Tag Archives: militariana

Engineering Tradeoff Q&A: Puma and Bradley

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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:

M2A2 storage space

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.

M2A5 Bradley Proposals

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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.

Hull Changes
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.

Turret Changes
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.

  1. Finally. Wish they’d finally designate an M1A3 Abrams… ↩
  2. 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. ↩
  3. Or a derivative of the Mk. 44, like the M813 on the Stryker Dragoon. ↩
  4. 25x137mm Depleted Uranium APFSDS is roughly equivalent to 30x173mm APFSDS, so some well-made DU rounds should give yet more punch to the 30x173mm. ↩

Handicapping the FFG(X) Contenders

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Big Navy announced the finalists for the FFG(X) program a few days ago. Let’s have a look.

In the interest of spicing things up a bit, I’ve assigned some moneyline odds to each competitor.

FFG(X): buying 2012’s frigate in 2020

The Navy ended up a little behind the eight ball after its insistence on buying the all-but-useless Littoral Combat Ship, which we’ve trashed on several occasions1. Rather than build a frigate as the Perry class was running out of lifespan, they built a weird fast corvette with no striking power and found themselves paying $700 million a pop for effectively useless ships.

FFG(X) is a stopgap measure to take care of the actual business of naval combat while the LCS contractors get their collective acts together, in which the Navy will spend $20 billion to buy twenty actual, effective combat ships.

LCS variants: Less Crappy Ships

The two contractors for the LCS have each assembled a bid using their LCS as a base for a real fighting ship. Both have unrefueled ranges of less than 4,500 nautical miles.

Austal Frigate: -300

Austal’s entry is based off of their trimaran Independence-class, a design I like aesthetically and for a few practical reasons (that giant flight deck among them). The Austal Frigate cuts a few feet off of the flight deck to add a stern platform to hold twin- or quad-pack Harpoon launchers (or other SSM launchers), as well as a towed sonar. Earlier Austal Frigate proposals put the VLS in the superstructure, on either side of the main mast, but someone must have realized what a terrible idea that was in practice; in the final proposal, one VLS 8-pack is forward of the superstructure, and one is at the aft end of the flight deck.

I was going to gripe about how 16 VLS cells seemed a little light, but it appears that’s the fit most of these frigates have, sadly. At least the ESSM can be quad-packed; 32 ESSM and 8 fancy Standard Missiles is an acceptable combat load, I guess.

Freedom Frigate: -400

The Freedom Frigate is the LockMart-brand LCS frigate, with very little to differentiate it from the Austal Frigate beyond its more conventional design. Same armament: 16 Mk. 41 VLS cells and a gun. Similar aviation capacity, although it has a smaller hangar. (Both only ship one MH-60 in normal circumstances, though.) I think the basic Freedom-class has less to recommend it than the basic Independence-class, which is why I give them a lesser chance here.

Not-invented-here options

Various European navies have interesting frigate choices. Two of them made it to the final round.

FREMM: -1000

As much as I like the FREMM, I don’t think it’s a very likely choice for the US Navy. The VLS system is wrong, and I have no idea how easy it is to plug a Mk. 41 system into the Sylver A43 hole in the FREMMs.

Too, it also depends on the FREMM version. The French FREMM is well-kitted for anti-air and anti-surface-unit warfare, with 32 VLS cells in all, Exocet launchers, and even support for land-attack missiles in the larger 16 VLS cells. It only has one helicopter, and only the anti-submarine versions carry a towed sonar.

The Italian FREMM has a faster cruise speed, a faster top speed, two helicopters, an improved radar, two guns, and (in the anti-submarine fit) anti-submarine missiles, but it has fewer cruise missiles and is only fit with 16 Sylver A43 VLS cells.

Both have long range, north of 6,000 nautical miles. Both are expensive, between 600 and 700 million euro per unit.

Keeping in mind the various incompatibilities which would have to be addressed, and the fact that the ship is built by ‘Fincantieri Marine Group’ no matter how much they claim they’re from Wisconsin, I think the FREMM is one of the less likely options.

F100: -450

The F100/Álvaro de Bazán class of Spanish frigates came as a bit of a surprise to me; I hadn’t heard much about them, but clearly I should have been paying closer attention.

The F100 is an Aegis frigate. Yes, you heard me right; besides the related Fridtjof Nansen class, they’re the only frigate-size ships to carry the Aegis setup. Fittingly, the Spaniards did not skimp on missiles. The F100 carries a full 48 cells of Mk. 41 VLS, for a standard combat load of 64 ESSMs and 32 SM-2s.

Its anti-ship capability is a bit more suspect, at only eight Harpoons, but those are in deck launchers and easily retrofit should the Navy come up with an actual decent sea attack missile.

It carries decent anti-submarine weapons and a torpedo decoy, along with a single helicopter, but does presently lack a towed array, a missing feature which could come back to haunt General Dynamics. I don’t know if it would be an easy retrofit, but it’s certainly something the Navy would want addressed.

Beyond that, though, the F100 strikes me as the blindingly obvious choice from the final competitors. There’s zero reason to complain about its anti-air fit, and its anti-ship fit is no worse than most of the other competitors. (Eight Harpoons seems to be enough for the Navy.) A helicopter is more important for modern anti-submarine warfare than a towed array, and one presumes that the F100 could probably ship one if it comes to that, given that a variable depth sonar and a towed array are on the requirements list and General Dynamics still entered the F100. It has 4,500 nautical miles of range, and doesn’t cost any more than the other options on the list.

Why do I not make it the favorite among the options, then? Because the Navy has already plowed a ton of money into the LCS, so they aren’t canceling it, and if they buy a non-LCS-based frigate, then they have to pay both to buy the new frigate and eventually turn the LCS into one. I expect political concerns to hamper the European designs, despite the fact that both the F100 and the FREMM are objectively better in every useful dimension than either LCS or LCS frigate conversion.

The Coast Guard rides again

But wait! There’s a dark horse contender.

Legend-class/National Security Cutter: -2500

While the Legend-class cutters are the right size, have superb range (it’s reduced to 8,000 nautical miles for the bid), and, as Coast Guard cutters, have tons of internal room for weapons and whatnot, selecting a cutter as a base for a frigate design would require the Navy not only to admit the Coast Guard exists, but also to admit that the Coast Guard built a better ship than they did. Not going to happen.

Program canceled or delayed beyond the point of usefulness: +250

I’m not a pessimist by nature, but this really does seem like the most likely outcome to me.

  1. It’s one of our favorite punching bags. If we’re missing a segment for the podcast, I’ve been known to say, “Have we beaten up on the LCS lately?” ↩

What’s In a Bradley?

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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.

  1. 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) ↩
  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. ↩
  3. 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. ↩

What Does a Puma Carry?

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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.

Resurrected Weapons: XM307

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Here’s yet another attempt to replace the Mk. 19 GPMG and/or the venerable M2 HMG. The XM307 was part of the same program that gave us the XM29 OICW, and later the XM25 once the OICW failed. The program itself emerged from a 1980s study saying that weapons development had reached a plateau, and that the next breakthrough would come with the integration of airburst-fused high explosives into the US Army’s weapons. They had tried to schedule a breakthrough in the late 1960s with SPIW. They failed. Now, a new generation of engineers would try their hand.

The XM307, or Advanced Crew Served Weapon (ACSW), had the same airburst principles as the XM25 and XM29. The gunner would use an integrated fire control system to get the range to target with a laser rangefinder, set an airburst distance, and then shoot rounds at the target. Except now with automatic fire. Let’s look at a quick size comparison chart:

XM307M2Mk. 19
length52.2″65.1″43.1″
barrel length25.1″45.0″16.25″
weight50 lbs.83.78 lbs.77.6 lbs.

It’s definitely lighter. Plus, it’ll bring a flatter trajectory than the 40mm grenades of the Mk. 19, so it should be easier to score hits with. Those are pluses. And, the M2 doesn’t pack an explosive punch. All good things so far for the XM307. So let’s talk lethality.

From autocannons, we know that autocannon ammunition makers don’t think a 25mm autocannon shell holds enough explosives to make an airburst fuse option worthwhile. We know there are lots of deployed 25mm systems, so there’s plenty of incentive to try. Big market, but nobody’s bothered. This isn’t a perfect comparison, of course. Sizes may vary, but if there’s a difference, the autocannon has the bigger projectile. A 40mm Bofors fires a much bigger round than the 40mm Mk. 19. Still, it’s cause for concern.

More concern comes from the test deployment of the XM25. In Afghanistan, while there are plenty of accounts of airburst rounds scaring Taliban fighters away, there are no accounts of it actually killing anyone. And this should be its best chance for success: taliban fighters don’t wear any kind of protective gear. None. If it can’t get kills there, what about when it encounters troops wearing actual modern armor? At least the Mk. 19 has a long history of being effective against unarmored opponents. It starts somewhere. Also note that lots of comparisons with 40mm grenades make a comparison between 25mm Airburst HE-Frag and 40mm HEDP, which is going to be less effective in the pure-antipersonnel role than 40mm HE/HE-Frag.

Now, the XM307 has automatic fire capability, and a belt feed, unlike the XM25. We’re not limited to a one round for one round comparison, which means we’re going to get into “stowed kills” type computations. Clearly, the XM307 holds more grenades in a box than the Mk. 19, so we can try to come up with some notion of relative effectiveness. Or we could, if we had a lot of ammo and a proving ground. Unfortunately I don’t, and I don’t know if the US Army tried this computation. The XM307 was cancelled in 2007.

Another obvious option is to integrate the airburst fusing and targeting system into existing 40x53mm grenade systems. So you’d still have the option of using existing grenades that work, plus you wouldn’t have to develop an entirely new round and ammo system. Someone at DoD actually thought of this, and the Mk. 47 was born. It’s lighter than the Mk. 19, fires the same 40x53mm grenades, and is equipped with a targeting system to set the fuses of airburst grenades. In US Service, that would be the Mk. 285. It’s in limited use in the US Military, and has seen export success with Israel and Australia. So let’s go with that, because it’s way less cost and risk.

Verdict: Funding Denied by the Borgundy War Department Ordnance Procurement Board

Resurrected Weapons: The LWMMG

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Around 2010, General Dynamics independently1 developed what they called the Lightweight Medium Machine Gun. This weapon was designed to fill the “capability gap” between the M240/MAG-58 GPMG, chambered for 7.62x51mm and the M2 Heavy machine gun, chambered for 12.7x99mm. The idea was to be able to “overmatch” enemy PKMs in a weapon that was still man-portable like an M240.

The cartridge chosen was the .338 Norma Magnum2. This cartridge was designed to fire the excellent 300 grain HPBT .338 projectiles from rifles that had actions too short to accept the .338 Lapua Magnum cartridge. It was chosen for this application for its excellent ballistic performance at range, to really allow the LWMMG to stretch it’s legs.

Clearly, the .338 Norma Magnum has a lot more recoil energy than the 7.62x51mm round used in the M240. But General Dynamics wanted to maintain portability, and their goal was to maintain the “footprint” of the M240. So it couldn’t be too much heavier or larger. To accomplish this, General Dynamics used the same recoil system they had developed for the XM806. Having the barrel, gas system, and bolt recoil together meant they could distribute recoil forces easier, and not have to use as much weapon mass to do so. The LWMMG ended up being able to use the same tripods as the M240, and is three pounds lighter than the US Army standard M240B. Later versions of the LWMMG cut two more pounds off the weight.

The US Military opted not to procure the weapon, and I don’t really blame them. While the weapon is about the same weight as the current GPMG, the ammo is heavier, round-for-round. And, frankly, the extra range over 7.62×51 is usually wasted, because of line of sight considerations or target discrimination considerations. If you are in PKM range, he is in M240 range. Or range of vehicle weapons. Or mortar range. There are lots of other ways to deal with that sort of opponent. And you’d be adding another round type and spares type to the logistics trail. The use of other weapon systems is an even better idea if the enemy comes with modern body armor.

Let’s get some numbers on the ammo weight side, since this ends up being pretty significant. We’ll look at the weight of 100 linked rounds of 7.62×51, .338 Norma Magnum, and .50 BMG. 100 rounds isn’t a basic load, but it’s a nice round number to work with. Your basic load/vehicle load will probably be some multiple of that.

  • 7.62x51mm NATO — 6.625 lbs.
  • .338 Norma Magnum — 12 lbs.
  • 12.7x99mm BMG — 29 lbs.

Can it replace other weapons? I wouldn’t use it to replace existing 7.62x51mm GPMGs, because of ammo considerations and because that range is really not needed in general. It’s wasted on the regular infantry and the training and optics available to them, plus it’s almost twice as heavy. The .338 Norma Magnum round is also entirely too powerful for a semiautomatic or select-fire Marksman’s rifle, so 7.62x51mm would stay in the inventory. The LWMMG also isn’t going to replace the M2, because you’re giving up some range and a lot of soft target terminal performance with the smaller, lighter round. To be fair, General Dynamics never proposed it as such. It’s a marvelous technical solution in search of a problem. Cool, but I’d rather spend the money on other things.

Verdict: Funding Denied by the Borgundy War Department Army Ordnance Board

  1. I.e. without a solicitation or RFP from the DoD ↩
  2. Not to be confused with .338 Lapua Magnum, which is a bit longer. ↩

Red Flag 18-1 Kickoff

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It is on like Donkey Kong.

This year’s first iteration of the USAF’s aerial war games, Red Flag, kicks off today. There will be day and night exercises. There will be tons of the best simulated combat we can set up. Two things make this year’s Red Flag a little different than most.

First, the guest list. Red Flag is always an invitation only affair. For this one, it’s Diamond Super Platinum members only. Which means Australia and the UK, in addition to America. That’s it. Nobody else.

Pretty hardcore, right? You may be wondering why. There’s likely going to be some testing of sensitive capabilities. Also, let’s look at some interesting notifications for aircraft operating in Los Angeles Center airspace and flying in and out of airports in the Las Vegas area.

Arrivals and departures from airports within the Las Vegas area may be issued non-Rnav re-routes with the possibility of increased traffic disruption near LAS requiring airborne re-routes to the south and east of the affected area. Aircraft operating in Los Angeles (ZLA) center airspace may experience navigational disruption, including suspension of Descend-via and Climb-via procedures. Non-Rnav SIDs and STARs may be issued within ZLA airspace in the event of increased navigational disruption. Crews should expect the possibility of airborne mile-in-trail and departure mile-in-trail traffic management initiatives.

Huh.

Among other things, the US DoD is cranking up a bunch of high powered GPS jammers in the Nevada Test and Training Range, and this might interfere with nearby civilian traffic. Consider yourself warned.

It’s about time we did some training in a no-GPS environment. See how we cope and develop TTPs. That’s what Red Flag is for.

Resurrected Weapons: XM806 Heavy Machine Gun

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The Browning M2 is nearly 100 years old, and it is still a very effective weapon. It is heavy and made with decidedly old-school manufacturing techniques. The XM806 was an effort to replace it with a newer, lighter machine gun, still chambered for the classic 12.7×99 mm BMG round. The XM806 was a development of the cancelled XM312, which was a prospective heavy machine gun that could be easily converted to fire 25×59 mm airburst grenades.

The XM806 preserved the recoil system of the XM312 (and its grenade launching sibling, the XM307). This system had the barrel and bolt move forward when the trigger is depressed, forcing recoil forces to overcome the forward momentum of both the bolt and barrel.

The XM806 weighs only 40 lbs (18 kg), less than half the weight of the M2. It has less recoil than the M2, and it’s also easier to disassemble. On the other side, it has about half the rate of fire of the M2. For present uses, a reduced rate of fire probably isn’t a huge deal. We’re long past the days of expecting a heavy machine gun to be an effective antiaircraft gun.

While the weight savings are eye-popping, one might question the point. 40 lbs is still too heavy to easily manpack, and the weapon is still very bulky. And 12.7mm BMG ammo is big and heavy. It’s going to be a bother for a team of light infantry to deploy, and they’re probably going to be better off with GPMGs supplemented by antitank weapons, not least because of the weight of the ammo. As for vehicles, the difference between 40 and 84 lbs is basically immaterial. We can mount M2s on dune buggies. We can mount M2s on aircraft and helicopters. The weight savings really don’t get us much in terms of more usability in the roles that we normally find ourselves using a heavy machine gun. And (again) we still have the weight and bulk of ammo to deal with either way, which is a much more significant issue for small vehicles.

Probably a depressing way to look at it. But the biggest thing here would be cost, and it’s really hard to compete with an established system. When the US Army cancelled the project, they diverted funds into improving the venerable M2, and I can’t fault them for it. At least the XM312 added a new capability.

Verdict: Funding Denied by the Borgundy Army Ordnance Development Board.