I have a weird conspiracy theory about this bridge

They were playing Poly Bridge two and a half centuries before us.

Dude, you had one job: enjoy your trip!

The opposite banks move closer over time-you can see it flatter in old pictures… solved.

Wait, is it really made from cast iron? Surely it's extremely brittle.

1:55 direct path to Eiffel Tower? Isn't there a bit of sea in the way? 😬

I would say that there is equipment that can measure ground motion that accurately, though I tend to believe you, because I perked up the moment you said "306mm" because that's an AWFULLY convenient number.

tom reassess because the arch below is a perfect curve and it would be bent like the bridge deck or broken apart.

I live in Shropshire and had been wondering what on earth you could find here that was worthy of your time, given that it is a little boring….but you didn't let that defeat you! I don't recall ever seeing so excited about a topic in one of your videos before? 😁

Wasn't the bridge damaged and rebuilt in it's past though?

Would measuring the circle arch underneath also indicate its shrink? i would imagine if you drew it to its measurements on a piece of paper the result should be 1 half of a circle, but instead it would be an prolate spheroid, hm?

…find where they cast it, that's going to be a discovery when it happens – those are big components

I wonder if you can give footage to the @CorridorCrew and do an gausian splat to measure things?

it was a measuring contest because someone told a brit it was not possible.

we invented the road after all, this is not a stretch to have be done. just look at the things we've made, invented, done. your conspiracy theory comes off as… misunderstanding.

Finally a place I have been before the video was made!

Not sure if anyone else has already suggested this, but I had a thought while watching and some quick napkin maths and Googling backs up the theory – the bridge peaks into the middle to allow ships to pass under it.

The average "trow" of the 18th century, the most common vessels sailing the Severn, had an air draft (height from the waterline to top of the mast) of up to 50ft or so & the clearance in the mid point of the bridge is ~60ft. If the bridge was flat, it would be nearer 40ft, thus stopping a lot of very important cargo from getting down the river.

Now we just have to wonder why the hump – either the designers made a mistake, forgot the height they needed to design at or something shifted (geologically?) and they had to adjust the design. Perhaps if they'd already completed the stone supports, it was too much work/expensive to extend/reinforce them, so they just built the ironworks with a hump in the middle. But, because of the need to allow shipping down the Severn, they had no choice but to do something… anyway, that's my conspiracy theory 😉

i find it more likely that the did the construction relativly flat and then one day they noticed they wasnt that more flat? And i belive that the plans where lost how all old docoments are lost: misplaced, accidently destroyed or just discarded (unlikely) but when they for example moved the records some sometimes get lost. Nobody in construction would be bothered with the difference of the plan because nobody in those days really bothered about imprections like that.

I went to see the Iron Bridge around 20 years ago when there had been massive flooding, so much so that it just looked like a normal bridge because of the volume of water under it.

5:17 Erm the stone supports are not symmetrical on the real thing but seemingly are in the painting…? Are we just ignoring that? 😂 The ironwork keeps going south of the main arch, and should be seen to, I think, the left side of this image (I think this painting is looking west). Also, when you look at the stonework tops either side of the bridge, they are much lower than they are today – though I guess it could have been raised afterwards? But when you look at the walkway/carriageway height and then the man who is leaning on the wall to the left of the arch in the painting, he's need to be on his knees…? So unless there was some weird walkway dropdown separate from the carriageway before the crossing that has since been covered up, that doesn't really make sense. Also, the railings aren't the same, but they're maybe the most likely thing to be changed out over time, so I won't look too deeply into that. So I think the take away there is that the painter was either willingly adapting it in ways he thought looked more "aesthetic" – or he didn't even see the bridge himself and copied from others paintings or drawings.

Actually a compliment to its design and material. A brick bridge would have broken. The flat road on top of the circle bent very nicely over time.

Here's another theory – conspiracy or not – Tom gets more animated and speaks ever faster the more advanced the conspiracy theory he is presenting.