[HN Gopher] Wavy walls use fewer bricks than a straight wall (2020) ___________________________________________________________________ Wavy walls use fewer bricks than a straight wall (2020) Author : caiobegotti Score : 437 points Date : 2023-07-27 13:16 UTC (9 hours ago) (HTM) web link (twistedsifter.com) (TXT) w3m dump (twistedsifter.com) | LegitShady wrote: | "Hackernews discovers first year university engineering | statics/analysis from articles that are really just reposts of 3 | year old reddit content" | pests wrote: | Sorry, didn't realize you knew everything in the world already. | LegitShady wrote: | 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. | pests wrote: | Congratulations. | toss1 wrote: | 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? | asimpletune wrote: | 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. | HideousKojima wrote: | 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." | judge2020 wrote: | 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. | gymbeaux wrote: | So wavy walls use more bricks than straight walls | kgermino wrote: | For the same function, wavy walls use fewer bricks | adamc wrote: | No, because they are stronger and can therefore be thinner. | But the why is important. | gymbeaux wrote: | Wavy walls use more individual bricks, but less "brick" | meesles wrote: | 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 | [deleted] | hammock wrote: | 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 | eimrine wrote: | 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. | 542458 wrote: | 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? | bell-cot wrote: | > ...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. | adamc wrote: | Came here to mention just that. | Roark66 wrote: | "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" | NeoTar wrote: | "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. | [deleted] | em-bee wrote: | _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. | serial_dev wrote: | > 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? | kristjansson wrote: | 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. | throw9away6 wrote: | I've seen this design when making ultra light weight structures. | It does work but can be difficult to manufacture | DriverDaily wrote: | Also, looks harder to mow the lawn. | CrzyLngPwd wrote: | But surely more fun :-) | throw9away6 wrote: | No lawns in metallic structures | ilyt wrote: | At cost of like 5x the space ? I guess if you have cheap land but | bricks are at premium it makes sense | omoikane wrote: | 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. | | https://splint.org/faq.html#quest2 | carapace wrote: | https://en.wikipedia.org/wiki/Gaussian_curvature | jolt42 wrote: | 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. | adamrezich wrote: | wouldn't that depend on how tall the wall is? | ilyt wrote: | It would be strength/brick use tradeoff. | | I want to know how that compares to just adding some rebar | along the way | geeky4qwerty wrote: | 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! | wkdneidbwf wrote: | 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 | geeky4qwerty wrote: | 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!" | 93po wrote: | I think you overestimate what people would reactively think | when reading this headline | DrBazza wrote: | 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. | Retric wrote: | 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. | londons_explore wrote: | 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. | | [1]: https://math.stackexchange.com/a/1500468 | [deleted] | Retric wrote: | 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. | chrisweekly wrote: | "athletics" -> "aesthetics", right? | hinkley wrote: | > these are curved for athletics. | | Autocorrect strikes again. | [deleted] | [deleted] | gweinberg wrote: | 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. | turnsout wrote: | If you have plenty of space but you're tight on money, it's an | ingenious solution. | geeky4qwerty wrote: | 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. | CalRobert wrote: | 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) | londons_explore wrote: | 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. | turnsout wrote: | It is if you're selling sheep milk and you don't want to | lose your flock. | bee_rider wrote: | 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. | toast0 wrote: | 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. | devilbunny wrote: | 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. | gswdh wrote: | [dead] | scott_w wrote: | It's relative. You might be "tight on money for building a | wall" so you save money by building a wavy wall. | [deleted] | HWR_14 wrote: | 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. | araes wrote: | 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. | HWR_14 wrote: | The difference is people enclosing 100 acres today are | either wealthy estates or using non-brick fences for | farmers. | BurningFrog wrote: | Pre industrialism, almost everyone was dirt poor by current | standards. | seabass-labrax wrote: | 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. | oatmeal1 wrote: | Also IMHO it looks horrible. | amelius wrote: | The solution for the space problem is obvious: just make the | wall wave in the longitudinal direction instead of the | transversal direction. | surfpel wrote: | > 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. | tetrep wrote: | > *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. | kbenson wrote: | > 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. | hammock wrote: | Do you also think corrugated cardboard is wasteful? | geeky4qwerty wrote: | Yes, of course I do, just like I believe that the Australia, | like false equivalencies, don't exist. | vehemenz wrote: | The extra space doesn't have to be fully wasted. You could | plant bushes or small trees in the concave sections. | Lutger wrote: | 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. | hammock wrote: | Applies to flat walls not wavy, but espalier,[1] a way to | cultivate trees in tight spaces, is one of my favorite things | ever. | | [1]https://en.wikipedia.org/wiki/Espalier | jacquesm wrote: | I'm doing this with an apple tree right now :) | developer93 wrote: | 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? | hammock wrote: | Fair point. I've personally never seen it | ZeroGravitas wrote: | 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 (53degN). | nottorp wrote: | Interesting, locally the same word is used for the | structures used for cultivating climbing plants. Haven't | really seen it done with trees. | mattmaroon wrote: | 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. | tomxor wrote: | 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. | yboris wrote: | Every dip in the wave is an opportunity to plant beautiful | bush, flowers, or shrubbery. | travisgriggs wrote: | 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. | pm215 wrote: | 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. | gowld wrote: | The important part is | https://www.johndcook.com/blog/2019/11/19/crinkle-crankle-ca... | [deleted] | fnord77 wrote: | looks infuriating to mow around | Prcmaker wrote: | 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. | badcppdev wrote: | We need your expertise here please: | ttps://news.ycombinator.com/item?id=36899973 | Lio wrote: | 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 | | 1. https://m.youtube.com/watch?v=6-7hcPXwpBQ | cantSpellSober wrote: | 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... | surfpel wrote: | 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. | cantSpellSober wrote: | 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." | surfpel wrote: | > > 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. | jamesmurdza wrote: | This looks similar to the way corrugated steel is harder to bend | due to a higher "area moment of inertia". | nonethewiser wrote: | 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. | gxs wrote: | Interesting pictures. | | Not a complicated subject, but somehow seeing it with straight | lines made it completely obvious and intuitive vs the wavy | wall. | autoexec wrote: | 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. | jrockway wrote: | I'd've called it a chazzwozzer. | version_five wrote: | They're in the lorry and the larder and... | mcpackieh wrote: | That's just like, your opinion man. Worm is a cool word. | Maybe we can compromise and call it a wyrm fence. | autoexec wrote: | Wyrm fence is a great name! I'd use one to keep my hoard of | treasure safe | oxygen_crisis wrote: | A worm fence sounds like it should be a couple inches tall | and several feet deep, to block the worms. | NavinF wrote: | 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 | autoexec wrote: | 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. | hfivivfub wrote: | 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. | ChainOfFools wrote: | 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. | fsckboy wrote: | > _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 | tssva wrote: | The park service uses this type of fencing a lot. | helb wrote: | they don't use less wood than a straight fence though :) | shirleyquirk wrote: | 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. | sn9 wrote: | 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. | Cerium wrote: | 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. | bin_bash wrote: | it's not for stability, it's because it doesn't require posts | so it's cheap and quick | drtz wrote: | But it is for stability. Try making a straight fence with no | posts and see how stable it is. | gowld wrote: | Lots of things "don't require posts so it's cheap and quick", | but this version makes a stable wall. | nonethewiser wrote: | > it's not for stability, it's because it doesn't require | posts | | That's stability | silisili wrote: | 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? | javier123454321 wrote: | Yeah but more space, and are therefore the wrong choice a lot of | the time. | deaddodo wrote: | 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). | Slava_Propanei wrote: | [dead] | csours wrote: | Or it's a way to brag about how much space you have. | FrustratedMonky wrote: | 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". | Sharlin wrote: | 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!" | ehnto wrote: | 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. | episiarch wrote: | 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. | Jemm wrote: | fewer bricks than a straight wall with supports. | Terr_ wrote: | 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... | PawgerZ wrote: | 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. | anArbitraryOne wrote: | 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: >> >> >> >> ? | Prcmaker wrote: | 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. | badcppdev wrote: | 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. | kulor wrote: | 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 | | 1. https://www.imdb.com/title/tt6301490/ | fredley wrote: | In the UK these ate known by the wonderful term "Crinkle crankle | wall" | Underphil wrote: | That is written in the best first paragraph of the article. | MR4D wrote: | TLDR: they don't need buttresses, hence the savings. | pfdietz wrote: | 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. | devilbunny wrote: | 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. | pfdietz wrote: | 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. | devilbunny wrote: | 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. | etskinner wrote: | 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... | jansan wrote: | 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. | dtgriscom wrote: | 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. | gottorf wrote: | Driving in the Boston area is hard enough already, we don't | need to add wavy walls into the mix ;-) | xxpor wrote: | It took me way too long to see that the cars are driving on the | right, so this is Cambridge MA, not Cambridge UK. | andai wrote: | 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. | dontrustme wrote: | 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. | dontrustme wrote: | -signed, an architect | CodeSgt wrote: | 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. | chaostheory wrote: | Well, tbf the article doesn't even try to explain how wavy | walls are stronger than straight ones, or how fewer bricks are | needed. | amelius wrote: | 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. | ethanbond wrote: | 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. | horsawlarway wrote: | 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. | ke88y wrote: | 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. | gswdh wrote: | [dead] | HWR_14 wrote: | "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. | andy800 wrote: | The University of Virginia, designed by Thomas Jefferson, | features numerous brick serpentine walls. | | https://www.google.com/search?q=uva+serpentine+walls&tbm=isc... | throwaway894345 wrote: | I'll save folks some reading: they're comparing a very thick | straight wall with a much thinner wavy wall. | deaddodo wrote: | 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_. | throwaway894345 wrote: | > Kinda weird to summarize it without the crux of why. | | I agree, the headline did a very poor job of summarizing. | dang wrote: | 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) | spread_love wrote: | Another "article" summarizing a reddit post. They even took the | top comment and put it at the end | | > _wavy walls that lawnmowers surely detest!_ | BobMackay wrote: | 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. | hyperhopper wrote: | This headline is awful and sounds sensational. | | Better headline would be "wavy walls use fewert bricks than | thicker straight walls" | ilyt wrote: | and like 5x the space | rkagerer wrote: | TLDR: Because they can be one brick thin. The waviness works just | like corrugated cardboard. | hammock wrote: | 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 | oniony wrote: | You can also peel the label of a tin (can) of baked beans in | your cupboard to see the the ripples added for rigidity. | finnh wrote: | as a bonus, they make canned cranberry sauce visually | appealing on the Thanksgiving platter :) | singleshot_ wrote: | 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! | vharuck wrote: | 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. | oxygen_crisis wrote: | Same principle as concave bottoms on wine bottles (though the | concern there is more about jostling and impact during | transport than pressurized contents). | jerry1979 wrote: | I think the Christian Science Monitor is perfectly fine. | https://mediabiasfactcheck.com/christian-science-monitor/ | WorldMaker wrote: | 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. | yetanotherloser wrote: | ...being anti-hospital in the 19th century sounds fairly | rational to me? | WorldMaker wrote: | 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). | zhte415 wrote: | Aluminium's also more expensive than steel but experiences | sufficiently less breakage to justify the price. | anamexis wrote: | 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. | hinkley wrote: | I really liked this video when I watched it. I may have | watched it twice. | mcpackieh wrote: | 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#Physica | l_and_che... | pletnes wrote: | Also in the current design you can stack them. This is probably | worth something in terms of wrapping of pallets of cans. | [deleted] | gowld wrote: | Standard video: | | "The Ingenious Design of the Aluminum Beverage Can" | | https://chbe.illinois.edu/news/stories/engineer-guy-ingeniou... | | https://www.youtube.com/watch?v=hUhisi2FBuw | Cthulhu_ wrote: | Same with cans, corrugated sides, tops and bottoms are for | strength and pressure resistance. Actually most corrugated | anything is done so for strength. | codyb wrote: | 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. | 3cats-in-a-coat wrote: | Same about waviness on plastic bottles. | | https://www.riverkeeper.org/wp-content/uploads/2018/04/bottl... | rvba wrote: | The waviness around makes it easier to hold them too. | Although to some degree it might be marketing as well? | 3cats-in-a-coat wrote: | 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. | tonmoy wrote: | 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 pi _L /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 | 2_L/l number of bricks which is fewer than the wavy walls | eastof wrote: | 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 2 _pi_ 2 ~= 12.56, while | the straight wall takes 8*2 = 16 bricks. | contravariant wrote: | 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. | hinkley wrote: | Sines are about 1/.7 (40%) longer aren't they? | contravariant wrote: | 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. | hinkley wrote: | 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. | tln wrote: | 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? | gowld wrote: | Corrected link: | https://www.johndcook.com/blog/2019/11/19/crinkle-crankle- | ca... | dang wrote: | Thanks! I've corrected the link in the GP comment. | nfriedly wrote: | 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. | tokai wrote: | Fruit Walls | | https://99percentinvisible.org/article/fruit-walls-before-gr... | trhr wrote: | 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. | esafak wrote: | So, when it comes to pressure, the straight wall isn't "gonna | take it"? | | (twisted sifter) | | I'll show myself out. | qwertox wrote: | 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 2p = 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. | secondcoming wrote: | You need to use two brick width for stability. | qwertox wrote: | 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. | Rumudiez wrote: | 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 90deg 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... | aeyes wrote: | One brick wide walls often have a thicker pillar for | stability every couple of meters. | londons_explore wrote: | And two brick thick walls often have pillars... So | pillars aren't a good indicator. | AnimalMuppet wrote: | 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... | jguimont wrote: | Ever built Lego? | AnimalMuppet wrote: | Maybe, a long time ago. | | For those whose childhood is a long way behind them, would | you explain? | jguimont wrote: | 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. | drakythe wrote: | 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. | di456 wrote: | The base proportion to the height. | | Two bricks wide has a 2x wider base. | deaddodo wrote: | 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. | ilyt wrote: | Take a piece of paper. Try to put it on its edge. Now bend | the paper in zigzag and try again | alecst wrote: | > 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. | paiute wrote: | https://www.johndcook.com/blog/2019/11/19/crinkle-crankle-ca... | jwilk wrote: | That's the same post that is linked from the original | article. ___________________________________________________________________ (page generated 2023-07-27 23:00 UTC)