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Two Way River

Use gravity to reverse part of the flow of a river.
  (+6, -1)
(+6, -1)
  [vote for,

The ancient Egyptians were able to ship materials both directions on the Nile because the prevailing winds blew the opposite direction than that of the flow of the water. This invention is a way to use gravity to cause part of the flow of a river to reverse and a fully laden ship can then go both ways using sea anchors.

Beside a river dig two tunnels, one stair step shaped and one under that sloped to almost match the terrain. Locks are installed at the ends of each step on the upper tunnel. A ship enters a lock and water from the river raises the ship to the top of the step. Then while water continues to flow into that end from the river, the water in the tunnel is drained at the upstream end by the lower tunnel. When the ship is carried by the stream to the next lock the process is repeated.

You may note that the lower tunnel probably needs to drain back into the river a couple of nodes downstream. This means there probably will be a series of lower tunnels but you have the idea now. Got to love that free energy. You could even install some turbines at the ends of the lower tunnels if the flow warranted it. Two way shipping, power generation, no dams, no pollution, no reduction in total flow.

cjacks, Oct 10 2005

OT - a different approach to locks http://www.canal-du...re/pentemontech.htm
Saw this recently on a Rick Stein show - the "lock" is an inclined concrete trough with a moveable dam (giant squeegee) drawn by two diesel locos mounted on rubber tyred wheels. Bizarre! [coprocephalous, Oct 10 2005]

Tempe Town Lake http://www.tempe.go...akeHistory/dams.htm
Inflatable dams [half, Oct 11 2005]


       How is this functionally different from the locks found on canals?
angel, Oct 10 2005

       Locks on canals are used to lift or lower a ship to the level of the water on one side or the other of a dam. The ship still has to move on its own once out of the lock.
cjacks, Oct 10 2005

       I was trying to sketch up how this would work, I think you might get it with 4 side by side channels & numerous locks, possibly water bridges & tunnels, but I haven't completely worked it out yet.   

       I think this would be very expensive to build, but who knows, it may pay off in the very long run.
Zimmy, Oct 10 2005

       I think I'd like to bun this, but I'm having a hard time getting my head around it. An illustration would help. I am envisioning this as a rising canal using locks that runs parallel to the river, each section connected to a fill pipe that is fed from the river upstream and a drain pipe that is fed to the river downstream. Yes?
wagster, Oct 11 2005

       This could be done with three 'canals' beside each other. All three are basically in parallel, and lets label the main canal with the normal water flow to be 1; the one beside it 2; and the final one 3. Links are made between the canals 1 and 3, going through canal 2 onthe way. Each link has a gate.   

       Lets label the gates a, b, c etc as they go downstream.   

       The first gate between canals 1-2, we can call a(1-2).   

       Now if we open d(1-2) and b(2-3), the centre canal will have reverse water flow. As the ship moves we can open c(1-2) and a(2-3), then close d(1-2) and b(2-3).   

       ______________1 <=<= main water flow

Ling, Oct 11 2005

       As long as there’s “Do Not Enter” signs posted for spawning salmon (talk about one step forward - two steps back), +.
Shz, Oct 11 2005

       Maybe I'm missing something but wouldn't the fact that the rivers are not flat but sloped down be a problem? Sooner or later the water in the opposite channel will be pulled down by gravity. If you were sending both channels down in the opposite directions that would work... but then one channel would end up deep underground. ... the whole idea of free energy just rubs me the wrong way ... where would that energy *really* come from?
ixnaum, Oct 11 2005

       //When the ship is carried by the stream to the next lock the process is repeated.//
And this is where the magic occurs. Since the ship is sitting at one end of the 'tunnel' (actually a lock), there is negligible flow of water to take it upstream before it touches bottom, so towing would be required.
ldischler, Oct 11 2005

       are the locks actively pumping? or is it all 100% passive?
ixnaum, Oct 11 2005

       So it's a set of locks running parallel to the river, with plumbing and valve work such that upstream flow can raise the level of the current lock, while the next lock drains downstream. Once appropriate levels are reached, the gates between two cells are opened. Since the valves are still opened, an artificial "upstream" flow is formed from the downstream lock to the upstream lock, and the vessel moves "upstream" to the next cell. Close the gates, re-position the valves, and repeat.   

       This could be a completely passive process, and would not require sea anchors.   

       I can't see this as a particularly fast process, nor would it be cheap to build the locks, but I don't see any technical reason that it couldn't work. [+]
Freefall, Oct 11 2005

       I had originally thought of using sea anchors like half round parachutes. But I suspect over time shippers would switch from flat bottom to half round bottom barges. Properly ballasted and loaded they would fit the channel (created with tunnel boring machines) closely and the sea anchors wouldn’t be needed.
cjacks, Oct 11 2005

       It's the draining of a lock that causes the current that carries the boat forward, opposite the direction of the river current?
half, Oct 11 2005

       I figured the anchor was to stop the boat, if necessary, so the main engines could be off.   

       It fills and drains at the same time, [half].
Shz, Oct 11 2005

       [Shz], I tried playing your above tab on my guitar, but it sounded odd...
normzone, Oct 11 2005

       Oh, okay.   

       Here, on the Salt River in Tempe (Near ASU), they have created a lake in a normally dry river. The dams are bladders inflated with air.   

       A contiguous series of similar bladder dams could effectively create a series of "moving locks" in an upwardly sloping channel, transporting a volume of water and boats upstream.   

       A boat enters the low end of channel. A bladder dam inflates behind boat, trapping water at the present level. A bladder layered on the upstream side of the previous bladder inflates, displacing it's equivalent volume of water and therefore raising the level of the boat. The next layered, upstream bladder inflates thus displacing it's equivalent volume of water and lifting the boat again. This series of bladder inflations behind the boat form the leading edge of the moving lock for the boat downstream (even if there is no boat there). Bladders on the downstream side of the "wave" would be deflated in progression as well to allow the next boat to come along behind (and this boat to move forward).   

       Properly timed, it could allow boats to move along at a continuous rate through the channel like a water escalator. Monumental engineering task. Not passive, though maybe the falling water in the adjacent river could power turbine fans to provide compressed air.   

       I wonder if a similar process, if granular enough, could displace enough water to create an upstream flow without the bladders having to ever actually become dams. I wonder, but I don't care enough to actually figure it out. :)   

       The water escalator would likely not be practical at that scale, but maybe as part of a water (amusement) park...
half, Oct 11 2005

       I think you mean [Ling], [normzone].
Shz, Oct 11 2005

       There is a simpler way, if you choose your river(s) carefully. In my neck of the woods (SF Bay area) there are 2 "rivers" that are actually estuaries, and water flow is generally dictated by the tidal currents in the Bay below. (Petaluma R. and Napa R.)
csea, Oct 11 2005

       I think you have invented the “switched capacitor” reverse flow river [half]. It would be horribly inefficient to implement in pumped air, but a closed pipe (and therefore pressurized) filled from the river source could fill the bladders with only the cost of turning valves.
cjacks, Oct 11 2005

       When you're going halfbaked, you may as well go the whole way... Obviously, water is vastly more practical. I thought about filling them with water, but thought they might require extra strength to hold back the weight of more water. I thought they also might be able to deflate faster if filled with air...he says as though he's headed to the garage to start building the system.   

       Some dams similar to those I cited are filled with water.
half, Oct 11 2005


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