
Magdeburg Water Bridge - tosh
https://en.wikipedia.org/wiki/Magdeburg_Water_Bridge
======
mhb
Well, here's the photo that should be in the article:
[https://www.cntraveler.com/stories/2013-05-13/magdeburg-
wate...](https://www.cntraveler.com/stories/2013-05-13/magdeburg-water-bridge-
maphead-ken-jennings)

~~~
ralfd
Or this one:

[https://media.wired.com/photos/59327bdd9be5e55af6c25628/mast...](https://media.wired.com/photos/59327bdd9be5e55af6c25628/master/pass/water_bridge.jpg)

Wired Article:

[https://www.wired.com/2011/10/physics-and-the-magdeburg-
wate...](https://www.wired.com/2011/10/physics-and-the-magdeburg-water-
bridge/)

~~~
jannes
Interestingly, the wired article has the text "Image via Wikipedia" below the
image.

The image must have been removed from the wikipedia article since 2011.

~~~
ejbam
[https://commons.wikimedia.org/wiki/Category:Wasserstra%C3%9F...](https://commons.wikimedia.org/wiki/Category:Wasserstra%C3%9Fenkreuz_Magdeburg)

(Also check out the subcategories)

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mdturnerphys
I took a narrowboat over the Pontcysyllte Aqueduct [0] a couple summers ago.
It's really strange to be on a boat 130 feet up in the air, especially with no
guard rail on the side.

[0]
[https://en.wikipedia.org/wiki/Pontcysyllte_Aqueduct](https://en.wikipedia.org/wiki/Pontcysyllte_Aqueduct)

~~~
Doctor_Fegg
Pontcysyllte is magical, not least thanks to its setting in delightful
countryside.

Barton Swing Aqueduct is in an unattractive patch of urban Manchester, but
impressive in engineering terms. It’s a canal-over-canal bridge which can
swing aside to let big ships through:

[https://en.m.wikipedia.org/wiki/Barton_Swing_Aqueduct](https://en.m.wikipedia.org/wiki/Barton_Swing_Aqueduct)

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analog31
If I'm thinking it right, the weight carried by that bridge is much greater
than for something like a typical road bridge. On the other hand, the weight
also doesn't increase at all when a ship passes over it.

~~~
trianglem
Surely the weight increases, the displaced water needs to go somewhere right?

~~~
brazzy
It (mostly) doesn't stay on the bridge.

~~~
trianglem
As in it overflows over the sides?

~~~
RandallBrown
It would overflow out the ends of the bridge

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kozak
And no matter how heavy are the ships that are crossing the bridge, the weight
of the bridge always stays the same as when no ships are crossing it (provided
that water level stays the same). See also:
[https://en.wikipedia.org/wiki/Falkirk_Wheel](https://en.wikipedia.org/wiki/Falkirk_Wheel)

~~~
jimbo1qaz
[https://en.wikipedia.org/wiki/User:RealGrouchy/FalkirkGearin...](https://en.wikipedia.org/wiki/User:RealGrouchy/FalkirkGearing)
is a fun explanation of how the gear system works.

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tobltobs
Imho even more amazing are those water bridges of the Canal du Midi. Built
around 1670.

[https://www.beziers-in-mediterranee.com/sites/ot-
beziers/fil...](https://www.beziers-in-mediterranee.com/sites/ot-
beziers/files/styles/image_fond/public/visuel/peniche_pont_canal_0.jpg)

~~~
tomarr
I'm sorry but as an engineer there is no way aqeduct is from 1670, it looks
mid 1800s (and definitely no earlier than 1800).

Edit: Google shows canal du midi is indeed from 1670 but this aqeduct section
is later, completed in 1858 (the order was decreed by Napoleon himself
according to wiki)

~~~
tobltobs
Thanks for pointing out this mistake. Here is one of the canal bridges which
have been built around 1670.

[https://fr.m.wikipedia.org/wiki/Pont-
canal_du_R%C3%A9pudre](https://fr.m.wikipedia.org/wiki/Pont-
canal_du_R%C3%A9pudre)

and one from 1690:
[https://en.wikipedia.org/wiki/Cesse_Aqueduct](https://en.wikipedia.org/wiki/Cesse_Aqueduct)

~~~
tomarr
Ah yes, they are both very nice structures that would have taken some good
engineering at the time. I wonder what would have been used as the impermeable
water barrier - puddle clay or similar?

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p1mrx
I wonder if any navigation software needed a rewrite to handle the "water on
top of water" case.

~~~
ralfd
Google Maps shows it correctly with bridge borders.

Apple Maps does not.

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mhb
Other water bridges: [https://www.scoopwhoop.com/Water-
Bridges/](https://www.scoopwhoop.com/Water-Bridges/)

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Tomte
The other, possibly more famous one, is in Minden. It's the same canal, but a
different river.

~~~
_Microft
Here is an aerial picture of the one in Minden. _Wasserstrassenkreuz_
translates to _waterway interchange_.

[https://upload.wikimedia.org/wikipedia/commons/4/47/Wasserst...](https://upload.wikimedia.org/wikipedia/commons/4/47/Wasserstrassenkreuz_Minden.jpg)

~~~
Tomte
In front is the old one (but rebuilt), that may not be used by commercial
shipping, behind it the wider new one.

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markvdb
The highest boat lift in the world was in Belgium until recently:

[https://en.wikipedia.org/wiki/Str%C3%A9py-
Thieu_boat_lift](https://en.wikipedia.org/wiki/Str%C3%A9py-Thieu_boat_lift)

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CWuestefeld
Here's one in New Jersey [1], carrying the D&R Canal parallel to the Delaware,
across a tributary creek. It's part of a park, you can bike or hike across
here, and I was really quite astounded the first time I came across it.

This whole area is pretty much paradise to bicyclists, from the D&R Canal's 70
miles of towpath, to the 15 miles of the Colombia Trail. There's a huge amount
of riding to be done, completely off roadways and safe from cars.

[1]
[https://commons.wikimedia.org/wiki/File:The_Mapleton_Aqueduc...](https://commons.wikimedia.org/wiki/File:The_Mapleton_Aqueduct_in_The_Delaware_and_Raritan_Canal_State_Park,_Princeton,_NJ,_USA_-
_panoramio.jpg)

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dakna
If you enjoy engineering marbles like that, I recommend checking out this boat
lift:

[https://en.m.wikipedia.org/wiki/Niederfinow_Boat_Lift](https://en.m.wikipedia.org/wiki/Niederfinow_Boat_Lift)

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0db532a0
The Falkirk Wheel, while being a glorified lock, is pretty cool as well:
[https://en.m.wikipedia.org/wiki/Falkirk_Wheel](https://en.m.wikipedia.org/wiki/Falkirk_Wheel).

~~~
philo23
And for something a little older doing something similar, there's the Anderton
Boat Lift built in 1875
[https://en.wikipedia.org/wiki/Anderton_Boat_Lift](https://en.wikipedia.org/wiki/Anderton_Boat_Lift)

~~~
iSnow
Or the Niederfinow boat lift, which is on the same canal system as the
Magdeburg water bridge, just 200km to the east:
[https://en.wikipedia.org/wiki/Niederfinow_Boat_Lift](https://en.wikipedia.org/wiki/Niederfinow_Boat_Lift).
I am glad they decided not to tear down the old one (from 1934) but built the
new one right beside it over the last years.

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persephonee
The bridge is visible from the nearby Highway. Its an amazing structure and
shipping goods by ship is eco-friendly/cheap too.

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joe_the_user
_Work started in 1998, with construction taking six years and costing €501
million._

Given that large US construction projects always seem to come out costing
multiple billions of dollars, this seems quite cheap. The Eastern span of the
Bay Bridge ran about $8 billion and Boston's Big Dig also multiple billions.

~~~
brazzy
We Germans have noticed this deficiency in our history of construction
projects and are currently making up for it in one go with the new Berlin
Airport: original planned opening in 2011, still not done and currently about
3.7 billion EUR over budget.

