Parvusimperator is fond of a certain sort of infantry fighting vehicle: it should be big, heavy, share parts commonality with his tank, and transport a whole platoon of infantry. It may come as a surprise to you that this is not the only sort of IFV¹.

The Hoplon, parvusimperator’s design, fits certain scenarios very well: your Golan Heights, your Fallujah, perhaps your Fulda Gap. Those sorts of scenarios are important, but in exchange for its superb performance there, the Hoplon gives up some other capabilities that other IFVs offer, and other IFVs can be nearly as good as the Hoplon in the Hoplon’s preferred field of play.

I’ve always been a BMP-3 fanboy, so we’ll talk about the Hoplon and Namer relative to the BMP-3. We’ll kick things off with the biggest difference…

Mobility
Otherwise known as the dreaded M word. The BMP-3 is the obvious winner here. Its advantages stem from its weight: fully kitted out, it tips the scales at less than 20 tonnes.

This means that it need not bother with complicated, failure-prone fording mechanisms. It can simply swim its way across a river. That’s right: it’s fully amphibious, which is an important quality for an infantry-carrying vehicle. Mechanizing infantry usually improves their speed of tactical movement while reducing their ability to cross or occupy rough terrain. An amphibious IFV actually adds some terrain-crossing ability: infantry can’t really cross or occupy a river on their own. More generally, a lighter IFV leads to enhanced tactical mobility overall: lower ground pressure means lighter vehicles can move across a wider variety of terrain, in which another vehicle might bog down².

Enough about tactical mobility, though. There’s another kind of mobility where the heavy IFV concept falls down: the capital-M sort, Strategic Mobility. How many Namers or Hoplons can you fit into your C-130? Zero. How many BMP-3s? One! How many Namers or Hoplons can you fit into your C-5? One! How many BMP-3s can you fit into your comparable An-124? … six.

Now, airlift is not the be-all, end-all of strategic mobility, but, being the hardest part, it’s a good place to start. Certainly, airlift is the way you want to move your stuff when it absolutely, positively has to be there tomorrow. Being able to fit your IFVs into your smaller air transports, freeing up your big transports to move tanks, is a significant win for putting a mechanized force somewhere fast. You can get by with rail and road transport if you’re a purely continental power, but I would suggest that the world is too complicated a place for anyone to call themselves a truly, exclusively continental power.

A lighter vehicle is also somewhat easier to transport by rail: it doesn’t call for specialized rolling stock, whereas your standard flatbed rail car would be hard-pressed to stand up to a Namer-sized vehicle. Road transit is also easier, because of reduced road wear, and again, a lesser need for overspecialized vehicles.

Ship-based transport is a wash, but you can put just about anything on a boat. Hoplon or Namer don’t get any points for being easily transportable that way.

Armament
We should start by talking about what an IFV needs to do. Infantry are versatile, able to do almost anything on the battlefield; their vehicles ought to be too. This is why most IFVs have an autocannon armament. The autocannon can engage fellow light vehicles, enemy infantry, aircraft, and to some degree, dug-in positions. You’ll note, however, that tanks are not on the list. Although infantry armed with proper missiles represent a serious threat to tanks, IFVs, generally, do not: they don’t hide as well as infantry, and unlike infantry, they can’t spread out for protection against deadly point fire. IFVs equipped to defeat tanks are therefore so equipped for purely defensive purposes: anti-tank missilery is not a headline capability on an IFV. Ideally, your IFV won’t be in evidence when the tanks come a-knocking; that’s why you have infantry antitank teams.

On to the BMP-3, then. It does indeed have an autocannon: the 30×165 2A72, a variant of the 2A42 you might know from past Ka-50 posts. The 30×165 cartridge, while a little lighter than the NATO-standard 30×173, is nevertheless quite punchy, by IFV standards; the BMP-3 carries 500 rounds split between high-explosive and armor-piercing types. Little needs to be said about the autocannon. It’s an autocannon. Every ex-Soviet state and Russian arms buyer in the world uses this one. It works as advertised.

Next, though, the BMP-3 goes a little bit off-script. Mounted coaxially with the autocannon is a 100mm rifled medium-velocity gun. “But why?” you ask. “That’s way too small to shoot at a tank, and the autocannon is good enough, right?” Not altogether! You may recall the infantry tank from the Second World War: a bad idea, but one based on a germ of truth. Infantry don’t have a good way to deal with a really stout dug-in position. Launchers can help, but tend to be short-ranged and inaccurate. Mortars are nice, but they’re an area weapon. What the infantryman really needs is a good-sized, say, 100mm HE-chucker, able to keep up with him as far as terrain crossing, and able to bear rapidly on any intractable enemy defensive position. So, stick one on the IFV. The BMP-3’s 100mm gun is an infantry support gun, which is important tactically, but also logistically: it doesn’t have much in the way of anti-tank use, so what ammunition it carries is all for, y’know, supporting the infantry.

Which isn’t to say it has zero anti-armor use. It carries eight gun-launched missiles; although they won’t do much against a modern tank, they provide an extra-long-range punch against lighter enemy vehicles.

Three 7.62mm machine guns—one coaxial in the turret, and two bow guns, each with 2000 rounds of ammunition—round out the weapons fit.

What it comes down to is that the BMP’s armament is hyper-focused on its role as an infantry fighting vehicle. It doesn’t faff about with anti-tank weapons it should never have reason to use, if deployed correctly. It simply gets on with the business of employing every piece of hardware it possesses to defeat the sorts of enemies the infantry it carries is most likely to be facing.

Protection
We come now to a category where the BMP falls down a little compared to its HIFV competition, but really, of course it does. They’re literally tanks, with the tanky bits taken out and seats put in. It isn’t like I was somehow going to miss this one. I just don’t care, and here’s why you shouldn’t, either: doctrine. I gave three scenarios where the Hoplon-Namer school of IFV design excels: the Golan Heights, the Fulda Gap, and Fallujah. Let’s look at each one.

The Golan Heights, as parvusimperator mentioned, is probably one of the most featureless regions on the planet which is nevertheless worth fighting over. It’s flat, and there’s nowhere to hide. If the enemy can see you, the enemy can peg you with a missile. Now, if you’re advancing in proper combined-arms fashion, with your tanks and IFVs working in concert, what happens? They shoot at your IFV and it shrugs off the hit, or they shoot at your IFV and it dies, but either way, they aren’t shooting your tanks. The tanks are your true breakthrough weapon: IFVs are just there to deliver your infantry to hold the ground you’ve just captured with your tanks, and to provide some extra punch when they get there. Losing a few doesn’t matter; tanks are the bigger, juicier target, and a combined-arms advance against an ATGM-equipped position should rightly see most of the missiles headed for the tanks anyway.

The Fulda Gap presents different challenges. You (presuming you’re a Western power) are on defense. You’ll be facing tanks and IFVs pouring through the West German forests, but you have the edge: you get to dig in, which nullifies a lot of the survivability edge. Missiles mounted on the IFV are less of an advantage in this scenario, because your men can simply dismount and use their own ATGMs.

In Fallujah, the Hoplon’s edge is slightly more pronounced: it can eat an RPG shot from the front, and that helps when you’re turning a corner or going down a long street. That said, you’ve taken your armored fighting vehicle into an urban area. That is not a low-risk proposition. You’ll want a TUSK-style kit however heavy your IFV is: if Big Army and the United States Marines found that the Abrams needed specific upgrade kit to be safe and effective in cities, your IFV is going to need the same³. The single most important upgrade out of your TUSK kit is slat armor, which is lightweight compared to real armor, and will do a number on that most common urban threat, the RPG.

Beyond that, an autocannon and coaxial machine gun alone are insufficient armament for city fighting. Much better to have a 100mm HE-thrower, so you can bring down the front of a building in response to an RPG shot, and some independent machine guns, so you can hose down multiple targets at once.

Ergonomics
We come to the BMP’s weakest point: its ergonomics. Tank-based IFVs and APCs have cavernous internal spaces and proper rear exits. For some reason, the BMP-3 puts the engine where that rear exit ought to go, robbing the troops inside of both convenience and survivability⁴. Getting out of a BMP involves at least a little bit of climbing.

In this picture, you can see the troop compartment: once you go over the engine (the raised section beneath the opened top doors), you drop into the troop compartment, which is behind the turret. (The turret’s fighting positions are enclosed by the two white pillars.) Three seats are placed with their backs to the engine compartment, and two are placed on either side of the turret base. Two more jumpseats can be folded down between the three seats in front of the engine, but five is a good capacity estimate for troops carrying any real amount of gear.

To get in or out, you have to do one of two things: open the top doors and jump up onto the engine, or leave the top doors closed, and crawl out the back. Neither one is as fast as a traditional rear door, and the safest way—crawling—is much slower. If you’re willing to further handicap your exit speed, you can probably stash some gear on one of the crawlways, which might be handy if you’re carrying an ATGM team, say.

Really, though, the BMP’s design follows its ergonomics. It’s almost purely an infantry support vehicle, which can incidentally carry five infantrymen. I don’t know what the prevailing Russian doctrine is, but the BMP is not a good battle taxi. Its job, as far as carrying infantry goes, is to get them close to the battlefield, not reliably serve to move them around thereupon. Once the infantry has disembarked, preferably somewhere out of direct enemy fire, they can advance with the BMP in support. It can serve in the battle taxi role—it’s quick, has decent terrain-crossing ability, and can fit an admittedly small number of infantry—but that is not its natural home.

Luchtbourgish Advantages
The BMP requires some doctrinal modifications relative to your HIFV or HAPC: namely, in situations where it is likely to encounter tanks, it must be used in close concert with tanks, and in combat generally, the infantry should be disembarked earlier and fight their way to their stopping point, with the BMP providing fire support. Urban survivability requires specific urban survivability upgrades⁵.

These modifications may not be for you. I don’t think they’re for parvusimperator or Borgundy. Survivability in a limited area of operations is too important for his purposes. Luchtburg, however, is a different story.

The mobility of lighter IFVs, and the BMP particularly, meets a Luchtbourgish need. The country is mountainous, swampy, and filled with rivers. An IFV which can swim has a huge mobility edge over one which doesn’t: it can easily penetrate the Luchtbourgish interior where a heavier vehicle or a tank might get bogged down.

The armament fit is perfect, too: busting up a cartel camp in the jungle is tricky with infantry or lighter vehicles, because the drug lords have moderately heavy weapons; an IFV which can take hits from machine guns and grenades while dealing out heavy punishment in return is ideal for Luchtburg’s aggressive enforcement of anti-cartel laws.

Finally, air mobility is of critical importance. Luchtburg is an expeditionary power with global interests. The BMP-3 is easy to ship rapidly, which lets Luchtbourgish forces enter the fight faster, which helps protect Luchtbourgish interests worldwide.

1. You’ll recall that parvusimperator also recently wrote on the Namer, Israel’s ‘IFV’, but that’s more properly a heavy APC, its own class. It’s designed to transport infantry in safety exclusively, not to provide added firepower on the battlefield.
2. Heavy APCs and heavy IFVs (Namer and Hoplon) have tank-like ground pressures of 12-15 psi, ordinarily. Standard IFVs (the range from the BMP-3 up to, say, the unupgraded Puma) tend to be in the 6-8 psi range, which is approximately the range of a standing human.
3. Unless you’ve bought Namer, but Namer is basically frontal-strength armor all around.
4. Don’t get me wrong, putting the engine in front of the troops is bad for the engine if you take a hit, but it’s better to lose an IFV alone than it is to lose an IFV and everyone inside it.
5. Surprisingly, I don’t think the Russians have any. I can only find one or two pictures of real BMPs equipped with slat armor. (ERA and active anti-missile systems are obviously out for a vehicle intended to operate closely with infantry.) The rest are kitbashes. Parvusimperator says the Russians were mostly concerned with plunging fire from tall Chechnyan buildings and mines, so they didn’t bother. Frontal and side-on shots are still plenty likely in lots of the world, though, so I stand by this recommendation. Or just slap ERA on and establish a minimum safe distance, though even the Russians aren’t quite that cynical. (The Americans have done this on Bradleys with good results in Iraq. -Ed.)