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Envision: Civilian and Military vehicles where rubber wheels are not used in the far future. All vehicles are tracked instead, tank tread style.

In order to achieve greater speeds, said vehicles use electromagnets to hover above metallic surfaces, roadways, inside star ships, stations and what have you. They can also be reversed to attach to surfaces and, where applicable, traverse walls and ceilings. This mode is basically a high speed cruise mode and not for other uses.

All roadways on planets are in lower areas to minimize the damage caused by a vehicle moving in a such a manner to go flying. Roads are cut into the ground in the countryside, in cities they would follow the same idea with bridges for pedestrians to walk over them.

Effectively there are "floatways" for high speed transit, while side roads require standard tank tread movement. However, I would like to keep the electromagnets contained to the vehicle and not have external requirements aside from a metallic surface.

Let us assume:

  • Keeping the vehicle stable is not a concern
  • Production cost is not an issue
  • Power supply is adequate for the task
  • These vehicles are not trying to achieve more than a foot above the metallic surface beneath them
  • The magnet polarity can be fine tuned and/or adjusted with ease

My questions involve the following:

  • Can the treads themselves be energized to produce the effect, or should the emitter be somewhere else?
  • How would the vehicle move while levitating? Could the treads be used as a pulling effect on the vehicle. While pushing the vehicle up, the treads rotate pulling the vehicle in whatever direction, effectively still using the treads as the source of mobility? If not, what methods would work that involved electromagnets?

Edit: I've been looking around and wanted to share some ideas

This design shows a standard tracked approach

These magnets react with the 'track' to provide a closed loop Mag-Lev system. The tracks on the Mag-Lev system are very thick and robust, with each link fashion like a tooth with a deep root, and counts as full armour plate! Trying to shoot off the tracks on a Mag-Lev is virtually pointless, as even if the links break the track will not come off as each link is treated as an individual unit

This one theorizes a solid "track" instead

There are already maglev trains out there that operate on a pre-set path (tracks, of course), so the key would be to make this design mobile... thinking about it, you could "bend" a track into a circle so you're perpetually moving down the track like a train, except the track is moving around the wheel axis, if that makes sense at all.

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Unfortunately, unless the metallic surfaces on which the vehicle is travelling is also magnetized, magnetizing the vehicle treads will always attract the vehicle to the surface.

Magnetizing vehicle tracks has been used before with some success; in the latest season of BattleBots shown on ABC in the U.S., the winner of the tournament, "Bite Force", had a track system with permanent magnets to increase the robot's gripping power on the metal floor of the arena. This allowed the robot, which used a combination of the basic "pushing" and "flipping" strategies, to hold its own in scrums with similar robots, while keeping it nimble enough to get around behind the weapons of the "spinnerbots" it faced, including the runner-up "Tombstone" it faced off with in the finals.

Levitation, however, is always going to be tricky, because the forces keeping you in the air have to provide both the repulsion from the ground to overcome gravity, as well as the horizontal and rotational stability to keep the vehicle upright (usually necessary to maintain the repulsion force) and maintain control over your position and direction of movement. Magnets require a very fine balance, especially because of their dipole nature; like charges repel, opposite charges attract, and all magnets have both, so all it takes it rotating a little too far in any axis and the attractive force on the opposite side of the magnet (which is of equal strength to the repelling force on the side facing the ground) becomes irresistible, and then your vehicle is upside-down and crushing itself flat against the ground.

There's all sorts of "Applied Phlebotinum" you could use to have a vehicle attract or repel itself from any surface; I'd recommand a hand-wave over trying to use magnets, as most people's intuitive understanding of how magnets work from playing around with them in grade school will create dissonance.

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  • $\begingroup$ +1 to Applied Phlebotinum. No reader blinks an eye at hovercars in SF, because we expect hovercars in (certain subgenre of) SF. $\endgroup$ – RonJohn Jul 25 '18 at 2:48
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You're pretty close to Maglev Trains with this one, so I would research SCMaglev (the Japanese high speed train) and Electrodynamic Suspension (EDS) in general.

With EDS you don't actually require magnets in the train - or tracked vehicle in this case - because the train-tracks do all the work. The rails create a magnetic field, which creates eddy currents in the metal train. These eddy currents create magnetic fields in the opposite direction, and thus the track repels the train! By varying the current in the tracks or by providing additional currents in special "side-walls" you can push the train forward.

So you don't need electro-magnets in your tracked vehicle: standard issue iron tank treads will work just fine (for terrestrial travel, at least).

A couple of issues to consider:

Control - A highway system of high-speed-maglev is going to be logistically complex: the rails push/pull the tanks around, so system is going to have to provide orders to various sections of track to energize in very specific time frames and patterns. You're building a train system with many small trains instead of few large ones, and a trains system without train stations for that matter!

Low Speed-Ops - the levitation part of EDS only works at higher speeds: otherwise the eddy currents aren't strong enough to lift the train. EDS trains have wheels for low speeds, and then lift off the track as they come up to speed. Wheels are generally more efficient than treads: there is far less internal friction. Getting your tanks moving fast enough to levitate in the first place could be a challenge.

Reasoning - No one would give up something a simple and powerful as a rubber wheel for something as complex and inefficient as a tank tread without a good reason. Building and maintaining complex systems is expensive. For tanks, the ability to off-road and withstand small arms fire without a loss of mobility was worth the expense of creating and servicing treads. You will require something equally compelling to justify your mass shift to this model.

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A superconductor will levitate over a magnet like it was on rails.

So you put a magnetic line down your float ways, and when the vehicle is ready it just engages the superconductor and float down the road, maybe propelled by air or jets.

Likewise the superconductor can be turned into a magnet to allow it to stick to surfaces, like a ships hull, or whatever.

If you really don't want any magnets in the road, you could sheet them with copper and float your vehicle over it like the Arx Pax Hendo hoverboard.

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