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

[Golan2072]

CT-LBB4 Mercenary posits that:

All vehicles have sufficient free-flight performance that ground combat
vehicles effectively no longer exist having merged with aircraft.

In a sense, I'd expect most TL12-13 combat vehicles, then, to look more along the line of VTOLs or helicopter gunships rather than ground vehicles with their wheels/treads replaced with grav units and the turret still protruding from their roofs, rather than being mounted on their underside (to attack ground targets below them). But most depictions of grav vehicles I tend to find in Traveller books still look a bit like ground vehicles in terms of orientation and general shape.

So how do Grav "Tanks" look like in YTU? Like flying tanks, like gunships, or like something else?

 

[CosmicGamer]

Gun on top. Use pictures of similar vehicles from Supplement 6 as a reference. I also consider these a type of portable gun emplacement used for defense while sitting on the ground.

Something to think about: If your antigrav vehicle has the capability of inverted flight and grav plating within for occupants, does top and bottom matter?

 

[Timerover51]

Gun on top. Use pictures of similar vehicles from Supplement 6 as a reference. I also consider these a type of portable gun emplacement used for defense while sitting on the ground.

Something to think about: If your antigrav vehicle has the capability of inverted flight and grav plating within for occupants, does top and bottom matter?

It does when you land and shut things off.

 

[CosmicGamer]

It does when you land and shut things off.

Maybe you land on the tail
:devil:

 

[McPerth]

Something to think about: If your antigrav vehicle has the capability of inverted flight and grav plating within for occupants, does top and bottom matter?

Something else to think about (taken from another thread):

In fact, can any gravitic craft fly inverted, or the gravitics push only "down", so being nullified (or at very reduced power) if pointed to another direction (as would be pushing "up" (akin of a helicpter)?

Are gravitic plates muti-directional or they are directional?

According MT:SOM, and talking about thrusters (so not sure how can this be extrapolated to gravitics), plates give 100% thrust to its intended direction, up to 25% to 90^o angle and only 10% in opposite direction, so, if gravitics work likewise, should you fly inverted you'll have only 10% thrust, not enough to avoid falling.

 

[aramis]

Something else to think about (taken from another thread):



Are gravitic plates muti-directional or they are directional?

According MT:SOM, and talking about thrusters (so not sure how can this be extrapolated to gravitics), plates give 100% thrust to its intended direction, up to 25% to 90^o angle and only 10% in opposite direction, so, if gravitics work likewise, should you fly inverted you'll have only 10% thrust, not enough to avoid falling.

I don't see why they wouldn't... but note that probably some of the plates are aimed other than straight down on faster gravitic vehicles.

It seems to me that the differences between T-Plates and gravitic thrusters is what "slope" the local gravity well must be at for them to grab... too flat and they don't grab.

 

[McPerth]

I don't see why they wouldn't... but note that probably some of the plates are aimed other than straight down on faster gravitic vehicles.

It seems to me that the differences between T-Plates and gravitic thrusters is what "slope" the local gravity well must be at for them to grab... too flat and they don't grab.

I undrestand gravitics akin of a helicopter, just changing the method to get the thrust, form a rotor to grav plates, where its main thrust is straight down, but can be somewhat directed on other directions for speed, but in this case it would be mostly aft directed, as there's where you use to apply more acceleration.

In any case, I have serious doubts on them having straight up thrust capability, that is what they'd need to fly inverted.

Off course, some speeders, with their airframe streamlining, might fly inverted out of wing produced thust if enough speed is built (something quite likely), but as for grav tanks, APCs, etc., I keep thinking on them as helicopters, that can perhaps perform a loop (I've seen one helicopter doing so), but that cannot fly inverted, as the thrust that keeps them flying will note exist then.

 

[CosmicGamer]

A craft can/should (to me) be able to operate in a variety of locations. This includes no/little atmosphere locals. There are plenty of these in Traveller.

Grav vehicles can reach space and maneuver into bays and dock with space stations and so on. So it would seam to me that without the use of typical aerodynamics for turning and maneuverability, grav drives would need some directional capabilities.

Personally I've never put that much thought into it. I'm not a science guru. There are several possibilities, don't know how plausible, off the top of my head.
1) Multiples of the drives that face in different directions. Some may not produce the same thrust and are just for maneuvering.
2) Like harrier jets, the drive and the body of the craft are not stationary. Unlike a harrier, the grav drive would face the direction required to provide lift and thrust and it's the rest of the craft that changes orientation to angle weapons or whatever other reasons one may have for such. Not sure what all the different Traveller material has to say about it but until I hear contrary, the grav drive can operate through the hull of a ship or vehicle so this rotation may be occurring within and need not be depicted in pictures as exterior rotating drives.
3) The Grav Drive design is such that it can utilize gravity and produce thrust no matter what the orientation.

I never decided how specifically it works. I like to think there is some variety with different worlds and cultures possibly doing things a little differently. I also like my futuristic science to be a little fuzzy so that it is more plausible and less likely for people to say "it can't work like that". As I always say, if we could completely spec it out today we would have the technology now and it would not be future tech.

EDIT: Perhaps 1, 2, and 3 are possible variations of the technology at different tech levels.

 

[Golan2072]

A few images I found online which are similar to what I had in mind:

http://shimmering-sword.deviantart.com/art/Transport-Gunship-196333556

https://star-sphere.obsidianportal.com/wiki_pages/dragon-orbital-gunship

http://www.deviantart.com/art/Gunship-concept-273868454

http://www.deviantart.com/art/dropship-concept-273867817

http://s4.postimg.org/bkbab8fju/sttheo_01.jpg

Some alien GAFVs (Grav Armouyred Fighting Vehicles):

http://www.deviantart.com/morelikethis/185924540

 

[Reban]

So how do Grav "Tanks" look like in YTU? Like flying tanks, like gunships, or like something else?

Grav Tanks IMTU

Things you need to know
1. I've converted from using FF&S to T5's VehicleMaker.
2. I've always thought of grav vehicles moving like fully aerobatic helicopters.
3. OTU tanks are one trick ponies. Big guns that float.
4. I once read a great HIWG paper that basically said grav tanks use their high (jet like) speed to re position operationally over great distances and then move tactically like attack helicopters.

So T5 can produce two different types of grav combat vehicles.

The ground grav tank is very much a classic tank that floats, heavy armor, disappointing speed and strangely restricted as to the type of terrain it feels at home in. Its not your classic flying tank.

You can get much closer to the classic Traveller grav tank by building a grav flyer and adding armor. What you get is a fast moderately armored vehicle with a suite of weapons systems.

So what do grav tanks IMTU look like? The first kind are vehicles in the 4 to 10 dton range with thick armor which on most faces is sloped. The turret which may be manned or unmanned contains a weapon capable of defeating an amount of armor equal to the grav tank's own. You could think of these grav tanks filling a similar role to the British Infantry Tank of WW2 e.g. the Churchill, or as a mobile strongpoint.

The second type has a more aerodynamic hull shape but could not be called rounded as it incorporates stealth surfaces. If you want a visual image think F22 or F35 surfaces on a flattened ellipsoid hull. The main gun is carried in a dorsal mounted turret. Secondary weapons in a chin mounted mini turret and something missing from most grav tank designs a ventral weapons bay for rocket or missile ordnance.

I arm my grav tanks with either a fusion cannon or mass driver. Secondary armament in the chin turret is for killing infantry or soft skin vehicles, anything it would be overkill to use the main gun on. Anti-armor missiles should be carried by grav tanks, either in a launcher mounted in the turret, co-axial to the main gun, or in the ventral bay. Unguided rockets can also be fired from the bay. Finally a grav tank should be able to "spot" for other weapons systems, calling in artillery or other weapons strikes. This mix of weapons is based on the Commanche scout/attack helicopter.

I place the crew, usually a pilot and commander, together in the hull along with a jump seat for a FO, specialist or senior commander.

Intellectually I have a little problem with the idea putting a turret on top of what is basically a fast aircraft, but I like the visual an I rationalize that it could be blended into the hull shape, be lift promoting, and be fixed forward for fast flight. The illustration of the heavy tank on p.22 of T20's Traveller Aide #6 Against Gravity is what I see when I think of a grav tank.

 

[McPerth]

A craft can/should (to me) be able to operate in a variety of locations. This includes no/little atmosphere locals. There are plenty of these in Traveller.

Grav vehicles can reach space and maneuver into bays and dock with space stations and so on. So it would seam to me that without the use of typical aerodynamics for turning and maneuverability, grav drives would need some directional capabilities.

I agree they must be able to opérate in a variety or conditons, if they are Imperial Army/Marines (or at least Colonial) or other multi-planet agency (incluiding some merc groups), but not so much if they are from one single planet army(es) and never thought to leave it.

Even so, IMHO, there's a single factor that will be assumed anywhere grav vehicles ae expected to work: gravity, as they don't work well outside a gravity well. This may well mean that interior artificial gravity can be seen as unnecesary luxury, as they are not intended to work at zero-g, so the crew will sure notice they are flying inverted (as in nowdays planes).

Another possibility is that the interior gravity is needed to have inertial compensors, that may be quite useful in speeders and other high acceleration grav craft, but in MT (the only verion I know that enters in such life support/environ detail, AFAIK, you can install inertial compersonrs without (interior) grav plates.

Personally I've never put that much thought into it. I'm not a science guru. There are several possibilities, don't know how plausible, off the top of my head.

Frankly, neither had I given it much a thought till now, and neither I am a science guru. This jsut came to my mind when Reading the other thread I quoted.

1) Multiples of the drives that face in different directions. Some may not produce the same thrust and are just for maneuvering.

This will need to install redundant systems (in severla directions), increasing the cost of the vehicle by a significant amount...

2) Like harrier jets, the drive and the body of the craft are not stationary. Unlike a harrier, the grav drive would face the direction required to provide lift and thrust and it's the rest of the craft that changes orientation to angle weapons or whatever other reasons one may have for such. Not sure what all the different Traveller material has to say about it but until I hear contrary, the grav drive can operate through the hull of a ship or vehicle so this rotation may be occurring within and need not be depicted in pictures as exterior rotating drives.

I've always thought about the grav plates as being so, plates, taht exert the main forcé perpendicular to them. having them movable, as harriers rotors, will need quite more volumen than to have them fixed, relying on lateral thrust(craft inclination for maneuvering

3) The Grav Drive design is such that it can utilize gravity and produce thrust no matter what the orientation.

That's why I said I am not sure about how extrapolable to them is the explanation about thrusters in MT:SOM, but if it is, any lateral(reverse thrust will be at too diminished rate to keep the craft flying, unless it has many thrust to spare...

 

[McPerth]

So how do Grav "Tanks" look like in YTU? Like flying tanks, like gunships, or like something else?

I see them more like current tanks, just without the tracks/wheels, as depicted in most traveller pictures (e.g. MT:101 vehicles). Perhaps I' mtoo contamined by those pictures...

I beleive the best way to keep multidirectional fire wihtout too disorienting the crew and the maneuvering of the craft is by a turret, so I keep believeing they will have one.

I also believe they will jockey for position and try to use terrain cancelment in combat, moving mainly NOE in combat zones, as any higher flying craft would be too vulnerable to (mostly) beam wapons, that give you no time to react once you're locked on. This will forcé the turret to be on the top, if you want it to be of any use when "hull down".

I expect most grav vehicles to have flat bottoms, to ease their landings without need of landing gear, and for APCs at least, to have also (but not only) bottom hatches to release the troops without landing.

 

[CosmicGamer]

I agree they must be able to opérate in a variety or conditons, if they are Imperial Army/Marines (or at least Colonial) or other multi-planet agency (incluiding some merc groups), but not so much if they are from one single planet army(es) and never thought to leave it.

Grav Drive techs capabilities are not specific to tanks. They need to include a functioning air raft and other vehicles that can reach a ship in orbit, a space station or a moon. But I do agree. Like I said. Variety. All implementations need not be the same.

as they are not intended to work at zero-g

While I'm no science whiz, I know even the furthest out planet, as large as it is, is kept in orbit by the suns gravity. So I do believe there is plenty of gravity available and zero-g is not something that needs to be discussed in regards to grav drives. Please feel free to correct me if there is something somewhere in some supplemental rules that quantifies a certain minimum amount of gravity required for the grav drive to function.

 

[McPerth]

While I'm no science whiz, I know even the furthest out planet, as large as it is, is kept in orbit by the suns gravity. So I do believe there is plenty of gravity available and zero-g is not something that needs to be discussed in regards to grav drives. Please feel free to correct me if there is something somewhere in some supplemental rules that quantifies a certain minimum amount of gravity required for the grav drive to function.

There are several references in the various Traveller versions about grav drives losing thrust as they are farther a gravity well.

Current MT consolidated errata (v2.21, released 02/23/2013, available on DonM signature, page 28) specifies that gravitic drives drom to 50% output when acting farther than 10 diameters from a gravity well, and ITTR having read in this board (sorry, I cannot give you exact reference) about TNE ot T4 that thruster drives (that are assumed to "push" against the solar gravity well) also loses power beyond several solar radi (this time ITTR it wa about 2000 radi).

 

[aramis]

I expect combat gravs to commonly have 3 basic hullforms... in a CT/MT/T20/T5 TU

Tank-like - because it's pretty well optimal for surface-hugging ops in support of ground forces. Low, slow.

Helicopter Gunship like - Take an AH64, pull the rotors and replace with grav. Medium speed, medium agility.

Airplanes. With 1G lift, and the rest into forward thrust. As it speeds up, the airfoils take over the lift, and the lifter shifts to aft thrust mode... faster than the other modes. Long and skinny, probably staggered biplane wings (which have been noted as being more mass-efficient in IIRC Popular Mechanics). Not terribly agile, but blindingly fast. Lands like a helo (except in emergencies, when it can glide in), flies like a jet. Used Air-to-Air, and for some Air-to-Ground roles.

In a TNE setting... due to the different nature of gravitics, you get mostly tilt-pod and vectored thrust aircraft; most look like variants of the AV-8B or the Osprey, but can rotate over much faster. Essentially, in TNE, you cannot replace the thrust agency modes, but you can do more with them. So, the airplanes have 747's with a 100m take-off roll, and harriers that pull a full 2g's straight up. You add wingless harriers to the mix, too, as the vectored thrust is plenty to lift 2% of the craft mass.

 

[creativehum]

This thread intrigued me. I poked around and found this piece of artwork that I found inspiring.

Also, I remember reading the quote from Book 4 years ago and my brain exploding. I was a teenager, suddenly being tasked to dream up how military units would be redefined given this only partially described technology.

Reading this thread made me realize, as Aramis suggests above, there will be a variety of applications and unit structure. We could assume this will be based on needs of the units, money available, and culture/history that led up to the creation of hardware and military formations up to that point (both locally and across interstellar space).

 

[Golan2072]

They'll probably be a bit similar in role to a Mil Mi-24 "HIND" attack helicopter - i.e. designed as a flying IFV, though with thick tank-style armour and heavy guns thanks to what the TL13 gravitics can carry...

 

[creativehum]

Here are some images of Flying IFV from Chris Moeller's IRON EMPIRES comic book.

http://2.bp.blogspot.com/-j2OwQmT0jYc/VCnw-QoEhLI/AAAAAAAANRU/r8J9VyVeyNc/s1600/6%2B0001.jpg
http://obskures.de/s/obswpc/uploads/2014/09/ironempiresarmordrop.jpg

In the Iron Empires universe, naval ships are termed Hammer, and ground troops are Anvil.

 

[Reban]

This thread intrigued me. I poked around and found this piece of artwork that I found inspiring.

The only thing I don't like about that interpretation of the grav tank is that the turret sits proud of the hull. For me that creates two no noes:

1. The shell trap. The angle created where the turret and hull join creates an area where any explosion is contained and magnified. I'd rather see the turret blended more with the hull.

2. Aerodynamically having a turret that just sits on top of the hull creates both drag and turbulence in flight. Again a more blended turret would make a better vehicle.

There are plus points two. The overall plectrum shape and airfoil cross section, best seen in the Astrin in the background, are good for both control, stability and lift in atmospheres. The curved surfaces should count as sloping which contributes to the effectiveness of the armor. The overall clean lines and conservative size of the hull means less surface to hit and less surface to armor.

 

[CosmicGamer]

Current MT consolidated errata (v2.21, released 02/23/2013, available on DonM signature, page 28) specifies that gravitic drives drom to 50% output when acting farther than 10 diameters from a gravity well

And is there any other increments or is 50% available out to 100+ diameters?

Again, I'm no science/physics whiz, but wouldn't a drive working at 1G near the surface need to work far harder than one out at 10 diameters where the gravity is much less. Thus the 50% reduction in max power would not be much of an issue?