CT Only: Do Grav "Tanks" look like Tanks?

[aramis]

Grav tanks would merge with attack helicopters; whereas gunships rely on the game mechanics of their space specced hulls and speed for protection, and their space specced weapons for lethality.

Grav will generally replace hovercraft, helos and small fixed wings.

A lot depends upon how one approaches the development stages.

If the early stages only work to a few hundred meters, then you get heavy lift aircraft with just barely half a G of grav at takeoff - more than enough to cut takeoff roll on pavement to about 1/3 (and overall ground effect roll/hover to a total of about 2/3) of the unassisted. So, your KC-135Z which needs about 3700m, converted to a KCG-135Z2, needs about 1200m of pavement, and another 1200m of wheels-up ground effect to get up to speed, and then final rotate.

Likewise, in a proximity only start, hovercraft are the ideally replaced item. (well, also WIGE aircraft.) It's from here that we get our "grav cars" - the air/raft and g-carrier are clear inheritors from this (short) era. We get some attack craft, too - naval hovers are used for landing actions and for naval recon, but can be equipped for anti-shipping (tho' for various reasons are either not so equipped or such configuration isn't released). Hell, it's not like they can't mount a couple 40mm Bofors.

As the proximity requirement decreases, we get helicopter rotors replaced with grav lift. Attack helos especially, as they need to operate in congested airspace, and also rescue helos. Transport helos are likely to be amonst the last replaced.

And also air-to-air fighters and bombers get grav assist as soon as fusion/electric/ducted-fan replaces jets... again, not as replacement for the fixed wings, but to augment and improve performance of the fixed wing (and variable geometry) aircraft.

Also, fusion powered grav immediately opens up SSTO/DSTO (Single Stage To Orbit/Dual-Stage To Orbit).

Even if Grav only works for 100km, it still allows a much easier SSTO and DSTO. SSTO is limited by the (roughly) 10% payload limit.

Note that the White Knight & Spaceship One combo is a DSTS, and proof of concept for DSTO. It's just a bit underpowered for SSTO. If your initial stage is grav assisted, ti goes faster and higher on the same fuel. The landing gravs on the payload stage are also probably on during lift...

And, once it gets powerful enough, go to near max alt, throw as much lateral speed on as you can, then switch to rockets for the burn to orbit.

 

[Condottiere]

I may have simplified the evolutionary steps, but they're the logical progression based on the game mechanics.

You could throw in the inherent inefficiency and complexity of procurement process that infects the military industrial complex, and allow some developments that just are technological dead ends.

Shadowrun has a class of vehicles called panzers that are armoured VSTOL aircraft that would simulate low flying grav combat craft, ground effect vehicles by themselves had always the skirt vulnerability. Vehicle design is not something that I spend a great deal of time perusing through, being more interested in feeling out spaceship design.

Militaries, and paramilitary organizations might well have compromised with other technologies, either due to cost, security constraints and/or lack of industrial capacity.

The reason I tend to equate grav tanks with attack helicopters is that a near peer opponent will have the means to take them down, which means nap of the earth in a hostile environment will be the preferred means of moving about, with the added benefit of ground clutter.

The reason I believe a gunship will be a smallcraft designed for CAS is due to their very thick skins, which allows them to both soak up damage, and travel very fast, minimizing the window of detection and reaction that opposing battlefield weapon systems have to lock on and shoot them down.

 

[aramis]

I may have simplified the evolutionary steps, but they're the logical progression based on the game mechanics.

You could throw in the inherent inefficiency and complexity of procurement process that infects the military industrial complex, and allow some developments that just are technological dead ends.

Shadowrun has a class of vehicles called panzers that are armoured VSTOL aircraft that would simulate low flying grav combat craft, ground effect vehicles by themselves had always the skirt vulnerability. Vehicle design is not something that I spend a great deal of time perusing through, being more interested in feeling out spaceship design.

Militaries, and paramilitary organizations might well have compromised with other technologies, either due to cost, security constraints and/or lack of industrial capacity.

The reason I tend to equate grav tanks with attack helicopters is that a near peer opponent will have the means to take them down, which means nap of the earth in a hostile environment will be the preferred means of moving about, with the added benefit of ground clutter.

The reason I believe a gunship will be a smallcraft designed for CAS is due to their very thick skins, which allows them to both soak up damage, and travel very fast, minimizing the window of detection and reaction that opposing battlefield weapon systems have to lock on and shoot them down.

The problem with the Attack Helicopter (AH) comparison as primary is that an attack helo is inherently a fragile beast. You cannot armor rotors effectively. Based upon the design and combat sequences, you CAN armor a grav tank's gravitics. And the design sequences, starting around TL12, put the capabilities of vehicle armor past all but the luckiest man-portable weapon shots.

So, while an AH at TL 8 in the real world is capable of killing almost any tank it can see (usually about 10 of them, actually, provided it spots them one at a time), and the average ground combat unit (infantry platoon or armored squad/vehicle) has a weapon which can take it out in a single shot. Your "near peer" is a false equation. Any attack helo is a sitting duck if it cannot kill before it is in naked eye range. Hell, man pack SAMs have taken down the best armored AH's made....

Most tanks, however, can survive a single hit on the best face with their own best weapon at least a third of the time. In Striker, this holds pretty true - both for ground tanks and grav tanks.

So, odds are that the attack helo role disappears as armored aerial gunships become less armored fixed wing VTOLs....

The Attack Helo has it's place - but its place isn't the same as the grav vehicles one can design.

My usual forays for Striker designs were hybrid fixed-wing and gravitics, inspired by Space Opera. That role, the ground attack fixed wing, is particularly enhanced by the transfer speed and aerodynamics of a jet, with the lift capacity of gravitics and fuel range of a fusion plant (even given Striker's abominable fuel rates). Armored like an APC, fast as a jet, agile as a helicopter, and armed like a strike fixed wing, the only thing it would fear would be slow enough to avoid - ground armor.

Think an AC130 Specter, but with the capability to carry armor equivalent to that on an M113 APC, and fuel for a week, plus VTOL and hover, and higher speed (around mach 0.9)...

Or an AV-8B Harrier armored up the same, with a full air to ground and some air to air.

And note also - the air-to-air missiles tend to do a bit more damage, but less penetration - they're about multiple minor hits. And the grav fighter and grav ground attack aircraft are probably able to survive them well enough.

That's rapidly going to escalate into air combat being essentially mach-speed fixed forward gun tanks...

Plus, barring some major issues with code hackability, manned attack craft (armor or air) are likely doomed, but for whatever reasons, that's socially unacceptable in Traveller's setting. Perhaps the trust issue simply becomes too much, and the AI too unstable...

The interim is going to definitely see hybrids at some point, if only to increase payloads.

Oh, and those small craft gunships? Judging from the striker mechanics, or the MT ones for that matter, they're actually LESS armored most of the time than the grav tanks. They have to be, because of the operational duration of a small craft, and the increased power demands of high-orbit and system operational gravitics. And the need to have AG and IC. And toilets.

 

[Condottiere]

1. Manned fighter - for a variety of reasons, the manned fighter isn't going anywhere at the present, and likely the next, technology level. Drones will be increasingly used in a variety of roles, independently, as swarms, but also as force multipliers of a single pilot or a strike aircraft flight.

2. How far this extends to and through tech level fifteen is speculative, since human casualties at an interstellar level have less immediacy; while can be factored in, would not become the overwhelming aspect in any decision to commit military forces.

3. If you can keep training and retention costs of human pilots below the cost of purchasing and maintaining a drone pilot, you also have an economic case.

4. Other than that, cyberwarfare that can tap, corrupt or control opposing networks or drones has to be considered a viable threat.

5. Moving past that, Mongoose doesn't have a unified design system, and by the nature of the platforms involved, whether due to the operatic aspect or not, spaceships are inherently more robust than a planetary vehicle. But common sense says that you really don't want to loiter around if you don't have to, just be able to react fast and accurately when the ground forces identify a target or really would like some immediate close support.

6. Sustained support would come from their armoured fighting vehicles, in which the grav tank would just be the perfect fusion of mobility, protection and fire power. If you can park a gunship like the the Lockheed Hercules Spectre, you're operating in a permissive environment.

7. Your high tech infantry platoon is going to resemble Heinlein's vision, rather than funny film fascists, and will have adequate ground to air defences on call.

8. That's not to say that you couldn't armour grav tanks to shrug most of them off, but that should come at the expense of mobility. And tanks would still be pretty good at killing other tanks.

9. Ortillery would have to be considered, not just the basic dropping of heavy things on the static or the slow moving, but light speed energy weapons and smart missiles, so grav tanks might survive better by not being in any one place and trying to blend with the terrain.

 

[Major B]

Think an AC130 Specter, but with the capability to carry armor equivalent to that on an M113 APC, and fuel for a week, plus VTOL and hover, and higher speed (around mach 0.9)...

I couldn't stop myself from pointing out that APC really stands for Aluminum Personnel Coffin.

Not arguing the validity of your point. I just recommend using another vehicle for comparison. M2 BFV perhaps.

As an infantry platoon leader I understood that when mounted, stick close to the tanks because they are targeted first. Then hope you don't run out of tanks until you get to the dismount point.

 

[Golan2072]

As an equivalent what I had in mind was the Mil Mi-24 "Hind" attack helicopter, which was sometimes considered as a "flying tanks" or "flying IFVs" - but with grav-thrusters instead of rotors so that you can armor it in a far more efficient manner. Or maybe a rotorless, grav-thrust Mil Mi-24 would be the G-Carrier equivalent?

 

[Patron Zero]

My thoughts would be based on if the grav tank is deployed to fight in specific environments, vacuum or 'full' atmosphere, such would greatly determine the components-design of said vehicle.

Another is if heavy armor is discarded for increased agility, modern-world AFVs are heavily clad because of their lack of the ability to 'dodge and dart' from incoming fire, developments at higher tech levels would grant such.

One other factor is the theater of deployment, is it open country where swift movement is guaranteed or is such to tight labyrinth-like urban settings where crawling about slowly is more likely. In the city-setting there's more chance for defenders to ambush an AFV with heavy weapons of their own, in such the need for heavy armor is a must.

 

[Condottiere]

Generally speaking, armoured vehicles should specialize; either MBTs or personnel transporters, though the transports could have armour and some form of fairly lethal weaponry.

 

[aramis]

My thoughts would be based on if the grav tank is deployed to fight in specific environments, vacuum or 'full' atmosphere, such would greatly determine the components-design of said vehicle.

Another is if heavy armor is discarded for increased agility, modern-world AFVs are heavily clad because of their lack of the ability to 'dodge and dart' from incoming fire, developments at higher tech levels would grant such.

One other factor is the theater of deployment, is it open country where swift movement is guaranteed or is such to tight labyrinth-like urban settings where crawling about slowly is more likely. In the city-setting there's more chance for defenders to ambush an AFV with heavy weapons of their own, in such the need for heavy armor is a must.

the physics are pretty ugly vs slugs - by the time the round is detected, you render crews injured paste to avoid impact via acceleration. And nigh impossible vs energy weapons.

 

[samuelvss]

One other factor is the theater of deployment, is it open country where swift movement is guaranteed or is such to tight labyrinth-like urban settings where crawling about slowly is more likely. In the city-setting there's more chance for defenders to ambush an AFV with heavy weapons of their own, in such the need for heavy armor is a must.

A tank maximizes its advantages by being a stand-off weapon system, where the deck and belly are protected by distance and mother earth respectively, allowing designs to maximize the armor coverage of the frontal arc while preserving mobility. Getting the tank too high undercuts the latter's advantage; being in a truly 3D battlefield, such as built-up areas, defiles, and the like essentially negates the former's, as happened in Grozny.

 

[Condottiere]

I've always liked assault tanks with short howitzers, though the lessons the Russians drew from there was a high velocity anti-aircraft autocannon, with missiles and grenades.

 

[samuelvss]

I've always liked assault tanks with short howitzers, though the lessons the Russians drew from there was a high velocity anti-aircraft autocannon, with missiles and grenades.

For an assault gun, I really liked the idea of the CEV. Two words: Demo gun. That said, the size of the charge limited it's utility in a few situations. There is a lot to be said for fast and accurate. One smaller round doesn't do the trick, then you can pour in a few dozen more. But if 60 lbs of HEP is too much, well sorry 'bout that...o:

 

[Jetrock]

How does low gravity and thin/no atmosphere affect grav tank design? Obviously in a Luna-like environment, the advantages of streamlining disappear, but lower-tech gravitic drives don't need to generate lift if there is less gravity to fight in the first place. Pressurization and life support are mandatory, but one assumes that is standard for any grav tank capable of orbit or high altitude. Low-gravity/thin-atmosphere environments also blur the line even more between spacecraft and ground vehicles. Would a high-tech, wealthy mining colony be better served by buying off-the-shelf grav tanks intended for atmospheric environments, or purpose-built grav sleds for keeping Zhodani invasion forces away? And do they stay as "tank-like" as the canonical Traveller grav tank?

How about hostile/corrosive atmosphere fighting? If the atmosphere is too thick and opaque for accurate targeting/sensors, do shoot & scoot/ground-hugging tactics still apply?

 

[aramis]

How does low gravity and thin/no atmosphere affect grav tank design? Obviously in a Luna-like environment, the advantages of streamlining disappear, but lower-tech gravitic drives don't need to generate lift if there is less gravity to fight in the first place. Pressurization and life support are mandatory, but one assumes that is standard for any grav tank capable of orbit or high altitude. Low-gravity/thin-atmosphere environments also blur the line even more between spacecraft and ground vehicles. Would a high-tech, wealthy mining colony be better served by buying off-the-shelf grav tanks intended for atmospheric environments, or purpose-built grav sleds for keeping Zhodani invasion forces away? And do they stay as "tank-like" as the canonical Traveller grav tank?

How about hostile/corrosive atmosphere fighting? If the atmosphere is too thick and opaque for accurate targeting/sensors, do shoot & scoot/ground-hugging tactics still apply?

The greater the pressure differential, the more beneficial a spheroid habitat capsule becomes. An aluminum egg holds in around twice the pressure of a cylinder of same thickness, and out somewhat more.

 

[McPerth]

How does low gravity and thin/no atmosphere affect grav tank design? Obviously in a Luna-like environment, the advantages of streamlining disappear, but lower-tech gravitic drives don't need to generate lift if there is less gravity to fight in the first place. Pressurization and life support are mandatory, but one assumes that is standard for any grav tank capable of orbit or high altitude. Low-gravity/thin-atmosphere environments also blur the line even more between spacecraft and ground vehicles. Would a high-tech, wealthy mining colony be better served by buying off-the-shelf grav tanks intended for atmospheric environments, or purpose-built grav sleds for keeping Zhodani invasion forces away? And do they stay as "tank-like" as the canonical Traveller grav tank?

How about hostile/corrosive atmosphere fighting? If the atmosphere is too thick and opaque for accurate targeting/sensors, do shoot & scoot/ground-hugging tactics still apply?

While most grav tanks (and other published grav vehicles, for what's worth) work on fusion power, it's quite expensive, and I don't rule out some working on fuel cells (and not using energy weapons, but missiles/guns). Mosre so at lower TLs (TL 8-9, depending on the Traveller versión you use), where fusion plants are, aside from expensive, quite large.

See that in this case, the lack of atmosphere is decisive, as they then have to carry their own oxygen for the power plant.

 

[Condottiere]

You tend to prefer minimizing refuelling and re-arming, and fusion engines seem remarkably suited for both functions.

 

[Reban]

You tend to prefer minimizing refuelling and re-arming, and fusion engines seem remarkably suited for both functions.

Exactly. The switch to Fusion and Fusion+ means POL (Petrol Oil Lubricants) requirements for an army completely change.

Petrol and Oil disappear, replaced with H2O with which you can either fuel Fusion+ or crack for Hydrogen for Fusion plants and oxygen for troops to breath.

Lubricants don't disappear but I can't imagine gravity based drives have many moving parts.

 

[McPerth]

You tend to prefer minimizing refuelling and re-arming, and fusion engines seem remarkably suited for both functions.

At TL 15, probably (unless you have Budget constrains), but at TL 8-9 (depending on the version), when the first grav tanks appear, fusion is quite expensive and very large (and heavy).

Using MT numbers (as I don't own Stiker), at TL 9 the mínimum fusion PP is 10 kl, cost 2 MCr and weight 40 metric tons.

 

[kilemall]

How does low gravity and thin/no atmosphere affect grav tank design? Obviously in a Luna-like environment, the advantages of streamlining disappear, but lower-tech gravitic drives don't need to generate lift if there is less gravity to fight in the first place. Pressurization and life support are mandatory, but one assumes that is standard for any grav tank capable of orbit or high altitude. Low-gravity/thin-atmosphere environments also blur the line even more between spacecraft and ground vehicles. Would a high-tech, wealthy mining colony be better served by buying off-the-shelf grav tanks intended for atmospheric environments, or purpose-built grav sleds for keeping Zhodani invasion forces away? And do they stay as "tank-like" as the canonical Traveller grav tank?

Depends on your view of what antigrav is.

Is it effectively 'gravitic thrust', or repulsion?

IMTU it's repulsion and so in a weaker gravitic enviornment the same grav module size has less gravity to 'push off of', but also less weight, and so it has the same 'lift' at normal Earth 1G, heavy planet 2G or small planet/moon .5G.

Your mileage may vary.

 

[Mako]

What 15mm Grav Tanks Look Like

This:













The last one, shown above, is a Superheavy, 15mm, Topgun Grav Tank gliding along just above treetop level, stalking its prey.

All of the other vehicles shown are from the Topgun 15mm Grav Armor range.