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# Portable Canal

Ship Locks on Rail Wheels (lots of them!)
 (+8, -1) [vote for, against]

The giant floating city glides toward the port. Awaiting it is the mouth of a somewhat ordinary-looking, though quite appropriately large, canal lock. The floating vessel enters the lock and the massive doors close.

Instead of changing the water level in the lock, in preparation for opening another set of doors, leading to a canal, this lock has wheels. Maybe a few hundred of them. There are railway tracks extending from the water toward the land, at least a dozen parallel tracks and maybe more, to simultaneously carry the distributed load. Appropriate hauling equipment pulls the lock-car, with water, vessel and all, onto the land.

An overland journey begins, following the many tracks toward the next port. If the distance is far enough, the train can pick up speed, eventually reaching, say, three hundred kilometers per hour. No ship ever went so fast!

At the destination the train slows, and the pulling engines exit along side-tracks, while new pusher engines come up behind the lock-car. At some point gravity will want to increase the speed of the lock-car toward the water, and these engines now work to ensure this happens safely/slowly.

When finally stopped, the lock opens its second set of doors, and the giant floating city begins moving toward its next destination.

With an appropriate U-turn set of tracks, the lock-car can prepare to return to the first port, on a completely separate large set of tracks, allowing multiple ships in multiple lock-cars to be using this system simultaneously, in both directions.

 — Vernon, Apr 08 2008

Half-size Panzer http://blog.mlive.c...ath_story_here.html
As mentioned in an annotation [Vernon, Apr 08 2008]

Locomotive-powered canal http://en.wikipedia...Montech_water_slope
Pick up 200 tons of canal, and carry it up a hill. [coprocephalous, Apr 08 2008]

Relative Ocean Levels http://www.springer...t/q176600w500u4811/
Not much of a description, but there it is. [neutrinos_shadow, Apr 08 2008]

Wikipedia on Panama http://en.wikipedia.org/wiki/Panama_canal
(for reference) [neutrinos_shadow, Apr 09 2008]

Giant Floating City http://www.freedomship.com/
Here's your floating city. [Noexit, Apr 09 2008]

The World http://en.wikipedia...World_(cruise_ship)
A floating city that is at sea now. [Noexit, Apr 09 2008]

The Falkirk Wheel http://en.wikipedia.../wiki/Falkirk_Wheel
A vertical version of the same idea [james_what, Apr 09 2008]

Well over 12 train tracks http://www.nytimes....side_CA1.ready.html
...still barely enough to hold one oil tanker, let alone a floating city. [DrCurry, Apr 14 2008]

Old idea! https://books.googl...v=onepage&q&f=false
Popular Science cover article, November 1932 (pg 43). The existence of which was widely forgotten, heh. [Vernon, Sep 08 2015, last modified Sep 09 2015]

 You'll need superb sealing, as there is unlikely to be a large enough supply of replacement water during the land transport phase.

 Also won't the boat bump around inside the lock due to acceleration/decceleration forces plus wind loading?

 /the train can pick up speed, eventually reaching, say, three hundred kilometers per hour./

E gads man, that's a whole lot of momentum. One word for you: emergency stop.
 — Texticle, Apr 08 2008

[Texticle], any problem with wind could be solved by putting a roof over the lock-car, heh. Water seals should not be a big problem. When we can keep pressurized water from getting into a sub alongside the moving propeller shaft, when the sub is a hundred meters down, we most certainly can manage a simple static seal. As for "emergency stop", we just copy a bumper sticker from the Mel Brooks' movie "SpaceBalls": WE BRAKE FOR NOBODY. This is the HalfBakery, after all! (I just saw an article somewhere about a half-size Panzer tank reproduction. There is a place set aside for it with a sign that reads: "Panzer parking only. Violators will be totaled")
 — Vernon, Apr 08 2008

You wouldn't need seals, the lock could just be a tub that comes up from underneath.
 — marklar, Apr 08 2008

There's just one problem with this magnificent megaproject: where do we get giant ship-cities in the first place?
 — qt75rx1, Apr 08 2008

 This is, if I am making the correct sense of it, somewhat Baked. Not big enough for a floating city, maybe, but mechanisms exist for transferring a canalboat from one canal to another (at a different level) by physically moving the lock.

 (Sorry, no idea what to search on to find a link.)

But I'm wondering why the floating city needs to go overland at all, when it is possible to simply float to any place it might conceivably want to go.
 — DrCurry, Apr 08 2008

 What [marklar] said about just using a giant tub. No seals or gates needed, just enough space in the harbors for the tub to descend into.

If the craft and the car are designed for each other, there need be no water transported at all. Just line up the hard points over the chocks, and Bob's your uncle.
 — baconbrain, Apr 08 2008

 I specified "giant floating city" as the largest thing likely to be put to sea. When the Panama Canal was built, the locks were quite a bit larger than any ship of the day; they planned for future ships. But they didn't think big enough; lots of ships today are too big for that canal, and there are plans to widen it at huge expense. I'm simply trying to think big enough for the long long term.

I wonder if somebody built such a railway across, say, Honduras, whether it could be done less expensively than the Panama Canal widening project. It only needs to be wide enough to handle todays largest ships (I think aircraft carriers are sometimes called "floating cities"), but could be widened much more easily than a canal, when appropriate.
 — Vernon, Apr 08 2008

 Since the early 1800s, there have been discussions about building a canal through Nicaragua. There are currently some efforts to get it going again.

This idea, if implemented, will need some provision for smaller boats.
 — baconbrain, Apr 08 2008

 Vernon: But floating cities? Those could easily have an extremely deep draft, and be many miles wide. A little tricky to place on a railway track, let alone in a lock of any design.

 If you want to think that big, how about just removing the land bridge between the Americas? But before you do that, consider the change in climate that that land bridge caused, or the currently severe Antarctic conditions created the removal of the land bridge between South America and Antarctica.

If it's big enough for a ciy, it's big enough for current and storm systems, and that's no good thing. (Of course, living where I do, my sense of the size of a city may be a little skewed compared to yours.)
 — DrCurry, Apr 08 2008

 /how about just removing the land bridge between the Americas?/

What's the difference in elevation between the Atlantic and the Pacific in that area? Should the land bridge be removed, what would the equilibrium look like and how long would it take to reach that point?
 — Texticle, Apr 08 2008

 That doesn't seem like much to me. So the Panama locks are just to allow for land undulations, rather than elevation differences at either end?

Surely just dig a deeper trench through the high spots, and do away with the need for locks.
 — Texticle, Apr 09 2008

//Surely just dig a deeper trench through the high spots//
This was the original French plan, back in the early days, but they were overwhelmed by the depths of the cuts required (as well as accidents, diseasse, deaths, etc). <linky>

[DrCurry], what do you mean, "a railway track"? I specified at least a dozen! All to be used simultaneously! And just add more if you are upgrading for wider load.
 — Vernon, Apr 09 2008

 [Vernon] Laying the rail is not the difficult bit, carving out hills, filling in ditches, and crossing roads to make a relatively level route is the hard part. Adding more rails means you'd have to widen every gorge and bridge.

With that in mind it has very little advantage over a canal.
 — marklar, Apr 09 2008

12?! 1200, more like, and that would still only work if you mounted Manhattan lengthways, and just forgot about the boroughs. You have woefully underestimated your task.
 — DrCurry, Apr 09 2008

You could just dig a big ditch and float it across.
 — nomocrow, Apr 09 2008

Or you could look up ship railways, which are the same thing without the water. Ships sit on blocks on big railroad cars, and the proposers go bankrupt.
 — baconbrain, Apr 09 2008

Yeah, I'm not sure why we need to take the weight of the ship, distribute it across the floor of the lock, and then distribute the weight of the lock across a shedload of railway lines. Why can we not just distribute the weight of the boat across suitable railroad cars in the first place, and miss out the massive weight of a city-sized lock full of water? If we have to submerge the cars at each end of the line somehow, well, so be it.
 — david_scothern, Apr 09 2008

 Why not just make the cargo containers themselves float? Then you could hook them all together and pull them like a big boat snake with tugboat shaped like a serpent's head.

It could also have a large wooden badger at the end, for the caboose. Canals would be narrower and easier to build, and it would already be all hooked together if you want to put it on some kind of rail system.
 — nomocrow, Apr 11 2008

nomocrow, your anno is an idea in itself. Post if forthwith.
 — BunsenHoneydew, Apr 15 2008

 [nomocrow] you should post it as an idea.

You could have sections every so often that are bow (as in archery) shaped so that ships can pass through them and the containers can use locks in groups.
 — marklar, Apr 16 2008

entertaining and useful. [+]
 — Voice, Sep 09 2015

 [annotate]

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