"All right. How do "Grav tanks" work?" Topic

I have seen several new releases lately. All look about the same. How do they work?
And don't give me a (intelligent donkey) answer like " Thry reverse or negate gravity, old chum!"

Let's get real now. Unless you can explain how they work , and how you can fit the power plant on such a small vehicle, I'm afraid we are talking fantasy rather than SCIENCE fiction.

Heim Theory says it "could be possible"…..

The concept uses electro magnetic fields to "cancel out gravity"….

Not sure how much power is needed. However, it does requires some sort of "unobtainium" to carry the massive current density required.

So, fantasy or fiction? not sure. Maybe if we came up with the right superconductive material we might be able to do it?

When the mining ship gets back from that planet with all those blue guys we can give it a try :)

I think H. Beam Piper had a better concept, more Gunship less tank.

But the Rule of Cool does seem to dominate

Since they violate all known laws of gravitics they are fantasy, for now.

Well, seems to me they are a lot like battle mechs and walkers…. not very practical.

Saber6 has it right, we have them in our SciFi games because they are cool, not necessarily because they are practical :)

I think H. Beam Piper had a better concept, more Gunship less tank.

He also had (contra-)grav tanks. They traveled on contragrav then settled onto their treads when in combat (Uller Uprising) firing their 90mm guns!

When three Higgs Fields were explored it was found that we could transfer energy between the fields such that gravitational mass and inertia mass could be separated and. in a small locality, the field value of one could be lowered at the expense of raising the other. This lead to the present technology allowing for grav vehicles, orbital shuttles of reasonable reaction mass use and space fighters. Wikipedia entry for grav fields 2150

but sounds scientifically enough to explain 3 of our present theory impossible things we use in our gaming.

x42

'Unobtanium' – possibly the Uup element discovered and
added to the periodic table after Lazar's 'revelation'
for which he was roundly roasted ?

They have miniature nuclear power plants that power their gravity generators which suck in air, compress it and then expel it to hover and move around. This gets rid of those messy rotors that hovercraft have reducing the vehicles vulnerability.

There is no requirement that we be able to explain something to call is SCIENCE fiction.

• We like grav tanks so we game with grav tanks.
  
• We like space ship games so we invent FTL travel
  
• We like space fighters so we game with space fighters
  
• We like big stompy robots so we game with big stompy robots

If it requires scientific explanation then there is NO science fiction, just HandwaviumFantasy

Magic. Or each tank lays down a "road" of magnetic stuff and then the oppositely charged super magnets (cooled to a very low temp) keep the mag-lev tank off the ground and then jet engines (or prop engines) send it hurtling through the battlefield. Also the magnet roads are picked up behind the mag-lev tank and redeposited in front of it. Implausable, I know.

Since they violate all known laws of gravitics they are fantasy, for now.

Agreed … breaking the sounds barrier or splitting the Atom was fantasy at one time … Heck men and their flying machines were fantasy at one time.

Well, seems to me they are a lot like battle mechs and walkers…. not very practical.

I agree … but it does not stop me have a bunch in my 6mm sci-fi forces ! Even though I'm not really big a Mech/Titan fan …

I think H. Beam Piper had a better concept, more Gunship less tank.

But the Rule of Cool does seem to dominate

That is kind of how it is explained about Hammer's Slammers ACVs/GEVs. Hover AFVs lifted by fans, etc. … John Treadaway can explain it better than I. AND yeah ! Can't always ignore "COOL" !

•We like grav tanks so we game with grav tanks.

•We like space ship games so we invent FTL travel

•We like space fighters so we game with space fighters

•We like big stompy robots so we game with big stompy robots

If it requires scientific explanation then there is NO science fiction, just HandwaviumFantasy

Yep … When it some to sci-fi we all have a level of "reality" we have to put to the side at times. A level which we can suspend our beliefs of science and fantasy. For example, I find most of the GW 40K fluff and many of their model designs/machinations just so over the top it is just plain silly. I prefer the Hammer's Slammer storyline/ fluff. Yeah, yeah, I know … I have a lot of 6mm Sci-fi that is GW Epic … but I also have a Hammer's Slammers 6mm Task Force also. So when is coms to gaming, my GW Space Marines are more like "real" soldiers then the GW silliness, etc. … And whether my 6mm Slammer AFVs are ACV/GEVs or Grav or ? It really does not matter. Save for the movement rules for a GEV AFV many be a little different from a Grav AFV ? Bottom line … always do what works for you … not me. Especially in Sci-fi gaming and life in general for that matter …

I would assume they float in a fashion similar to the conjectural "Alcubierre" drive, creating a bubble of warped space around them, effectively flying upward at the same rate that gravity is pulling down.

As an SF writer, when I've ever had to explain anti-gravity I take the tack that since gravity is the effect of space being curved by matter (a gravity well) then the anti-grav device operates by creating a pocket of 'uncurved' space occupied by the vehicle.

There's really one way on the immediate horizon, and it assumes that the EmDrive works (and is not a really cool way to fool test equipment). Basically, load up the underside of your vehicle with EmDrives.

The problem is, that's "anti-grav" in the same sense that a hovercraft is "anti-grav". You're countering the weight of the vehicle with just enough lift.

And the thing probably handles like it's on ice, so another point to Beam Piper.

As for "true" anti-grav, there's some math that indicates that you can theoretically assemble matter with negative mass, which means that its gravitational force would repel normal matter. (But still attract itself.) I assume this theory is correct for Star Noir's Alcubierre Drives.

The down side is that it's a form of anti-matter.

Choose your response:

1.) Very well.

2.) Dark matter.

3.) Negative energy.

4.) Reverse the polarity.

5.) The process is not actually "grav" or gravity based; that's just a convenient slang term, originally derived from misinformation released during development in hopes of misleading the enemy into wasting resources on fruitless lines of research. The actual process is magnetic in nature. Superconductors use magnetic induction effects to interact with the planet's magnetic field, thus creating a suspension effect; rapid manipulation of this effect across multiple planes produces movement and maneuvering capability, as well as instantaneous anchoring effects during firing.

6.) The gostak distims the doshes. Everyone knows that.

7.) How does a 19th century commander located more than a scale mile from his troops over undulating, broken terrain, somehow issue instantaneous orders getting a body of men he can neither see nor hear to wheel perfectly to the right and charge the exposed flank of a body of enemy troops he can also neither hear nor see? Unless you can explain that, you're not gaming history, just fantasy.

:-p

Most people can't understand how gun powder works, or how an engine that runs on diesel is differant from Gasoline, so it you don't know how you mark13 grav tank works its OK. In the words of a great tanker "l only ride'em, I don't know what makes 'em work"

WOOF … WOOF !!!!

The REAL explanation is classified, so eat plasma death Winston!

Parzival for the win.

"Let's get real now. Unless you can explain how they work , and how you can fit the power plant on such a small vehicle"

One is a question of revolutionizing our understanding of natural forces. Not something *this* forum is likely to do at your whim, and certainly not over lunch.

The other is a matter of engineering, and an entirely different argument. Until we know what makes the drive tick, the required power is an unknown. The most likely answer will be related to the fact that we can lift objects off the ground with presumably less efficient technologies already. If required power remains proportional to effect, then the power supply will not be the issue. The size and mass of the physics bender (the grav drive) compared to its lift will be the kicker.

Certain super conductors, when reduced in temperature, produce an electro magnetic field that enables them to apparently ignore the effects of gravity. When they are in this super-cooled state, they hover and can remain stationary at any angle you choose. They can also move around, above metallic tracks.

At the moment, scientists are working to increase the temperature that this effect will occur in certain superconductors… at present the temperatures are still way below zero degrees C.

Assuming that your Grav tank is in the future and the rate of scientific development continues at its current pace, it is reasonable to assume that the scientists have found a superconductor that will operate at temperatures above normal average temperatures and have also worked out how to tailor the magnetic field to work on any surface.

Here's some science:

YouTube link

So in theory, you wouldn't even need a power source if the superconductor generated the magnetic field at normal temperatures… all you'd need is to direct the field (possibly using electro magnets or just by pointing the plates in different directions).

Does that work for you?

Do what works for you … is what I always say. Is it Grav or ACV/GEV ? Does it matter ?

They use electrostatic charge. Its not true anti-grave but that don't stop people calling it that. Other than that Mmmmmm pass.

Quantum Hamster Cages.

Wishful Thinking!

Magic beads

Cats and buttered toast.

There's no such thing as gravity; the Earth sucks.

If you push the case too far, gravity itself is fantasy – it's there, damned it we're really sure how it works.

Advanced, miniaturized, cold fusion power plant.

Why not? It is science FICTION.

Depends on type of operation: The Lexus ad proves that maglev is possible with enough superconducting magnets. This accounts for the Star Wars skimmer types. big honking room-temperature superconducting magnets.

The Renegade Legion style main battle tank with the speed of a ground-attack plane and maneuverability of a helo gunship? PFM. Pure freaking magic. And that's WITH an onboard fusion bottle or two.

gameplay wise, I prefer the Renegade Legion tech.

"All right. How do "Grav tanks" work?"

Nicely, until you flip them over and the anti-grav drive smashes them into the ground and they 'dig' themselves toward the mass center of the planet (but they usually explode long before then. ;-)

Think of a "grav plate" as 2 parts: The lower part creates (or is) an energy field that pushes against the top plate (which is attached to the mass of the vehicle.) (Equal/opposite reaction stuff.) The stronger the energy field, the more mass it can push (ft/lbs per sqr inch.) The more "solid" (i.e. doesn't move) the lower part is, the more the efficiency. This creates "lift". Oh, and it cycles 186,000 times per second. Yes, all that makes my head hurt, too… ;-)

A fusion powerplant provides the power to the grav plating on the bellies of the vehicles (at least in advanced designs – older models have grav repulsor pods which are more easily damaged in combat, but provide lift, albeit less efficiently and powerfully than those from grav plating).

The vehicles with pods are usually slower, and are for the most part restricted to NOE level flight (nap of the Earth), with the occasional brief pop-up maneuver possible for some models.

Advanced designs with grav plating are much faster, can maneuver very similarly to VTOLs or jets, and can drop in from orbit, or climb up to orbit independently, as desired. The plating is also very robust, and due to its strong anti-grav field, typically deflects most, if not all projectiles and missiles away from the undersides of the craft, so act much like protective shielding as well.

The grav plates and/or repulsors of most designs provide lift, and when focused appropriately, also forward, and/or angular propulsion, permitting the vehicles to turn, and sideslip in flight.

Grav tanks in Striker had nuclear reactors and generated antigravity to float.

Nothing unscientific about that!

Whilst I'm nota vast fan (geddit?) of ani-grav, I can accept it as a concept. I would also postulate that there are different versions depending o th technology and approach, same as there's external and internal combustion engines – and the latter might be split into diesels, petrols and els *, for example – but they can all drive cars.

These different types have been mentioned – pressor beams; genuine ant-grav repulsors; elctrostatic charge stuff – who knows? Maybe those systems and others are all used.

I'm a bit worried that anyone worries about it, though! Especially when one considers other tech – warp drives; matter transporters and aliens that are all bipeds and speak american english…

Me? I like Blowers (obviously)

John T

* jeezus – the bleep machine stopped me saying "vankels" (replace the 'v' with a 'w'… what is the world coming to

"vankels" are just rotary petrol engines, aren't they?

I'm a bit worried that anyone worries about it, though! Especially when one considers other tech – warp drives; matter transporters and aliens that are all bipeds and speak american english…

Good points John. I figure the aliens intercepted all those TV and radio transmissions emitting from Earth. And they liked the American movies and TV shows best …

"vankels" are just rotary petrol engines,

I think it is Wankle. And If I remember correctly … yes …

The gritty details are going to be setting dependent, but are not entirely pointless to worry about, as they influence the design and function of the resulting vehicle.

Grav drives that are just cancelers will still need fans or jets for motive power and may need control surfaces as well. By comparison, "whole tamale" grav drives could be installed in a featureless egg and still be able to dogfight, or need emitters on one or more faces to do so. The size of those emitters is also a variable. These factors influence the art, any technical expositions a writer might indulge in, and, in our case, how the miniatures look.

A certain set of assumptions for grav can make the vehicles look just like ACV craft ("blowers"), while others end up like 40k's Eldar and Tau, or Shirow's VTOLs, or Star Wars floaters.

Fusion powerplants and antigrav propulsion are certainly no more fantastical than FTL travel, so……..

Me? I like Blowers (obviously)

Are you sure about that John?

This reminds me of the 'Heisenberg Compensator' question.

For those that don't know:

Someone pointed out you could never have a transporter that could 100% accurately reproduce an object due to the Heisenberg Uncertainty Principle.

Michael Okuda made a nod to this in Star Trek by introducing a device called a 'Heisenberg Compensator' to (supposedly) address the problem.

Some fan at a convention was adamant about wanting to know more, and asked 'How do the Heisenberg Compensators work?"

Okuda replied: "they work very well."

Point being – if game designers or sci-fi writers knew how to build anti-grav systems, transporters, or warp drive they wouldn't be wasting their time on writing games or sci-fi novels.

Maybe the one exception was Arthur C. Clarke.

"6.) The gostak distims the doshes. Everyone knows that."

No they don't. And I will never say they do!

As to the OP- There are several scientific and/or pseudo-scientific explanations for a gravity-resist ( Preferred term from Heinlien's "Friday", as Asimov showed what "anti-gravity" would really do in his tale "The Billiard Ball" ) vehicle. But basically, the engine directly pushes against the gravitational force exerted upon the vehicle to raise and hold it above the surface of the planet it is "on", then uses some means to propel itself in different directions using either a frictional shear force against the gravity field or some other means like jets.

Arguably, if you had such a drive system, you could be using less energy than say a helicopter, since part of a helicopters power goes into forcing the blades through the air against friction rather than all going into crating lifting thrust.

But yeah, i do laugh sometime sat people who describe grav armor as "more realistic as hovercraft" as we *can* build one at present- with some drawbacks, let us be honest – but are as far from building the other as Faraday was able to use his knowledge of electricty to build a pocket calculator.

After the General Unified Field Theory was solved in the 23rd century gravity manipulation became child's play. Everyone knows that!

Which is another way to say that Parzival is right. :)

-Will

They just by-pass the gravitational field around themselves. Simples.

That doesn't require much energy, so power is not an issue.

It's "W" ankel as w*ankel was the developer's name.

Not w- ankle.

The RL tanks A/G drives allowed them to FALL perpendicular to the force of gravity according to the fluff.

It's "W" ankel as w*ankel was the developer's name.

Not w- ankle.

So we are allowed to use pseudo profanities providing we capitalise them? Good to know!

Yes, I should have used a captial 'W' as we all should use a capital 'D' when we say Diesel* (but usually forget). And yep Wankels, Diesels and … well regular spark induced petrol engines (2 stroke and 4 stroke, horizontally opposed, V8's and all the rest) are just variations of internal combustion engines.

The point I was making was that for any given setting there doesn't have to be just one version of anti-grav.

Blowers? Nice image bashytubits! Remind me not to do that!

John T

* and not just when we say "Vin Diesel"

It's "W" ankel as w*ankel was the developer's name.

Not w- ankle.

Oops ! My bad …

I view it like Asimov's Billiard Ball. And once we accept that we're creating a field that negates gravity, it's not much of a stretch to assume we can modulate the strength of that field. Maneuvering isn't by fans, but by directing that field modulation. The limiting factors become CPU power, reactor power, materials science, inertial dampeners.

Zephyr1's description sounds like standing in a bucket and trying to pull yourself up. Sorry.