A needlessly complicated but awesome bridge.
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- čas přidán 30. 08. 2023
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Stan Wagon has written an article about all of the maths involved in the bridge: community.wolfram.com/groups/...
Designed by Thomas Randall-Page. www.thomasrandallpage.com/
Engineering by Alfred Jacquemot (then of Price & Myers). www.pricemyers.com/about-us/p...
You can ride the MoMath square-wheel bike in NYC or Stan Wagons's at Macalester College in Minneapolis.
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Visit Cody Dock in East London. codydock.org.uk/
Huge thanks to my Patreon supporters. They keep my bridges rolling. / standupmaths
CORRECTIONS
- None yet, let me know if you spot anything!
Filming by Alex Genn-Bash and Christopher Brooks
Editing by Christopher Brooks
Written and performed by Matt Parker
Produced and drone flying by Nicole Jacobus
Scene stealing by that cat
Music by Howard Carter
Design by Simon Wright and Adam Robinson
MATT PARKER: Stand-up Mathematician
Website: standupmaths.com/
US book: www.penguinrandomhouse.com/bo...
UK book: mathsgear.co.uk/collections/b... - Zábava
If you want to see all the maths, check out the Stan Wagon write-up: community.wolfram.com/groups/-/m/t/2917199
Thanks to Jane Street for sponsoring my video and the Hat Competition. I want to see loads of SUM viewer entries! momath.org/hatcontest/
@@DontReadMyProfilePicture.57shut up spambot
ALSO there's a math youtuber that had an entire series about shapes moving flatly when given a specific plane, pretty sure he got started through SoME, his name is Morphocular
Wouldn't it have been better to have a little gearbox on the winch. Then you could have a ratio that would only take a couple of minutes to move the bridge. If you're struggling you could then change gear to make it easier but take longer.
I had an architecture student today I told about math in design and sent him this video. Very fortuitous. Great video too.
what are you talking about not being an applied mathematician, you apply math to the real world for all kinds of stuff, like those disco balls
Pulled a fast one on Tom Scott didn't ya?
We call it Dereking around these parts
Hand cranking for 20 mins! I’m not sure I would call that a fast one 😉
@@cam5556 until Matt gets reverse-dereked by tom
@@MrWshaw a Parker Derek?
Well, Tom is retiring the format, so someone needs to pick up the torch.
When artists and architects team up, engineers invent new swear words
lol, yeah.
lol
Usually because the clever marketeer already sold it!
Yet it is the new solutions that engineer invent that forward the industry. New inventions are new ways to build.
@@BEdwardStover No doubt, and there is nothing like a practical implementation to show the flaws and/or benefits of a design. Paper is very patient, but moving parts may scream at you!
"you can't just turn up and start cranking it" applies to most places tbh
There were 69 likes on this comment before I got here. 😥 I'm so sorry.
Scrolled for this. 8th comment down.
“You’ve gotta contact people in advance” advice that can apply to so many areas of life
Sadly true
challenge accepted
"This bridge turns so efficiently that all physical labour is now done by one Australian man."
underrated
I would like to take the roll.
Neat 📸
Nice reference, mate
Tale as old as time.
Architect: Hey this looks cool, should be easy!
Civil Engineer: Oh brother here we go again.
Tribute to RCE.
Then the mechanical engineer turns up and.... WFT? 20 minutes? What were you thinking? Put a bloody motor on it! And all the pedestrians and boaties cheered wildly. :)
@@robguyatt9602Or just a series of gears to provide some mechanical advantage? Seriously, this is not difficult. Twenty minutes of cranking is a *lot*.
@@iluomopeloso It does have gears to give advantage, that's why 1 person can crank a wheel to make it turn. That comes at the expense of making it a lot slower, however.
Yea, I was thinking of RCE when they started discussing the challenges.
@@iluomopeloso If you want to make it go faster with gears, it'd require MORE force.
"Not normally an applied mathematician" made me lol. Great design
Yep solid joke.
As an extremely amateurish maths student, I sure enjoyed this gaffe, mostly because I understood it.
But he's at least standing up!
A real zinger line
Although nobody forced him to do it, let hope he didn't derive any work related injury to his rotator cuff.
I feel a missed opportunity to have a tiny scale model of the bridge for people to play with near the crank. And of course a way to tie them together so the model moves when the big one does.
Anytime you put something out to the public to "play with" it's going to be broken in short order. Then good luck getting the funding to fix or replace it.
@@pvanukoffYou are so right. One time I made a diorama for a science project that was on display to the public and some "prankster" hit it with a AGM-65 Maverick missile carrying a WDU-20/B shaped-charge warhead fired from a F/A-18 Hornet.
@@pvanukoffNot always, especially if it's designed with a bit of thought-there's a standard I call _shroomer-proof_ at Burning Man-but you're unfortunately right most of the time.
@@nomadMik Don't worry, the universe just made a better shroomer
Turns out the maths don't work on the smaller models
"There's poetry in it and it "only" takes twenty minutes of winding..." thus speaks a true artist.
Spoken like someone who won't be doing the cranking.
@@fghjconner Or by one who doesn't need to wait 40 minutes to get to the other side. 😱
Yeah, I love the engineering behind it, but 20 mins to turn by hand... idk about that one
Also “zero effort!” Lol what a joke.
Nah, artists are okay with doing mundane activity for an incredibly long time if it's part of the process of making something new
This feels straight out of the poly bridge leaderboards
made by aliensrock
@@NoNameAtAll2 Sponsored by Niff-Tea.
@@Magpie_Media I understood that reference!
@@NoNameAtAll2 The hate for hidraulics makes me think it was made by a certain Civil Engineer actually
@@mauri7959and not an imaginary one, but a Real one
idk, personally I've always thought we needed more complicated bridges. Why should buildings get all the fun?
Trust me, a normal draw bridge is pretty complex.
@@kempo_95 yeahhh... but with engineering inflation these days (with rotating buildings and huge overhanging glass infinity pools and crazy twisting designs and whatnot), complexity just doesn't buy as much as it used to, and I think bridges are due for a raise 🤪
Compared to normal drawbridges, this one is remarkably simple. It's kinda fancy is all.
How much of other people's money do you think you should be entitled to spend on such things? Buildings are privately owned, so they can waste as much as they want.
Based
Haha, Matt's joke while he was cranking the wheel that he usually isn't an "applied" mathematician was funny
It's genuinely a pleasure to see an artist come up against engineering issues when it comes to scaling something up. Art and science are the two best things humans do and they don't interact often enough for my tastes.
And when he did, he punted it to the engineer...
@@scania9786 and the engineer got to experience some art! I'm sure they get bored of pumping out square concrete structures all day...
@@thewhitefalcon8539 No, we don't, art is a stupid waste of time and is nothing like science, technology, engineering, or math.
@@MegaLokopowow! What a depressing statement! I'm not here to throw shade on anyone's preferences, but do you truly believe that art is just a waste of time? No music, free expression, or even movies? Just math problems and scientific research?
Again, not trying to put down your preferences, that statement just seems a bit heavy-handed. 🤷♂️
@@MegaLokopo This MF eats grey nutrient paste only
Nice idea ! But I wonder.... would a peddling mechanism ( like a home trainer ) with a big gear ratio not be more practical to move that bridge? It would make moving that bridge easier and pleasant than turning a hand crank for 20 minutes.
My RSI is flaring up just thinking about it.
A bike with it's original gearbox so each person can choose his own pace.
My money is that, if there is ever more than a couple boats a week needing it moved, there will soon be an electric motor on it.
@@88porpoiseI was thinking that, too, but I think the pedalling idea would be a nice compromise that would at least put the electric motor off.
My 'simple' solution would be to just have an attachment for a hand drill that can spin the pin in place of the crank. You always have the manual backup, but don't have to crank for 40 minutes in the elements (both ways, remember) just to get a boat through.
This bridge looks like a mathematician's dream and an engineer's nightmare, and it sounds like that's exactly what it was.
Maybe a boring engineer! It seems like this guy was quite up to the challenge, and is better for it in the end.
@@grahamwilson8843 It's not boring, I'll give you that. But the amount of shortcomings, drawbacks and potential failure points this design has would never make it in any public contract.
No engineer would ever proudly list the need for a hand crank in order to detect suspicious noises from failure as a feature, not even the not boring ones.
@@jAujAl1 Its not like the bridge will collapse like a drawbridge does. If the Center of Mass is well in the middle, I doubt it would roll much if the cables snap(additional safety mechanisms aside).
@@jAujAl1 That's not what the hand crank is for, the hand crank is for opening and closing the bridge. That it also functions as a failure detector is the result of having a simple system: You get direct observation of issues thrown in for free. Adding a seperate interface with sensors would add more failure states, increasing the chance of unexpected interactions and requiring higher training level of operators.
Complexity (i.e. more parts and tighter coupling of said parts) may sometimes be necessary, but it is never in and of itself a good thing. At best complexity is a necessary evil.
@@the11382 Cables snapping is not the failure point I'm worried about. If anything, the constant height for the center of mass ensures the square is always at an equilibrium and won't move if the cable snaps.
What I'm worried about is the integrity of the square structure. The uneven mass distribution adds a lot of stress to the beams, and a square is not that strong of a shape in the first place, especially a square with literal cut corners. Add the fact that the whole cube lacks two edges, and that the resting place for the bridge will have the concrete weighted edge stay upward in equilibrium, and I could perfectly see the bridge snap sideways after some wear.
Awesome video, i love how matt almost seems annoyed that "this is reality and there is friction" 4:57
Needs more lube 💦
I love the synergy of the artist-engineer partnership. I'm a chemist that works with chemical engineers and I love the reality/hate the resistance that they inject into a solution and they roll their eyes a lot.
I think what's going to happen is the novelty of hand-cranking the mechanism will wear off and it will eventually be fitted with (also a low-tech, non-sensored) version that uses a motor to do the cranking. It will have to have a momentary switch that a person will hold until the bridge has made it's transition.
Maybe in London, among artists and hipsters.. but canal folks across the rest of England don't seem to mind operating Victorian-era locks by hand. However, Matt's dismissal of motorized operation, and how safe it can be, is indeed rather thoughtless.
Or they could just add more gears and pulleys to make it more efficient. As Archimedes said, get a large enough lever and fulcrum and you can move the world.
You know somebody is going to turn up with a battery Drill!
@@ferretyluv Sure, but making it easier makes it slower and visa-versa.
The dismissal reasons felt a bit weird to me to be honest. It's not that hard to design around the problems that he stated just by using a cordless drill with a torque limiter.
I worked like 50 seconds from this bridge. Used to sit there on lunch breaks and stuff. Super cool bridge, they were trying to get it done for ages and had a gofundme or something for it and needed £200k or so which I don't think they reached. Odd little area in the middle of the industrial estate with few people passing through. The number of people passing through should shoot up a lot by around 2030 when nearby housing devellopment(+ a possible huge data center) are done so the river path/Lea Way is finally completed all the way to Canning Town and the thames so it'll actually be a useful route for lots of people to use. At the moment the path this is on is pretty much pointless since it doesn't go anywhere. They're wanting to build up the rest of the site with a few more things eventually.
So nobody wanted it and even still they are cursed with it.
Yep, that confirms my opinion about this being overengineered. I and some guys in their 20s with welding skills could make an elevator style of bridge for under 50k. 200k for that, good gosh!
@@awesomeferretI mean, it's meant to be art, not the most effective solution
a bicycle kind of setup would probably make more sense 😄
Super interesting, this just motivates me more to finally continue my maths degree soon🙌❤️
Most unpowered things on the English canals are cranked: e.g. lock gate paddles, lock guillotine gates, canal bridges. So, it's consistent.
@@chriswest1996 still, pedalling would make it a lot easier.
@@korenn9381 Pedaling is very effective compared to hand cranking, for sure.
Took me a good moment to understand that because I assumed you wanted to incorporate the bike into the bridges design trying to comprehend what that could even look like
@@monhi64 the mother of all peeny-farthings
This is the best Tom Scott video this year. I really love the designer's idea for having tradition and interactivity in the bridge.
It appears the designers did not anticipate that people would need to be kept from attempting to cross the bridge when it is absent.
Yes that crossed my mind too. It means the bridge will be out of action for over 40 minutes every time it has to be moved.
@@ferncat1397 the only other solution would be a full draw bridge, which would probably be 10x more expensive. This is just a piece of metal with a rope and crank
If I were blind or hard of seeing, I would never go anywhere near this, word.
I think from what he said about needing to contact people to use the bridge that the crank won’t always be attached or accessible
@@short600 the problem of not noticing the bridge is drawn is not related to the problem of someone drawing the bridge when you weren't supposed to.
I love the fact that an elliptic integral showed up. Here we are centuries after Euler and others first studied them. Of course, as mathematicians showed long ago, elliptic integrals do not have elementary anti-derivatives hence the need for numerical methods. I seriously hope they make a plaque on the bridge with the integral.
I forgot this was a Stand-up Maths video and not a Tom Scott video whilst the architect was talking
It should automatically lift a barrier across the crossing as its rolls, and then lower it as it rolls back.
One could just integrate some light weight skirting on the pedestrian ends at the "top", hopefully without totally throwing off the center of gravity that is at the heart of the whole endeavor. When the bridge flips, the barricades are also then in position.
It’s not even open yet
Seems like a much simpler (but less cool) design variation would be a straight track along the canal walls (at a lower elevation), and a circular bridge, with a flat bridge deck part way up from the bottom of the circle. Same approach with adding weight along the upper portion of the circle to move the center of gravity to the center of the circle. It would take a longer track however as the circumference of a larger circle would exceed the perimeter of the current design.
This video has such a "tom Scott" vibe. Nice work.
There's some irony building a complicated bridge like this and yet caring about removing the complexity of electronics.
cant wait for that wire there using to give n whip around slicing the person cranking it n half n causing the bridge to move to quick breaking n sicking a boat underneath
@@karls8103 Probably won't happen.
Also, you should brush up on your grammar.
Whoever arranged funding is also a genius, or will hopefully be remembered as one. Funding functional art is a risky endeavor. This one turned out so well (both in artistry and functionality) that it could be a nice funding model. There should be prizes, you know.
This feels like something Tom scott would make
The crossover we all need.
@@terrynicol2098technically, it's a bridge
An unexpected bonus of this would be also that the bridge cleans itself! Now, the canal on the other hand...
Good idea! Time to make a rotating canal!
@@ZedaZ80 Already exists: see Falkirk Wheel
How do I see you everywhere
Just one thing to add, it's very easy to detect if a motor is suddenly pulling too hard, by measuring the wattage of it, it will take more power of the bridge is stuck for the motor to move, so if you just put a fuse type electrical component on it, that would do it
$20 cordless drills even have a similar feature to avoid stripping screws. I do understand the ritual and human aspect part, just that 20 minutes is a bit too long, especially when it's twice a week.
@@ZacDonaldyeah… it will have a motor (or better gearing) soon.
i think there are torque limiting gears. Lego mindstorms kits had one
@@thewhitefalcon8539 you mean clutches? Tapping drills have them to not break the tap. Cars too, to be able to start.
But CNC machines just measure the power of the main spindle to notice if it's too easy to spin. That means the tool broke, and they stop.
The trouble with all of those mechanisms is making them account for variable loads. On a windy day the base load could be higher than a "triggering load" on a calm day. I'm sure it's a solvable problem if you allow for other inputs, but I don't think it's as straightforward as a basic torque limited motor.
That's really cool. I always loved the square-wheeled bike.
It would be nice if there was a scale model of the bridge next to it that people could wind whenever they liked.
That animation at 6:45 helps tremendously to explain the challenge that they had to calculate.
"When you have a person rolling it and something goes wrong they stop." (Paraphrasing)
This man has too much faith in people.
"It got a bit difficult to crank all of a sudden... so I just pushed really hard until it felt normal again!"
Says the person who broke the gearbox.
It's not even about people being "good". If you're opening the bridge for the first time, you have no idea if it's supposed to be completely smooth the whole way, or if it's normal for it to get difficult. Indeed, you _expect_ it to be difficult to move an enormous steel cube, so you're definitely going to force it if it gets stiff.
I think my real issue with the idea that motor operates bridges will just break is that he has no idea that bridge operators exist, or what they do.
The only caveat to this statement that I can think of is that it's in London, not Los Angeles or Moscow. In the UK, it's usually the canal boat operators who operate the bridges and locks themselves, and they mostly have experience with this kind of thing.
I'm not sure that's a valid caveat.
@@Vinemaple Certainly most locks and bridges on the UK canal network are operated by the boater. There are some exceptions for high-traffic locks where the Canal and River Trust operates the locks to coordinate between multiple boats and make things go faster. However, from the video, I get the impression that this bridge is on a small branch off the main canal that's only used to get to one boatyard or something like that. If that is the case, since only customers of that yard would pass through the bridge, it _may_ be that the yard's staff operate the bridge, rather than the boater.
I feel like this is the sort of problem engineers live for. I feel like a lot of the job is probably running through the motions, walking well-troden ground and just applying it to something in particular. Meanwhile, this is a hyper-specific challenge that hadn't been solved yet, and require some, well, enginuity!
The bridge is cool, and the hand crank is quaint, but I feel like the 20 minutes of manual labor to lift it is going to get old really fast.
Thankfully a robot or migrant will do it for us
*and another 20 minutes to put it back
its never going to be used don't worry, it is a bridge that opens up to nowhere and no one is going to want to park their boat there.
It's idiotic if you ask me. Only over shadowed by the reasoning behind it.
You cam have a hand crank and a motor, it's not one or the other... But no he think that'd somehow impact the bridge. Thus creating an annoyance for many.
@@P.G.Wodelouse That is kind of beside the point though.
8:48 the animation reminds me of the mechanical act of monkeys swinging from trees. I've heard tree swinging is actually a very efficient way to travel based on the conservation of forces or something that I don't fully comprehend, but this animation kind of alludes to it in some way I can tell
that act of travel is known as brachiation if you need a fun new word to throw around
It's efficient for the same reason that you don't need to use a lot of energy to swing on a swing.
Oh hey anyone else seen those videos about roads for square wheels? Made for a SoME I believe, maybe SoME2? Great videos
Yeah, it was SoME I, it generalised the problem as well.
Morphocular, i believe
‘I’m not normally an Applied mathematician’ great stuff. What a fabulous piece of engineering and maths.
I like how the hand operated theme is continued from the hand operated locks in the canals.
Should have put a bike as a cranking mechanism. Better power, plus it's so fashionnable and poetic
Yep. A motor would be even better, but a bike would have been hipster-acceptable.
A design that allowed more than one person to power the bridge at the same time would be a massive improvement.
Upvoted for the kitty near the end. That's a cool cat that appreciates the mathematical purr-cision that went into making this bridge work!
Very fun!
Trust a mathematician to enjoy solving this issue with 'hard' maths. I would have modelled the 'rolling cube' with it's round corners and set the edge to draw the curve for me. The tooth profile could be achieved in much the same way.
Somehow I'm reminded of comments made by a certain engineer about architects while playing Polybridge.
PS: Oh, and I'd want a motor.
Really channeled Tom Scott for this video. I half expected it to end with "One take!"
Seriously, they should have added a gearbox to the crank so you could get it going and then switch gears to make it go faster with more resistance on the crank as a side effect.
It's one thing for it to be very easy to crank, but a whole other when you have to keep cranking for 20 friggin' minutes!
Noooo think of all the added complexity (and ignore the fact that gearboxes in cars with several hundred horsepower last for hundreds of thousands of kilometers with nothing but semi-annual oil changes).
Bring your powertool with a custom tip, and boom.
It's not just that, it's also very uncomfortable to crank something that's too easy to crank. And dangerous. For me it was when my bike threw the chain off and I tried pedaling, leg slipped off, into between the wheel and frame, ending in a front flip onto concrete. In this case it's probably only maybe hitting my arm into the box... But humans are made for slower, more torque kind of crankage
No they can't do that because then it would make sense
@@valinhorn42 those cost way too much. A bike chain and sprocket set should be enough for this
I had a smile on my face all the way through that video. What a perfect marriage of new and old! Somewhat reminiscent of how Gaudi used the cutting edge Math of his time in the Sagrada de Familia cathedral.
Worth mentioning the material. It's probably that corrosion resistant steel, with a protective layer of rust.
They missed the opportunity to power it with a humansize hamsterwheel😂
I love everything about this I wish more people made things overly complicated in the name of art and mathematics
You're paying, right? I'm certainly not willing to pay. Because all the extra time it takes to engineer overly-complicated things isn't free. Not to mention the massive increase in maintenance costs.
No you don't lmao
@@iluomopeloso Okay go live in your world of boring grey concrete blocks with endless highways, the rest of us prefer to live in a world that's a little bit interesting.
10:58 "You can't just show up and start cranking it"
I'm an adult.
This is officially my most favorite bridge now! I didn't have a favorite bridge to begin with.
nice! Would as well be interesting to see the shape that retains the height of the center of gravity taking the assymtreic weight distribution into account.
Center of gravity would then be way too low and the bridge surface would only move up a foot or two.
yes, you're probably right. @@MichaelOnines
Very needed complications indeed.
If you change the handle to a hex bolt, you can use a drill to mororize the bridge. That will maintain the simplicity and the ability of a human to interpret feedback and xan speed up the process.
And you can still have a crank handle if someone doesn't want to bring their battery-powered drill.
But that's not the fedora solution, and that's what we apparently needed here.
@@jasonpatterson9821 fedora solution?
@@drooplug the guy who designed this has all the earmarks of a "hipster," which in internet terms is sometimes a "fedora" because of how prevalent that hat is in that culture.
You are probably not going to believe this,, when I was in year 9 at school, I went to a Technical/Stem school were we focused on engineering, so plenty of Math and Science, languages, two, and Science. It was quite tough and many students dropped out very early on, I wanted to drop out at the end of year 10 when my dad said to me, "You will stay in that school until you are done or you are 60 years old, what ever comes first". The bridge (similar, not that bridge, lol!) and drilling a square hole was what my "team" of "think tanks" came up with. We came up with almost exactly the same design, but my teacher was not impressed, he wanted to know what is the practical use for it and we replied, NO use what so ever other than being an elaborate plan to flees the local Council. He was amused and gave us a pass mark. Thank you Mr. Pelican (what we called him behind his back, he had an old Vespa Scooter and a Helmet that had a visor just like a baseball cap and he looked exactly like a pelican treading through water and every now and again would stop with the one foot on the ground just like a Pelican hunting for small fish.
You could also make that bridge work upside-down by providing stairs on the ground by the "open" position, so it could be open for pedestrians all the time, except for when it is actually rolling.
10:30 A mathematician in its natural environment: doing no work.
What were the odds that a person running a project in an up and coming, "revitalized", former industrial area NOT wearing a hat and having a beard?
Too low to calculate
That person still decided that pointless manual labour and wasting time are things that are worth it for the sake of "the poetry in it", so...
Really glad you were able to show the information for how the teeth were designed. I was mesmerized by their varying shapes and how they fit into the design of the track.
I can't help thinking it would look just as good to have the frame be circular running on flat track and the walkway would be as a chord of the circle. And obviously much easier to design.
What if they made it a stationary bike rather than a hand crank?
I don't see why we don't have more bike powered things tbh.
This is so fudgin cool. Great job explaining the motivation behind this and capturing the important bits from the engineer, Alfred.
Such a fun idea. I'm sure kids will love the idea of a whole metal and concrete bridge being moved by a single guy turning a crank.
It's amazing how smart people are, to develop something like that. Way beyond what I could do!
i guess i hate fun, because my first thought when I saw that it took 20 minutes of hand cranking to open was just "oh, so it's a worse bridge than the off-the-shelf solution"
I guess I don't understand what fun is. Cranking a bridge for 20 minutes to open it, and another 20 minutes to close it doesn't sound like fun to me. Especially when all the pedestrians who want to use it are standing around watching me and growling.
No, no, you misunderstand. The fun part is when you happen to wander through that area after a few too many drinks in the middle of the night and there's nobody around to stop you. Then in the morning the neighbourhood finds the bridge upside down. Every Friday and Saturday night until a concrete box with a steel door is built around the crank.
@@johnladuke6475 A) it's loud, genius, so no one can do it without notice, B) I bet the crank is removable (and that's why you need to phone them) but sure, keep finding straw problems to bash...
You just have no soul. Can't you see the artistic purity, the poetic perfection, of the ritual of hand cranking a bridge for nearly an hour?
@@beeble2003 it's "fun" to these rich artsy people, for whom an hour of (light) manual labor is a novelty.
You lost me a 4:27, YES motors can know when something's wrong there's an entire safety automation industry out there.
I guarantee you this bridge is gonna end up with either a motor mounted on it, or just "stuck" in the pedestrian crossing position within a year.
His argument is that, because there's no motor, you don't need those sensors. It's a stupid argument, but it's the one he's chosen to justify his impractical design that denies pedestrians the ability to cross the river for 45 minutes at a time.
@@TricksterRad I bet it actually gets stuck at some random angle.
@@TricksterRad Not to mention the chances of vandalism. If that handle's not locked down securely the bridge will end up the wrong way whenever a miscreant has 20 minutes to burn. Alternately, undoing or cutting the crank cable will render it motionless.
I have serious concerns about the engineer who allowed the architect to remove all the safety features.
Kudos to the guy at 11:32 for being so patient with the applied mathematician
There are a couple of great videos by Morphocular on how to calculate paths for bizarre wheels to smoothly roll on and vice versa
but did they add a tray/gutter to catch all the change and junk that will slide off the leading side of the deck and into the water every time it's inverted? The tray would need to have an overhang to retain the items when inverted and sloped one shore to bring all the catchings to one side or the other upon being righted
No I don't think so. But I don't think any draw bridge has anything to catch items. Not on purpose at least.
Artists came up with the idea, of course they didn't. Sensible people would have gone with a circular cross section, the entire thing just screams "It's more important to be a special snowflake than being practically minded".
@@kempo_95 the thought only comes up here because while typical draw bridges would naturally collect small dropped items at either shore by the hinge, this just flips them into the canal... it could be a kind of neat passive mechanism to also be able to check the little tray at one end of the bridge for coins or lost keys or misc treasure as you cross... and keep that (admittedly small amount of) stuff out of the canal
You could make sweeping the bridge part of the opening ritual.
This reminds me of Minecraft item-farming.
Nice - if only the guy who decided to make it hand cranked was there to crank it every time it is required to open it 😉😉 Pretty sure he'd soon fit a motor
With a Square bridge I was expecting this video to be sponsored by SquareSpace
I've cycled on this bridge about 10 times now and never realised it moved like this.
why not use a bike instead of a hand crank? you can put in significantly more power and if you got some killer legs you can just shift up and get done with it in 2 min rather than 20
The maths of this is way beyond what most engineers would dare to try to understand
False, these sort of integrals are taught to every engineer in a standard calculus II class. And, every engineer needs to take a differential equations class after calculus. And most, if not all, must take a numerical methods class (although most calculus texts also cover numerical methods of integration and differentiation). That is why engineering is so hard. The math is no joke, but it is all applied math versus the highly theoretical/abstract kind that mathematicians study.
"New mathematical challenge" is a terrifying phrase in the context of infrastructure.
Nice! I grinned through the whole video. Thank you!
So my question is how many crank rotations does it take to rotate it?
seems like the normal pace was ~2 rotations a second. that's 120 revolutions a minute, so around 2,400 rotations to raise or lower it. double this number for the "round trip."
The electrician in me couldn't leave that manual. Automate!
What happens if there's a powercut?
I designed a similar mechanism. I did it geometrically, as in at this position, it matches this arc and at that position the tooth profile follows that arc, then slapped and tangent arc of the average between the two point.
There is just so much beauty in its chunky, functional design, I'm so happy that a bridge exists like this!
I’d imagine that if instead of rounding the corners with circles they did it with ellipses, and put one of the foci of each ellipse at the centre of mass, finding a curve to roll on would have bean much easier. I didn’t do any calculations, it’s just an intuition
I'm expecting Matt to calculate as many digits of pi as possible from the rotating bridge.
This looks to be an ideal application of a Squircle! That would ensure a much better transition between flats and corners.
Also, letting the fixed pins roll would reduce the contract friction and thus the cranking force, not to mention reducing wear on the cog pins and teeth.
Letting the pins roll does require bearings, which are going to need care. It would increase maintenance requirements.
The Musee des Arts et Metiers in Paris has a gallery of dozens of non-circular gearsets. Some of them are quite bizarre. Well worth a visit.
So interesting, but so sub-optimal, in so many levels.
I wonder if the maths was really necessary. It seems to me that it would be possible to discover the needed bends of the track using accurate scaled technical drawings. Design the square first, and then rotate it and mark the distances from its centre of gravity.
On a smaller scaled object I’d agree. Because the weight of the bridge is so much, if the center of gravity moved up or down a measurable amount, the ability to move it by hand would be greatly reduced. I think the tricycle shown in the video is a really good example. It used simpler mathematics because the corners were still sharp but the construction was less than perfect so you can see that it still hops a bit and the rider is not putting in consistent force to the pedals.
@@troycongdonI suppose it depends on how accurately the design can be realised full-scale. Even if you have the location of the pins in the wall of the canal down to fifteen decimal places thanks to maths, what workman could install them that accurately? Concrete needs to set, and things shift when setting.
@Lindybeige I think that is why all of the important bits are made of steel. At least 12 of those 15 decimal places are irrelevant but whatever tolerance you choose to work to is the tolerance you accept for the vertical motion of your center of gravity. Steel is easier to work to higher tolerance than concrete and the interface between the two can be shimmed then grouted to make placement of the steel precise. I do have concern that as parts settle the bridge will become stationary. They mentioned that as they checked their work they found they had fabricated to a fraction of a unit over the length of motion so it appears their workmanship was kept to the same standards as their maths.
@@lindybeigeI imagine it was just a case of if they could be certain the maths was right, there’s no harm in doing it! But I think doing it as a drawing would work, it would just depend on how accurately you could get it. They could be working to a tolerance of 1mm, in which case on a 1/10th scale drawing you’d need an accuracy of 0.1mm which would be pretty tough to do.
Of course it was, for many other, than mathematical reasons. First, you must assure that project is safe and won't end in lawsuits. Also, a lot of extra forces aome as factor, you have to measure ability to bend, wind, temperature that causes steel to compress/extend and so on...
Fabulous! There's hope for us yet!
Make more of these types of video! This was so fun to watch!
Laughed too loudly for the 'applied mathimatician' joke 😀
I suppose that it's classed as green energy when operating the bridge and it's good to see that engineers and architects can get along. 🥴👍
Always nice to see a new bit of math that seems silly and impractical be used in something ultimately beautiful and amazingly complex!
This feels a bit like an extended Tom Scott video in the way it's framed (at least the first chunk of it). Just more maths-y. So all around a fun time!
Isn't this a path that you could discover simply by rotating the shape while sliding sideways, and tracing/mapping the appropriate bottom edge?
Yeah that’s what I thought
You run into a limit of scale models where the mass and material interaction can cause tiny differences leading to large gear/pin mismatches, so you'd have to do it real size. And then you'd have to build an axis, which would add weight, which means you'd have to remove that weight equally from both sides, then roll the bridge while the axis is carried by two very strong very stable vehicles that move perfectly parallel and level with gravity at the bridge's centre of mass. And once you've done that you'd need to remove the axis and add the removed weight. With another big downside: The removed weight would be structural, so now your construction isn't structurally sound. Which means you have to build two near-identical bridges (except one has the axis) so you can place the axis-less bridge after measuring out the path with the axis bridge.
@@bramvanduijn8086 using a program obviously, not a scale model
@@bramvanduijn8086 software model. The point is to trace the path of the bottom edge of a rotating square - why use math (or physical models now). The math isn't accounting for material interaction either.
I'm glad we got to hear from Alfred, the real star.
Such a brilliant design! Bloomin' love it.
Got a thumbs up just for the applied mathematician joke
Okay, so that's very pretty and all that, but they should build stairways at either side of its inverted position so that when it has to be inverted people can still walk across the upside down section
Ah yes, stairs that go nowhere on either end of a waterway, that _definitely_ won't lead to any unfavorable tabloid headlines following any incidents!
@@ParasocialCatgirl two things...
*1* poopyhead negative takes just kill the vibe.
*2* uhh.... Besides, Isn't that what gates are for?
@@SumNutOnU2b two things...
*1* I'm not killing the vibe, just pointing out why your idea would never seriously be implemented.
*2* Unless one were to spend even more money to make the gate substantial enough, _certain_ people are just gonna climb over it anyway and incite the media circlejerk.
So your idea is to tack a bridge to the bridge for when it is closed so people still have a bridge. You're basically building two bridges now.
@@ParasocialCatgirl uhh.......
*1* well, duh! Poopyhead!
This ismy favorite video this week.
A hand-cranked rolling square bridge is a delightfully twee idea if you live in a gentrified artist commune.
It is significantly less so if you’re one of the boaters who are stuck waiting 20 minutes for some granny to crank it into place.
Boaters are used to hand operated locks, this is exactly where the inspiration was taken, innit? Not a grany but the boaters themselves would crank for passage.
Unless you for some reason go through here all the time it'd probably be a fun experience, and a nice way to integrate history and modernity.