OT: Engineering question...

[Old Ironsights]

Do you build a Brigde ofer a Canal, or a Canal over a River?











A: Both!



Water Bridge in Germany. Six years, 500 million Euros, 918 meters long. 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.

Question #2:

Did that bridge have to be designed to withstand the additional weight of ship and barge traffic, or just the weight of the water?







I'll leave the Answer to a "Eureka" moment...

[Buck Elliott]

Ships & barges displace their weight in water...

[mescalero1]

I would like to see a picture from underneath.

[Chuck 100 yd]

Just the water.

Question, does a truck (enclosed van trailer) full of birds weigh the same when the birds are flying as when they are setting?

[Dave B]

The design would have to withstand the additional weight as well (weight of water + ships and barge traffic).

Thanks,

Dave B.

[44magHunter]

It would have to be built to withstand the additional weight of barges.

[madman4570]

That is cool. fantastic pic!

[AJMD429]

I believe the 'additional weight' of the ship would push it into the water, and displace that weight of water, which since the ends are open and theoretically connected to large/infinite areas would move 'off' the bridge, there would be no additional weight, unless the boat were so deep it touched bottom.

The water would be EASY to support on a bridge in the sense that it would be the ultimate in evenly distributed loads, but potentially DIFFICULT in that it needs contained/can leak, and could develop resonance or simply waves which could place huge strains on the structure that would NOT be evenly distributed. Still, that much water sure as heck would weigh ALOT!

[Ysabel Kid]

Seen that pic before - and it is simply cool!

[Old Time Hunter]

Just wait until some barge driver rams one of the supports, it'll be one for the ages.

Those people standing on the sides add more stress than the ferries passing thru the water.

[jhrosier]

Back home in Illinois we called them aquaducts.
There was one in my home town of Ottawa where the Illinois-Michigan canal crossed over the Fox River.
The canal had been unused and drained before my time but the aquaduct stood, and may still.

Jack

[RIHMFIRE]

Yeah.....but hows the fishing....

priorities boys!

[Old Ironsights]

The design would have to withstand the additional weight as well (weight of water + ships and barge traffic).

Thanks,

Dave B.

"Eureka Moment" was the clue.

As the others have said, anything placed in water displaces the water in direct proportion to their volume & mass.

[jeepnik]

Just the water.

Question, does a truck (enclosed van trailer) full of birds weigh the same when the birds are flying as when they are setting?

That's one of those "elevator" questions. You know the one, if I jump up at the right moment as the elevator crashes to the ground will I be okay. In theory, you could jump fast enough, but the top of the car would be crashing down, so... Splat!

[Hobie]

There are several such aqueduct bridges in Europe. It is REALLY neat! Canal boats are neat! Great post!!!

[Rimfire McNutjob]

When I first saw the picture in the post I was guessing Dutch / Netherlands but the Germans are nuts too I suppose.

[KWK]

That's old technology. This British job, circa 1800, is a real canal aqueduct. It's still in service, for pleasure boaters.



Such a bridge has to be strong enough to handle water at its greatest expected depth. The boats might make a tiny change in that depth, but it is limited by the spillways at the nearest locks.

[gunslinger598]

cool pic

[Buck Elliott]

It would only need to bear the additional weight if there were locks at either end of the span, which enclosed the water passing over the lower canal.