Hacker News new | past | comments | ask | show | jobs | submit login
The Afsluitdijk (theafsluitdijk.com)
239 points by jacquesm on Dec 21, 2019 | hide | past | favorite | 100 comments



Less commonly known facts about the Afsluitdijk:

The plans for the dyke originally included a railway line. This never happened, but the idea has resurfaced frequently in the past century.

The Afsluitdijk was also a defensive structure, part of the defence of Holland (the collective name of the two provinces that are home to the government and a large part of the population). When the Germans invaded, the Afsluitdijk fortress with its concrete fortifications (called kazematten) and strategically advantageous position actually held, i.e., it never fell under combat, despite attempts to overtake it. The Germans went round the other side of the IJsselmeer and the Netherlands capitulated before the Wehrmacht could take the position.

The Kazematten museum on the dyke can be visited, and should appeal to all military aficionados.


The defensive position at Kornwerderzand can still be seen clearly on satellite imagery and maps:

https://www.openstreetmap.org/#map=15/53.0706/5.3351

The bunkers covered the approaches by sea and dyke quite well from the piers extending into the sea and lake.


For those interested in what it protects: https://i2.wp.com/upload.wikimedia.org/wikipedia/commons/thu...

Also, this enclosure lead to former islands being enclosed by new land: https://en.wikipedia.org/wiki/Schokland


For those wondering: https://www.google.com/maps/place/Afsluitdijk,+Netherlands/@...

Only after looking at the map did I realize how big it actually is.


Or if you want a more detailed and up-to-date map:

https://www.openstreetmap.org/#map=10/52.9846/5.1904


For another size reference: traversing it takes about 20 minutes. 20 minutes of nothing but water on both sides. It's quite a surreal drive the first time.


Currently the afsluitdijk is undergoing a major upgrade. The hydraulic tests (scale 1:2) have just about been concluded. Unfortunately not too many videos are public, but found this short one https://m.youtube.com/watch?v=58W6870d1PM


The video says scale 1:3, but still impressive.


The afsluitdijk allows for saline sea water right next to clean fresh water due to the rivers ending in the ijselmeer displacing the seawater form the inland sea. I wish the Dutch government would fund projects like redstack which try to generate energy from the saline difference on the afsluitdijk while they renew things. It seems so much easier to do both infrastructures at once (redstack and blue energy as a whole is still expirimental though).


From the featured page: "At the Afsluitdijk we are using water currents and the confluence of fresh and salt water to produce energy."



One of my favorite Youtube channels, The Tim Traveller, did a video on this dam/highway: https://www.youtube.com/watch?v=6r6zcMl2Xmw


Another great video, thanks.

I’m enjoying his videos on the Low Countries. Lots if fascinating details in an area I sid not think to be interested in.


That video was somewhat inaccurate :-/


It helps if you explain in what way


The geometry, hence tiling, of the concrete blocks used is quite interesting

https://www.youtube.com/watch?v=HvUG6VNcNR0


The craziest fact about it is that mats of willow branches are a major part of its internal structure. Sustainable rebar


In the Netherlands a lot of houses are sitting on wooden poles that stand on sand plates below the surface. The problem we have right now is drought. As long as wood sits below the water it will not rot. But since we had some very dry years the water levels in the ground have gone down and the wood might start to rot and attract fungi.


Even today willow branch mats are still used. They are used primarily for support structures during construction so durability is not always an issue (though of course submerged wood lasts pretty long anyways).


When I visited Amsterdam I saw these ancient looking witch's brooms everywhere- when they clean the streets, it's guys with witch's brooms in front of modern cleaning trucks. I talked to a number of people who said they worked better than the modern style (and indeed, watching the cleaners do their job, it was clear the witch's broom excelled at reaching into tiny corners and pulling out things before the truck came through).


There's lots of wood under Manhattan and Philadelphia, too.


Underground, by David Macauley, is a great book about what it's like underground in Manhattan. https://www.amazon.com/Underground-David-Macaulay/dp/0395340...


From wikipedia:

> The Afsluitdijk (Dutch: [ˈɑfslœydɛik] English: "Enclosure Dam") is a major dam and causeway in the Netherlands. It was constructed between 1927 and 1932 and runs from Den Oever in North Holland province to the village of Zurich in Friesland province, over a length of 32 kilometres (20 mi) and a width of 90 metres (300 ft), at an initial height of 7.25 metres (23.8 ft) above sea level.

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


Also interesting are the art projects that were created as part of the dam's modernization project. Icoon Afsluitdijk: Lighting at zero consumption

https://urbannext.net/afsluitdijk/


There's an entire "state" (well, a province) called Flevoland with around 2.4 thousand square km which wouldn't exist today without that dam.



Would engineering be able to keep up with something like Meltwater Pulse 1A [1], when sea level rose at 50mm/year? Could climate change cause another pulse like that?

[1] https://en.wikipedia.org/wiki/Meltwater_pulse_1A


Truly impressive design and engineering work here! Not to mention the commitment to the project.


Interesting fact is that Hendrik Lorentz, the Nobel prize winning physicist, did much of the calculations on how the tide would affect the structure. Based on his calculations the structure was moved to a spot were the movement of the water would have less of an influence.

It’s quite a feat of math and engineering considering that no computers were available to do real simulations.

Interesting paper describing some history and some of the math involved: https://ilorentz.org/history/zuiderzee/Lorentz_linearisation...


> ...commitment...

When 26% of your country lies below sea level you tend to be motivated ;-)


This. That is why people here prefer to go at it together. They’ve been joining forces for centuries to battle the water. (Next to the Afsluitdijk is the “Oude Bildtdijk“. It was made in the year 1500.


Really? It hasn’t motivated Bangladesh.


Not successfully, but it has motivated e.g. Japan to combat earthquakes (with building design). On top of that, Bangladesh is a poor country.


This is also new to me as a Dutchman: a bus for bicycles!

https://theafsluitdijk.com/fietsbus-dienstregeling/


I've done the Friesland->Noord Holland direction once against a force 5 wind and I distinctly remember wishing for that bus to come into existence so there you have it :)

(This was 30 years ago or so).

I cycled around the lake inside 24 hours, it was quite the trip.


There is also a smaller version called the Houtribdijk: https://en.wikipedia.org/wiki/Houtribdijk

This dijk runs from the city of Enkhuizen to Lelystad and is about 30 KM in length.

Instead of four lanes for traffic, it has only two lanes as it is not as wide as the Afsluitdijk.


How does that fish migration route work?

Is it simply that the winding path means a slower flow from higher to lower level? i.e. water at a gentle slope and thus slower flow?


Any idea what this will cost? Also, unrelated, did anyone else notice that this only uses letters from the home and top rows of the keyboard?


> Any idea what this will cost?

The budget for design, construction and 25 years of maintenance is ~€550 million.[1][2][3]

[1]: https://www.cobouw.nl/infra/nieuws/2018/02/bam-van-oord-en-r... [2]: https://www.rebelgroup.com/en/projects/a-winning-plan-to-rei... [3]: https://deafsluitdijk.nl/wp-content/uploads/2014/05/presenta...


I don't think the renovation will be very expensive. The creation was, but it was the first step in creating a shitton of land, and also the first step in protecting a lot of coast from storm surges.


The Dutch I've met pronounce it something like "UFF-sly-dike". Worth visiting if you're in the area.


I like how the concept image of the new A7 highway prominently also shows bike lanes with a couple of bikers :)


I thought this was going to be an ad for a keyboard layout.


Not to be confused with Opleidingsinstituut Qwerty.

http://qwertyopleidingen.nl/


I'm overly happy that I'm not the only one who thought that.


What about it makes it sound like a keyboard model? As a Dutchman I'm having a hard time ignoring the real meaning and seeing what keyboard related thing it resembles in English.


The middle row of a Qwerty keyboard starts asdfghjkl, and I think that to people who aren't used to it that looks similar.


It even uses 7/9 QWERTY home row letters (asdfjkl) and only three non-home-row letters (tui, all from the top row). That feels very credible as keyboard-mashing output!


It looks like I rolled my face over a keyboard.

None of the potential substrings make any sense to me, so it’s one long jumble.


Hehe okay. Not sure it's mentioned anywhere: it consists of two words (similar to English compound words like "sundial"): afsluit and dijk, where dijk pronounced similar to dike and means the same. Afsluit is less close to English and means "enclosure". The enclosure dike.

Wikipedia says "enclosure dam", which is more accurate since a dam has water on two sides, as the afsluit-dijk does, but that's not what we call it in Dutch. Then it would have been afsluitdam -- yes, dam and dam are the same in Dutch and English, just like dike and dijk are very similar. Wonder why! :-)

Edit: not sure why you're being downvoted?! I always find it rude when people downvote without comment (also on stackoverflow, I typically comment when I see it on my own or someone else's posts).


As a native English speaker with Dutch colleagues, I've always thought Dutch was remarkably close. Once you kinda figure out pronunciation patterns a lot of it is very similar. Written Dutch is the only language I intuitively perceive the cognate rrelationships with.


Supposedly we are the second-closest language to English linguistically (I'm not sure by what measure - I'm not a linguist). Only Frisian, which has many similarities to Old English, is closer.


FWIW, the German translation would be "Abschlussdeich".


Ah. That’s where the name Dijkstra comes from, ey?


I don't know what the -sta suffix means, aside from that it's a last name suffix (Hoekstra comes to mind, a last name which could be translated as corner-stra or angle-stra). It's not very common though and I can't think of any other -stra names. My first thought is that someone named Dijkstra historically constructed dikes, but then Hoekstra constructed... corners or angles?! Unless hoek had a different meaning in the middle ages, that can't be it.

Edit: https://nl.wikipedia.org/wiki/Dijkstra (English page does not contain the important part)

Apparently -stra comes from some germanic word meaning "owner". I suppose Hoekstra owned the corner house and Dijkstra the dike.


> The suffix "-stra" is, like "-ster", derived from the old Germanic "-sater", to be translated as a seater or resident.

-- https://nl.wikipedia.org/wiki/Dijkstra (through Google translate)


That's how I felt when reading about Djedkheperew (an Egyptian pharaoh) the other day.

https://en.wikipedia.org/wiki/Djedkheperew


Whereas I wondered the precise meaning and original tongue of this insult.


Or an IKEA product.


Speaking of Dutch engineering feats, I realise now that we kind of dodged a bullet there in terms of pronunciation. The mutex could easily have been called the afsluitdijkstra ;-)


> The mutex could easily have been called the afsluitdijkstra ;-)

That's amazing/hilarious :) But I bet they'd quickly shorten it to a13a ;-)


It’s the first part that’s hard! Dijkstra is easy and a pretty common name—at least in Ontario, spelled Dykstra.


Dijkstra is easy to spell because it contains the three most popular FORTRAN integer loop indexes.

https://stackoverflow.com/questions/1147312/who-invented-i-j...

Speaking of control flow, Dijkstra worked closely with Bram Jan Loopstra:

https://en.wikipedia.org/wiki/Bram_Jan_Loopstra


Interestingly dijkstra is a Frisian name. Frisian is closer to english than Dutch is.


When a Dutchman writes "ij", it looks like "ÿ".


Yeah especially when writing cursive. It's because it's technically one character or something. It's even got its own unicode: ij

Not sure if it really counts as a ligature, though.


Makes sense. It’s a common phoneme :P


I guess the pronunciation of afsluit might be approximated as "uhfsloit".


Yes, with a small correction - "uit" is loosely pronounced as "out". A huis is pronounced like a house. Well, close enough anyway :)


The english "out" is pronounced like the dutch "oud". Would you say "oud" and "uit" are the same? An afslouddijk sounds different from an afsluitdijk. The english "oid" (as in humanoid) I think is closer to our "uit" sound than "out" would be.


Disclaimer: don't speak Dutch; no training in Dutch; going solely off of wikipedia.

Wikipedia tells us that Dutch "ui" is the diphthong /œy/ and "ou" is the diphthong /ɑu/. The English MOUTH vowel is conventionally /aʊ/ in American pronunciation, and the CHOICE vowel is conventionally /ɔɪ/. I will analyze them as if they were /au/ and /ɔi/.

It's clear that the MOUTH vowel is the best available English match for Dutch "ou". The difference between [a] and [ɑ] is minimal.

Dutch "ui" is trickier. /œy/ starts with a front vowel, which isn't true of /au/ or /ɔi/. /ɔ/ is a better match in terms of vowel height. (According to the notation. This is a case where you're probably better off just listening to samples; vowel notation is quite sloppy.)

/y/ is the high front rounded vowel, a sound which, like /œ/ (mid-low front rounded), does not exist in English. It has two obvious approximants: FLEECE (/i/), the high front unrounded vowel, and GOOSE (/u/), the high back rounded vowel. If you choose FLEECE, prioritizing the vowel's frontness, you'll end up thinking that "ui" should correspond to the English CHOICE vowel -- the first part of the diphthong has been moved back, and the second part has been unrounded, but compromises have to be made. If you pick GOOSE, then you'll end up on the MOUTH vowel -- in this case, the first part gets moved back and lowered somewhat, and the second part also gets moved back but preserves its lip rounding.

Is either of those choices objectively right? No. You might prefer thinking of "ui" as CHOICE on the grounds that that makes it different from "ou", but that runs into the problem that (according to wikipedia again) Dutch also includes an "oi" diphthong which is a close match to English CHOICE.

You could think of the root of the problem as being that Dutch has three high vowels /i/, /y/, /u/ (spelled "ie", "uu", "oe" among other ways, according to https://en.wikipedia.org/wiki/Dutch_orthography ), where English has only /i/ and /u/. You're going to end up with collisions somewhere.


I guess the 'ui' and the 'g' are hardest to pronounce correctly for non-native Dutch speakers.

We have a tongue-twister for German and English people that goes like this "Ik eet uitsluitend gefruite uien in mijn geruite keuken" (you can have Google Translate read it out loud). Meaning is "I only eat fried onions in my checkered kitchen".


> Meaning is "I only eat fried onions in my checkered kitchen".

That sentence is more ambiguous in English than you might think! I'm curious which of these meanings are compatible with the Dutch:

1. The only thing I do in my checkered kitchen is eat fried onions. (Other activities don't take place in the checkered kitchen.)

2. Fried onions are the only thing I eat in my checkered kitchen. (Other foods must be eaten elsewhere.)

3. Fried onions are the only type of onion I eat in my checkered kitchen. (Raw onions must be eaten elsewhere, but eating steak in the kitchen is OK.)

4. My checkered kitchen is the only place in which I eat fried onions. (I'll eat steak anywhere, but I won't eat fried onions outside the kitchen.)

5. My checkered kitchen is the only one of my kitchens in which I eat fried onions. (I'll eat steak in any kitchen, but I won't eat fried onions in my plain white kitchen.)

6. My checkered kitchen is the only checkered kitchen in which I will eat fried onions. (I won't eat fried onions in your checkered kitchen, but I will eat them in the bedroom.)


I believe it's more accurate as "I exclusively eat sauteed onions in my checkered kitchen".

The only one it's not compatible with is 4, in that case the word "uitsluitend" ("exclusively") would appear elsewhere in the sentence.

Each of the others are ambiguous when written, but should be clear given pronunciation (emphasis), or the tiniest bit of context.


Ha, that's cool. You found a lot of different interpretations. These also exist in Dutch. No. 3 comes closest to how most people would understand the meaning in Dutch, but some others like no. 4 would fit too.


I read it as having meaning #2 but it depends on the intonation and context. If you emphasize fried then it's #3. If we're talking about having fried onions and not in your kitchen I'd probably assume #4.

As for which ones work in Dutch, all of them.


Number 4 would be "Ik eet gefruite uien uitsluitend in mijn geruite keuken", though.

It mostly gets confusing for me because of moving back and forth between English and Dutch grammar, but any bit of context would make it a lot less ambiguous :)


Most things germans try to pronounce are just way off in general (living in germany, the topic comes up regularly), but by far the worst seems to be the sch as in Scheveningen or schatje. It usually turns into skatje and since that isn't a soft sound they morph it into an angry word to make fun of how our word for sweetie sounds after morphing.


I must admit that this is a little beyond me and I don't really understand what you're trying to say. Do I understand correctly that you're saying the vowel in choice is the best match for the Dutch "ui" when going off of the IPA notation, but that there exists no good match in English like there is for "ou"?


I'm saying that (1) there is no perfect or near-perfect match; (2) it isn't clear which available option is the "best" match, because the three obvious options each sacrifice something different.

If you're interested in the theory:

Vowels are generally thought of as being points in a three-dimensional space. The dimensions are:

1. Whether the vowel is high or low -- if your mouth opens wide (chin closer to feet), it's a lower vowel; if your mouth doesn't open far (chin closer to eyes), it's a higher vowel.

2. Whether the vowel is front or back. The traditional way to explain this to linguistics students is to give them all lollipops. You put the lollipop on the middle of your tongue with the stick jutting out of your mouth. You can observe that the stick juts farther forward when you're pronouncing the FLEECE vowel than it does when you're pronouncing the GOOSE vowel.

3. Whether, as you pronounce the vowel, your lips are rounded or not.

Dutch "ui" is a diphthong, a transition from one vowel to another vowel. It appears to be a transition from (lowish, front, rounded) to (high, front, rounded). This is difficult for English because, in English, all front vowels are unrounded.

If you'd like to preserve the lip-rounding aspect of "ui", you need to use back vowels, at which point the MOUTH vowel is a near-perfect (low, back, xx[1]) -> (high, back, rounded) match.

If you'd like to preserve the frontness of "ui", the English FACE vowel is available, which is a transition from (lowish, front, unrounded) to (high, front, unrounded). CHOICE is a different option; it's (lowish, back, rounded) -> (high, front, unrounded). With CHOICE, you're choosing to match the rounding (and not the frontness) of the beginning of "ui", but transition into an end that matches frontness instead of rounding.

Which part of a sound is more important for purposes of matching a foreign sound to a native sound is a very interesting question, and to the best of my knowledge nobody has any idea why different languages make the choices they do. My (American) ears think the MOUTH vowel is the best match for Dutch "ui", even though it's an even better match for Dutch "ou". But someone else might disagree.

For an example of "differential splitting", consider that in modern English, W, V, and F are three separate sounds. In Old English, W and F were "real" sounds ("phonemes"), and V was a variety ("allophone") of F. In modern Mandarin Chinese, W and F are also phonemes, and V is an allophone of... W. Clearly, if you speak modern Mandarin, what's important about the V sound is not the same thing that would be important if you spoke Old English.

[1] Rounding is less obvious for low vowels -- a certain amount of lip rounding is induced by opening your mouth so far.


That was actually very interesting! I understand what you are saying now (admittedly I first thought "more theory? Not sure", probably because I had a very hard time following your last comment). I actually get it now and feel like I learned something new. Thanks for that write-up!

As for

> My (American) ears think the MOUTH vowel is the best match for Dutch "ui",

I personally stand by my choice of the CHOICE vowel also after reading your comparison of the different options, but it's definitely a close contest.


W, V and F are also separate sounds in Dutch, but much closer to each other than in English. Wat, vat and fat are different words. The Dutch W is not bilabial like the English W, but just a "softer" version of the V. (In practice, V is often pronounced almost the same as F).


Can you make the ö in FÖHN? Because if you go from the "ah" in AFTER to the ö in FÖHN, right on the transition you'll do a good "ui" for AFSLUITDIJK.

Using the MOUTH vowel in that word would reveal an English speaker immediately ;-) (Germans mess it up differently ;-) )


Thinking about it some more, you can get more easily away with the "eh" in MEH (not the /ə/ but the /ɛ/). That way you'll sound like someone speaking with a The Hague accent, and if you're otherwise speaking English, this will most probably slip by completely unnoticed to most Dutch listeners (unlike OU or OI would).


Certainly not the same.

https://nl.forvo.com/word/ui/


That's my point ;) I think ui sounds more like the English oi than like the English/Dutch ou. I'm not sure there exists a word in English that contains the ui sound as we know it.


Pronounced


Yeah. Dijkstra is easy. It’s really common around the Hamilton, Ontario area where there’s a large Dutch population.

At least in bastardized Anglo pronounciation it’s always been: Dike-struh

No idea what it means, though from the context of this thread I’m assuming it has something to do with dykes!



Interesting. I like this guy.


It basically means dike-ster (from dike-sitter), someone who lives on or near a dike. The -a is a remnant of an old grammatical case.


Also spelled. Just as an example (and not only in Canada): https://en.wikipedia.org/wiki/Rick_Dykstra


Seems like afsluitdijk corresponds closely to the hypothetical English off-sluice-dike.


Sluice is a direct cognate to Dutch sluis, with the same meaning. The sluit in Afsluitdijk comes from a verb meaning "to close", which is indeed also cognate, but much more distantly: sluiten is inherited from a Germanic root sleutaną, but sluice/sluis comes from Latin exclūdō; both originate from Proto-Indo-European (s)kleh₂w- "hook, peg, nail", which has many descendants, from the Latvian verb for "to become" (via a meaning "to bend") and the Russian for "walking stick" to English cloister or French clé "key".


At first glance, I thought this was some humor post about an object with a name made by randomly mashing keys...


This post is in the front page of HN because of this initial confusion. Otherwise that was no larger deal compared to other projects that are going on around the world.


What's the confusion here? The site makes pretty clear it's about an engineering project, doesn't it?

And there's plenty of cool about this project, from the reusable kingsize lego-like blocks used to strengthen the dike, to the meandering river for fish passing throuh the dike. There's also a VR video.


The passage for fish is highly needed. Eels are almost extinct in the Netherlands. The adults are inside the country in sweet water, but they cannot get out due to sluices and pump stations. They get slaughtered there.

They need to get out to sea to make a journey to make offspring. That offspring sometimes gets caught in France on the way back, where it is grown and sold in the Netherlands. Fishing results from IJsselmeer can also be found in shops but they are not easy to catch anymore. I would think, for statistic reasons, the caught eels in France might be more sustainable than catching grown eels in the IJsselmeer. The real solution is to work out better sluices and pump stations, so fish can pass again.


I know, mega engineering projects dealing with sea level rise are so lame. But maybe if it were using block chain to hold back the sea...


Is this designed by the same people as https://ableton.com I wonder... Definitely a similar aesthetic.




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

Search: