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I see this a lot in the rural US with wooden fences but had no idea why it was done, but I guess its for the same reason (stability). Apparently they've done it since the 1600s.
https://www.louispage.com/blog/bid/11160/worm-fence-what-is-...
Still, this seemed totally unecessary until I realized this mean they dont have to put any posts into the ground. No digging holes, which would be really nice when you're trying to fence up very large acreage.
Those fences are also popular in places where it is cold in the winter. No posts in the ground means no frost heave. A fence like that can sit unmaintained for decades before it starts to fall apart.
Not digging post holes would help, but the real time savings would be in not having to saw the logs to produce boards.
It only takes a couple minutes to split the log, and would be less tiring than trying to saw the number of boards you’d need for a fence. You can also use smaller logs you’d otherwise ignore or use for firewood due to low yield when sawing.
For that matter, you don’t have to worry about milling, joinery, or bringing enough nails to fasten boards. You can also use green wood without any worries. All you have to do is stack.
In a world without power tools, the split-rail fence really was an ingenious design. It effectively removed the skill requirement altogether, and let you spend your time on more urgent tasks.
I used to make fences in Wales, with it famously rocky ground. The fences we made were effectively straight lines which were bound at each terminal point by big posts dug into the ground and braced with side struts. Installing one of these posts could take a full day.
Have you ever tried the wavy one? I'm curious to hear from a first hand experience
Nope. Never tried the wavey one. I can't remember hearing of wavey walls/fences until a few years ago.
Talking about all this again brings back some memories. My hands freezing from digging in the rocky soil. My hands aching from swinging the club hammer I used to compress the stones around the oak post to form a foundation. Trying to start the chainsaw in cold weather. Taking the tools back to the toolshed in a squeeky-wheel wheelbarrow. All good memories. It's been forty years since I made a fence but I could do it tomorrow with no problem, and gladly.
The US is so bad at naming things!
A Serpentine Wall sounds better than a Worm Fence or Snake Fence.
Crinkle Crankle Wall is a bit more fun than ZigZag Fence.
A Ribbon Wall seems like a nice thing to have on your property vs a Battlefield Fence.
I'd much rather have a Battlefield Wall on my property in the US than a Ribbon Wall or Crinkle Crankle Wall. The latter two sound ridiculous. I really like "Serpentine Wall", but it sounds a little too technical for everyday conversation with nontechnical people
I suppose it's subjective but Crinkle Crankle is better because it sounds so ridiculous.
Ribbon Wall doesn't sound any more ridiculous than same-shaped Ribbon Candy (https://en.wikipedia.org/wiki/Ribbon_candy) or Ribbon Cables (https://www.fxpstore.com/wp-content/uploads/2020/09/ribbon-w...), and ribbons don't call to mind atrocities or human suffering. Battlefields are terrible places where horrific things happen. That's not something I'd want associated with my own property.
Crinkle crinkle wall has to be the most British sounding britishism ever. Like something that would have been a subject of serious research at the Ministry of Silly Walls.
True dat, bruv.
And that's jenga.
And that's Number Wang!
The value in this is the historical dimension. Apparently, "crinkle-crankle" dates to 1598. So it's a pre-US term.
I agree that it's not a good look to automatically prefer the military term to the "ridiculous" one. It smacks of toxic masculinity.
"Crinkle-crankle" is obviously archaic, and it evokes folk art and (in the US) colonial culture. That is fairly neutral, as placenames go.
It doesn’t sound technical at all. It sounds like you’ve read a book or two beyond the abc and cat in the hat. But then, US education.
> The latter two sound ridiculous. I really like "Serpentine Wall", but it sounds a little too technical for everyday conversation with nontechnical people
ribbon sounds ridiculous and serpentine sounds technical? you are not a boomer. "Serpentine, Shel, serpentine!" -- Peter Falk
https://www.youtube.com/watch?v=A2_w-QCWpS0
Alan Arkin just died recently, RIP
This is a perfect summation of the differences between USians and British.
You want a BATTLEFIELD wall. I want a Crinkle Crankle
Please avoid nationalistic flamebait on HN. It leads to nationalistic flamewars, which we're eager to avoid - https://news.ycombinator.com/newsguidelines.html.
I realize some of this is lighthearted banter but sadly Mr. Internet can't really do that for very long.
I wouldn't say it's flame bait.
It just seemed to me a very good example of '2 nations divided by a common language'
But I'm more a celebrate the differences kind of guy.
But point taken about the internet being the internet.
As the janitor who has to put out these fires (mixed metaphor, but accurate) I promise you it's flamebait. That's a question of statistical outcomes, not personal taste.
It would be nice if it were otherwise but for that you need a much smaller and more cohesive group. Large internet forums can't work that way - the long tail is too big, and there's always a supply of triggerable commenters.
This is because you lost the Revolution.
Why is it referred to as a revolution? A revolution tends to refer to the overthrow of a govt within a single nations border, whereas one country splitting from another tends to be referred to independence.
I don't really see the cause and effect either. Surely the USs love of FORTRESS walls would be a reason they won?
Anyway, you say lost. I say we got rid of the tea wasters. Sounds like a win to me.
That's just like, your opinion man. Worm is a cool word. Maybe we can compromise and call it a wyrm fence.
A worm fence sounds like it should be a couple inches tall and several feet deep, to block the worms.
Wyrm fence is a great name! I'd use one to keep my hoard of treasure safe
Sounds like the name of a startup thats going to put fence contractors out of business in a few years before getting sued for not classifying their workers as employees.
Wyrm = dragon. Wyrmwall/fence would actually be a cool name.
I grew up around these fences and never heard them called anything but a split-rail fence. Seems apt.
I'd've called it a chazzwozzer.
Thats because you're Australian.
Although yours are probably highly venomous too.
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They're in the lorry and the larder and...
The park service uses this type of fencing a lot.
they don't use less wood than a straight fence though :)
they should be able to. same physics applies, right? poles dont have to be as thick or as deep to resist the same torque, and if you could somehow make the pales curvy/corrugated, they could be thinner, too.
Wooden fences tend to be only a plank thick, so there's no savings like there are with brick walls where the savings come from getting to build a single layer thick.
Raw lumber is much cheaper than sawn lumber, though. It's OK to use more, as long as the volume increase and price decrease works out favorably.
Yeah exactly… I guess there might be some waviness/height/length ratio where the extra length and the absence of posts evens out.
John Cook actually goes into the math of that here: https://www.johndcook.com/blog/2019/11/19/crinkle-crankle-ca...
Interesting pictures.
Not a complicated subject, but somehow seeing it with straight lines made it completely obvious and intuitive vs the wavy wall.
it's not for stability, it's because it doesn't require posts so it's cheap and quick
But it is for stability. Try making a straight fence with no posts and see how stable it is.
> it's not for stability, it's because it doesn't require posts
That’s stability
Lots of things "don't require posts so it's cheap and quick", but this version makes a stable wall.
I think one should also consider the failure modes when, for example, a tree falls into the wall. For a straight wall, it is possible that a falling section will propagate the failure along the entire length of the wall. For a wavy wall, it is likely to fail in shear, limiting the damage to one section.
Corrugated cardboard just is a wavy wall, sandwiched in between two straight walls.
You can also observe corrugated steel and its use in construction, shipping containers, etc. Because these are steel and stronger than paper, the sandwich layers are not needed
You can also peel the label of a tin (can) of baked beans in your cupboard to see the the ripples added for rigidity.
as a bonus, they make canned cranberry sauce visually appealing on the Thanksgiving platter :)
Ever notice there’s a subtle fold in the shape of an “x” in the middle of the sheet metal panels that make up ductwork?
Undulations for rigidity are everywhere!
If it wasn’t for fashion it would probably be the most popular building material for roofs. Make your roof out of that and at an angle and you probably never worry about leaks for decades.
It's all over the place in impoverished areas, often with a bunch of rocks or tires on top to weight it down. If you actually stay in such a structure though, it quickly becomes apparent how little it offers in the way of thermal or acoustic insulation. The sound in a heavy rainstorm can be deafening.
You can mitigate the issues with proper design, but at that point may as well use a real metal roof or a prebuilt.
Roof tiles are just that, but made of a material that stands water much better than than any metal. In any case, corrugated roofs made of asbestos where really popular until people realized they were not good for their health.
Car floor tunnels serve the same purpose. Increase rigidity at low material cost.
Another reason for some a wavy walls involves capturing more heat from sunlight over the course of a day, in this example for nearby plants:
> The Dutch, meanwhile, began to develop curved varieties that could capture more heat, increasing thermal gain (particularly useful for a cooler and more northern region). The curves also helped with structural integrity, requiring less thickness for support.
[0] https://99percentinvisible.org/article/fruit-walls-before-gr...
I learned about this and a lot more about walled gardens when I searched for the orgin of the term "walled garden" to do with technology today.
Very interesting. Thank you for the link!
Soda cans also have a counterintuitive efficiency feature: concave bottoms. If a can with a flat bottom held the same amount of soda, it would be shorter and have less surface area, but its metal body would need to be thicker to withstand the same pressure. In the end, it'd require more aluminum.
https://www.csmonitor.com/Science/Science-Notebook/2015/0414...
^Probably not the best article for this, but it was easy to find and has a link to a chemical engineer's video.
Engineer Guy (Bill Hammack) has a great video about this.
https://www.youtube.com/watch?v=hUhisi2FBuw
Edit: Just realized this is the same video you referenced. All of his work is fantastic.
I've encountered a few of his videos on wikipedia (creative commons license.) Pretty neat.
His 'drinking bird' video is used on the wikipedia page for the same: https://en.wikipedia.org/wiki/Drinking_bird#Physical_and_che...
I really liked this video when I watched it. I may have watched it twice.
> All of his work is fantastic.
Even that is an understatement, I love those videos
Same about waviness on plastic bottles.
https://www.riverkeeper.org/wp-content/uploads/2018/04/bottl...
The waviness around makes it easier to hold them too. Although to some degree it might be marketing as well?
It's a combination of structural variation, like with the bricks, and branding. Because as long as it's "waving" it doesn't matter how exactly it waves except in some critical areas, like where you hold it, the bottom and the top.
Standard video:
"The Ingenious Design of the Aluminum Beverage Can"
https://chbe.illinois.edu/news/stories/engineer-guy-ingeniou...
I think that's also why a pretty small kink in the can will make it tremendously easier to crush against your forehead as a party trick :-)
Or, more likely, it's a similar principle also at place in the design.
Same with cans, corrugated sides, tops and bottoms are for strength and pressure resistance. Actually most corrugated anything is done so for strength.
I think the Christian Science Monitor is perfectly fine. https://mediabiasfactcheck.com/christian-science-monitor/
The religious group that funds it has a questionable relationship to science including and despite "Science" being in its name. (It was started as a 19th Century anti-hospital group. We'd consider them "proto-anti-vax" in today's concerns and terminology.) They may be unbiased in reporting the news, generally, but there's still concerns about their relationship to reporting science given their name and the known beliefs of their church.
> there's still concerns about their relationship to reporting science
Can you provide any credible examples of concerns regarding their reporting on science topics?
...being anti-hospital in the 19th century sounds fairly rational to me?
Sure, you can't fault them for not having some good reasons behind their beliefs, based on what they knew and experienced at the time. You can certainly fault them for calcifying those beliefs into an entire church with rituals/rites devoted to such beliefs that then became somewhat obstinate in the face of later scientific progress and technological advancement (and then because of that also complicit in later struggles of science versus pseudo-science and conspiratorial thinking).
Treating a hospital as an absolute last resort in the 19th century would be rational, but I'm not sure being "anti-hospital" would be.
Also in the current design you can stack them. This is probably worth something in terms of wrapping of pallets of cans.
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Same principle as concave bottoms on wine bottles (though the concern there is more about jostling and impact during transport than pressurized contents).
Aluminium's also more expensive than steel but experiences sufficiently less breakage to justify the price.
The University of Virginia, designed by Thomas Jefferson, features numerous brick serpentine walls.
https://www.google.com/search?q=uva+serpentine+walls&tbm=isc...
Related:
Crinkle Crankle Wall - https://news.ycombinator.com/item?id=33155781 - Oct 2022 (1 comment)
Wavy walls use fewer bricks than a straight wall (2020) - https://news.ycombinator.com/item?id=25359550 - Dec 2020 (1 comment)
Crinkle Crankle Wall - https://news.ycombinator.com/item?id=21554986 - Nov 2019 (56 comments)
This feels a bit like diet clickbait...
"use fewer bricks than a straight wall"*
*A straight wall of the approximal strength and length of a wavy wall, not just length.
My counter would be that from a practical perspective the amount of space wasted by the wavy design seems to negate the usefulness of the design.
Probably makes the lawn crew dizzy when mowing it too!
The 'space wasted' on an estate of many hundreds, if not, thousands of acres is minimal. Given that often the bricks used were made and fired on site, it definitely saved on resources and labour.
There's a stately home close to me that has a very short run of one of these walls, and the remains of the old brick kiln up on the hill side. If you know what you're looking for, you can also still see the hollows in the ground where the clay was dug, now fill of trees and bushes.
It cost even less labor to use minimal bracing for strait walls, these are curved for athletics.
I suspect they are imitations of curved fruit walls popular in the 1600’s before greenhouses took off.
I don't think this is the case.
A wavy wall with a wave amplitude of X has the same toppling resistance as a straight wall with buttresses on both sides of length x/2.
Assuming this stackoverflow answer is correct[1], the sine wave has (slightly) less bricks.
A single repetition of the wave is misleading. For N repetitions of the wave you need N + 1 buttresses not 2 N.
Also, while brick is stronger in compression a buttress increases toppling resistance in both directions so you need to consider material properties not just the geometry.
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> A wavy wall with a wave amplitude of X has the same toppling resistance as a straight wall with buttresses on both sides of length x/2.
Where did you get that number from, and how does it change as you vary the distance between buttresses?
Assuming one pair of butresses (ie to prevent the wall toppling in each direction) per sine wave cycle.
But the math depends so strongly on how often the buttresses are needed, and the length of the buttresses, so you can't assume those things. The goal is a wall of equivalent strength, after all. If equivalent strength needs slightly less distance, or slightly smaller buttresses, the result could be thrown completely off in either direction.
"athletics" -> "aesthetics", right?
> these are curved for athletics.
Autocorrect strikes again.
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> hundreds, if not, thousands of acres
Sections (640 acres)
> *A straight wall of the approximal strength and length of a wavy wall, not just length.
The article suggests that, if you attempted to build a straight wall with a similar amount of bricks, that it would not be able to be freestanding (i.e. it would need to be buttressed or it would fall over). That's a significant feature of a wall to some people, so I don't think it's fair to dismiss the utility of that by suggesting that it's simply "less bricks for comparable strength," it's "less bricks for a freestanding wall."
If you want a freestanding brick wall, this seems to be the "ideal" way to do it, assuming you have the space required for the wave. I think the space needed would be a function of the wall height, so if you need a tall wall, you need more horizontal space for the wave and a wavey wall becomes less ideal.
> so if you need a tall wall, you need more horizontal space for the wave and a wavey wall becomes less ideal.
Not necessarily. You might need a straight wall to be thicker or have more buttressing in that case as well. The requirements for each (waviness, thickness, buttressing) likely change to different degrees based on height, so wavy walls could become less ideal, or they could become more ideal.
The extra space doesn't have to be fully wasted. You could plant bushes or small trees in the concave sections.
Indeed. Historically these walls have been used in orchards, where they are ideal. The wall serves an important function: it buffers heat. This can make all the difference, especially in late frosts, which are doom for the bloom. Of course, the added warmth can also mean you can grow varieties in a colder climate that you normally wouldn't be able to.
Applies to flat walls not wavy, but espalier,[1] a way to cultivate trees in tight spaces, is one of my favorite things ever.
I mean I don't see a reason why it couldn't be applied to wavy walls if they were high enough, it's just training isn't it?
Fair point. I've personally never seen it
This article mentions them, with photos:
https://www.lowtechmagazine.com/2015/12/fruit-walls-urban-fa...
Serpentine or Crinkle-Crankle walls, apparently a Dutch innovation.
> Although it's actually longer than a linear wall, a serpentine wall economizes on materials because the wall can be made strong enough with just one brick thin. The alternate convex and concave curves in the wall provide stability and help to resist lateral forces. Furthermore, the slopes give a warmer microclimate than a flat wall. This was obviously important for the Dutch, who are almost 400 km north of Paris.
> Variants of the serpentine wall had recessed and protruding parts with more angular forms. Few of these seem to have been built outside the Netherlands, with the exception of those erected by the Dutch in the eastern parts of England (two thirds of them in Suffolk county). In their own country, the Dutch built fruit walls as high up north as Groningen (53°N).
Interesting, locally the same word is used for the structures used for cultivating climbing plants. Haven't really seen it done with trees.
I'm doing this with an apple tree right now :)
It depends how you define "wasted". If it were a flat wall, it'd give the interior more space by just pushing it out to the furthest point in the wavy wall. I guess you could say that whatever the magnitude of the wall is would be wasted.
If you have plenty of space but you're tight on money, it's an ingenious solution.
Good point. I'd say if you're tight on money I'm not sure a wall should be at the top of your to-buy list.
If you own a large amount of land than the savings add up. Especially if you live 250 years ago (or you want to match the walls from then) when bricks were not produced and delivered in massive industrial processes and large estates were more common.
Even in the modern era the cost is still relevant. Bricks are still pretty expensive.
If I have 100 acres (square), I need ~2.5 km of wall, at ~150,000 bricks for a 1m wall single brick-width wall (deter animals, mark property).
At the online prices I'm seeing ($0.65), that's ~$100,000. If I have to make it all double width, suddenly its $200,000. $100,000 delta is still pretty relevant for a modern small scale farmer.
The difference is people enclosing 100 acres today are either wealthy estates or using non-brick fences for farmers.
Historically, lots of countries had laws saying you had to enclose your land. If you didn't, then you might lose it.
In the days before wire, brick walls were a cheap longlasting enclosure method, especially if wood or stones weren't easily available.
wire dates to ancient sumeria i think; it was used for money before coins (because it's easy to measure out any desired amount of gold or silver)
It is if you're selling sheep milk and you don't want to lose your flock.
I think that’s typically a job for fences, right?
This sort of wall is, I think, just an aesthetic way of marking a property line/get some privacy.
Drive through rural northern England and you will see vast numbers of sheep moving through pastures that are bordered by old dry-stone walls. The roads will even have equestrian gates alongside them when they have stock grids to prevent the sheep from using the road.
It's all about adapting to local materials. The same technique was used by early settlers in New England (think about the ending of The Shawshank Redemption) because they had to get the stones out of the ground in order to plow and harvest - rather than just make a pile, they used the stones to build walls separating fields.
Depends on how long you intend to keep livestock and what materials you have access to. Well built walls can last a lot longer than well built fences; but fences may be less costly initially. But it might also depend on how crafty/destructive your livestock is.
I have a few acres of land and annoying neighbours. Stuff like this is relevant (though in the end I just went with hedging, which is cheaper and good enough for privacy)
It's relative. You might be "tight on money for building a wall" so you save money by building a wavy wall.
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Pre industrialism, almost everyone was dirt poor by current standards.
They were also dirt poor by current standards after industrialism started. It was well into the 19th century that laws like the Education Act of 1870 and the Trade Union Act of 1871 started distributing power to the common people of Britain outside of the traditional quasi-feudal system.
this is an overly cynical take. headlines are brief by necessity. nobody would read that and think that a curved line from A to B is shorter than a straight line between the same points.
the first paragraph explains it,
> these wavy walls actually use less bricks than a straight wall because they can be made just one brick thin, while a straight wall—without buttresses—would easily topple over
I recognize the cynicism in my observation, but is it fully unmerited?
I put the following prompt in GPT4:
create a professional title and a click bait title for the following article
Then provided the article. This was the output:
Professional Title: "Crinkle Crankle Walls: The Aesthetics and Efficiency of Serpentine Wall Construction"
Click Bait Title: "You Won't Believe How These Weird, Wavy Walls Use Less Bricks Than Straight Ones!"
I think you overestimate what people would reactively think when reading this headline
Every dip in the wave is an opportunity to plant beautiful bush, flowers, or shrubbery.
> This feels a bit like diet clickbait...
This is fun clickbait. Straight to the point, totally random quirky trivia, and most of the page is nice pictures. Love it.
Do you also think corrugated cardboard is wasteful?
Yes, of course I do, just like I believe that the Australia, like false equivalencies, don't exist.
Walls have purpose beyond neatly cut lawns.
This wall would work well at road field boundaries where a couple feet makes less practical difference than the large saving in materials.
The solution for the space problem is obvious: just make the wall wave in the longitudinal direction instead of the transversal direction.
lol, a compression wall! sounds good, but is it?
No space is wasted, unless you need to squeeze in a rectangle thing (e.g. tennis court, driveway) into a tight lot. But boundary disputes in urban areas are already bad enough so trying to define a wavey boundary wont be fun! That said how much freaking character would this add to a back garden!
wikipedia says:
"leading to greater strength than a straight wall of the same thickness of bricks without the need for buttresses."
I was trying to figure out how lengthwise it could have fewer bricks.
Also IMHO it looks horrible.
Yes, it's clickbait and nonsense. Obviously a straight wall would use fewer bricks. Your brick wall is going to be one brick thick either way, nobody is going to try to somehow make the straight wall as strong as the wavy wall. Most likely the straight wall is already way stronger than it needs to be.
If either design is too strong, then over could just use thinner bricks.
However, as the article indicates, the straight wall would not be as stable as the wavy wall. It needs buttresses to prevent toppling. That's the key advantage of the wavy design.
Amen to this. In a tabloidish sense.
I read the title and thought "duh". Maybe others were intrigued and clicked, but for me, this is just obvious. I had lots of legos, and own more now as a grandpa than, er, uh, I should. I guess spatial reasoning about bricks just is second hand at this point.
What the article likely leaves out, is that the all of the "corner only" touch points are going to create a more "pourous" wall. And collection points for crap.
You can see from the photos in the article that the amount of waviness is not so large as to result in large angles between adjacent bricks -- the usual mortar between bricks connects them and doesn't even look like it's all that much larger a mortar join than for a straight wall.
I feel like everyone this far is missing something, or perhaps just I am.
I understand that a wavy wall will be stronger than a straight wall of the same thickness, therefore if you need that additional strength it technically uses fewer bricks to reach it.
That said, if the alternative is a 2 layer straight wall, is the wavy wall equally as strong? Or is it just stronger than the single layer wall?
Without knowing anything about the subject matter, I’d assume that the strength goes in order of single-layer straight, wavy, double-layer straight. No? Seems like needing just the amount of strength the wavy wall provides, and no more, would be a fairly rare use case. Leading to double-layer straights most of the time anyway.
The wavy design is probably just as strong as the double layer (possibly stronger depending on the direction of force).
The issue with a single layer wall isn't really the strength between bricks, or the bricks themselves - it's that a single layer wall has a very narrow base and is subject to tipping over.
The wave in the design makes the base of the wall act is if it were MUCH wider, preventing the tipping action of a single layer.
So the wavy design is only as strong as single layer of bricks, but it has a base 2 to 3 times the width of even the double layer wall designs. It will be much more resistant to tipping forces, but less resistant to impact forces.
The thing about most walls is they aren't really load bearing - they just delineate owned space - so the wavy design is great for large properties. Much less great if it's a tiny space and you're losing a good chunk of sqft to the wave.
Additionally: you need the wall to be "stable enough", not "equally as stable as a double-layer base". Possibly, double-layer brick walls are over-engineered.
The article also mentions buttresses. I presume you can build a single brick wall and keep that strong with a buttress every x meters. I understood from the article that a wavy wall uses less bricks than that.
It's a matter of stability more so than "strength", no? Having never attempted to push over a brick wall, I'd guess that it'd be easier to do so for a straight double wythe than a wavy single... but yeah, baseless intuition here!
The base of a double wythe wall is still only like 7", which if you're stacking say 84" of brick on top of that... seems pretty unstable to me.
"Strength" is used to refer to things like wind hitting the wall, not a car. That is, the wall toppling, not breaking. So the wavy wall with its wide base is quite strong.
Well, tbf the article doesn’t even try to explain how wavy walls are stronger than straight ones, or how fewer bricks are needed.
It doesn't need to, a child understands this. The only thing the article needed to explain was how the title should be interpreted, and it did fine in this respect.
If any child supposedly understands this, why does HN consider this novel? The questions in this post also don’t support your comment.
There’s also no need to be impolite. If it’s such an easy concept that you actually already understand, maybe explain it in layman terms instead?
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This looks similar to the way corrugated steel is harder to bend due to a higher "area moment of inertia".
Did my adblocker accidentally filter out the explanation?
Following the link which is supposed to explain another thing, why it is more resistant to lateral forces, it contains an explanation:
> The parameter a is the amplitude of the sine wave. If a = 0, we have a flat wave, i.e. a straight wall, as so the length of this segment is 2π = 6.2832. If a = 1, the integral is 7.6404. So a section of wall is 22% longer, but uses 50% less material per unit length as a wall two bricks thick.
"as a wall two bricks thick". Hmmm. Even bigger savings as a wall three bricks thick.
The point is that a straight wall one brick thick will fall down.
Though I didn't see any real explanation of why a straight wall one brick thick will fall down...
It doesn't have the vertical stability to stand on its own. You need to make it thicker (how thick depends on how tall, but the important aspect is the staggered construction of multiple layers giving a similar self-reinforcement) to give it the proper foundation. Keep in mind that it's multiple thin horizontal layers held by a relatively weak adhesive, not a solid object.
A wavy wall reinforces itself against the same forces (wind being the big one) allowing for thinner construction at an equivalent height.
Take a piece of paper. Try to put it on its edge. Now bend the paper in zigzag and try again
The base proportion to the height.
Two bricks wide has a 2x wider base.
Ever built Lego?
Maybe, a long time ago.
For those whose childhood is a long way behind them, would you explain?
Lego are just like those brick. If you just pile them on you have no strength, if you interlock them you have strength in one direction, if you have 2 rows interlocked, you have strength in 2 directions.
Imagine a posterboard, one of those 3 section things you can by at a supermarket kids use in science fairs. What happens if you attempt to stand that posterboard up with the sections in a strait line? Now take the outer two sections and place them at an angle to the central board. One will fall over by itself. The other will stand upright and even take a non-trivial amount of downward pressure (weight) before it falls over.
It works the same way with any thin and tall building, it needs to have support perpendicular to the main body. You'll note that most straight brick walls have thicker "towers" at regular intervals. Or it needs underground support, like concrete in the ground for a fence post.
Unrelated: Go buy a lego set! If you've forgotten the joy of LEGOs I encourage you to rediscover it. The kinds of sets they have available these days are vast and the cleverness of their building techniques needs to be seen to be appreciated.
You need to use two brick width for stability.
Is that what we're doing? If I remember correctly, the walls around the houses in my childhood neighborhood were only one brick in width. Also walls around cemeteries and such, I could swear they are not double-width walls.
Those are just veneers. My grandfather was a professional brick and stone mason. You can tell if a brick wall is load bearing if it has alternating directions: every so many bricks you’ll see one or more that’s been rotated 90° to connect the layers together
Veneer, all the bricks are in the same orientation: https://i.pinimg.com/originals/1b/65/ec/1b65ec6fdb488d3dab28...
Supporting wall, notice the alternating pattern: https://www.backwoodshome.com/bhm/wp-content/uploads/2015/12...
One brick wide walls often have a thicker pillar for stability every couple of meters.
And two brick thick walls often have pillars... So pillars aren't a good indicator.
Has someone figured out the ideal frequency / amplitude of the wave? Maybe the frequency that matches the strength of a one-brick straight wall? The pictures strike me as possibly wavier than needed.
It would be strength/brick use tradeoff.
I want to know how that compares to just adding some rebar along the way
wouldn't that depend on how tall the wall is?
There's been a one-brick-thick wavy wall off a busy road in Cambridge for at least fifty years: https://goo.gl/maps/sxTsPW71F317gwK88
It kept getting hit by cars until they finally installed a guard rail.
It took me way too long to see that the cars are driving on the right, so this is Cambridge MA, not Cambridge UK.
... wait... there's another Cambridge?
Does something about this design make it more likely to get hit by cars?
I guess the force of impact would be greater relative to scraping a straight wall.
It's at an intersection of a curvy four-lane road which is very busy at rush hour.
Driving in the Boston area is hard enough already, we don't need to add wavy walls into the mix ;-)
I believe I've read that some plants do better when planted in the concave portion of a wavy wall, because the bricks absorb warmth during the day and release it at night.
> As for the mathematics behind these serpentine walls and why the waves make them more resistant to horizontal forces like wind vs straight walls, check out this post by John D. Cook.
The linked post does not explain why the walls are more resistant to forces. It just calculates the difference in length.
That's the same post that is linked from the original article.
I first learned about serpentine walls via splint, which is a linter for C. The serpentine walls were visible on the front page until 2020:
https://web.archive.org/web/20200521064022/http://splint.org...
The FAQ explains why they chose this logo:
The walls are one brick thick, but because of their design are both strong and aesthetic. Like a secure program, secure walls depend on sturdy bricks, solid construction, and elegant and principled design.
The same reason is why my roof has corrugated metal sheeting, rather than plate.
This was a question I had students prove out. With the bending moment of inertia being related to the cube of the thickness for a flat plate, the maths trickles out very quickly.
We need your expertise here please: ttps://news.ycombinator.com/item?id=36899973
Thank you, hopefully I've been some form help or at least some food for thought.
Yeah but more space, and are therefore the wrong choice a lot of the time.
Which is why they are very popular in the less densely populated and large lot size areas of the English Country side. By the time of the New World, fast population growth meant the economics of brick production wasn't feasible and copious alternative methods were easier (wood/picket fences, wood studs+wire, chain-link or wrought iron/brick + iron). All less long lasting, but cheaper, quicker and easier to install with almost the same benefits (fencing of pets + livestock, property demarcation, security). Which is why you don't see them nearly as often outside of Europe (Asia having used their own alternatives better suited for their environment and needs, Africa having had New World techniques used during colonialism).
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Or it's a way to brag about how much space you have.
Yeah. Like how Lawns were a way to brag about how much land you have.
"Look, I have so much land I can just grow grass instead of crops, you plebs".
And the lawns of today’s middle class are of course still about signaling, it being very humsn for people to try to raise themselves up by adopting and imitating the lifestyle and customs of the class above them. "Look, I have enough leisure time to spend on an entirely superfluous activity!" or "Look, I’m wealthy enough to pay somebody to engage in an entirely superfluous activity!"
Particularly in arid climates it’s also "look how much I can afford to waste perfectly good drinking water!"
Something that gave me a chuckle growing up where I did in Australia: everyone's lawn died in the summer. You're weren't allowed to water it enough due to drought measures, and the summers are so hot they die off on the first heat of the season.
I notice a lot more people ditch the lawn for native plants now. Sure does look a lot less futile than spending a third of your lot on dead grass.
Many memories playing cricket on dry, prickly, dead grass as a kid.
Lawns don't usually die in the summer, they go dormant. You can usually distinguish between dead grass and dormant grass by observing the color: dormant grass is yellow, while dead grass is grayish.
Texas lawns commonly use some form of bermuda grass, which goes dormant during the hot season (typically late July to late September). Some lawns will mix in a rye grass which shows bright green color during this same season to preserve the look, but obviously this compromises the growth of both types of grass.
"Popularized in England" - maybe popularized, but such walls are by no means popular or common.
"The county of Suffolk seems to be home to countless examples of these crinkle crankle walls. On freston.net you can find 100 wavy walls that have been documented and photographed."
Although it's not explicitly said, let's suppose that every one of those wavy walls is in Suffolk. The population of the county is 761 350 - let's assume there are 100 000 homes (although there is the city of Ipswitch, it's otherwise largely a rural county where single-family homes will be common). So only roughly one-in-one-thousand homes in Suffolk has such a 'wavy wall'. Elsewhere in the country probably even less - e.g. I've never seem one.
Any for everyone complaining about mowing - do you actually have grass all the way up to your boundary wall? In my experience it's pretty common to have a flower bed running all the length of the boundary, so mowing would not be a problem.
So only roughly one-in-one-thousand homes in Suffolk has such a 'wavy wall'
yes, but you also need to take into account how many homes have any brick wall at all.
Anecdotally, I would say that flint stone walls are more common than wavy walls. I’ve see plenty of the former and none of the latter wham driving through the county.
that's not surprising. even without ever having been there i am aware of some areas of the british isles having a reputation for stone walls. but not for brick walls. which makes the question of the popularity of wavy brick walls even more interesting. how many non-wavy brick walls are there?
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The labor to build such a wall may dominate the savings in brick. But if you're building a brick wall, maybe you don't care much about either.
I wonder if this sort of structure could be built by 3D printing, say with concrete or even soil.
Labor is pretty much directly proportional to number of bricks placed. If you save on bricks, you save on labor.
If that was your point, sorry for misreading you.
In the era in which these were commonly used, bricks were largely made on-site or very nearby. So you saved on labor twice - once to make the bricks, and again to place them.
I was thinking of a comment in the John Cook link, where someone was saying these are fiddly to build compared to a conventional brick wall.
They're certainly fiddly to plan out compared to a straight wall (where all you need is a long piece of twine anchored at each end), but I assume that those building them use some kind of forms to help keep the angles correct.
There's actually a similar concept in 3D printing called gyroid infill, it's essentially a 3D version of the wavy wall:
https://www.wevolver.com/article/understanding-the-gyroid-in...
No they don't
> [Wavy walls] use more bricks than a straight wall of the same thickness
However they "resist horizontal forces, like wind, more than straight wall would."
> So if the alternative to a crinkle crankle wall one-brick thick is a straight wall two or more bricks thick, the former saves material
https://www.johndcook.com/blog/2019/11/19/crinkle-crankle-ca...
If a one brick thick straight wall can't stand, then you don't have a wall you have a pile of bricks. It's pointless to consider the impractical case.
Most will stand unless they need high wind resistance (or are buttressed).
There are many practical cases for a straight wall of bricks, it's not an "impractical case."
> > If a one brick thick straight wall can't stand
Caveat there is quite significant.
> There are many practical cases for a straight wall of bricks
Indeed the vast majority of cases yes.
> Caveat there is quite significant
and missing from the title
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Would it be stronger for the same amount of bricks if it didn't have the inflection point where there is no curvature, and instead had intersecting arcs like: ︾︾︾︾ ?
I think it would be less strong than a wavy wall of similar brick count, but still more efficient than an equivalent strength wall built in a straight line.
My mental reasoning for this is that a (pseudo) sinusoid spends a lot more of its path further away from the centre. Thinking of it as a point moving along the path through time, it will dwell and the peaks, and cruise through he centre. The contribution of each brick to wall stiffness will be related to the cube of the distance from the centre line (neutral axis), so more 'time' spent at the peaks is best. This holds true on the macro scale, but could vary on the scale of a half 'wavelength' as the lack of inversion of curvature could be beneficial there.
Everything moderately reasonable seems to be better than a straight line in this instance. In the limit, two much thinner walls, far apart, is the optimal solution, but that becomes unreasonable as those walls must be coupled together to provide strength.
I think you're asking if a series of arcs is stronger than a wavy line. It's a great question and I think the answer to that would require a full model of the two walls to calculate all the stresses, etc. But I think it would also depend on the question of "stronger against what?" A pushing force but at what point and at what angle. Even height might make a difference.
My gut instinct is that the point where a wavy wall changes from curving one way to another is a slight weak point and perhaps an angle there would actually be stronger. Might be totally wrong.
If you made the arcs deeper than the curves of the wave I think yes. If you just sliced and flipped the arcs from the original wave, no. It'd be a straightforward calculation for the moment of inertia but I'm too lazy to do it. It's all about placing the most mass farthest from the centroid line.
Tangentially related; as covered in The Blue Factory documentary[1], one of the challenges with the EB110's design was its flat sides. Curved body panels provide greater strength and importantly, reduces vibrations.
FWIW The Blue Factory had the same kind of charm as the General Magic documentary
Of course title is a bit of a clickbait, because they are comparing walls of same strength, not single row straight walls with curved walls.
But how does this compare with a straight wall with brick columns every two meters or so? My guess this is the best compromise, and maybe that is the best compromise, as it uses about the same number of bricks as a curves wall, but the area wasted is much smaller.
Not sure about the actual function that defines the wave, but let’s assume they are convex and concave semi circles. Then to make a wall of length L with bricks of l length, we need piL/l number of bricks. The linked Reddit post says a straight wall needs to be 2 bricks wide to have the same length, which needs 2L/l number of bricks which is fewer than the wavy walls
Semicircles seem excessive. At no point does the wall have an angle over 45 degrees, so a semi-circle which would be at a 90 degree angle for every inflection point seems way too wavy.
A sine wave is probably closer, which would give an arc length of sqrt(1+cos(2pix/L)^2). This has no reasonable closed form I can find but it seems like it would be about 21% longer than a straight line.
Edit: Also a semicircle is pi/2 times as long as its diameter, not pi times.
Sines are about 1/.7 (40%) longer aren’t they?
What would be about what you'd get if you made a sawtooth out of straight sections, pretty sure that's quite a bit longer than a sine wave would be.
Yeah I'm thinking of electricity.
A right isosceles triangle has a hypotenuse that's √2 (1.41) and 1/√2 = 0.71.
Stack Overflow seems to think it's around 2.4x, but I am not sure I could ever follow the math and I certainly can't now. I think the amplitude makes the difference here and SO is answering a different question, otherwise this article would be wrong and that wasn't my impression the first time I encountered this topic.
second edit: The article linked from this article says:
So a crinkle wall with amplitude 1.4422 uses about as many bricks as a straight wall twice as thick.
It's not one giant semi circle. Lets say each semi-circle has a radius of about 2 ft (judging by the pictures). Every 8 ft section (1 wave/one full cicle) takes 2pi2 ~= 12.56, while the straight wall takes 8*2 = 16 bricks.
Article links to this post with another derivation.
https://www.johndcook.com/blog/2019/11/19/crinkle-crankle-ca...
I'd like to know if this wavy wall technique requires non-square bricks to be stronger. And is it stronger against sideways forces along the concave and convex sections. If it's only the same strength as a straight wall then I'd think it'd be worse as a retaining wall?
Corrected link: https://www.johndcook.com/blog/2019/11/19/crinkle-crankle-ca...
Thanks! I've corrected the link in the GP comment.
Corrugated cardboard uses less paper than what it would take with flat paper, and the box weighs less.
A wavy fiberglass roof uses less cloth and resin, and less reinforcement, than flat composite sheets would require.
A wavy roadside guard rail made of sheet metal uses less metal than a flat guardrail.
A snowshovel stamped/moulded with kinks in it can be thinner than a solid one.
...
This headline is awful and sounds sensational.
Better headline would be "wavy walls use fewert bricks than thicker straight walls"
and like 5x the space
I saw the title and instantly thought, of Suffolk, England.
Quite pleasing to see it referenced in the article too.
Proper Suffolk that, like little pink cottages and good quawlity tea towels[1]. :D
I’ll save folks some reading: they’re comparing a very thick straight wall with a much thinner wavy wall.
The primary point is that you can't make an equivalently thin straight wall due to natural (wind and gravity, primarily) forces. Kinda weird to summarize it without the crux of why.
> Kinda weird to summarize it without the crux of why.
I agree, the headline did a very poor job of summarizing.
Yet, you did an even worse job expounding.
Nope. "Wavy walls use fewer bricks than a straight wall" is so misleading it may as well be a lie. Enjoy your day.
Yeah yeah, we got it. You're ignorant and stubborn.
Hah, what a strange thing to attack someone over. I’m not sure who “we” is, but I hope you can all move on from this.
> these wavy walls actually use less bricks than a straight wall because they can be made just one brick thin, while a straight wall—without buttresses—would easily topple over.
And what about a straight wall with buttresses? Can we make them just as sturdy with fewer bricks?
No, that’s sort of the point? There are fewer extra bricks used to make the curve than would be required to buttress / reinforce a straight wall.
> There are fewer extra bricks used to make the curve than would be required to buttress
Where does it say that?
The important part is https://www.johndcook.com/blog/2019/11/19/crinkle-crankle-ca...
I actually find that web page quite disappointing because there is no comparison of the relative strengths of the different wall shapes.
Comment was deleted :(
Very cool. So what is the optimal solution?
To maximize the strength and minimize the bricks used, is a sine the best shape, or is there a better curve, and what is the best period and amplitude of the waveform? Does this solution change with the height of the wall?
Most likely you want the smallest curve that’s achieves an acceptable amount of stability. Since the wave exists to prevent the wall from toppling, a pure sine is probably overkill.
So I guess a factor then will be how tall your wall is. A very tall wall will need a deep wave, just like a wall one brick high would need no wave at all.
Given how much OCD I have about naming variables and writing unit tests, I think if this was in front of my house, I'd take a sledgehammer to it. Fences shall be straight, damnit.
If you follow the link in the post explaining the math behind everything, it says:
"They use more bricks than a straight wall of the same thickness but they don’t have to be as thick."
"Use, more bricks that the straight wall" misses a point a bit, because a straight wall like this would easily topple.
A better description is "uses less bricks than a straight wall of equivalent resistance to horizontal forces"
The post also says this in the first paragraph:
> Popularized in England, these wavy walls actually use less bricks than a straight wall because they can be made just one brick thin, while a straight wall—without buttresses—would easily topple over.
In other words, a serpentine wall is stronger per amount of material used than a straight one. They also allow use of a single-thickness of brick without other supports
I would say like it is less prone to tipping over per amount of material. It is not stronger in the meaning of holding bullets. Source: tried to build a brick construction once.
True, but they use less bricks than a straight wall of the same strength, because the straight wall would have to be thicker or have buttresses. So it depends what you’re doing - does the wall have to withstand that kind of loads or not?
> ...does the wall have to withstand that kind of loads or not?
If you want the brick wall to last, and you aren't building it on either bedrock or a deep foundation ($$$) - then your three choices are (1) build it to withstand substantial horizontal loads, (2) pay more for regular maintenance, and (3) wall will topple due to forces from normal soil movement.
So wavy walls use more bricks than straight walls
No, because they are stronger and can therefore be thinner. But the why is important.
Wavy walls use more individual bricks, but less “brick”
Well, no. By length it's the same # of bricks if the wall is the same thickness.
It requires less bricks to wall off an area using a single-layer wavy wall than it does with a double-layer straight wall
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For the same function, wavy walls use fewer bricks
Came here to mention just that.
Not a physics person...but is this similar to the effect of 'rolling' thin pizza so it won't droop? Or is it strictly about being better at wind resistance?
If you're eating pizza somewhere windy
Another "article" summarizing a reddit post. They even took the top comment and put it at the end
> wavy walls that lawnmowers surely detest!
Lawn edges that can't be mowed, because of a house wall or something, are an issue at my place. If just leave the grass at the edge, it grows long, then grows to seed, and the long grass seems to expand in width inexorably over time.
I don't want to use a plastic-shedding line trimmer or herbicides. I end up pulling out the grass near the edge, leaving a bare strip that takes a while to grow back, but it's a bit labour-intensive.
I’ve seen this design when making ultra light weight structures. It does work but can be difficult to manufacture
Also, looks harder to mow the lawn.
But surely more fun :-)
No lawns in metallic structures
At cost of like 5x the space ? I guess if you have cheap land but bricks are at premium it makes sense
So, when it comes to pressure, the straight wall isn't "gonna take it"?
(twisted sifter)
I'll show myself out.
In the UK these ate known by the wonderful term "Crinkle crankle wall"
That is written in the best first paragraph of the article.
if you think of it from the context that the diagonal length of a brick is it's longest dimension, you can start to intuitively imagine how this efficiency in layout pattern is achieved.
-signed, an architect
“Hackernews discovers first year university engineering statics/analysis from articles that are really just reposts of 3 year old reddit content”
Sorry, didn't realize you knew everything in the world already.
I avoid getting my knowledge of the world from reddit reposts, and yes, I did take first year statics, as well as structural analysis 1 and 2, wood design, concrete design, steel design, and masonry design.
Congratulations.
looks infuriating to mow around
fewer bricks than a straight wall with supports.
TLDR: they don't need buttresses, hence the savings.
TLDR: Because they can be one brick thin. The waviness works just like corrugated cardboard.
Crafted by Rajat
Source Code