Military Ground Vehicles of Your Nation [NO MECHS] Type 6

[DnalweN acilbupeR]

But this brings about two questions which you ignore.
1: what stops the creation of a modern LRP?
2: what keeps the LRP as the only option to deal with all threats?

We likewise skip the fact that as a combined arms system where the tank is only a single piece and intended to work and be employed as such, the gun is largely irrelevant as long as it is capable enough.

1. Rifled guns cannot achieve the same muzzle velocities as smoothbore guns. A larger bore will always allow a more a powerful charge and larger penetrator in any case.
2. If you mean guided weapons, because I know these are popular, the LAHAT is a fairly crummy weapon in a tank duel. And an ammo rack full of Javelin equivalents will cost as much as a tank.

But capable enough for what? Being able to kill enemy tanks effectively (i.e. from the front) is one of the basic requirements of an MBT. The universally poor (American, British, German etc) performance of tanks that were not armed with effective (i.e. able to kill their likely tank opponents head-on at normal combat ranges) anti-armor weapons was a big factor in the convergence on big bore high velocity cannons as the definitive tank armament after WWII. Efforts to avoid head on armor clashes in favor of engaging tanks with dedicated anti-tank weapons (a feature of both Soviet and American doctrine, though in different fashions) were equally ineffective at preventing those clashes from occurring.

Is a 105mm gun useless? No, not at all. But if you have any reason to suspect hostile T-80U/T-90/M1A1/Leopard 2s might to show up, going out of your way to avoid the 120mm is just asking for trouble.

Why would you say that about the LAHAT? From what I understand it has top attack capability, what tank can withstand a 105mm tandem HEAT to the roof??

[Freihafen]

As an armchair general I am not qualified to comment on the reliability or build quality of LAHATs IRL, but one thing; as with any weapon that requires continued guidance after launch, you will have drastically longer enegagement cycles than when firing KEPs.

A KEP only takes a few seconds or less to reach the target. A typical ATGM could very well go into the 10s of seconds, in which time the gunner will be occupied guiding the missile and therefore not engaging other targets; a critical disadvantage.

For comparison, a M829-series KEP would reach a target 3 km away in under two seconds, while a LAHAT would at best take ten seconds.

That and the LAHAT costs (IIRC) around three times that of the M829A3.

My personal opinion is that in the context of use on a MBT it is a niche weapon for difficult targets, not a KEP replacement.

[The Kievan People]

1: while smoothbore will always allow more velocity, the increase is minor. Likewise larger bore means neither longer rod nor larger charge. These two things are relevant to the gun (or round/chamber) design itself and not relevant to the bore diameter. What is relevant is the increased area for the gas pressure to work on. A larger bore smoothbore will thus get velocity gains from those two features alone even with a reduced charge.

Yes if you hold charge mass constant you will get more power. But if you hold ballistic efficiency constant, you can also use a more powerful charge. The potential power of a larger-bore gun is always higher unless there is something radically different about the guns construction (made or unobtanium or whatever).

Since the issue of smoothbore v. rifle velocity is not quite the same caliber, I will deal with it in this spoiler block:

And the velocity limits of rifled guns are not a trivial issue. Smoothbores have been demonstrated at muzzle velocities over 2000m/s. Rifled guns max out at around 1500m/s. Modern 120mm APFSDS have muzzle velocities in the 1550-1750m/s range, already at or beyond the practical velocity limit of rifled guns. The optimum velocity (minimum energy to achieve constant penetration) for penetrating RHA is between 1.6-2.1 km/s, and the optimum velocity for penetrating exotic armor can be even higher.

The differences are not overwhelming, but when you consider how slowly APFSDS shed velocity, being on the right side of the optimumization curve can work out a significant edge in effective range.

2: I was referring to such options. Your assertion that it would include an ammo rack full of such rounds is preposterous.

I know.

But you know what isn't ridiculous? A full rack of APFSDS.

There is no reason a higher pressure 105mm gun with modern munitions should not be able to take on any modern tank. Defeating ERA for example is a matter of penetrator design not bore diameter. Likewise is defeating composite armors. The relatively minor improvements given by the greater piston area and the decreased friction are not enough to justify the major expense of replacing munitions when introducing a new gun that is backwards compatible and better ammo will do the trick.

Exotic penetrators are cool but the main figures of merit are length and impact velocity. And L/D is limited by aerodynamics to about 30, so length = mass. And mass x velocity is...

Exotic penetrators (things which are not just rods) are real, but it is highly unlikely they are actually being used. Nearly all the concepts that are in public literature are only genuinely effective at impact velocites over 2km/s. Since this is well beyond what tank guns are actually capable of things like segmented rods or extending rods have no real application to tank armament at the moment. The only exception may be certain tricks for defeating ERA, like a tip designed to break off without shattering the rod.

Of course I cannot rule out that there is some kind of secret exotic penetrator kicking around out there. But speculating about that would be fuzzy even by the very low standards of this thread.

If the expected threat were hoards of M1A2s where expenditures of special munitions would be high then I will concede the switch to a larger gun might be more worth it if only for the wearing of the barrel and easier/cheaper improvements. But as it stands Chebucto does not expect its meager tank force to fight that battle. It is expected, rather, to normally facer tanks such as the t-72b or older. The occasional ultra modern tank will not prove a problem. However with the current increase in proliferation of such vehicles the next gen tank project will be looking at other options. But I have that as initiating in 2010 and still in process of development in 2014.

25 years old is ultra-modern now? And the Leopard 2 is even older.

[Imperializt Russia]

If your example is the Humvee why not use the Humvee?

From what I understand, it's not armored enough for my needs.

It's not really armoured at all. Expedient "up-armouring" by units including lining the doors with PASGT vests, rated against handgun ammunition, light rifle fire and shell splinters.

[The Democratic Republic of Davida]

'Unobtanium'. Lol. I'd like to use that in one of my write ups.

[Questers]

/

You know that Arjun's gun has a muzzle velocity in excess of 1.5km/s right? In fact DRDO states it as 1.67. http://www.drdo.gov.in/drdo/pub/techfoc ... /arjun.htm

I think the point is not that rifled has this magic cap at 1.5, but that to get greater muzzle velocities you need to be pushing progressively (maybe exponentially) more propellent down that tube b/c of the gas leak. I don't think we're going to be seeing tanks shooting 2kms KEPs any time soon for a variety of reasons, so...

[Lemanrussland]

From what I understand, it's not armored enough for my needs.

It's not really armoured at all. Expedient "up-armouring" by units including lining the doors with PASGT vests, rated against handgun ammunition, light rifle fire and shell splinters.

The Army and Marine Corps also developed several armor kits for the Humvees, which added between 1,500 and 2,200 lb of armor, and often also added gun shields for the gunner.

It was actually a pretty big political scandal in the US, lots of our soldiers were being killed and had to resort to using scrap metal, PASGT vests and so on to provide some means of protection.

[Questers]

Should have stuck with the M113.

Sparky

Was

Right

[The Democratic Republic of Davida]

The Fennek seems pretty kewl:
http://en.wikipedia.org/wiki/Fennek

[Spirit of Hope]

Should have stuck with the M113.

Sparky

Was

Right

The Humvees weren't supposed to be used where they could be shot at, instead they were supposed to be used to move troops around. They served wonderfully in the the Gulf War and Invasion of Iraq.

[Questers]

Nobody ever said they were bad liaison vehicles.

[Anemos Major]

In practice, I don't think military vehicles typically try to travel that fast anyway.

Au contraire,Sun Zhu was a big advocate for mobility on the battlefield and many other commanders feel the same way.

Sun Tzu was a big advocate of there not being a battlefield if at all possible - and if there was to be one, you'd do best not to misunderstand what his perception of the benefits of mobility and the potential lack thereof were.

Mobility tends to be a bit less important with guided weapons and bullets/shells traveling at supersonic speeds, or hidden IEDs/mines that can flip 60-ton tanks over.

But on the other hand, if you have these stand-off weapons and shells, and clear areas being denied to you by IEDs and mines, there's an occasional argument to be made for tactical mobility as a mechanism by which to negate these advantages by closing with the enemy. Not always, and what you're saying is perfectly valid, but short of fighting an insurgency there's enough leeway for there to be different approaches to such issues.

An improved 105mm like IWS is perfectly capable of fighting the expected threats. Including modern MBTs.

Everything up to the last three words, alas. Consider it thus - at the point at which you have a 105mm capable of resisting and housing the pressure necessary, and equipped with a KEP capable enough to, engage and destroy a 'modern MBT', you'll have expended a ton of money essentially creating a weapon that shares zero commonality with legacy 105mm options. In which case, you might as well go ahead and opt for a 120mm option, which is a fairly cheap, given the above, way of achieving something similar to some extent.

If you mean light vehicles like the MGS or even light tanks like Stingray then no, I see no reason to infer that such vehicles would be fitted with a weapon that would damage the vehicle. Even ignoring their not having MBT engagement as a primary role.

Wouldn't necessarily damage the vehicle - given contemporary technology, at least, the mounting of low-recoil, high-velocity 120mm guns on vehicles as diverse as light tanks (CV90-120) to 8x8s (Centauro 120) is a pretty decent testament to the fact that gun technology has advanced to the point where weapons such as what you're describing can be mounted on 'FSVs' as described by you.

To date high pressure 105mm guns have not been fielded, entirely because when their development started a severe lack of real need was created. With the collapse of the WP the 120mm smoothbore was good enough both in numbers and capability. There was no need for making use of existing stocks when there was no threat. MGS got the M68 to ensure it had access to round types it needed for its role which did not then exist for the M256.

Eeh...

'High-performance' 105mm guns, for the most part, are really a phenomenon that post-dated the development of the 120mm smoothbore. The logic is fairly simple - with the fall of the Warsaw Pact, instead of having to consider ever-larger calibres and rounds to destroy expected ever-larger threats, the NATO-and-friends nations (not quite the 'forces of the free world') found themselves in a position where 120mm and 105mm stocks were both all they were going to get funding for, and all they really needed in the immediate to short term. Add to that the renewed recent onus on 'expeditionary' capabilities (embodied in figures such as Eric Shinseki over in the US), and what you'll find is that 105mm guns have in fact matured over recent years because of this duo of post-Cold War lines of reasoning.

Essentially, where 105mm upgrade programs were in existence before the end of the Cold War, their revival and further development (and adoption) was the result of a whole host of nations realising that they needed to bring the rest of their tanks up to scratch in the absence of any potential future procurement.

Incidentally, it's probably worth noting that the M1040 Canister and HEAT-MP, the 'round types it needed' I assume you're referring to, are new build or buys.

The situation here is different. Existing stocks are important and capability that can be squeezed from a 105mm higher pressure gun is good enough for all threats and more then enough for expected threats. This of course being with an introduction date prior to 1991. The argument holds strong until roughly 2020. But there is a replacement tank program for that which is not the same.

But the issue is that you can't actually use existing stocks to create the 105mm high velocity gun you're conceptualising. Consider it thus. To increase penetration, you need a better round. To allow for a better round, you need to increase the gun's pressure tolerances (and possibly remove the rifling) - and that involves altering both the barrel and the breech. To house a different breech, you need a different mounting... see where this is going?

[Riysa]

Question got buried, so I'll ask again:

Is 780 mm of RHAe vs KEP on the glacis too much to expect from a 54 ton tank?

[Chebucto Provinces]

I have to run so I can't comment fully. But I will mention that I find it amusing that while I have stated a few times outright that I am looking at a vehicle developed in the 1980s and fielded no later then 1991, there seems to be this assumption from the three of you now specifically debating me that the frame of reference is 2014. It is not, more like 1984-85. We are talking about a timeframe where ultramodern means Leopard 2A4. As I have said I will be making the multi-decades jump later when this is hashed out.

I felt I was clear enough on the time period when I specifically said it but I guess not.

[Urran]

I have to run so I can't comment fully. But I will mention that I find it amusing that while I have stated a few times outright that I am looking at a vehicle developed in the 1980s and fielded no later then 1991, there seems to be this assumption from the three of you now specifically debating me that the frame of reference is 2014. It is not, more like 1984-85. We are talking about a timeframe where ultramodern means Leopard 2A4. As I have said I will be making the multi-decades jump later when this is hashed out.

I felt I was clear enough on the time period when I specifically said it but I guess not.

T80?

[Yukonastan]

For a quick hit-and-run vehicle, LOSAT or CKEM missiles mounted on something like a Fennek reconnaissance vehicle?

It'd give that last-ditch antitank weapon if a reconnaissance unit behind the lines needed to run and had a single tank blocking it.

[Purpelia]

For a quick hit-and-run vehicle, LOSAT or CKEM missiles mounted on something like a Fennek reconnaissance vehicle?

It'd give that last-ditch antitank weapon if a reconnaissance unit behind the lines needed to run and had a single tank blocking it.

Give them something like the Spike that is fire and forget. That way they can shoot and run.

[Yukonastan]

For a quick hit-and-run vehicle, LOSAT or CKEM missiles mounted on something like a Fennek reconnaissance vehicle?

It'd give that last-ditch antitank weapon if a reconnaissance unit behind the lines needed to run and had a single tank blocking it.

Give them something like the Spike that is fire and forget. That way they can shoot and run.

These CKEM missiles go hypersonic. Take an APFSDS round, enlarge it, and slap a massive rocket booster on it. I'd personally imagine that you could stick them on a limited traverse and elevation mount, aim it like a cannon, fire it, and see smoking tank.

The question was about kinetic kill missiles, not guided warhead-based missiles, whether kinetic missiles would be an effective light antitank weapon.

[Purpelia]

Give them something like the Spike that is fire and forget. That way they can shoot and run.

These CKEM missiles go hypersonic. Take an APFSDS round, enlarge it, and slap a massive rocket booster on it. I'd personally imagine that you could stick them on a limited traverse and elevation mount, aim it like a cannon, fire it, and see smoking tank.

The question was about kinetic kill missiles, not guided warhead-based missiles, whether kinetic missiles would be an effective light antitank weapon.

I honestly dislike the whole concept of KK missiles. Why bother when you can just drop HEAT on top of his turret?

[Korva]

Question got buried, so I'll ask again:

Is 780 mm of RHAe vs KEP on the glacis too much to expect from a 54 ton tank?

If it is spaced and composite then it seems possible. With ERA/spaced/composite all combined then definitely. Or you could just have an incredibly sloped glacis.

[The Kievan People]

You know that Arjun's gun has a muzzle velocity in excess of 1.5km/s right? In fact DRDO states it as 1.67. http://www.drdo.gov.in/drdo/pub/techfoc ... /arjun.htm

I think the point is not that rifled has this magic cap at 1.5, but that to get greater muzzle velocities you need to be pushing progressively (maybe exponentially) more propellent down that tube b/c of the gas leak. I don't think we're going to be seeing tanks shooting 2kms KEPs any time soon for a variety of reasons, so...

I think I said practical limit

I wasn't actually aware of the Arjun's ammunition. The highest velocity APFSDS for a rifled gun I knew of were the British L23 (1531m/s) and the Israeli M413 (1495m/s).

It's what I was getting at in any case.

[Yukonastan]

These CKEM missiles go hypersonic. Take an APFSDS round, enlarge it, and slap a massive rocket booster on it. I'd personally imagine that you could stick them on a limited traverse and elevation mount, aim it like a cannon, fire it, and see smoking tank.

The question was about kinetic kill missiles, not guided warhead-based missiles, whether kinetic missiles would be an effective light antitank weapon.

I honestly dislike the whole concept of KK missiles. Why bother when you can just drop HEAT on top of his turret?

HEAT's overrated. KK missiles are fast and impact hard. Pretty sure that not a lot of APSes will defeat something that's travelling at Mach 7 with a rocket motor behind it.

[Immoren]

I am not sure how fast LOSAT/CKEM can acquire firing solution, but I'd imagine as "last ditch" attempt were short reaction times are/might be most important, run-of-the-mill KEP might be best bet.

[Freihafen]

Give them something like the Spike that is fire and forget. That way they can shoot and run.

These CKEM missiles go hypersonic. Take an APFSDS round, enlarge it, and slap a massive rocket booster on it. I'd personally imagine that you could stick them on a limited traverse and elevation mount, aim it like a cannon, fire it, and see smoking tank.

The question was about kinetic kill missiles, not guided warhead-based missiles, whether kinetic missiles would be an effective light antitank weapon.

Fire and forget missiles probably only have marginally shorter engagement cycles than hypervelocity missiles.

AFAIK MRM-KE is similiar to what you're thinking of: a KEP with rocket booster, plus guidance.

[Yukonastan]

I am not sure how fast LOSAT/CKEM can acquire firing solution, but I'd imagine as "last ditch" attempt were short reaction times are/might be most important, run-of-the-mill KEP might be best bet.

This would be something similar to a KEP except more suited to LGS Fennek-esque reconnaissance vehicles. No cannon to launch your run-of-the-mill KEP from, therefore rockets.