A needlessly complicated but awesome bridge. 

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/

Pulled a fast one on Tom Scott didn't ya?

When artists and architects team up, engineers invent new swear words

"you can't just turn up and start cranking it" applies to most places tbh

"This bridge turns so efficiently that all physical labour is now done by one Australian man."

Tale as old as time. Architect: Hey this looks cool, should be easy! Civil Engineer: Oh brother here we go again. Tribute to RCE.

"Not normally an applied mathematician" made me lol. Great design

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.

"There's poetry in it and it "only" takes twenty minutes of winding..." thus speaks a true artist.

This feels straight out of the poly bridge leaderboards

idk, personally I've always thought we needed more complicated bridges. Why should buildings get all the fun?

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.

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.

This bridge looks like a mathematician's dream and an engineer's nightmare, and it sounds like that's exactly what it was.

Awesome video, i love how matt almost seems annoyed that "this is reality and there is friction" 4:57

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.

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.

This is the best Tom Scott video this year. I really love the designer's idea for having tradition and interactivity in the bridge.

a bicycle kind of setup would probably make more sense 😄 Super interesting, this just motivates me more to finally continue my maths degree soon🙌❤️

It appears the designers did not anticipate that people would need to be kept from attempting to cross the bridge when it is absent.

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.

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.

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

An unexpected bonus of this would be also that the bridge cleans itself! Now, the canal on the other hand...

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

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.

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.

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

Oh hey anyone else seen those videos about roads for square wheels? Made for a SoME I believe, maybe SoME2? Great videos

‘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

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!

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

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.

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.

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?

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 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"

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!

This is so fudgin cool. Great job explaining the motivation behind this and capturing the important bits from the engineer, Alfred.

You lost me a 4:27, YES motors can know when something's wrong there's an entire safety automation industry out there.

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

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

"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?

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 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!

The electrician in me couldn't leave that manual. Automate!

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.

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.

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?

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

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.