural baffles of irregular ground and various types of plant growth.

They are basically creating baffles on, apparently, previously essentially flat terrain with little to no natural baffles.

I'm thinking given that context, it wouldn't take much to make a dramatic difference.

> The claim is that spacing the berms by the wavelength of the (presumably dominant) airport frequency creates greater reduction

It might work like a Bragg Grating: https://en.wikipedia.org/wiki/Fiber_Bragg_grating

This is the kind of insight and commentary that keeps me coming back to the comments section.

Noise power and perceived volume are nonlinear. When the article says: These simple ridges have reduced noise levels by more than half. they are speaking of power. This means a reduction in perceived noise of about 1/6th. It is about the minimum change at which a person says "Oh yeah, that's quieter."

Later in the article they mention including more measures from the airlines' planes and operating procedures to achieve a total of a 10db reduction, which gets rid of 90% of the energy and people will say "Oh yeah, that's about half as loud."

I work with aircraft (big helicopters) and field noise complaints. I find time of day and weather mean far more than actual noise energy. 7pm, sunset, calm wind, sunday = noise complaint. We never get complaints at 11am on a windy or rainy tuesday.

I am very polite on the phone, but if you choose to retire beside an AIRBASE! Our helicopters have been flying over your house decades before it was ever a house. Sue your real estate agent for not telling you exactly why zoning limits your neighbourhood to two-story non-commercial structures.

I live in the Hampton Roads area and realtors are very up front about jet noise and crash danger. There are maps of high and low noise areas, you are asked to sign a waiver stating that you are aware your home is in a high noise area, etc.

> but if you choose to retire beside an AIRBASE!

The problem with that position, at least in the UK, is that the social contract between the airport operator and the local residents was never revisited.

Most of the UK's airports and airbases date from the 1920s and 30s and are named after the nearest postal village, which are centuries old.

But a Dragon Rapide or a Bristol Bulldog from that period had a very small noise profile. When the big-props and the jets arrived the noise levels increased hugely, but the residents weren't given any concession. Society was required to adapt to the new noise and pollution levels in the name of progress.

And now the operators have the audacity to complain about local residents complaining. If you really want to operate 24/7 in a drone-free environment, go and build an offshore island airport.

Our helos are over 55 years old. Not many residents have been here that long.

Weather does have an affect on noise along with the differential between air temperature near the ground and higher up. It is common for the local government testing facility to send out notices to expect louder than normal booms from rocket testing during different weather.

I dont think it is physics. People are eating dinner outside in good weather. There is also a group dynamic. Some people call on speakerphone and it is obvious they are just showing thier dinner guests that they know my phone extension. That senario, the likelihood that people are eating dinner as a group outside, is the best means of prediction. We alter our operations as best we can accordingly.

There is a common joke in air forces, at least western air forces: Plane to loud? Did you see a red star on it? You're welcome.

My President's too loud, and I think there's a red star on him.

The difficulty is that helo operations are pushed around by the bigger/faster stuff. So it might be years before a combination of wind, weather and traffic cause us to approach/depart over a particular neighborhood. In an emergency, a SAR callout, we will fly over areas that might never have seen a flyover before.

> When the article says [...] they are speaking of power

Who knows what they are speaking of, it's a very poorly written article.

> The distance between the ridges are roughly equivalent to the wavelength of the airport noise, which is about 36 feet.


The airport noise is broadband noise, it doesn't have a definite wavelength. 36 feet means a frequency of 31Hz. 31Hz is not even the dominant frequency[1]...

[1] https://www.ndt.net/article/jae/papers/26-290.pdf

Funny to see this here :) Born and raised right next to what is now Buitenschot, lived there until 3 years ago. For the last few years, my brother and I had the unusual habit of going for a run over these ridges and ditches every Sunday.

There are in fact at least two listening ears, a few hundreds of meters apart, but they’re not exactly opposite each other so they don’t communicate. Also we never realized the meaning of that weird pond haha.


When was Buitenschot built? (I grew up a few 100 m further away, but left about 30 years ago; I had no idea they had built this there now.)

Hi fellow Hoofddorper :)

It’s relatively new, it was built between 2011 and 2013.

Is it just me or has Amsterdam/Netherlands been on Hacker News (and other outlets) more and more... almost feels like a weekly occurrence now. I've visited Netherlands last year and was fully impressed with their entire culture.

NL is small, densely populated and wealthy. That makes it an ideal testbed for lots of stuff so you will see a relatively large number of experiments taking place here some of which are newsworthy.

It's also why we have an enormous offering of car brands and models none of which are produced domestically. It's a good market to try new stuff in.

a small European country that has managed to become a global powerhouse in agriculture and technology—the Netherlands.

Humorously, the quote is from an article critical of The Netherlands:


The world seems to largely forget that the Dutch had a major empire at one time. I'm not quite sure why that is. But I think you wouldn't make a comment like this about, say, Great Britain. We read stuff about the US and UK all the time and take it as a given. No one is surprised to read the umpteenth American or British piece.

How The Netherlands manages to be such a powerhouse and seemingly go largely unrecognized as such strikes me as an intriguing question in its own right.

Speaking of Amsterdam Airport and noise pollution, through the whole airport there are speakers that repeat the phrase "Mind your step" every 10 seconds of so.


I've had to spend quite a bit of time at the airport unfortunately (say 6 hours each time) and it felt almost like Chinese water torture. I could hear it for the next day after leaving the airport.

I find it very hostile.

If you regularly travel through Schiphol, you quickly work out where and where not to sit. Don't sit for an hour at a gate closest to end of a moving footpath. You will indeed go mad from the "Mind your step" and other announcements.

If you leave from the D pier, for instance, enjoy a coffee at the restaurant halfway down until 30 mins before your flight departs. Then walk to your gate, getting there just in time to stand near the front of the queue for your boarding group.

(I had three years of travelling Schiphol to London each week, and now do it roughly monthly...)

Haha, thanks for the heads up. I've been there less than 10 times total and I tried to figure it out previously but I never wanted to go too far from my gate.

I'll keep this in mind for next time.

These are typically at the exits of the moving walkways to warn people that they are about to hit terra firma, and face first if they are not paying attention which is pretty easy given the length of some of them.

Hearing "Mind your step" all the time won't help with this. I was at Amsterdam airport and hearing this hundreds of times drove me crazy while at the same time wondering what it means. They should put up signs at the end of each walkway so you get a warning in context. Hearing "Mind your step" while sitting at the gate doesn't help.

Haha yeah even 20 minutes is too much.

You are correct but it's hard to escape that sound. Maybe I was always at the wrong terminal.

Article did not spesifically mention air layers, temperature inversion and downward refracted sound waves. Curved waves in the images imply this condition, no? Tropospheric propagation in hamspeak.

Changing the color of the landscape might also have a small effect on how the area heats up on sunlight and so how often unusual sound propagation develops. silly...

This could have been made into an awesome BMX/skate park. In terms of usage, I don't know what gets better return for public land.

Next time you're at a park with a skatepark, I bet you'll see it's packed, and generally there is a totally disused baseball diamond next to it.

There aren't that many people willing to go to a skate park next to an airport, it's way too far.

I once flew to China to skate SMP outside of Shanghai. Every year thousands of people go to Rutland, Ohio for Skatopia. If the airport is accessible by transit, of course people will go to use it. At least more people than would go to visit "land art".

Anyway, the point is that you're building it anyway and it looks super skate/bikeable because it's just a bunch of ridges. Add a few more obstacles and bam, awesome skatepark.

I wish SJC could do something more about the noise pollution. At every hour of the day starting at 6 AM sharp (and often at night past the "curfew"), there are deafeningly loud jets taking off and landing overhead to the point where it even disrupts indoor conversation. When I lived there in Santa Clara, I had to wear earplugs to sleep at night, and needless to say, I was out of there once my lease was up.

> The plan is to achieve a noise reduction of up to 10 decibels.

If they can achieve that goal, it sounds very good [1].

1. https://en.wikipedia.org/wiki/Decibel

Looks like the same design as in a https://en.wikipedia.org/wiki/Anechoic_chamber

> These simple ridges have reduced noise levels by more than half.

Great, now we can increase air traffic by a factor of two! /s

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact