# Maglev Wheels???



## Creator (Oct 23, 2007)

OK if you guys know that The maglev train moves on magnetic levitation but I wonder if this process can be reversed... in such a way.

I was thinking that this method may make a lot of things faster.... like Tankers?






Well those blocks can be the tracks of a tanker for example propelled by magnetic leviatation like the Maglev train.

Look I am just a fic writer but I want my readers or audience to believe that this tech might work..... So a bit of reality is still needed

I know it sounds crazy But if this thing can run... it can do a lot of things like say having a few motors running you have just one stretch of maglev track with the tanker treaded being magnetised and propelling forward.

I just need someone to see if the concept still works or if it is to work then what modifications to be done.


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## Nik (Oct 23, 2007)

Sorry, the link went to a log-in page...

Um, 'tanker', you mean track-laying vehicles like back-hoe / 'dozer or sno-cat ??

Well, yes and no: Yes, because linear motor will drive slides or conveyor belt, even shove appropriate material through pipe. Tech is un-wrapped cousin to both the stepper motor in CD player or hard-drive and 'electronically commutated' brushless DC motors.

Snags are torque and efficiency. Edge-effects and air-gap losses rise *horribly* with any clearance for eg dirt. For specialist applications, the cost is worthwhile-- IIRC, one app is pumping liquid metal !! If the machinery is big enough, gap and edge losses are reduced to 'tolerable'. For our scale, rotary electric motors, gears and hydraulics are still much more efficient...

( Check out drag-line mining tech... ; - )

FWIW, 'pancake' motors can be integrated into the support wheels you'll need for those caterpillar tracks...


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## ray gower (Oct 23, 2007)

Think what you are asking has been deployed on pretty well every 'hover car' in science fiction since Flash Gordon.

The concept of Maglev is that it neutralises the weight of the object, the left hand law (?) of magnetics then allows the whole thing to be drawn forward, though you could equally jump out and give it a good shove. The wheels are simply there to stop it hitting the ground and pushing it out the way when it breaks.

There is no reason, beyond the requirement for great gobs of power, why the magnetic fields cannot be produced on board the vehicle. Get the magnetic field generated strong enough and you would not need a track at all!

The practical science is that the whole lot uses so much more power than using wheels and an engine it is not worth the effort. The bigger the load the less the viability.

What have been used experimentally in tracked vehicles are linear motors. Instead of having rotors whirring around as in a traditional motor the whole thing is flattened out flat. It is not (yet) a fast propulsion method but has been developed into a solid-state drive making it ideal for use in otherwise hazardous areas.

Ultimately though, for science fiction, it is your job as the writer to convince me that it all works, no matter how ludicrous


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## Creator (Oct 23, 2007)

Here my concept art... so-called






Don't ask how is it going to attach to the track.... I will do that..... but it should move like a Maglev train except faster right??


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## ray gower (Oct 23, 2007)

Still don't see what you hope to gain. 

Tracks are not ideal for moving anything fast and Maglev counters gravitational effects, giving whatever is in its field buoyancy. The propulsion is more of a side-effect, there is no real motive power; Something that has no weight is easy to push.

Where you might be able to use the concept is to use your tracks as carriers and placing heavy delicate loads (think 1000s of tonnes) between them on a Maglev field. It occurs to me if that were done you would effectively have over half the mass outside of ground effect i.e. it would halve the load on the ground, allowing huge loads to be transported where they couldn't normally (over bridges, sand etc). That would speed things up relative to using millions of wheels and hovercraft air cushions which we do now. In theory you could move oil tankers of the sea going variety over dry land without them breaking up that way. That would be something interesting to watch going through the Channel Tunnel?


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## Creator (Oct 23, 2007)

Errr sorry I still don't understand.... 

if it can move a train that is over thousand pounds, it can also move treads that can carry a tank in this style... and will it be faster? It's speed I am looking for... a Maglev Train can so fast..... well if you apply this tech to well to what I was talking about in this topic.... it should work right but faster??

And yes it maybe able to propel maybe a bike's wheel perhaps without the center rod? I will draw more and let the science geeks here think about it tmr.....

I have got my tale's character wield maglev weapons that can punch a hole thru the armour of the bad guys or the hull of the ship or a sub.... and those weapons are at Mach 5 and above... it's done in reality but not portray enough in science fiction.


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## ray gower (Oct 23, 2007)

Think I may be catching up with you.
Your gun is what is commonly called a Railgun.
It uses an intense unstable (moving) magnetic pulse to propel a small pellet at trans-sonic speeds. The pellet has to be small and light for the magnetic pulse to overcome the inertia and pick it up. It is effectively the other side of the formula for Magnetic Levitation. You are trading mass for velocity. 99% of the energy is put into giving the small pellet the velocity to cause destruction. 

Maglev attempts to neutralise the effects of gravity by holding a mass inside a static magnetic field.

Think of surf boarding, you paddle around ages looking for just the right wave and then try and keep just ahead of the crest for the maximum speed. You would not expect a 60,000 tonne liner to potter around 'pore harbour waiting to catch a wave to take it to Perth.

So we have a static field (Maglev) for supporting a load and a linear one (railgun) for making small things go very fast. Linear motors (another rearrangement of the same formula) can move moderate loads at moderate speeds and as observed the moving armature for that can be incorporated in a tank track. But it's ultimate ability to draw a load is limited to how big you can get the magnetic pulse so as to draw the armature and there are physical limits to that.


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## chrispenycate (Oct 23, 2007)

Although I was in the wrong department to have Laithwaite (the inventor of the linear accelerator) as a professor, I was in the right university at the right time, (and built my own linear accelerator out of plastic drainpipe and TV deflection coils) The speed of the conductor depends on the spacing of the coils, and the frequency of the polyphase electric current, and there is a substancial tendency for the conductor to remain in the centre of the magnetic field, making it simultaneously a magnetic bearing and a drive system. Unfortunately for driving caterpillar tracks, the coil must completely surround the conductor (in this case, the metallic track) meaning that the bit at the bottom, where all the weight is applied, would have to have conventional bearings or an indirect drive, nullifying almost all of the advantages (particularly as tracks tend to be the first things to give up on vehicles using them, rather than motor bearings)
If you tried (answering someone else) to lift a reasonable wieght vehicle using the Earth's magnetic field, the currents you would need would be so enormous (you'd need superconducting coils, for a start) that they would be hazardous to unscreened lifeforms at several tens of metres; and the thing would drag in ferrous metals from hundreds of metres. Turn it on, and it would be like a cartoon, with cutlery flying in from all sides to stick itself to your magnetic shielding And even if you got a conductive roadbed, and got the thing off the surface, you'd have the same problem as with air-cushion vehicles; wide steering and slow braking. Works for trains, not for trucks. An intelligent road co-operating with an intelligent vehicle? Maybe, but I wouldn't put money on it.
And any of these solutions requires plentiful, cheap energy; they're not going to be ultra efficient.
You can actually feel a magnetic field generated by a few thousand amps; it induces currents into your nerve fibres. I suspect these devices are looking at two or three orders of magnitude greater than this, and leakage - well, don't go near one with a pacemaker, or anything electronic; this is close to a continuous EMP.


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## Nik (Oct 23, 2007)

Hi, there's also an upper limit to track-laying vehicles' speed because of the tension in the links.

You shove track around faster & faster, it tries to adopt a circular shape. It wants to be a wheel. Snag is your track-print needs to be flat, your linear motor is flat, your sprockets are tightly curved. You got a lot of momentum, a heap of loading on the sprockets and hinges, the potential for a near-explosion if a link fails...

Think high-speed 'chain drive' on machinery...

More scary, think of the problems of land-speed vehicles' wheels-- The fastest are solid metal, as anything flexible will so fly apart !!

Also, a subtle point-- Action & Reaction are still equal & opposite. You're pushing down, the floor gotta take that push. Look at 'air skates' for shifting heavy loads. The floor still carries all the weight, but you smear out the point-loading, save on tyres, bearings, crabbing steering, ackerman angles etc etc.

Whatever you do, if a bridge is rated 100 tons SWL, and your load is entirely supported by that bridge --air cushion, mag-lev, track-laying or many wheeled-- it better be within the rating...


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## Creator (Oct 24, 2007)

I see... but about my diagram, the maglev tanker tread might still work right? and also for circular tracks I was thinking that if this do not work for a tanker tread style maybe circular would be better...


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## Nik (Oct 24, 2007)

Hi, could you clarify what you mean by 'tanker' ??

Containerised ISO 'bottles', 20, 30 or 40 feet a lift ??

LASH barges ?

Panamax ?

Or 'megatonners' ??


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## Creator (Oct 24, 2007)

Tanker....


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## iansales (Oct 24, 2007)

That's a tank, not a tanker 

If each link of the track is separate and held in magnetic suspension.. and then accelerated forward by phasing the current in the magnetic coils... the uppermost section of the track would hold together. But once each link moved onto the forward edge of the track, it would fall out of the magnetic field and onto the ground. And if it did make it to the bottom of the track, it'd just be left on the ground as the tank moved forwards.

So no, I don't think your idea will work.


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## Rawled Demha (Oct 24, 2007)

lol, yeah, a tanker is normally a container for fluids...i think


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## iansales (Oct 24, 2007)

So are tanks. And battle tanks are so called because when they were being developed they were referred to as "water carriers" to keep their purpose secret.


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## Rawled Demha (Oct 24, 2007)

/me punches hisself in the head for being so stupid

so tanks are.

interesting about the codename though, i never knew that.


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## Creator (Oct 24, 2007)

Silly me too... maybe maglev tracks cannot be used in this way.... or does anyone have a solution to this problem..... 

Hover tanks on a cushion of air? whatathink?

Or ok... maybe this maglev wheels cannot work on a tank tread or maybe something round rather than elongated...? MAybe this can be used to drive.... well blades of a turbo fan or a duct fan minus the center rod to drive it....


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## Nik (Oct 24, 2007)

Edge drive...

Um, if you put the impeller blades inside a ring, you could wrap a motor around the outside...

Snag is the middle of the blades don't move fast to be useful, so you gotta blank them off. May as well put the motor there, have something to attach axle to...

But, put vanes on outside of ring, wrap motor inside that, slide the vehicle inside *that*, you got possibilities.
---

IIRC, propelling a MainBattleTank or other AFV is a grim trade-off. The US turbine powered Abrahms is considered an oddity, everyone else has gone for diesel. Um, probably perhaps a heavy-duty diesel can quaff anything from cooking oil upwards-- Albeit at reduced efficiency.

A snag with hover vehicles is they get better as they get bigger. Look at US' air-cushion amphibious landers, and the UK's *HUGE* SRN cross-Channel designs. The latter retired when Chunnel opened. I've crossed the Channel once by hovercraft, and it was a wild ride. Okay, the weather was *vile*, the regular ferries were delayed and the SRN cut across the infamous Goodwin Sands --We could see sand between the waves !!-- but a 50% bigger craft would have ridden smooth and level...

And even a hovercraft that big could only carry a couple of tanks...

A individual armoured 'Tank' of familiar size is too small for the air-cushion needed to support it, or to carry the engines to fill the air-cushion. 

Hmm, for militarised hover-craft used in scouting and light attack role, look at opening to 'James Bond' movie, 'Die Another Day'.

An armoured hovercraft would need to be ten, twenty, fifty times bigger to carry significant armour, to bridge obstacles. It would sound like a Space Shuttle launch and would be a Very Big Juicy Target.

Also, for obstacle clearance, a hover-tank needs enough power-to-weight to *fly* over anything it can't bull through...

SciFi-style hover-tanks have fusion power and multiple lift-fan nacelles--- Or enough AntiGrav to lift a small starship...
---

Please, keep looking: You gotta neat idea, you just need the right problem for it to solve...


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## Creator (Oct 25, 2007)

I am thankful for the support.... but now I am looking up on ekranoplans or ground in effect craft... It appears that they fly close to the ground like hover tanks... just add a turret or two and you get a hover tank....


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## StewHotston (Oct 25, 2007)

well, as long as you don't care about recoil


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## Creator (Oct 25, 2007)

recoil?


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## Nik (Oct 25, 2007)

*Ekranoplan flies in 'ground effect'.*

Ah, the 'Caspian Sea Monster' and its ilk...

Ekranoplan or Wing-in-Ground-effect aka WIG...

Trick there is the combination of ram-air cushion, and distance to build up speed. IIRC, CSM famously 'hopped' over several fishing boats...

There's a bunch of related vehicles, ranging from blown 'sidewalls' to fast boats with air-trap between multihulls and/or under 'step'...

And, IIRC, the RAF's Victor bombers, big triangular 'flying wings', had some very strange handling characteristics near ground because of the sheer area under the delta...

One feature in common is that they gotta keep a lot of speed to keep that ram-air cushion-- Like any fixed-wing aircraft, if they stop, they drop.

Um, IIRC, some of the earliest (1920~~30 era) flying-boats spent a lot of time in 'ground effect' until they burned enough fuel to climb out. When you look at those designs, they often had fat sponsons / winglets at water level to encourage this. Remember, getting into the air is hard, and big runways did not appear until WW2's big bombers...

Hmm, also research 'Moller' and related ducted-fan VTOL SUVs. Check their power/weight and stability requirements, and wonder at their long and oft-fraught history...


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## iansales (Oct 25, 2007)

*Re: Ekranoplan flies in 'ground effect'.*



Nik said:


> And, IIRC, the RAF's Victor bombers, big triangular 'flying wings', had some very strange handling characteristics near ground because of the sheer area under the delta...



Er, the Avro Vulcan was the delta-wing v-bomber, not the Handley Page Victor.


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## Creator (Oct 25, 2007)

Ok just a little work on my wacom... well the picture says for itself.


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## Delvo (Oct 25, 2007)

Creator said:


> recoil?


Recoil is the force pushing the gun back when the ammo goes forward out of it. The momentum of the ammo is exactly equal to the momentum of recoil, in the opposite direction. Momentum is mass times velocity, so a small, light piece of ammo moving very fast equates to a big, heavy object (like a gun and the person/thing holding it) moving much slower (as in, not supersonic and you can actually see the movement).

Recoil is why you can injure your hands or wrists by firing a hand-held gun that isn't properly aligned (and braced against your shoulder if it's a long gun), and why you see the gun, hand, and arm all jerking back and up with each shot, and why it feels like the gun just punched or kicked you in the hand/wrist/shoulder after you've fired.

It also applies to bigger guns. An A-10, an American attack plane, fires such heavy bullets at such a high rate that its recoil exceeds the maximum power of one of its jet engines, so the engines have to increase thrust while the gun's firing, just to maintain the plane's speed. The only way to put a bigger gun (or more of them) on a plane and still have the plane be able to fly while firing it is to use a modified cargo plane like a C-130, because its greater mass makes it harder to push around. A battleship's big guns' recoil rolls the whole ship a bit, and would sink most smaller ships if they foolishly had such a gun mounted on them and foolishly fired it.

And if you watch a video of a tank firing its main gun, you'll see the whole tank bounce and rock due to the recoil.

Now here's the catch: anything sitting on the ground is deceptive about recoil because it directs most of the force into the ground. That way, the momentum mostly goes into moving the Earth instead... by an immeasruably tiny amount, because the Earth is so much more massive. If all of the momentum of recoil went into moving the gun and gun-holder, they'd go falling back out of control much farther and faster. And that's the situation a tank would be in if it were hovering: its own gun would keep pushing it around each time it's fired, away from whatever its target was.


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## Nik (Oct 25, 2007)

*Vulcan.... My Bad.*

Vulcan, of course, of course...
My Bad.

Yes, the restoration team has just managed to get one back in the air.

Um, I remember being on a camp-site under flight-path of Anglesey's Valley Vulcans. One did a 'bump & go', came over at such low altitude that we felt the pressure wave.

FWIW, the people who fell over did so because they were staring...

---

Um, sorry, that design of the blades with open centre might be dynamically unstable...


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## Phil Janes (Oct 25, 2007)

I see three main drawbacks to this basic concept, as far as tanks are concerned. 

1. Terrain. MagLev works wonderfully on a perfectly straight track, but it’s not so good at cornering and bumps. 
2. Torque. For quick starts, stops and steep hills, you need a lot of torque which comes from gearing down from a rapidly spinning motor. MagLev is a direct drive motor with a fixed gear ratio of 1:1. 
3. Speed. As has been pointed out already, caterpillar tracks can only go around so fast, regardless of how they are driven. For military purposes, they must be designed to withstand an enemy’s attempts to break them. If you design them for greater speed, they will be more vulnerable to attack. 

My own vision for the future of superconducting MagLev is a long-distance meteor train inside a huge vacuum tube. Theoretically, if the tube is straight enough, such a train could travel faster than a satellite in low-earth orbit. The beauty of MagLev is its ability to use the deceleration of one train to power the acceleration of another train. With a small but steady input power, you could make each train go a little faster the previous one. If you maintain a constant total kinetic energy for all the trains in the system, you hardly need any energy input to keep them running. Temporary changes in kinetic energy would require some sort of short-term electrical storage—perhaps giant superconducting electromagnets. If you have to shut down the system, you’ll have to find some way to dump the excess energy—which might overload the nations power grid. 

After the astronomical initial cost, the biggest drawback to my train is vulnerability to terrorist attack. A well-placed IED outside the tube or inside the train would destroy a big piece of the system, killing all the passengers and anyone else within several square miles along the route. There’s good reason to call it a meteor train; a train moving at 18,000 miles/hour is the equivalent of a good-size meteor; its kinetic energy would be equal to its weight in C4 plastic explosive.


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## ray gower (Oct 26, 2007)

*Re: Vulcan.... My Bad.*



Nik said:


> Vulcan, of course, of course...
> My Bad.
> 
> Yes, the restoration team has just managed to get one back in the air.
> ...


For the sake of accuracy . 
It was the 'flying wing' bombers (B35/B49) that had extreme problems with low speed low level flight, they had a natural tendency to go arse over tip.
There are very few aircraft of any size that perform as well at low altitude as the Vulcan, rather fewer that size where the driver would dare to perform loops and rolls at 500 feet. They did have a high stall speed compared to Victors. 
It was the rather more conventional Valiant that had low-level problems in RAF service, the wings flapped too much, consequently they tended to fall off.
Nor have bombers ever been stationed at RAF Valley, though we did play host for a flight of Shackleton MR1s for a few months in the 80's.

Apart from the mechanical problem of creating blades strong enough to take the forces, the problem with a centreless turbine is you will not be able to compress enough air into the high pressure chamber for efficient burn or thrust. The air will leak back through the centre vortex of the funnel it creates. You need to close off the middle to fill the void


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## Nik (Oct 26, 2007)

*Again, my bad...*

Again my bad...

We naively assumed if Vulcans routinely went in/out of RAF Valley, they belonged there...

My understanding is Vulcans *loved* the air, were very reluctant to leave it, happy to float on 'ground effect', ready to rise...

And one did come over our camp-site low enough to astonish !!
---

Um, I wasn't so bothered by the air leaking up the middle of that sketch as those blades wobbling. Never mind 'hopelessly inefficient', it is a ticking bomb...


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## Creator (Oct 26, 2007)

Nah it's ok... that one was a failure. Well I am onto hovercrafts and ekranoplans now.... I don't think treads are going to do it for future tanks.... when wars are getting speed on their side.


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## Delvo (Oct 29, 2007)

Creator said:


> I am onto hovercrafts and ekranoplans now.... I don't think treads are going to do it for future tanks.... when wars are getting speed on their side.


You might be underestimating the speed of modern tanks. They can match the speeds of most cars and trucks on a highway. They can also go some places where the terrain is too rough for a hovercraft, and are much tougher because they can carry heavy armor while hovercraft need to be light and can't afford armor's weight.

There are already military hovercraft in use, of various sizes. Their most common application is amphibious operations, because they can so smoothly and easily go back and forth between moving over land and moving over water. They do have guns on them, but much smaller relative to vehicle size than a tank's gun is relative to the tank's size, because of the recoil issue; their main job is to move your own side's people and supplies, not to shoot at enemy targets. In other words, it takes a hovercraft bigger than a tank to use a smaller, less powerful gun than a tank's gun. And they're not particularly fast; tanks can outrun them.

If you want to carry tank-like firepower (or more) at a higher speed than tanks can go, you need true aircraft instead of hovercraft because hovercraft aren't so fast. Then you also generally get longer range because of the higher speed, and the ability to work over extremely rough terrain that a hovercraft or even a tank can't handle. Take a look at these:

AH-64 (attack helicopter; uses rockets instead of a big gun but the effect is similar)

A-10 (attack plane; uses rockets & bombs like an attack helicopter, plus a machine gun that throws heavy, non-explosive bullets at a very high rate instead of big exploding shells one at a time like a tank)

AC-130 (attack variant of C-130, a cargo plane; has a combination of different types of guns and bomb/missile launchers sticking out of its cargo area)


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## Creator (Oct 29, 2007)

How about the military vehicle called the Stryker.??


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## Delvo (Oct 29, 2007)

What about it?


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