Sci-fi Weapons, Vehicles and Equipment

Flanker: I instead of traditional cannon use a recoiless gun system or a counter recoil system.

Don't forget "blow out" pannels: when an ammo compartment gets hit, it explodes in such a way that ammo cooking off goes outside rather than tears the tank apart. That way only a direct hit can destroy the hovertank.

Nice ideas. Perhaps it would also be an idea to put blast doors between the ammunition compartment and the crew area ala the Abrams to provide extra protection for the crew? Or would that be covered under blow out panels?

^ The Abrams uses both. The ammo storage has a automatically closing blast door AND blowout panels above the ammo storage. Unlike video game portrayals, a hit to the rear turret of an Abrams (or rear engine compartment which has similar defenses) will at worst result in a mission kill for the tank rather than a catastrophic and thus crew casualties. There's no "jack in the box" effect unlike a lot of Soviet counterparts like the T-55 or T-72. To cause crew casualties to an Abrams the shot must be physically or explosively powerful enough to not only punch through the tough Chobham composite armor but also any ERA packages and then get into the crew compartment itself. Needless to say there have been few Abrams WIA or KIA because of that.

Hover tanks offer superior mobility, especially over otherwise impassible terrain. However, a hover tank needs enough thrust to physically lift the entire armored vehicle. As such, weight becomes the primary limitation. Add too much on and the tank stays grounded and immobile.

Because a hover tank isn't anchored to the ground, high recoil cannons aren't practical. You can add a compensation system but that adds to the complexity of the tank and with the weight limits of an air cushion system you're loosing out. Missiles and rockets, however, don't have recoil worth noting and can be fired off more rapidly than a single large cannon. On the other hand, many ground based missiles have a range of maybe 2-4 kilometers while the 120mm rheinmetall has a range of 6 kilometers. Furthermore, missiles tend to be bulkier than cannon rounds so it's likely that ammunition would be limited.

So hovertanks armed with anti-tank missiles would need to close into range as fast as possible, loose missiles as fast as possible, then flee before the enemy can bring their big guns into play. kinda like American civil war era cavalry.

How about anti-tank missiles that are launched from the main gun, like the Songster and Stabber (I think that's the right ones) ATGMs? It would be a two stage system, where the main gun fires it out, and then in mid-flight the flight surfaces and so on spring out and the rocket motor fires. As for why there aren't catastrophic failures due to shock, vibration, high temperatures and so on, I think we can safely handwave them with advances in material science and the durability/capabilities of seekers.

However, I think missile pods (like those on the Bradley, BMP series, etc.) would be much more common.

You do bring up an interesting point regarding the employment of hover tanks; I can also see them being used as ambushing units, hovering below the treeline (but above the earth) and then popping up to fire down on the targets. Nobody thinks to look up for tanks, do they?

The tank's armament would need to be capable of depressing far enough to engage, though. Either that or they would need to be placed far enough from the kill zone to render that a non-issue.

Dont think of a hovertank as a light tank. Think of it as an extremely heavy attack chopper. They use roughly similar weapons and tactics.

Yeah, I was trying to think of the hover-tank in terms of a lower performance (but tougher) attack helicopter, hence the pop-up/pop-down attacks.

Further discussion of how they'd be used would probably be better suited to the Sci-fi Tactics and Strategies thread, though.

They're way out there with tactical faster than light jump drives. Anyway, how do you seperate equipment from how it is used?

It's all to do with the emphasis; is the emphasis on the technology itself and how it works (i.e. "This is A Tank, it uses [this system], and has [Features XYZ]. Does this make sense?") vs. figuring out how the "end users" would actually employ that technology ("My army uses A Tank. How might my army use A Tank to achieve their goals? Their doctrine involves [ABC points], and A Tank might need to be used in [DEF situations]."). The difference between figuring out what your soldiers are armed with and the tactics used by the soldiers armed with those weapons.

Now, there is overlap (since one will necessarily somewhat shape the other), but I felt there was sufficient difference to make two seperate threads (Weapons aren't shaped entirely by doctrine, nor is doctrine necessarily shaped entirely by the weapons employed). A further example of the disconnect between weapons and tactics is aerial combat; though new techniques have been adopted to account for the advent of new equipment and weapon systems, many maneuvers remain largely the same (rolling scissors etc.).

I'm having trouble figuring out how to clarify what I'm saying, not least because when it comes to this sort of thing I'm not very good at articulating it.

Also, that thread's kind of deadish; I wouldn't mind (as the thread's caretaker/creator) if you switched topic. We tended to leapfrog around a lot anyway.

edited 19th Nov '13 11:23:21 AM by Flanker66

A hovertank with a high-recoil weapon could briefly land to fire it(maybe drilling into the ground too). Though you could limit that by making it slow to take off, and/or not able to immediately stop and drop.

Another thing to consider is the push it gets when it's hit.

@demarquis

If the hover tank doesn't behave like a light tank with an air cushion system then by what rights can we call it a tank?

They could also use outriggers like mobile cranes. Hover in place, lower the legs(possibly digging/drilling into the ground), fire, lift the legs and go. ie keep the pressure underneath/keep on hovering and just use the legs to stay in place/take the recoil.

Recoiless rifle systems are lighter then traditional guns because they don't need the heavy mounting and heavy breech of a more traditional gun. The only down side is if you mount it inside you need to channel the blast outside somehow or otherwise mount it externally which really isn't a huge deal. Such weapons can be fed by auto loader or linked ammo just like traditional weapon systems.

@Flanker: I'll keep all that in mind.

@Man in Grey: The "Frigate" says hi. But technically you are right, we should be calling them "Armored Ground Effect Vehicles". But that doesnt really roll off the tongue, eh?

edited 19th Nov '13 2:13:18 PM by demarquis

How about "Heavy Gunships"?

Ok here is the question.

When in operation is it a helicopter or a ground vehicle that uses some sort of ground effect, hover mode, or form of levitation like ducted fans (personal fav)?

Because I am thinking of vehicles like are seen in the Hammer's Slammers books but with just enough oomph to achieve a short term vertical lift for pop up attacks.

If it is more like that it is still pretty much a ground vehicle.

Things like gun elevation, depression, and traverse are ultimately determined by the guns type of mounting.

edited 19th Nov '13 8:09:42 PM by TuefelHundenIV

^^^ But AGV's does.

Or GAV or HAV. Ground Effect Assault Vehicle or Hover Assault Vehicle.

CP 2020 had large jet engines pushing aerodynes into the sky. Yes armored flying bricks (thrust over aerodynamics) but vulnerable to heat seekers.

In my 'verse, most larger "hovertanks" use either a small fusion engine or a jet engine to achieve ground effect. The lighter ones use ducted fans with an armored cockpit and sensors. Earth couples them to VTOL craft and helicopters. Cay Union use them exclusively as light tanks. The Southern Cross just uses light wheeled vehicles and helicopters instead.

edited 19th Nov '13 8:21:47 PM by TairaMai

I was about to clarify this, so your question is well timed!

Basically, it's anti-gravity tech that uses ducted emitters under the tank, hidden behind armoured skirts^* In other words, if the tank wanted to glide left, the emitters would have to swing right in order to push the tank the other way; the reason altitude is limited is because tanks obviously don't make very aerodynamic shapes, and the anti-gravity system works best at extremely low altitudes (so no zipping around the battlefield at 1,000 feet) so that the propulsion system can't be one-shotted. Cheaper or less technologically advanced hover tanks will probably use different propulsion, though.

In general you're right, though. Most of the system's thrust is devoted to keeping the tank floating. Although it can give the tank a shove and let it hover at a higher altitude for some time, putting that sort of load on to the ducted anti-gravity system and sustaining it for a long time might increase wear & tear or rarely invite a premature failure.

@Outriggers, landing and drilling into the earth:

That would deal with recoil, though it might be something of a liability in an offensive or during a fight with a maneuvering opponent (it's generally not a good idea to stop and then fire, hence all the gyroscopic stabilisation etc. in modern tanks to allow them to fire on the move).

@Names for hover tanks:

I like Hover Assault Vehicle and Armoured Ground Effect Vehicle.

If my tanks were to use a counter-recoil system, what peculiarities would that entail?

edited 20th Nov '13 3:16:12 AM by Flanker66

The easiest counter recoil system would be a one shot rocket loaded opposite the gunbarrel. When the main gun fires the rocket also fires to counter the recoil.

You could go old school and mount the main gun externally with an open breach ala WW 2 bazooka. Recoil would be a bare minimum but you'd loose muzzle velocity.

Or you can switch on the inertial dampener but since you've already got one physics violating system going (the anti-grav) I'm not sure you'd want another.

It's a soft sci-fi setting, so although I'd prefer there to be at least solid internal logic (and to avoid beating all semblance of physics to a bloody pulp), I can get away with technologies that thumb their nose at such things.

Basically what bel is describing is the counter recoil principle. This what is used with rocket launcher of all varieties as well as the recoilless rifle artillery pieces. The back blast helps mitigate the recoil forces it pushes back against the guns reward recoil. There are a couple of other unique options.

There is a theorized "counter blast/counter fire" that bel basically described. Where you don't have a traditional recoilless round but a dual component round. From a fictional work I read they used something like this for man portable anti-armor rail guns. The gun fired the projectiles off of a precharged capacitor that makes up part of the cartridge. The back of the cartridge which had a blast attenuator fired a counter blast to counter the recoil forces.

It should work in theory. The other option is something that was tested in real life. Where a equal or slightly less amount of mass was blasted out the back of the weapon a counter shot. The original method fired two slugs the aerodynamic projectile out the barrel front and a equal mass but preferably far less aerodynamic for the obvious reason out the back. Earlier attempts at this were used with black powder cannons to try and use more powerful guns on ships.

Instead what some systems do especially low impulse systems is the counter water is contained particulate mass instead. When the round is fired off the mass is shot out the back but air resistance and small particle size and/or low individual particle density drastically slows the particles down rendering them relatively harmless over a short distance. You don't usually get as much shot power with those systems compared to more common recoilless weapon designs.

See this here for better info

Recoilless guns get pretty good recoil. It is all about how carefully you balance the two forces. The Germans in WW 2 used them as paratroop light weight artillery platforms. Like this one. The Russians and other western powers still have recoilless rifle weapon systems in use and in inventory. It had a pretty good range for such a light weight artillery piece.

Other options include high density fluid recoil buffers, counter weight and recoil systems and other tricks of reducing recoil.

Anchor systems can be as simple as a quickly dropped and picked up mono pod. Some mobile artillery systems have anchors that deploy but that is artillery.

Another option is combining both gun and missile options are Gun Launched Missiles. A low impulse gun shot shoots it clear of the barrel and the main motor kicks in outside the barrel. You could fire low power gun rounds out of it. See vehicles like Sheridan for what I am talking about. The Russians have them for tanks and the US does as well.

edited 20th Nov '13 5:37:40 AM by TuefelHundenIV

Not anymore. Unless we adopted LAHAT under the radar, we have no gun launched guided munitions at the tank level. The Shillelagh is retired and the MRM got cancelled a few years ago.