Tom R
Active Member
[Broken External Image]:
The photograph displayed above is one of a real structure, a kilometer-long "concrete bathtub" water bridge over the Elbe River in Germany that joins the Elbe-Havel canal to the Mittelland canal near the eastern town of Magdeburg.
As Deutsche Welle described the bridge upon its completion in 2003: Taking six years to build and costing around half a billion euros, the massive undertaking will connect Berlin's inland harbor with the ports along the Rhine river. At the center of the project is Europe's longest water bridge measuring in just shy of a kilometer at 918 meters. The huge tub to transport ships over the Elbe took 24,000 metric tons of steel and 68,000 cubic meters of concrete to build.
The water bridge will enable river barges to avoid a lengthy and sometimes unreliable passage along the Elbe. Shipping can often come to a halt on the stretch if the river's water mark falls to unacceptably low levels.
Plans for joining the two canals had been conceived as far back as 1919, and construction on such a project began during the 1930s, but first World War II and then the post-war division of Germany put the project on hold until after German reunification was achieved in the 1990s.
http://www.snopes.com/photos/architecture/waterbridge.asp#photo says it's True for those that like to debunk everything.
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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 below.....
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.
The photograph displayed above is one of a real structure, a kilometer-long "concrete bathtub" water bridge over the Elbe River in Germany that joins the Elbe-Havel canal to the Mittelland canal near the eastern town of Magdeburg.
As Deutsche Welle described the bridge upon its completion in 2003: Taking six years to build and costing around half a billion euros, the massive undertaking will connect Berlin's inland harbor with the ports along the Rhine river. At the center of the project is Europe's longest water bridge measuring in just shy of a kilometer at 918 meters. The huge tub to transport ships over the Elbe took 24,000 metric tons of steel and 68,000 cubic meters of concrete to build.
The water bridge will enable river barges to avoid a lengthy and sometimes unreliable passage along the Elbe. Shipping can often come to a halt on the stretch if the river's water mark falls to unacceptably low levels.
Plans for joining the two canals had been conceived as far back as 1919, and construction on such a project began during the 1930s, but first World War II and then the post-war division of Germany put the project on hold until after German reunification was achieved in the 1990s.
http://www.snopes.com/photos/architecture/waterbridge.asp#photo says it's True for those that like to debunk everything.
_______________________________________________________________________________________________________________________________
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 below.....
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.
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