"Hammer's Slammers Combat Cars/Hover Tanks - probable?" Topic

What's the thought on these things — is there actually a benefit to a hover-anything on the future battlefield?

And grav-tanks? Obviously, this technology doesn't exist — but has anyone read anything about anti-grav research that's out there in the "real" world?

Air cushion vehicles are a bit tough to control with precision, and without the fusion power and thick trans-uranic armor, a lot of terrain will be unreachable.

Research into the nature of gravity is ongoing, as I understand it. Sufficient understanding of gravity may show a way to selectively negate or re-direct it, but I'm not going to hold my breath.

You are so going to get lit up on this, by a certain TMPer who despises all things related to hovertanks. Just to forewarn.

As to hover (as in air-cushion or ground-effect vehicles), I think it has its applications, most notably the amphib aspect. It has more limitations than anti-gravity technology — land mines would still be an issue, for one, and keeping fans intact to provide lift would be challenging. Stability when firing a high-recoil weapon (such as a 120mm smoothbore) and ability to tackle steep slopes are other issues that would need to be adequately addressed.

As for anti-grav, I don't think there's anything like that even remotely in the cards. Heck, physicists still don't understand what causes gravity in the first place, so I don't think they're in a position to create anti-gravity.

Javelin98 – who has a problem with hovertanks???

Anti-grav is way more likely to be used with military vehicles than Air Cushion Vehicles when it comes to armoured vehicles as they have a lot of drawbacks. Too many to even be considered for use with tank-like applications.
Anti-gravity, on the other hand, we won't see for many years.

There are no benifits for ACV AFV over tracked ones. Maybe the ability to move sideways and therby keeping the thicker front armour facing one way while moving in another direction. That ability isn't much compared to the backdraws, though as I can see it. The ACV's inability to properly force through vegetation, rubble or climb slopes, for example. They cannot effectively move over ditches as they will lose pressure and drop to the ground.
Or the fact that they kick up a lot of dust. If you put armour on an ACV they must have one hell of a pressure in the cushion not to drag the armour along the ground. Higher pressure means more dust kicked up, which means the vehicle is easier to spot from a distance. ACVs kick up dust even when standing still if chamber pressure is to be kept. That is a huge backdraw.
Nah, we won't see armored ACVs other than like in those amphibian vehicles that are already used.

No wonder theres no such thing as GEV's yet. And they've always said there would be flying cars and domed cities in the 21st century. Maybe it is because we build an off-road vehicle that can't go over a curb.

GEVs (Ground Effect Vehicles) exist, but are of limited application. ACVs (Air Cushion Vehicles, aka "hovercraft") are a form of GEV, as are those big stubby-winged heavy lifters the Soviets tried for a while.

The most common civilian use for ACVs is as over-water ferry vehicles, and several militaries use them for amphibious landing craft.

The "Ground Effect" is a phenomenon of airflows around a body at *low* altitudes (generally no more than 10m) that enhances lift, allowing air vehicles that stay in that zone to be designed with less concern for lift and more (typically) for payload mass.

Hey, I ain't naming names! If you look for this subject through some of the threads of the past six months, you'll probably see who I'm talking about.

Javelin,,, You were correct, and Stymnos…

IT IS I!

ACV Combat vehicles are about the stupidest thing that could exist!

For the same price that you can build an ACV COMBAT vehicle (one which was capable of performing in a combat situation without failing as soon as it took a hit to a fan or skirt), you could build roughly 50 to 100 regular tanks.

There is that speed thing that people bring up… That is more of a myth than anything else. Unless an ACV has flat terrain to run on… It is slow as christmas. By flat terrain, I mean the earth under it and relatively few shrubs and bushes, which can be passed over relatively quickly, anything that significantly breaks the skirts for more than a second or two will send the ACV crashing into the ground…

Why do you think that there are no COMBAT ACVs in service (The LCAC is NOT a combat vehicle. It is a logistical supply craft that is capable of doing relatively high speed combat landings of tanks, one at a time, where it runs off as fast as it possibly can if under fire) anywhere in the world when obviously if they provided any sort of bonus there would be ALL sorts of DARPA programs.. There WERE DARPA (or its predecessors) programs back in the 70s. They showed that ACVs sucked as combat vehicles.

Now, what about GEVs… GEVs are different than ACVs, GEVs fly over the ground in "Ground effect"… Again, MANY tanks for the price of a GEV, and GEVs may be easier to armor than an ACV, but guess what? Do you know what that armor does to the power required to make that think fly in GE? Each doubling of the armor requires that the power be doubled^2 (4, 8, 16, 32 times the power at each doubling). For that kind of power you could create regular tanks that could run at 100MPH or armored turbine engines, and have fuelers to follow them around…

For the money to build GEVs or ACVs, you could build highly armored gun-ships that would do a better job; mounting 5 inch naval guns on them, or 30mm AT cannon… Actual flying is WAY cheaper than trying to stay in GE or on Air Cushions only in places where the terrain will cooperate.

GEVs and ACVs were nice "Sci-Fi" concepts. Even with fusion power it is likely that some other form of propulsion will continue to outclass even grav vehicles until the technology becomes. I actually like Gravitic technology, but infortunatel, it will still have many of the same power requirement problems until we solve some of the basic principles of physics…

Javelin, in the future, feel free to use my name…

As for Anti-Grav research…

Teh only things that are currently being done to look into what gravity is in the first pplace are experiments for the Large Hadron Collider and a few other particle accelerators that have not yet been built.

They believe that they need to use a whole new quanta of particles (many Molecules rather than sub-atomic particles) to be able to see gravitic interactions in a lab, and that will require some blazing fast things to get them to the reletativistic mass needed to produce observable gravitic affects, and possible particles that interact with gravity (The mythical "Graviton" or some other particle). I can say no more than that…

I have said it before – The way GEVs are treated today will have no effect on how the will develop in the future.

The perfect example is excavators and other lifting/digging vehicles; 50 years ago, all that technology was cable and gear, because everybody in the field "knew" as sure as their own names that all that fancy hydraulic business would never work on a larger scale.

Look at the next few diggers you see.

Same with hovers. The 'kick up a lot of dust' business aside ( Look at an Abrams at speed in Iraq sometime :), there is no reaosn you cannot have the advantages of hovercraft in a hybrid form that does away with the problems – Low pressure traction tires or swing down struts, or even the belts laid down by the pressure of the air blast as suggested by the Manchester Institute of Technology way back in 1974. Indeed, on application of hover technology is practical today; Imagine a self-propelled howitzer that has a hover base – As soon as it deflates the cushion, it settles down like a bunker on any fairly level ground, and can scoot like the dickens when needed.

Powerplant technology is the only major technical drawback for hovers at present; Although the other is political and financial – Americans refuse to fund something that in their minds cannot exist. One reason why the hovercraft ferry across the Channel went belly up, the American banks refused to put money behind something taht was as unlikely to work as a female US president, never mind that it had been working for some decades, and in parts of the world still does.

Actually, one good thing about the green movement is that they support limited footprint transport and hovercraft are in that category; They can run on grass strips instead of roads, and apart from noise issues are a lot more friendly as neighbours.

One of the more recent news articles on gravity experimentation:

link

If we ever detect such waves, we might just get somewhere.

But hovertanks look just too cool on the gaming table.

There are multiple principles that determine the whys and why nots of everything. Tactics, armor, weaponry, terrain, blah, blah, blah. None of these are constraints.

Power is everything. Got enough power?

Then nothing stands in your way.

With a fusion plant you could make a tank that hops from one point to the next or centipede tank. Efficiency doesn't matter when you hit the fusion level of power sources. No fusion plant? No effective hovertank like Hammer's Slammers. Certainly no grav-drive.

And they said buggy-whip makers would never go out of business.

Allen

Always have a use for a good buggy whip.

"And they said buggy-whip makers would never go out of business."

I believe that they now cater to the S&M crowd…. ;)

Antigrav vehicles are silly. If you can manipulate gravity, you can make weapons of such terrible might that armored vehicles would be completely antiquated. That being said, they're fun in games just like giant robots.

There are some other antigrav tricks besides finding and then generating gravitons (if they exist). The time-average mass of an object can be manipulated (the old juggler on a flimsy bridge problem). I'm sure there are also some crazy theories out there as well — some of them possibly correct.

Hi Guys,

One of the biggest problems with ACVs / GEVs is with high-recoil weaponry… which leaves missiles as primary AT armament… and cannons still rule the current battlefield.

The other big problem is that ACVs / GEVs have a tremendous number of moving parts and are maintenance nightmares… much like helicopters. It's simply cheaper to field wheeled or tracked vehicles.

As far as sci-fi goes, ACVs / GEVs require a specific atmosphere… so vacuum fighting simply isn't feasible.

Traveller 2300 was my favorite game with ACVs / GEVs.

Ultimately, as far as hypothetical sci-fi technologies go, antigrav / contragrav / grav technology is a better deal. ACVs / GEVs are a poor man's technolgy in a grav universe.

Shalom,
Maksim-Smelchak.

Walrus,

ACV/GEV: Too noisy as well, and I was not referring to hybrid tech…SPA is also not a combat vehicle. They are make primarily for NON combat roles (other than laying down fire at a distance). They are not really intended for waiting around for combat forces to turn them into scrap. The NLOS being a possible exception, but it is only capable of defending itself for a VERY short period and not against Armor.

I also applaud the use of ACVs in non-combat roles where they are suited, as in low-footprint vehicles to use in artic tundra or deserts that have fragile soil structures such as diomatasceous earth.

Augustus,

Even if you have the power, you are still wasting it to use it on ACV or GEV technology, they are wastful and difficult to steer. All having more power would mean would be that you were using more of it than you needed to. You would still be mopped up by those who used it more judiciously and efficiently. It is the physics of ACVs that make them unsuitable to combat purposes (with the exception of possible hybrids, but that would still not be a floater, it would be a ground vehicle that used some sort of blower to decrease the footprint or Ground pressure)

blackscribe,

We currently have NO idea of what Gravity even is [beyond the F=G(m1*m2/r^2)formulae] and how it works… If we could control gravity like we do electricity then we may be able to make gravitic guns that could crush things, and Grav-tech may be just as unsuitable to combat vehicles as ACVs. But, if all we learn to do is to create an inverse of the gravitational constant (Meaning that we make gravity for a certain place or thing negative/pushing instead of positive/attractive) then we probably wouldn't do us any good to try to use that as a gun of any type.. Maybe as some sort of sick land mine. We may also only find that we can only control the direction of gravitic force; making things fall sideways or up…There are just too many known unknows and unknown unknowns.

The thing is we just don't know… But with ACV/GEVs… There really isn't a thing that we do NOT know about them. There are neither any known or unknown unknowns (No unknowns). ACV/GEV tech is ALL engineering, and NOT about the discovery of any unknown or undescribed forces. We already know that it sucks A S S for combat vehicles (They have been doing research on this for over 50 years now with the same results EVERY time: It just is not worth the effort.

oldgamer,

I meant NEW research. They have been using old mines for 20 years now to try and see gravity. LIGO is just the newest and biggest so far that we have built, and the research that I was describing was in the detection of gravity particles, and not waves. Two components of possibly the same force, just like the photon (Wave and particle properties)…

M18 Hellcat: 75 miles per hour on special tracks…

Maybe _you_ want to do 150 mph in a hover across real-world terrain, but _I_ sure don't. If I'm going that fast, I'd better be on either a racetrack or in something that can lift off!

Now, in defense of hovers (sort of): helicopters were simply impractical for a long time because ICE (internal combustion engines) couldn't generate enough power-to-weight to make them fly effectively. Turbines, however, surprised everyone and offered a solution. It's _possible_ that another leap in power-to-weight would make hovers more practicable. However, they'd still have a lot of the problems that others have pointed out.

Maybe it's just me but the noun in Science Fiction is…fiction!

Typical war gamer discussion – the historical wannabes have to find reasons for the highly unlikely and just plain wrong/weird part of fantasy and Science Fiction. Isn't there a Mogami cruiser discussion that would be more fun for them?

Damn straight it will take a major science breakthrough to allow GRAV and GEV AFVs possible. And true they might (almost assuredly will) turn our as incredibly cost INEFFECTIVE. But it's part of the genre.

And, yes, I am a historical player at heart although I also 'cross the line' for SF, VSF and Fantasy.

emckinney,

You have hit upon the basic problem with ACVs… Flight, To effectively solve the terrain and vulnerability problems it is just more efficient to make the vehicle FLY.

Then it is no longer an ACV but an aircraft of some sort.

As I mentioned in one of my previous posts, it would be cheaper to armor up either a helicopter or Airplane of some sort than to try to use an ACV. You would still have the recoil problems us a main gun in an aircraft (it could only fire along the axis of the craft unless it had extensive recoil damping and mass of its own (like the C-130 Gunships)

Multi-Scale Gamer,

It will take a major breakthough in Grav tech to make them possible… GEVs will still be limited to what we currently know about them. Unfortunately there are not really any more aerodynamic secrets to pry out of the universe to make ACVs or GEVs any more pratical.

Haven't looked it up lately, but IIRC Hammer's tanks had both a fusion plant and fired what was, given the fact that the tank weighed 70 kilotons or over 1000 times as much as an Abrams, effectively a recoiless round — a 20 mm slug of copper converted to plasma.

But then, as David Drake pointed out in the afterword to the collection originally published as "Hammer's Slammers" he's a writer, not an engineer. And he was writing stories about an armored cav regiment, not developing new technology. Mostly, IIRC, he wanted to get away from the weaknesses of treads.

I also seem to recall, (and I'm sure someone will correct me if I misremember), that top speed for his tanks was about 35 kph. How much of a roostertail a 70,000 ton vehicle going about 16 miles per hour will raise is, at least, arguable.

No… It is NOT arguable. A 70,000 ton vehicle is goping to rais ea rooster tail about as big as teh World Trade Center when it is just sitting still if it is an ACV or Blower (what Drake called his ACVs). The 70,000ton vehicle is going to need to put out 70,001tons of thrust in order to lift itself off the ground (70,000 tons would make it essentially able to be lifted by the slightest touch). That means that there are 70,000 tons of thrust rushing out of the exhaust of the blowers/turbines that keep the thing afloat in the air that are kicking up dust when the thing is standing STILL. Moving it at 35kph would require that it accelerate a bit before reaching 35kph unless it wanted to kick out another few thousand tons of thrust to accelerate faster than a few m/s^2.

Even if it were only 70,000 pounds, it would still raise a rooster tail the size of a large Apt Building when standing still.. It is the turbines keeping the thing in the air that cause the blowing dust and noise…. a GEV is going to create much less of a mess (Create a dust cloud), but then you cannot operate in Ground Effect in a 70,000 pound vehicle at 35kph. You would need to be going a bit faster than that to get any real advantage out of GE tech.

Drake's desire to get away from tracked vehicles was a well intentioned one, but unfortunately… He REALLY needed to look into what he was talking about a LITTLE bit more.

Even a 20mm slug of copper converted to plasma uis going to create a recoil in relationship to teh amount of energy that it creates. many people seem to be under the impression that certain types of energy weapons have no recoil. Even large lasers create a recoil from the ionizing gas in front of their emitters. Plasma weapons would be no different than placing a rocket engine at the front of your gun. That IS what comes out of an Ion engine, a VASIMR (OR VASMIR depending upon which acronym you are fond of), or your simple fusion reaction.

Now, if the vehicles weigh 70,000 tons.. Then a 20mm slug of copper is not going to produce enough recoil even when converted to plasma (which produces a HELL of a lot more recoil than the shell just being throw at a few thousand fps).. So, I will give him that if his vehicles just weighed the 70,000 pounds (a difference of a factor of a couple of thousand) even then a gun would make little difference. It would just have a small problem of the rubble its exhaust was blowing around to contend with. It would be like a large hurricane under or near one of those things…

Actually, Drake said his blowers weighed in at about 150 tons (130 for the command tank). Combat Cars were 30 tons. And a Tank's 20cm main gun could still stall the tank from recoil. At 35 kph, or faster. The tanks could get going incridebly fast (over 100 kph) if they had good, solid flat ground to go over. The Blowers would typically advance at 35kph in rough country, however.

The blast of air from under the skirts is mentioned in Drakes writing almost constantly: (a couple quotes I remember off the top of my head)
'Following a blower too closely was a good way to get your bow slope blasted to a high sheen'
'Tranter, I'll bet my left nut that you can blast enough grit off this surface [a gravel road] that …'
***************
Using air pressure to reduce ground pressure is done in small patrol gunboats now. They're called Surface Effect Ships. When they're on step, with the blowers running, they're incredibly fast (65 knots, anyone?). The problem is that the blowers are maintenance hogs, and by the nature of the beast, the system is limited to smaller ships.

Wing-In-Ground Effect (the Russian monster planes) is an interesting phenomenon, but requires a lot of power to get the plane lifted in the first place, and then you can't slow down too much (like under 100 kph), or you'll stall and fall out of the sky. WiGE is the best option for lifting large masses of armor at speed (as a combat gunship), but you'd still have some serious problems, mostly related to signature. They're LOUD, and not easy to hide on radar (except in the shadow of terrain). They also have a max effective ceiling of 1/2 the wingspan above the ground, making it hard to deal with trees.

Thanks, Lion in the Stars…

You seem to know a bit more about this stuff than the average TMP poster. I have a problem of not wanting to dig for much and assuming that people can just go google.

But, you have effectively pointed out my main points…

LOUD! (You can hear the Russian GEV from about 100 miles away in the Black Sea)

Specific requirements for speed and or energy.

Small operational envelope.

Limited Operational terrain or environment.

Notice also that I limited my comments to LAND warfare… There are ALL kinds of roles for Both ACV and GEV tech at sea, especially the hybrids like the SES or combination SES and SWATH ships (Is that the correct acronym… Let me go google…Yes, Small WAterplane Twin Hull). They can get REALLY cooking at sea in those things, where a high constant speed is usually a better thing, and lack of an ability to brake is less of an issue (althogh they can break FAST in these things compared to regular ships). The sea is also an environment where you can make ACVs more maneuverable than you can on land…

I was just about to chime in about SCV uses in the meritime theater, when Judas hit it. Y'all seem to be forgetting how well the PACVs worked out in Vietnam in IV Corps. On the Plan Of Reeds, they were exceptional in combat. I've talked to a pair of SF guys that worked with them for patrols with their CIDG troops, and they had nothing but high praise for them (and their crews). They were also phenominal along the waterways and coast for patrol, interception, and inspection.
As for weapons, the biggest thing they packed were .50cals and Mk-19 AutoGLs, no "big gun". I can't see a ACV using a big gun, unless it stops and settles to fire, which puts it in serious danger. Missiles on the other hand….
I think that ACVs have their applications, and at teh moment, and probably in the medium future, they won't be in front line combat. If you can silence the fans, address the mass-to-lift issue, thrust up inclines, and weapons recoil, along with armoring them, then they could be useful, but only in the right setting.
Until AG comes along, wheeled and tracked vehicles are going to be the way to go. Even once AG vehicles get here, I'd bet that they wouldn't fly very high, as by then lazers, etc, will probably have come of age, and anything getting above the horizon will be toast.

Having said the above, I must admit that I like ACV and AG vehicles. I know they aren't practical, but they look cool and spiffy. To some, that's what counts.