German Water Bridge

[rlortie]

The Germans are at it AGAIN! WATER BRIDGE .. OVER A RIVER!!!
Even after you see it, it is still hard to believe ! Water Bridge in Germany.... What a feat!

Six years, 500 million euros, 918 meters long.......now this is engineering!

This is a channel-bridge over the River Elbe and joins the former East and West Germany, as part of the unification project. It is located in the city of Magdeburg, near Berlin. The photo was taken on the day of inauguration.

To those who appreciate engineering projects, here's a puzzle for you armchair engineers and physicists. Did that bridge have to be designed to withstand the additional weight of ship and barge traffic, or just the weight of the water?
Answer:
It only needs to be designed to withstand the weight of the water!

Why? A ship always displaces an amount of water that weighs the same as the ship, regardless of how heavily a ship may be loaded.

Remember your high school physics, and the fly in an enclosed bottle project? Similarly, the super sensitive scale proved that it didn't make any difference whether the fly was sitting on the bottom, walking up the side, or flying around. The bottle, air, and fly were a single unit of mass and always weighed the same.

[ovyyus]

The bottle, air, and fly were a single unit of mass and always weighed the same.

Unless the weight measurement is taken during the time it takes the dead fly (it had an instantly fatal heart attack while standing upside-down on the inside of the lid) to free-fall drop from the top of the bottle to the bottom. Weight during drop = bottle - fly.

Or unless the measurement is taken as the dead fly impacts the bottom of the bottle after it's free-fall from the lid. Weight at impact = bottle + (fly x deceleration).

Amazing bridge.

[AgingYoung]

The only improvement I could see they could make to that bridge is if they put a ferris wheel in it to move the ships off the water bridge down to the water it's crossing. On a serious note that's got to be a first to have a water way over a water way.

Gene

[docfeelsgood]

aging young ; tnis concept is not new at all . the erie canal from albany to buffalo new york bridged every brook and stream its entire length. including one viaduct west of fultonville that crossed the mohawk river still partially standing . it opened in 1825 . all boats were towed by mule teams . so also included were the "tow paths" on the edges . doc

[AgingYoung]

What's up Doc. Long time no hear. I actually didn't believe a word you said and had to research the matter myself. I found this:


Darned if you weren't right. :)

Gene
ps edit: I was perusing the erie canal web site and found this image that I think better describes how they built the erie canal. What a chore.

Where the Erie Canal crosses the Mohawk River near Schenectady, N.Y.

[John Collins]

Yes it's amazing but the Victorians built several to carry canals here in little old England, over road, rivers and valleys.

John Collins

[AgingYoung]

Doc,
I also just found this:

It seems the romans had a few also. I guess aquaeductus have been around for some time.

Gene

ps edit:

A ship always displaces an amount of water that weighs the same as the ship, regardless of how heavily a ship may be loaded.

If that water is displaced up the side of the aquaduct the bridge has to be able to support it also.

[trevie]

The next design, will be the river under the sea. I guess we could fill the channel tunnel up with water and put a boat on it!

[ken_behrendt]

Yes, aquaducts are nothing new, but they are usually not big enough to accomodate a boat!

Hmmm... what happens if that "Water Bridge" springs a leak?


ken

[SeaWasp]

Hmmm... what happens if that "Water Bridge" springs a leak?

Then you have a waterfall! LOL!

Spiros.

[rlortie]

If that water is displaced up the side of the aquaduct the bridge has to be able to support it also.

Thats funny! I was always told that water seeks it own level.

A boat entering a lock must use more power to push against the water that is flowing out upon displacement. The same applies as the boat leaves as the water is rushing in to replace the hole left by the boat.

Spiros, A leak in the bridge would create a water fall, but where as you have water from one river dumping into another it's called recycling. LOL

Ralph