Yes, it’s been about 24 years since Sweden made its choice. And it’s no secret that they ended up going with a variant of the Leopard 2A5 with improved armor (or, more technically, an armor package that was proposed but the Germans didn’t opt for because of budget cuts). But I found a presentation on the trials, complete with previously-classified armor comparisons. The comparisons are twenty four years old, but they’re actual hard data, and I love data. No guesstimates here.
A few years ago, I wrote an MBT comparison for our procurement games. Since then, I’ve learned a lot more about the Leopard 2 and the M1 Abrams, we’ve seen some upgrade programs for both tanks, I’ve gotten enough data on the South Korean K2 to write on it, and Russia has introduced the T-14. Also, I love tanks. So let’s do another roundup. As always, I’m limited to open source guesstimates only.
The T-14 has a brand new 125mm gun, which can handle higher pressure rounds. So it’s almost certainly better than previous Russian guns. Whether it’s better than the latest Western stuff depends on whose propaganda you’re reading. I’m inclined to guess it’s going to be similar to the latest Rheinmetall options. Possibly a bit better because it’s newer.
Both the K2 and the newest Leopard 2 variants use the longer L55 version of Rheinmetall’s 120mm smoothbore, which gives more velocity than the Abrams’ M256 (a derivative of the Rheinmetall L44). Which would be better if all other things were equal, but they aren’t. The Americans use depleted uranium APFSDS rounds, which work better than tungsten (which Germany and South Korea use), all other things being equal (they still aren’t). Overall, tungsten sabot rounds from the L55 and depleted uranium sabot rounds from the L44 are about equal as far as armor penetration estimates are concerned. New rounds continue to come from the Americans, and there’s a plan to upgrade the L55 to the L55A1 which can take higher chamber pressures. Also, the Americans have finally added the capability to interface with datalinks on gun rounds in the SEPv3 Abrams, and this is present on the guns for Leopard 2 and K2. So this is very roughly a wash. Some magical person might be able to point to specific advantages of one option or another against specific targets, but this is all I’ve got with unclassifed, dodgy sources.
Damn it, this is classified too! UGH. In all seriousness, this too will be a wash in the main, because everyone’s got about the same technological problems, even if they come at it a little differently. Abrams and Leopard 2 have been receiving consistent upgrades, so their frontal armor should be just as good as the newer K2. T-14 has unclear amounts of protection on the turret, but only the gun is mounted there. Hull frontal protection should be good across the board too, given upgrades. Note that the Leopard 2 and Abrams have excellent side protection kits, should you wish to use them in cities full of scumbag insurgents. T-14 seems to have some quality skirt options as well, but K2 lacks similar levels of optional side protection. In terms of active protection, T-14 comes fitted with hard-kill APS systems from the factory, Abrams is getting Trophy kits installed (they’ve passed trials and money is allocated), K2 is fitted for but not with hard kill kits and the Germans are still trialing their hard kill setup. I should also point out that in the past the Americans have been reluctant to offer up their best armor technology in export models. The Abrams with export-level armor would be expected to be less good than the latest Leopard 2 variant or K2.
So you’ve been hit, and your armor is penetrated! That really sucks. Now what?
T-14 isolates the crew completely from the ammo. There are also blow-out panels on the bottom. Not sure about the turret, it might get wrecked, or there might be venting measures there. So those are all good things. On the other hand, the T-14 has the smallest crew compartment, so that means any penetration there is going to cause more problems. There’s always a bigger IED.
Abrams has the vast majority of it’s ammo in the turret bustle, again with blow-out panels. There’s also hull stowage for six more 120mm rounds, also with blow-out panels. Alternatively, if lots of hull hits from RPGs are expected, this can be emptied of ammo without too much difficulty. It’s only six rounds. Abrams has the biggest protected volume, which is why it uses fancy exotic materials for protection, but it also makes it very difficult to wound everybody.
Leopard 2 and K2 both have blow-out panels for their ammo stowage in the bustle. However, both have a large hull ammo rack (about 20 rounds or so) next to the driver up front. Neither has much in the way of bulkheads isolating this ammo and neither has blow-out panels for this stowage. Protect that hull, guys. Crew compartments are moderately sized, and should provide reasonable levels of safety due to dispersion. Leopard 2 is bigger internally than K2, and gets a bit of a nod here.
Also, while not strictly a survivability thing, more room means easier to jam upgrades in. So in order of most upgradeable to least: Abrams, Leopard 2, K2, T-14.
Also known in some cultures as “driving around the battlefield.” Everybody’s got a 1,500 hp engine. K2 and T-14 should have a significant advantage from being 10ish tons lighter than the latest Leopard 2 and Abrams variants. Both K2 and T-14 have had transmission problems recently, however. Abrams has the gas turbine engine, which comes with some maintenance advantages because of the fewer small parts, but it is a very thirsty beast. The latest Abrams tanks have protected auxiliary power units, but I don’t have much data on how much this improves fuel economy. The Leopard 2 has a pretty boring twin-turbo diesel powerplant that seems to work well.
Once again, the lighter tanks get the points here. I would be inclined to argue that the difference doesn’t matter for the purposes of ship-based transport, but a win is a a win.
The bureaucrats always get to put in their two bits. NATO-related stuff is going to torpedo the notion of a T-14 buy. Also, it hasn’t even passed Russian trials yet, and we don’t like being early adopters of anything. Otherwise, it comes down to who your friends are. America may not sell you the best and latest depleted uranium stuff if they don’t like you enough. The Germans may not support you with spare parts if you go off to war with the stuff. South Korea is new on the market and doesn’t have the same ability to bundle deals like the others.
I did find the approximate unit cost of a K2 on the internet. Unfortunately, costs of the others are going to be determined by upgrade package, which is kind of a bummer. Also, for all tanks, a lot depends on the terms of the purchase and what other equipment is included (spares, weapons, training tanks, etc.). So I’ll go out on a limb and say that a similar level of outfitting is going to cost about the same for new builds, and I think that’s pretty reasonable. I can’t adequately work out who might offer the best package deal. However, unlike the other two western competitors, there are a ton of old Abrams tanks sitting in the American desert. So the Americans ought to be able to give you a better deal on overhauled and upgraded tanks, and they probably will be available faster. Also, given relative labor costs, there might be advantages to the K2 or the T-14.
So which do we go with? Whichever one can get us the best pricing deal and meets the political obligations. I don’t see much difference overall with any of the options, at least not in any way that matters. MBTs don’t really have different schools of thought like IFVs do, so which one is not a big deal. They all provide reasonable quality; it remains to get them in reasonable quantity. One might argue that the large stock of old Abramses gives that an advantage, if modifying is cheaper than buying new. Or one might argue for the extensive, already-trialled options list available for the Leopard 2, or the newer K2 with more standard features and lower lifecycle costs from having a smaller crew.
I finally worked out answers to a few things that puzzled me for a while, and figured it might be fun to post here in a sort of Q&A format. This follows our articles looking at loadouts for the Bradley and Puma IFVs. Having read those articles, you might be wondering the following:
- How does the Bradley manage to carry so much ammo?
- The Puma IFV has an unmanned turret, so no turret basket, and it’s pretty large. So why does the Puma only have space for six dismounts?
The space under the turret on the Puma, where we would expect a basket to be on a manned turret, is actually a bunch of storage bins. It takes up about the same amount of space that two more shock-resistant seats would. So that’s where the space goes.
That begs more questions. Why do we need those bins? The Puma requires storage bins under the turret because the Puma’s sponsons contain fuel and various systems. They can’t be used for storage. On the smaller Bradley, the sponsons are empty and open to the cabin. So the space behind the bench seats can be loaded up with tons of stuff for both the vehicle and the dismounts. Check out this picture to see what I mean:
Happily, this picture shows the space being used with things you are probably familiar with, like a cooler and a bunch of 2-liter bottles. In combat conditions, we’d expect this to be full 25 mm ammo boxes and TOW missiles for the Bradley, plus food and ammo for the crew and dismounts. If you give up that storage space, you have to put the stuff somewhere else. And you can’t easily relocate stuff for the dismounts outside of the crew compartment. Hence, storage lockers. Note also in the above picture the floor panels at the bottom left. These can be lifted up to access yet more storage space. This space is normally used to fit 25mm ammo. We can also see some storage space under the bench seat. Convenient, but not the best when dealing with antitank mines.
The Puma uses the in-cabin storage lockers for stuff for the dismounts, and it has a bunch of external compartments to hold the 30mm ammo. The Puma was designed with protection and survivability first. The Germans went to a lot of trouble to put in decoupled running gear to minimize the number of penetrations into the hull for the suspension, since penetrations mean weak points for mines. This meant that the sponsons had to hold more suspension gear. Plus, the Puma’s designers tried to isolate the passengers and crew from the fuel and ammo.
The Bradley was designed in an earlier time when survivability was not as paramount, and its designers put firepower first to counter the expected hordes of Soviet light armor. If the Bradleys could take those out, American tanks would be free to concentrate their fire on enemy tanks. Or so the theory went. While possessing a bit of a glass jaw, the Bradley proved to be an excellent vehicle killer in Desert Storm, and was a good fire support vehicle in Operation Iraqi Freedom.
The US Army is continuing to look at options to improve its Bradley fighting vehicles. In the wake of the termination of the Ground Combat Vehicle, the US Army sought a cheaper incremental upgrade process, consisting of two engineering change proposals. ECP1 improved the suspension and tracks, and ECP2 improved power generation and internal networking. For the record, Bradleys that have received both ECP1 and ECP2 are designated M2A4.1
But the US Army is not content to stop there. Further upgrades are being considered, and they consist of a series of proposed changes to both the hull and turret. The final M2A5 will probably consist of some combination of these.
ECP1 added a reworked suspension to handle more weight. Let’s use that weight. The reworked hull design proposal uses a bunch of design work from the successful AMPV program, which is based on a turretless Bradley. The reworked hull should accommodate more armor and likely some kind of active protection system.2 It’s also somewhat taller than a regular Bradley. The biggest difference is a bit of hull stretch to accommodate an eighth solider. No extra roadwheels will be added. I’m curious about the new seating arrangement.
This is a little less interesting to me, because these proposals aren’t really anything we haven’t seen before. The conversion from 25x137mm M242 to 30x173mm Mk. 443 is something that’s been trialed before and proposed before. Again, ready capacity decreases from 300 rounds to 180 rounds. Gains include armor piercing growth room,4 ammo commonality with the Stryker Dragoon, and the possibility of using airburst rounds. Not on the docket is any change to the TOW missile launcher. I might have expected Javelin instead, but that doesn’t look to be in the cards.
Alternatively, as ever there are rumors about the US Army investigating foreign made IFVs. I would expect the ASCOD 2 and the Puma to be on the short list of candidates being looked at. Maybe they’ll try to license one. Or maybe not.
- Finally. Wish they’d finally designate an M1A3 Abrams… ↩
- The system hasn’t been chosen yet, and it might get integrated into the turret. Or not; the TOW launcher is kind of in the way. ↩
- Or a derivative of the Mk. 44, like the M813 on the Stryker Dragoon. ↩
- 25x137mm Depleted Uranium APFSDS is roughly equivalent to 30x173mm APFSDS, so some well-made DU rounds should give yet more punch to the 30x173mm. ↩
Let’s take a look at what’s in a Bradley, courtesy of Hunnicut’s excellent work on the vehicle. Some of the information below is a little old (it’s from back when the M60 was the US Army’s squad support weapon), so I’ll make estimates for more modern systems as appropriate.
–Equipment for Vehicle Subsystems–
- Fuel: 175 gal.
- Engine oil: 26 qt.
- Ready 25mm rounds: 300
- Stowed 25mm rounds: 600
- Ready 7.62mm rounds: 800
- Stowed 7.62mm rounds: 1,4001
- Ready TOW missiles: 2 missiles
- Stowed TOW missiles: 5 missiles (Or 3 TOW missiles + 2 Javelin missiles, see below)
–Equipment for Dismounts–
- Stowed 7.62mm rounds: 2,2002
- Stowed 5.56mm rounds: 5,3203
- Stowed AT4 Rockets: 3 rockets
- Stowed ATGMs: 0 or 2 Javelin missiles
Curiously, in the tables in Hunnicutt’s book, both AT4 and M72 LAWs are listed as carried. In the text he mentions that AT4s were carried instead of LAWs and stowage was altered accordingly. I’ve gone with the latter here. We can also see that the Bradley is absolutely loaded with ammo.
- In Hunnicut’s table, ammo for the coax M240C is noted separately from the ammo for the M60 that’s to be deployed with the squad. I have preserved the distinction here (See also note 2) ↩
- These might also be used in the coax gun, since they’re still linked 7.62x51mm. Alternatively, this space should hold about 3,300 rounds of 5.56mm belted ammo for M249s, which is the current squad automatic weapon of the US Army. ↩
- Originally these were separated out for the M239 Firing port weapon and the infantry’s M16s, but the M239s didn’t work very well, and later versions of the Bradley plated over the firing ports. In any case, the M16 and M239 use the same magazines, so I haven’t split the ammo out here like Hunicutt does. ↩
Here’s a list of stuff that a Puma carries, at least according to Tankograd’s wonderfully photo-laden book on the vehicle.
–Equipment for Vehicle Subsystems–
- Fuel: 900 L
- Ready 30mm ammo: 200 rounds
- Stowed 30mm ammo: 161 rounds (in seven-round boxes)
- Ready 5.56mm ammo: 1,000 rounds
- Stowed 5.56mm ammo: 1,000 rounds
- Ready ATGM: 2 missiles
- Stowed ATGM: 0 missiles
- Grenade Launcher, Ready Rounds: 12 76mm Grenades -OR- 24 40mm grenades
–Equipment for Dismounts–
- Stowed 5.56mm ammo for dismounts: 1,500 rounds
- Stowed 40mm grenades: 36 rounds
- Stowed frag grenades: 30 grenades
- Stowed smoke grenades: 7 grenades
- Stowed signal rounds: 20 rounds
- Stowed rockets: 4 Panzerfaust 3 rockets and 2 launchers
- Stowed Water, 1.5 L bottles: 32 bottles
The Tankograd volume doesn’t make mention of how much of the 5.56mm ammo stowed for the dismounts is in magazines and how much is linked for the dismounts’ MG4. 1,500 rounds doesn’t seem like all that much for six men, but perhaps the Germans trust their supply. It’s nice that Tankograd notes how much water the Puma usually carries.
The Component Advanced Technology Test Bed was another late 80s American test program to investigate new systems for future tanks. As we’ll see, it looked quite a bit different from the TTB, and where the TTB was testing a very specific change (namely the unmanned, low profile turret) the CATTB tested a variety of new technologies in a more conventional layout.
CATTB shared an Abrams hull, but the turret was new, and came with a bustle-mounted autoloader. The autoloader was very similar to the one on the Leclerc or K2. A new gun was tested, the XM291, which came in both 120 mm and 140 mm versions. The 120 mm version provided a lower-risk alternative to the 140 mm. The turret had rather large forward armor arrays, plus reasonably thick side arrays and a decent amount of roof protection. And I have no idea why they decided to mount so many smoke grenade launchers on there, but they did. This was before the advent of soft-kill active protection systems, but might not go amiss on a tank today with the right cueing system.
As you can see from this rear view, the CATTB also came with a new engine: the XAP-1000 diesel. The Cummins/Allison XAP-1000 was based on the advanced Cummins XAV-28 V-12 diesel, a low-heat rejection engine. It used only oil coolant and has no water in the cooling system at all. Higher temperature exhaust gasses were tapped to run the APU. I don’t know a ton about this engine, but the US Army has a history of backing highly advanced diesel engines that end up being problematic. I would suspect similar things with the XAP-1000. Again, the project went nowhere. Later in the 90s, the Abrams was going to get a new engine as an offshoot of the Crusader project, but the proposed engine was not the XAP-1000. Instead, a gas turbine was chosen.
CATTB is a lot more of a conventionally designed tank. I do really like its lines. The project which was supposed to lead to the Block III MBT ended up leading nowhere due to changing priorities. Though, it is not at a museum. It is in the long term storage section of the Sierra Army Depot in Hurlong, CA. Make of that what you wish.
Let’s talk some more about the 140 mm tank gun, that late cold war weapon that never was. Perfect for killing Soviet Supertanks that never were. And making your new tank way cooler than everyone else’s. The fastest way to get more armor penetration is to just build a bigger gun with more muzzle energy. A lot more.
As you might imagine, a 140 mm round is quite a bit bigger than a 120mm round. Let’s take a look, because these numbers are damned hard to find:
First, a typical 120 mm APFSDS round for the era, the American M829A1. The legendary Silver Bullet that slaughtered the tanks of Saddam’s Republican Guard. Some variations in length and weight are to be expected amongst 120 mm rounds. Newer rounds are a little heavier, but the size is constrained by ammunition storage racks and the existing chambers. The M829A1 is also the round that was in service while the 140 mm was under development.
M829A1 120 mm APFSDS
* Length: 984 mm
* Weight: 20.9 kg (46 lbs)
And now, the round to replace it. Producing 23 MJ at the muzzle, more than double that of the 120mm. The mighty 140. Dimensions were fixed by the NATO countries that were all developing their own versions of the round.
XM962 140 mm APFSDS
* Length: 1,482 mm
* Weight: approximately 40 kg (88 lbs)
The length and weight of the 140 mm stand out. This round would have been a royal pain to handle. It’s also a bit fatter, so autoloaders could handle fewer rounds. This explains why the K2 Black Panther, otherwise similar to the Leclerc, can only hold 17 rounds in its autoloader compared to 22 in the Leclerc. The K2 is ready for 140 mm, needing only a barrel change. Interestingly, the round count in the Black Panther matches those for the M1-CATTB prototype, which had a similar, belt-style autoloader in its bustle. Don’t worry, we’ll talk about the CATTB in a future article.
NATO-standard 120 mm rounds like the M829A1 are unitary rounds. One big piece, like an oversized version of the cartridges you load into your guns at home. Because of the large size of the 140 mm rounds, these were made as two-piece rounds. Unfortunately, while I can find dimensions for the round’s overall length, I don’t have dimensions for the pieces. Until I can find one to measure myself, we’ll have to make do with some pixel counting/scaling, which yields a length of about 1,024 mm for the upper part of the round, and about 461 mm for the lower part. Which is still big and annoying for autoloader development. Length of the upper part of the round is heavily influenced by the length of the APFSDS projectile. This also would affect a design using a carousel autoloader like the TTB, since carousel (and therefore hull) height and turret height are constrained by the requirement to lift and rotate the rounds into position.
Based on the standards of the day, the 140 mm gun made more than twice the energy of the 120 mm at the muzzle. Of those 23 MJ of muzzle energy in the 140 mm, 14 MJ goes to the penetrator. Running the numbers meant that the 140 mm APFSDS could punch through more than 1,000 mm of RHAe at a ‘battle range’ of 2 km. For comparison, we’ll pull some open source estimates for M829A1, which give it a penetration of 700 mm of RHAe1.
Now, those are some really good numbers2. Of course, there’s a price to be paid. Even with the two-piece construction, everyone working with the 140 mm designed with autoloaders. Which meant significantly reworked turrets for the British, the Germans, and the Americans at a minimum. Plus, ammunition capacity would drop.
Upgunning to a 140 mm round was the simplest way to get a lot more armor penetration capability into a tank. At least from a weapon/projectile design standpoint. It would have required some serious reworking of then-extant designs, but such is life. When the Soviet Union imploded, the armored threat of the projected Future Soviet (super)tanks evaporated, and the 140 mm gun projects were quietly shelved. 120 mm rounds are continuing to get more development and the latest are quite a bit more effective than the M829A1. Lower cost, likely lower capabilities, but this decision makes sense given the circumstances.
- There’s some variation in this estimation depending on source. Open source disclaimers apply, etc. ↩
- They’re also a trifle disingenuous. Nobody is armoring their tanks with a meter of rolled homogenous steel. Literally nobody. A more advanced penetrator design can exploit effects on the not-steel that people actually armor their tanks with. Similarly, the armor might be designed to radically degrade (read: break up) the penetrator, which can be sort of but not really captured in RHAe estimations. So the RHAe numbers don’t actually tell the whole story on either side of the design puzzle. Oh, and the numbers themselves are the usual open-source estimates3, so they’re probably all wrong. ↩
- If you’d like to try your hand, start running through the Odermatt equation. And then remember that Odermatt wrote for tungsten-based penetrators, and M829A1 is depleted uranium, so you’ll need to tweak it. ↩
The M1 Tank Test Bed (TTB) was a late-80s prototype to test unmanned turret design concepts and compare them to a modern, manned-turret design: the then-state-of-the-art M1A1. The TTB was not necessarily intended to be what the next MBT would look like, but it was intended to shake out some design concepts and see if they were worth considering in the future. So let’s take a look.
Some of you may notice a resemblance to the T-14. Both use similar unmanned turret design concepts. Such designs have been kicked around since the 1950s by many different groups of tank designers, and all for similar reasons of being able to reduce protected volume (and hence reduce design weight for a given standard of protection). The M1A1 weighs about 57 tonnes. The TTB, with a similar protective standard and the same 120mm gun (and a similar ammunition capacity) was reckoned to weigh about 15% less, for an approximate TTB weight of 48.45 tonnes. Interestingly, this is very close to the published weight for the T-14.
TTB also, of course, reduced crew to three men and put in an autoloader for ammunition handling. The design was intended to improve crew safety by completely isolating the crew from the ammunition. The autoloader itself was a large carousel, holding all ammunition below the turret ring. Let’s look at some pictures.
It’s sort of like the autoloader on the T-80, though NATO 120mm ammunition is one-piece, and is therefore a little more annoying to design an autoloader for. The autoloader built for the TTB held 44 rounds and this could be expanded to 48 or even 60 rounds with minor design changes. All of the ammo was stored in a ready configuration because the crew would be unable to move ammunition from a reserve magazine to the autoloader’s ready magazine (as on the Leclerc for example). The TTB autoloader was extensively tested, and could manage a rate of fire of one round every 12 seconds. Spent case bases or misfired rounds were ejected out a small hatch the back. The autoloader could be supplied through the rear hatch, and also had an unloading mode where it could slowly present rounds for removal. The autoloader weighed about 1,400 lbs. empty.
Some might question the vulnerability of such a design. However, statistically the vast majority of tank hits occur to the turret. Tanks like the T-72, for example, ran into trouble because of the ignition of their unprotected reserve ammunition stowage in the turret, not hits that set off ammunition in their autoloaders. And again, complete isolation from the ammunition should keep the crew relatively safe.
The TTB program was dialed back with the end of the cold war and was finally cancelled in the mid 90s. The autoloader design was used in the M1128 Mobile Gun System version of the Stryker.
As for the TTB prototype, it’s at the National Armor and Cavalry Museum at Fort Benning, and has recently been restored and repainted.
As mentioned earlier, the US Army is concerned with short range air defense systems again. And they’re looking at various versions of COTS systems to fill this need. We’ve looked at the new Bradley SHORAD vehicle. Now, let’s take a look at one based on the Stryker, called the Stryker Mobile SHORAD Launcher (MSL).
What GLDS has done is cut off the back portion of the regular Stryker to make something flatbedded. Then, they added the turret off of the M1095 Avenger and then Boeing modified that turret.
The M1095 Avenger is a 1980s vintage SHORAD system that put a pair of quadruple Stinger launchers on a turret, and mounted the turret on the back of a HMMWV. Putting the turret on the back of a Stryker gives the turret better all-terrain capability, as it matches the mobility of the rest of a Stryker Brigade Combat Team. Crew protection should also be better. On the other hand, it will be more expensive.
Like on the Bradley SHORAD, the newer Avenger turret is more versatile. Options for each side include the regular quadruple Stinger box, a set of launch rails to accommodate four Hellfire missiles, or a set of launch rails to accommodate three AIM-9X Sidewinders. It also has an improved IR imaging system, which has a laser to guide the Hellfire missiles.
As before, there’s no radar. Both of these launch systems will need some degree of external cueing. A lack of radar does keep the cost down. Depending on expected threats and usage, this may or may not be a severe handicap.
One further usage is on the HMMWV successor, the JLTV. You can still mount this newer, multiuse Avenger turret on light tactical trucks like the JLTV, as seen here at the AUSA expo:
This version has an M230 LF gun instead of one of the missile boxes.