RovingPedant said:

schnuersi said... So far no major nation has adopted wheeled IFVs.

Hi,

Just joined the forum, interesting discussions,

As far as "no major nation adopting wheeled IFV's", one needs to consider South Africa, in the Bush Wars against Angola (and the Cubans).

In terms of numbers of tanks/AFV's involved, the battles got pretty big.

And carried on for long periods.

And it used, and uses, a LOT of wheeled vehicles quite successfully.

From IFV's to SPG's.

One point is the terrain is not like Western Europe: not so much mud or swamps to go though.

There's a good RAND study directed towards Australia's latest decision to go wheeled or tracked for its new IFV's (it went tracked as you know).

http://chrome-extension://ieepebpjnkhaiioojkepfniodjmjjihl/data/pdf.js/web/viewer.html?

file=https%3A%2F%2Fwww.rand.org%2Fcontent%2Fdam%2Frand%2Fpubs%2Fresearch_reports%2FRR1800%2FRR1834%2FRAND_RR1834.pdf

I think there is not a SINGLE correct answer to the choice, I think it's best to have BOTH, and use the variant that suits the case at hand the best.

Sure, if you are in Ukraine in late winter/early spring, you need to deal with the mud.

And tracks are the best for that.

But how often does THAT arise with most armed forces of big countries?

Most times it's little bush wars, and COIN you're dealing with.

Where the right wheeled vehicle can be the better option.

Welcome to the forum.

In terms of can one design a wheeled vehicle to handle soft ground (mud, muskeg, swamp etc) as well, or better than a tracked vehicle, that RAND report I just posted the link to makes some interesting points:

- You want BIG tires to optimise performance (page 118) (I've read somewhere, maybe in this report, but perhaps elsewhere, that there's in effect a max size in tire you can select in terms of various factors like mounting it on the vehicle, and making it, and the tires the USMC are using are close to that max size)

- Due to the max size of tires you can effectively use on a wheeled IFV, you tend to max out at +/- 35 tons (absolute limit 40 tons)  if you want to get good mud mobility, so if you need lots of armour and size for troops, this tends to constrain your choices (page 141 and after)

Thanks.

I was just going to say "Hi", but then I saw this discussion, and it's something I'm quite interested in: mobility.

There's a Canadian researcher who has written a LOT (as in over a dozen peer-reviewed papers and at least two text books) on off-road mobility: J.Y. Wong.

And he's got some computer software that can model how a given tracked system behaves on various types of surfaces.

He's even got screen shots of it, and says how easy it is to use.

I'd love to try it, but so far it seems elusive to actually get a copy of it!

Lots of mentions of it but nothing that says where you can get access to it.

http://journals.sagepub.com/doi/10.1177/0954407018765504

This is one of his recent ones, but he's been at for DECADES.

stancrist said:

For instance, remove the turret from a Bradley IFV and turn it into an APC. It will be lighter, faster, but the same armor protection.

Yes but it will not be able to perform the function of an IFV anymore. It ceases to be one without the turret and weapons suite.
The weapons suite is integral to an IFV.

stancrist said:

LOL. "Not an infantry transporter." LOL.

Just because some guys can sit in the back doesn't make a vehicle a dedicated infantry transporter. There are lots of AFV that can carry additional passangers that are no infantry transporter.
The main function of the IFV is to fight with its own weapons. The dismounts are only deployed when they absolutely have to.

stancrist said:

Mechanized infantry are not infantry?

No they are not Panzergrenadiers are classes as armored forces. Part of the armored corps as are tank destroyers, armored recond and armor. Their main function is MOUNTED combat. With the ability to deploy dismounts for limited time and missions should the situation require it.
This makes them different in concept, doctrine and tactics to infantry regardless if motorised or not.
Its the same with Soviet/Russian doctrine. The BMP equiped units are an organic part of the armor regiments. The BTR and other APCs are unsed in the motor rifle regiments in other words infantry regiments.

The main function of the IFV is to fight with its own weapons. The dismounts are only deployed when they absolutely have to.

You don't seem to know how and why the BMP and the HS.30 and later Marder evolved. Their existence is directly linked to a mobility focussed understanding of manoeuver warfare and in depth operation. This is why IFV are fighting vehicles first and troop carrying is an add on.

stancrist said:

Second, the IFV is not optimized for fighting other vehicles.

Of course it is. The IFV is optimised to fight all other vehicles except tanks. It can do that if equiped with ATGMs but its primary function is to take on other AFVs.
Its plain obvious in the design of the BMP-1 for example. Except for the MG it only carries anti armor weapons.

stancrist said:

IFV: Designed for transporting infantry; armor protection greater than that of the APC; armament more capable and flexible than that of the APC.

Nope. That is a better armed APC.

WarthogARJ said:

As far as "no major nation adopting wheeled IFV's", one needs to consider South Africa, in the Bush Wars against Angola (and the Cubans). In terms of numbers of tanks/AFV's involved, the battles got pretty big.

If the Ratel really is an IFV can be debated. I am not familiar enough with SA doctrine to comment on it.
What I can tell is that from the German perspectice the Ratel is no IFV. It does not fullfill the requirement. It lacks cross country mobility (by German standards which are very different from African ones) and it lacks protection. How well is it protected? Somewhat between STANAG K3 and K4? To be an IFV a vehicle must be duelling capable. Which requires at least protection against its own main gun, better against the main gun of its counterpart. This for example is why the Marder allready has STANAG K6 armor.
I am aware that the situation in Africa in General is different. Very diffrent. The fact that for example the French Army makes massive use of wheeled vehicles is a result of that. The thing is i am not certain that a true IFV is even needed under such conditions. Yes it can be used but its propably to heavy and with to little operational mobility.

WarthogARJ said:

I think there is not a SINGLE correct answer to the choice, I think it's best to have BOTH, and use the variant that suits the case at hand the best.

Fully agree.
My background is focussed on a major conflic in Europe or close to Europe. NATO and homeland defense in a peer or near peer conflict. LIC and COIN are of little concern. Because its becoming increasing unlikely and because the experience in the last decade showed that equipement that has been designed for HIC works great in LIC and COIN as well.

WarthogARJ said:

ure, if you are in Ukraine in late winter/early spring, you need to deal with the mud.

Not only Ukraine. All over Europe. Just die varying degrees. Lots of water result in lots of mud.
Agricultural areas are especially problematic.

WarthogARJ said:

But how often does THAT arise with most armed forces of big countries?

Its their primary function. If its actually happening or not is irrelevant.

WarthogARJ said:

Most times it's little bush wars, and COIN you're dealing with.

No most of the time a military does nothing. COIN and bush wars are a concern for some. For some other for a limited time. But its an after thought. It has to be. Unless of course the main mission of a nations military as described in its constitution is intervention.
 

WarthogARJ said:

Where the right wheeled vehicle can be the better option.

Better is debateble or very dependent on the circumstances. Its the cheaper option. In Afghanistan the wheeled vehicles have been much more limited compared to the tracked ones. Operational distances have not been that long. Never the less lots of wheels have been deployed. What is actually happening in theatre is often not because of its the better option from a technical or tactical point of view but because its political acceptable and the least expensive option.

WarthogARJ said:

- You want BIG tires to optimise performance ...
- Due to the max size of tires you can effectively use on a wheeled IFV, you tend to max out at +/- 35 tons (absolute limit 40 tons) if you want to get good mud mobility, so if you need lots of armour and size for troops, this tends to constrain your choices (page 141 and after)

This is really nothing new.
But its also a fact that a 35 t 8x8 wheeled AFV will have worse cross country mobility than a 35 t tracked vehicle. The difference is more pronounced on certain terrain.
What usually is overlooked are statements like "the 8x8 has adequate mobility..." which means is bad but someone has decided to accept it anyways. I have witnessed several mobility test and read lots of reports. Its allways the same. You can't change the physics involved. Yes there have been improvements but the current technical platau has been reached decades ago.
If its about soft ground the one thing that matters most is ground pressure. For slippery ground its contact area. If moving at high speeds over uneven ground its wheel movement and suspention absorbtion. In all of these a tracked vehicle is superiour. Not because of some technological trick but because of simple physics.

schnuersi said:

It lacks cross country mobility (by German standards which are very different from African ones)

I think locale is important in terms of mobility. Cross country mobility in Germany / Ukraine / Sweden etc may require tracks due to the mud and wide open countryside.

However other countries have much different climates. Cyprus, for example, is a mix of dense urban cities and hard sunblasted earth; wheeled IFV's might prove the better choice for them as a Turk defender due to the superior road mobility and reduced maintenence.

Taiwan is primarily a mix of hyper ubranization and steep forested mountains. Realistic counter invasion IFV chicom blasting is likely to be primarily focussed in the cities / approaches to the cities. 

For a QRF to defend a giant city like Taipai, wheeled IFV's may also be preferable / offer superior mobility.