Fishbreath and I often like to laugh at the Russians and the goofy naming conventions that they have for things that have been produced a lot, like the T-55, the T-72, or the Su-27. That said, they’re not the only ones to do it, and the naming schemes for my favorite tank, the M1 Abrams, are particularly annoying. Here they are, in order (ish) of when they were first made.
1. There were two rather different prospective designs for the M1, one made by GM and one made by Chrysler. Both designated XM1 for the trials to see which was best. Figuring which XM1 is which is an exercise left to the reader, who will no doubt find it enlightening. 2. IP for ImProved. 3. -HA for Heavy Armor, i.e. it’s got first generation depleted uranium armor. 4. M1A1HA subsequently upgraded with second generation depleted uranium armor. Unofficial, but included for completeness. 5. -HC for Heavy Common, i.e. made with second generation depleted uranium armor. 6. -D for Digital. An M1A1HC upgraded with electronics to the M1A2 standard. No factory reconditioning is expressed or implied by this designation. 7. AIM for Abrams Integrated Management. Earlier model factory reconditioned to be like-new, and then a whole bunch of electronics are added. 8. As -A1AIM v.1, but also upgraded with third generation depleted uranium armor. 9. -SA for Situational Awareness. As -A1AIM v.2, but with a confusing new name. See -A1AIM v.2. 10. -FEP for Firepower Enhancement package. As -A1SA, but for the USMC. See -A1SA. 11. -KVT for Krasnovian Variant Tank. M1A1 modified to look like Soviet tank for training purposes. 12. Export variant for Iraq. Because they got their butt kicked twice by Abrams tanks, so they figured they might as well buy some. 13. SA for Special Armor. Export variant for Morocco. Not to be confused with the other M1A1SA. 14. -SEP for System Enhancement Package. Adds third generation depleted uranium armor and some improved electrical systems. 15. Even better electrics. 16. TUSK for Tank Urban Survival Kit. Makes the tank better suited for urban warfare. Technically, may be applied to any variant. Usually seen applied to A2, A2SEP, and A2SEP v.2s. 17. TUSK II has better supplemental armor than TUSK. 18. Tank Test Bed. M1 variant used for a bunch of late 80s experiments. 19. Component Advanced Technology Test Bed. A more-radical, experimental, late-80s tank. 20. The Grizzly Combat Mobility Vehicle. No, I can’t use the name again because that’s not the designation. I didn’t write “Abrams” after every designation up there, did I? 21. Wolverine assault bridge. 22. Panther II Mine Clearing Blade/Roller System. 23. The Assault Breacher Vehicle25. 24. Armored Recovery Vehicle. No, roles do not count as part of the designation, or else I would have written “MBT” after a whole bunch of things up there. 25. What’s the difference between Combat Mobility Vehicle and Assault Breacher Vehicle? No idea.
Because I’m much too lazy to make and link comment threads reliably, comments are now open by default on new posts. (We still reserve the right to close comments on certain posts for which ‘blog comment thread’ is the wrong venue for a productive conversation, but really, we mostly talk about procurement stuff right now, and on that topic, we already disagree pretty diametrically.)
Hopefully you’re more guilty now to leave a post uncommented. 😛
My last tafl post was deeply theoretical. Very shortly, this one is going to take a turn for the deeply practical. First off, though, there’s some theory housekeeping I need to handle. Because the Copenhagen and Fetlar variants are both difficult AI problems, and because Copenhagen has some additional rules which are computationally hard to check, I decided to start with brandub, a much simpler tafl variant. Brandub comes from Ireland, and is played on a 7×7 board. The king’s side has five pieces, and the besieging side has eight, arranged in a cross. The king participates in captures, and is captured by two besieging pieces instead of four. He escapes to the corners. Any piece may cross the center square, but only the king stops on it.
Computationally, brandub is in a much easier class than the 11×11 variants I’ve discussed. The upper bound on its state space complexity is a mere 4.4 x 1015, using the estimation technique I described in the previous post; for comparison, checkers1 is on the order of 1020. Its game tree complexity is at least 1.3 x 1036, which is also not overwhelmingly distant from checkers’ complexity (though harder—tafl’s state space complexity is frequently lower than comparable games, but its game tree complexity is frequently higher). This makes it a good place to start—for one, it means that it doesn’t matter how slow my code runs.
So, to kick things off, I started with what the business calls GOFAI—good old fashioned AI—techniques. The simple version is this: you play every possible move from your current position to a few moves out, and pick the best outcome. It ends up being a little more complex than that, though. If you’re not curious, you can skip the next few paragraphs.
The particular GOFAI technique I’m using right now is a straight implementation of the minimax algorithm. After generating a game tree from the current state to a given search depth, the algorithm evaluates the tree’s leaf nodes. An evaluation is a single number, describing whether the state is good for the besieging side (nearer positive infinity) or good for the defending side (nearer negative infinity). The details aren’t important just yet, although I’ll get into them later. Anyway, the algorithm is predicated on the assumption that both players are perfect—they’ll always make the best move they can make, given the situation. It follows, therefore, that the best move at a certain depth is the one which leads to the best state for him: the most negative for the defender, the most positive for the besieger.
As an example, with the besieger to move and a search depth of three, there are four levels to the tree2:
1. A position with the besieger to move. 2. All of the positions, defender to move, resulting from every one of the besieger’s possible moves. 3. All of the positions, besieger to move, resulting from the defender’s possible responses to those moves. 4. All of the positions, defender to move, resulting from the besieger’s responses to the defender’s responses.
The algorithm starts at the tree’s leaves, the nodes at the fourth level above, and runs the evaluation function. It then moves up a level. The besieger is to move, and all of his possible moves have a child state which has an evaluation attached to them. The besieger picks the move which yields the best outcome for him, which is also the worst outcome for the defender. (Although the tafl board is asymmetric, the game, in the theoretical sense, is not—a good state for the defending side is a bad state for the besieging side, and vice versa.) The value of each node at the third level becomes the value of its best child (for the besieger). The algorithm then moves up to the second level. The defender is to move, and he has a set of moves and child states with evaluations attached, as we just derived. He picks the best outcome for himself, which is also the worst outcome for the besieger. The value of each node at the second level becomes the value of its best child (for the defender). The algorithm then moves up a level, and, at the first level, the besieger has a list of moves and child states with evaluations attached to them. He chooses the best move out of his options, and that’s the move he makes.
As you might have guessed, if you had a computer of infinite power, you could just explore the game tree until you found a win, loss, or draw for every sequence of moves from your starting state. In fact, we call games for which this is possible3solved. The evaluation function for an infinitely powerful computer is extremely simple:
1. Has the besieger won in this state? Return positive infinity. 2. Has the defender won in this state? Return negative infinity. 3. Has neither of the above happened? Return zero. 4. Ignore draws for the purposes of this example, or declare them a win for one side, or something.
The algorithm will explore until every branch reaches an end state, then work its way up through the tree. Since it assumes perfect play, it will provide a sequence of moves which yields a victory for one side from the current position, and there’s nothing the other side can do about it—the whole game becomes inevitable. Perhaps fortunately, this is extremely hard for most games; tic-tac-toe is somewhat less thrilling now that it’s solved.
It also reveals a weakness in, or at least a caveat with, the minimax algorithm: since we do not have computers of infinite power (in fact, my current implementation is able to look ahead only one ply further than the example I gave above), its playing ability depends either on achieving deep lookahead to compete with humans, who can look ahead much more selectively than computers can, or on having a good evaluation function. I haven’t really attained either goal yet.
I see that I’ve already written about a thousand words, and I haven’t even made it out of the first point on my supposed outline for this post. I suppose I’ll just have to write a couple of ’em. Next time I’ll get into the practical considerations in implementing an AI algorithm like this. Probably the time after that, I’ll write about evaluation functions, and perhaps after that I’ll write about some improved algorithms. The latter requires that I actually implement them, though, so we’ll see how the timing works out.
1. 8×8 draughts, if you aren’t an American. 2. The term of art is ‘plies’, singular ‘ply’—since a response to a move is called a reply, clearly a single move must just be a ply. (Math and computer people, am I right?) 3. Wikipedia has some interesting reading on what it actually means for a game to be solved—the definition I’ve given is what’s referred to as a ‘strong’ solution, where a computer has brute-forced the entire game tree. There are two other kinds of solved games: those solved ‘ultra-weakly’, which is to say, by abstract mathematical reasoning, and those solved ‘weakly’, by some algorithm which does not explore the entire tree.
This is Pacific War, a 1992 release by Gary Grigsby. I’ll come back to that.
I’m on something of a Pacific Theater kick, for an unusual reason: over at the Something Awful LP Archive, I’ve been reading an AAR by a guy called Grey Hunter. The game is War in the Pacific: Admiral’s Edition, the Grigsby/Matrix magnum opus, covering the whole war in excruciating detail. It’s the kind of thing I would love, if I wanted to drop the $80 on the price of entry, and the several hundred hours it would take me to actually get through the war. Fortunately, I can read the 1,320 entries in Grey Hunter’s AAR much more quickly than I can play the game myself, and so get a feel for the flow of things more than the day-to-day minutiae of supplying the twelve-man garrison on Rarotonga. I’ll come back to that.
One of my favorite wargames, as you’ll know if you follow Many Words Main in the slightest, is the Command Ops series. Its conceit is that, as the player, you have to deal with all the handicaps real field commanders had to deal with. Your orders have to percolate down to your subordinate commanders, and hours pass as they dawdle (from your perspective) to plan a simple attack on a defensive position. You tear out your hair, watching the map as they miss the enemy battalion just behind the hill and happily claim success after wiping out a poor company of engineers. You celebrate your own cunning when your men just finish setting up when an enemy attack lands. It is, as the title says, a compelling wargame. But what does that mean, really? ‘Compelling’ is one of those review words1 that doesn’t mean anything absent a better definition. Let me explain what I’m trying to convey.
Ian W. Toll, one of my favorite naval historians2, wrote a book about the first six months of the Pacific War. I’ve always regarded Toll’s biggest talent as immersion. He writes vividly, with a knack for putting the reader into the mind of the people who were there. Near the beginning, he quotes Chester Nimitz, on his experience in the first few months of the war: “From the time the Japanese dropped those bombs on December 7th until at least two months later, hardly a day passed that the situation did not get more chaotic and confused and appear more hopeless.” That gets at the crux of it, I think. I’m still in the first few turns (weeks) of my game of Pacific War, and I don’t think I’ve ever felt more despairing while playing a game. The deck is stacked so heavily against the Allies in the opening weeks: the Japanese are everywhere, and you categorically lack the planes, men, and ships to do anything about it. It has a very strong sense of place, and that is compelling. Command Ops has it, too: in the AARs in the archives at Many Words Main where I follow along in a history book, I find myself worrying about the same sorts of things as commanders on the field did. I find myself feeling exactly how CINCPAC Nimitz did.
I mentioned I’d be coming back to War in the Pacific. As I hinted, I don’t own the game, and I’ve never tried it. It’s possible I might find it compelling in the same way, but reading through Grey Hunter’s AAR, I think it’s not a settled thing by any means. In the course of spending forty-five minutes to an hour working through a single day, I think I might lose sight of the bigger picture, and games about the Pacific War are ultimately games about an entire theater. The sense of place flows out of watching the long arc of progress, and at a certain scale, that’s hard.
So, for me, compelling wargames capture a sense of place. That doesn’t preclude them from being grognardy, but it does preclude them from swamping the feel with detail. Pacific War is just about right, I think—accurate enough to yield plausible results, broad enough in scope to engender the emotional investment I crave.
Pacific War is freeware, courtesy of Matrix Games. You can find it at their website, or at my mirror.
While Borgundy agrees with the Russian view that the best weapon to combat a tank is another tank, and combined arms with plenty of tank-infantry cooperation are the keys to success, this does not mean that the infantry should not have weapons for killing tanks. It’s all the more important since most modern western IFVs don’t mount anti-tank missiles. While Fishbreath’s challenge isn’t strictly accurate structure-wise for mechanized infantry, the general point holds. We’ll need two weapons: a man portable anti-tank guided missile (henceforth ATGM), and something unguided that can defeat tanks up close with the secondary purpose of battlefield demolition. We can’t really do away with the rocket launcher requirement, because the rounds are cheap and useful for blowing up bunkers and the like, plus if a tank gets in close, they don’t require any guidance preparation. Guidance is clearly required for longer-range shots.
We’ll start with the relatively simple unguided case. With a general trend towards western suppliers, and the unfortunate demise of much of the French arms industry, our choices are rather limited. We first must answer a simple question: how much tank should we be able to kill with a rocket? Requiring penetration of heavy front armor, with likely ERA kits will drive up the weight (also the cost, but not by much–these are unguided weapons after all). The Panzerfaust 3T is probably the most powerful available rocket, should be reasonably capable of dealing with most modern frontal armor, even if ERA equipped, and comes with a computerized sight to aid in making long range shots. However, it weighs 33.5 lbs (15.2 kg). If we accept side penetration only, we have choices. The standard one-use only rocket is the Saab AT4, which weighs 14.8 lbs. Alternatively, for a somewhat heavier (20 lbs or so) reusable weapon, we could go with the Carl Gustav with it’s wide variety of available rounds. That said, we do really want the properly tank-killing potential of the Panzerfaust 3T. Since our army is heavily mechanized, we have an infantry fighting vehicle to help carry the load most of the time. We also have the IFVs gun, which provides a useful volume of high explosive support. However, the 35mm Bushmaster III chain gun on our IFVs isn’t really capable of killing tanks from the front, but it is reasonably capable of engaging them from the side. The Panzerfaust 3T at least adds an additional capability to the squad. Plus, there are large stocks of T-72 and T-80 tanks that could be pressed into service that can shrug off frontal hits from either AT4s or Charlie Gustav rounds.
On to the guided weapons. This is a little harder, because there are lots of similar systems available. First, taking stock of the threat, we should look at enemy armor. Again, we see the same problem as before of getting stuck in the race between armor and shaped charge warheads, made worse by the range requirements. For this reason, some modern missiles have attempted to get around the problem by attacking the top armor, which is thinner. The Milan missile doesn’t use top attack at all, but it’s basically obsolescent. Other missiles have better range, tank-killing power, and fire-and-forget options. The heavy hitters in the competition are the Israeli Spike and the American Javelin, both of which have better guidance and bigger warheads than the Swedish BILL 2, which uses an overflight top-attack rather than a diving top attack flight profile. Javelin and Spike are similar missiles at similar price points, but the Spike has a longer-range man-portable version, and it has the option to keep the gunner in the loop with a fiber optic cable. Javelin can only do a fire and forget launch mode, but it has a better seeker, and both the Javelin missile itself and it’s reusable command launch unit are lighter. Cost is roughly comparable. We’ll take lighter and more effective within the range that ATGM shots are likely to be taken, so we’ll take the Javelin.
So, that should settle the challenge. That said, given our heavy and heavier options above and recent experiences in Iraq, there’s a need for a light rocket for demolition work, especially in urban settings and for bunker busting. It is also a useful squad capability, as it can be used to maximize shock effects in the initial moments of contact. For these uses, we want something light and cheap. Issues of carrying capacity can be handily resolved by our IFV, because it can carry what isn’t needed. This can be considered a bit of an “arms room” for the squad, provided we don’t go too overboard. For weapon choice, we can actually go even lighter than the AT4 with the older, Vietnam-era M72A7 LAW. It’s rated for about a third of the armor penetration of the Panzerfaust 3, but it only weighs five and a half pounds. It’s a perfectly adequate demolition rocket, and the light weight means it’s easy to add to the squad’s loadout even when there are no tanks around. It’s not a fancy warhead, but it’s cheap, light, and cheerful, and compliments the big panzerfaust 3 well. Plus, lest you think I’m cheating by buying more types of weapons than originally called for, the US army still buys old M72A7 LAWs plus the newer, more formidable AT4s, and Javelin missiles. And the Germans supplement their Panzerfaust 3 with Matador rockets.
One of the most basic ways to describe the computational complexity of a game is its state space complexity—that is, the number of unique positions possible for a game—and that’s where I’ve started in my analysis of computer tafl. For now, and probably for every post I write on tafl and mathematics, I’m going to stick with Fetlar rules tafl or Copenhagen rules tafl1, on an 11×11 board.
To start off, we can make an extremely, extremely rough estimate. The board has 121 spaces, and each space can be empty, occupied by a besieger, occupied by a defender, or occupied by the king, so to get an absolute upper bound, we can just do this:
7 x 1072 is surprisingly close to the rough estimate for chess (1.9 x 1071; chess has thirteen states per space and 64 spaces). We know the actual state space complexity of chess to be in the vicinity of 1047, however, so we can clearly do better. And, if you think about it, we’re not even trying all that hard. Our current estimate permits some flagrantly illegal positions, like a board entirely filled with kings, or the board with no taflmen.
There are plenty of obvious constraints we can use to tighten up our guess. For one, any reachable tafl position has to have at least three taflmen: one side must have two taflmen, to have captured the second-to-last piece from the other side, and the other side must have at least one taflman left, or else the game is over. For another, there are only 37 taflmen to place.
An intermediate question presents itself: in how many different ways can three to 37 taflmen be placed on 121 spaces? Well, that’s a question for combinatorics. For any number n of taflmen, the number of unique arrangements of those taflmen into 121 spaces is:
And, since I’m a programmer, and loops come naturally to me…
So, we have 3 x 1031 ways to arrange our taflmen onto our board. Going forward, I’ll multiply it by one quarter2, although it hardly matters at this scale3. This picture is also incomplete—it’s not an upper bound, because it doesn’t account for taflmen belonging to the besieging or defending sides. For every arrangement of n taflmen on the board, there are a bunch of distributions of the taflmen between the besieging and defending sides, and a bunch of options for the position of the king within the defending side.
So, since I am still a programmer, time to break out the nested sums. For every number of taflmen i between three and 37, consider the distribution of taflmen between the sides. For valid positions, let k be the number of pieces on the defending side, between one and i – 1. We need only consider one side. From a logic perspective, it’s obvious why: answering the question, “How many ways are there to assign k taflmen to the defending side?” contains in its answer the answer to the question, “How many ways are there to assign i – k taflmen to the besieging side?” Since the two sides exist on the same board, the number of defending positions is the number of attacking positions. (There’s a mathematical argument in a footnote4, if you don’t buy this.)
Anyway, that insight gets us most of the way there. We have one more thing to account for: the position of the king. One of the defending taflmen must be the king for this position to be valid, and the king is distinct from every other defending taflman. Any one of the k defending taflmen could be the king: that is, there are always exactly k distinct arrangements of the defending taflmen for any distribution of taflmen between the sides, so we multiply the two numbers together.
There we have it: the number of possible arrangements of taflmen on the board for every valid number of taflmen, multiplied by the number of ways to split a certain number i of taflmen between each side, is a much better bound on the number of possible positions. It’s still not perfect: mainly, this model permits some positions where pieces have illegally stopped on restricted spaces, and I’m probably missing some other things, too, but it’s a close enough bound to make an interesting point.
11×11 tafl games have an upper bound on state space complexity on the order of 1043. Chess, as I mentioned earlier, has a state space complexity on the order of 1047. This might seem like evidence against my theory that tafl games are more computationally complex than chess, but I’m still convinced. Ultimately, state space complexity is a poor measurement of computational difficulty. Consider backgammon: its state space complexity is on the order of 1020, but backgammon AI is a more difficult problem than chess AI.
There is another metric to introduce: that of game tree complexity. State space complexity measures the number of possible positions for a given game. Game tree complexity measures, in a sense, the number of ways to get there. Consider a tree of every possible game of tafl. You start, obviously, with the starting position, then create a leaf node for every possible move by the defending player. At each of those leaves, create leaf nodes for every possible response for the defending player, and so on until every possible combination of moves has resulted in a game-ending state. (We’ll assume there are no ways for games to go on forever.) The number of leaves at the bottom of the tree is the game state complexity.
This number, Wikipedia remarks in its typical laconic style, is “hard even to estimate.” This is true. Wikipedia also remarks that a reasonable lower bound can be established by raising the branching factor, the average number of moves possible at any given step, to the power of the game length in plies (that is, one player moving once). This is where things start to get interesting.
The accepted figure for chess’s branching factor is 35. From the starting position, each player can make 20 distinct moves. (Pawns forward one or two squares, or knights to the inside or outside.) Chess games last, on average, about 40 turns, or 80 plies. The game tree complexity of chess is at least 10123. Backgammon’s branching factor is 250, and its average game length is about 60 plies, so its game tree complexity is at least 10144.
I don’t have a figure for tafl’s branching factor. Aage Nielsen’s tafl site has a tournament running right now, using the Copenhagen tafl rules. Once it’s finished, I’ll look at some positions from the midgame and the endgame and try to work out a good average. In the interests of providing a number, I tweaked OpenTafl’s debug script to print out a count of the number of possible moves on the opening turn. The besiegers can make 116 moves, and the defenders can make 60, for an average of 88. High-level tafl games seem to go on for about 40 turns or 80 plies, from my observation so far. This yields a lower bound of 10167, which rather blows chess out of the water.
Let me try to contextualize that number. Relatively simple 11×11 tafl games are, as far as I can tell, more computationally difficult than any historical abstract strategy game besides go. Not only that, but larger tafl games (15×15 or 19×19 variants) seem likely to me to be more difficult than go.
If you’re not well-read on the subject of board game artifical intelligences, you may have missed what a crazy thought that is. Go is the benchmark for hard AI problems. Computers were playing chess and backgammon at grandmaster levels by the end of the 1970s. Computers still can’t beat professional go players in even games, and the hard tafl variants are probably harder than that.
This is a seriously cool game.
1. Here are rules for the Fetlar and Copenhagen variants. If you don’t care to read them, here’s the summary: they’re more or less identical for my purposes here, played on an 11×11 board with 12 defenders, one king, and 24 attackers. 2. Think about it: any arrangement of taflmen on the board is functionally identical if you were to rotate the board 90 degrees beneath them in either direction, or 180 degrees. 3. Remember, with scientific notation, 8 x 105 divided by four is 2 x 105. Or, indeed, 8 x 100 divided by four is 2 x 100. 4. Let i be the number of taflmen on the board, k be the number of defending taflmen, and i – k be the number of besieging taflmen. The number of distributions of taflmen for the defenders is:
Therefore, k taflmen have already been accounted for—the besieging side can’t choose them, because they’ve been chosen as defending taflmen. We do not choose from i, we choose besieging taflmen from from i – k, which yields:
When considering the APC, we must consider what we want it to do. We already have IFVs to do the front line combat. We have trucks that can transport lots of stuff or men relatively easily and cheaply. We need something in between. Something to handle supportive combat roles that can take fragments and bomblets better than a truck, but needn’t be hardened against serious gunfire. Something to haul mortars, escort convoys, transport wounded, shuttle soldiers, do light and medium vehicle recovery, and basically do a whole bunch of odd jobs.
The obvious choice would be the M113A3, but this vehicle is quite old and not in production any longer. It’s still almost certainly available on the used market, but it’s somewhat protection limited due to the old powertrain and suspension, and we certainly couldn’t rely on procuring the numbers and spares we want from the secondary market. Plus, it’s almost certainly a violation of the spirit of the rules, and makes for a rather boring post. We certainly won’t be giving up the M113s we have, but onward we go to find something more modern.
We can restrict ourselves to requiring a heavy machine gun in a remote weapon station for self defense and no more. An automatic grenade launcher might be a useful alternative, but the heavy machine gun is, in general, more versatile. In any case, either would fit in a weapon station of that size class. Any larger weapon would have a significantly greater footprint in the vehicle, which would compromise its primary transport duties. We’d either have a 20/25mm “giant machine gun” that would need a ton of ammo or a 30/35mm cannon that would require a coax gun and a second ammo supply. So we’ll stick with the one heavy machine gun for self-defense. Mortar carriers will, self-evidently, carry a mortar. This will probably be 120mm, which is a good standard size, and there’s not much reason to go smaller when you have a nice vehicle to haul the mortar and its ammunition around.
Let’s now come to the “Armored” portion of the vehicle. This is what’s separating it from a big truck carrying stuff around. The current modern standard seems to be protection from heavy machine gun fire all-around, and this seems reasonable considering the sorts of threats that it’s likely to face as a second-line unit. In general, mine protection has also been widely increased as part of the lessons learned in the Iraq campaign. While this is less relevant to those of us planning a conventional warfare first approach, our vehicles might encounter hastily laid mines as well in an effort to disrupt rear areas. Plus, with modern vehicles, there isn’t really an alternative. Increasing use of wheeled vehicles as IFVs has led to a plethora of turreted versions, which we’ll skip, and heavier front armor, which we don’t have much of an option on either.
The two biggest contenders here are the Boxer MRAV and the Patria AMV. The Boxer MRAV is rather more modular, since you can actually swap rear mission modules with a crane. It’s also somewhat better protected than the Patria, and more expensive. The Patria has won significant successes in the export market, and comes with more variants already fielded. MRAV comes out of the box with all of the fancy battle management computers that the cool kids like. It’s the extra systems integration and the basically future mission proof design of the Boxer that lets it win out here. With modules that can be swapped out in a couple of hours, the life of the Boxer can be extended with hull refurbishments and new modules containing new stuff. Even though it’s more expensive than the Patria AMV, it’s still cheaper than the VBCI and the Stryker.
While working on some background research for Fishbreath’s fourth challenge, I discovered two unfortunate things about the Puma IFV. First, while most information I can find claim that it will have the capability to mount and shoot Spike ATGMs, no evidence that this is actually proceeding is available. So we’d likely be stuck paying integration costs. Which brings me to the other, bigger problem: cost. The Puma IFV costs about $11 million or so, and is only in low rate initial production, so more changes could be forthcoming. They’ve already had to redo the suspension by adding a roadwheel and change the armor layout. This is over twice the cost of any competing vehicle.
Unfortunately, we’re already pushing one buy to the legislature of an overbudget supervehicle that we’re expecting to come down in costs. But the Puma doesn’t have the order backlog that the F-35 does, and asking for two from the Legislature is bound for trouble. So it is with heavy heart that we must change our pick of IFV to the CV9035. It does give us a much better gun, two more dismounts, and a proper coax gun for our troubles. Oh, and it’s widely adopted with costs well under control. Congratulations BAE-Hagglunds.
P.S. For those of you expecting a quick resolution to the fourth of Fishbreath’s challenges, you’re going to be disappointed. Finding pricing information is a pain for both of us.
When I set out to work out what sort of small arms I wanted for Borgundy, I decided to start, rather sensibly, with the caliber for my infantry arms. And I was all set to write something full of hate for the 5.56x45mm NATO round and how inadequate and lame it is. But when I thought about the gun-writer orthodoxy, I started coming up with some problems. So let’s go back, and start from where we can all agree on things. Namely, World War II. The greatest of them all. First, we figured out that full-power rifle cartridges (which I’ll call ‘full power cartridges’ from here on, because I’m a lazy typist), have too much recoil energy to be fired from a normal infantry rifle (usually about 9 or 10 lbs). Somewhat satisfactory results could be achieved in the M1918 Browning Automatic Rifle, but that weighed about 24 lbs. Second, we knew that rifle cartridges possess sufficient power (for some definition of power that I’ll leave deliberately vague) to kill a man out to distances of over a kilometer. However, for most soldiers, such hits will never happen. Statistical studies showed that 90% of infantry engagements took place at ranges less than 300 meters. But why should this be? Clearly, sniper exploits would tell us that one can see much further than 300 meters in most parts of the world.
Consider that a rifle bullet will need about one second to reach a distance of 600 meters from the shooter. In that time, a reasonably fit man who is aware that he is being shot at can sprint 5-9 meters, in any direction he pleases. It will probably be from cover to cover, but we could think of this as in some random direction that would certainly be unknown to the shooter. So the chances of hitting the target at such distances are very low, unless the target is unaware or you can fill the area with bullets with your machine guns. For this reason, the Germans sought an effective range of about 500 meters or so for the 7.92x33mm round, the first of what I’ll call the “Short Rifle” rounds. This gave them a bit more range than they thought they’d need, but because they didn’t need the power of a full power round, they could make the bullet lighter and manageable on full automatic. And fully automatic fire is a great force multiplier. Submachine guns were very popular and effective weapons, but they have a very short effective range of 50m. The German StG-44 pointed a way forward, trying to bridge the gap between a service rifle and a submachine gun, and by all accounts was very successful.
After World War II, we know that NATO stuck with full power rounds with the 7.62x51mm NATO, and eventually changed over to 5.56x45mm NATO, which is a classic example of a small caliber high velocity (SCHV) round. Currently, “everyone” (or at least every chairborne commando gun-writer) says that the 5.56mm round is inadequate, and that we should move to something in the 6.5-7mm range. However, the extant examples of such rounds, the 6.5 Grendel and 6.8 SPC, not to mention the .300 Blackout, resemble the short rifle rounds with somewhat better external ballistics. Certainly as far as weight and recoil energy are concerned. Which brings up an interesting point if we look East. The Soviets adopted a short rifle round, the 7.62x39mm, shortly after WWII, as did the Chinese. If the modern 6.x proponents were correct, we’d expect at least one, but probably both of these major powers to have stuck with something similar in the short rifle round. But they didn’t. The Soviets went to SCHV with the 5.45x39mm round in the early 1970s, and the Chinese went to the 5.8×42 in the 80s. Let’s see if we can’t reason out why.
The Soviets and the Chinese would have had access to M16 rifles and their associated 5.56mm ammunition as a result of the battles of the Vietnam war, and weapons were almost certainly taken from captured stocks in North Vietnam for further study. And they found a lot to like. 5.56mm weights about half as much as full power rounds like 7.62mm NATO, and about two thirds as much as short rifle rounds like 7.62x39mm. This means that a soldier can carry more ammo for the same weight (because no one ever actually reduces the soldier’s load, despite every utterance to the contrary. Sorry S.L.A. Marshall). More ammo was a boon for the war planner. Not only does it allow units to hold a position for longer, but units that have fought through a chance contact or ambush aren’t in dire need of resupply. What’s more, smaller rounds are easier to make in bulk, and easier to ship. Perfect if you have a big army that is going to need tons upon tons of ammunition to slay the foreign devils.
Another helpful advantage is the flat trajectory that simplifies aiming at combat ranges. With the right zero, a soldier does not need to adjust his sights or his aim to be able to hit targets within combat tolerances from 0 to 300 meters, or across the practical range of the soldier. We might think that a flatter trajectory would let us get reliable hits at ranges beyond 300 meters, but this is not the case. In addition to the problems of evasive targets mentioned previously, it is very hard to distinguish targets at ranges beyond 300 meters when they do not wish to be seen. While it is easy to spot and engage nice big silhouette targets at ranges of up to 500 meters even without optical sights (see the USMC rifle qual), soldiers who are trying to live to see another day by using cover and camouflage to hide themselves are very difficult to spot at longer ranges. So the SCHV rounds make basic combat shooting easier, but they don’t remove the requirements for fancy optical sights and marksmanship skills at longer ranges.
But what about lethality? Are SCHV rounds effective enough to justify making a switch? Admittedly, I’ve sold the accounting guys already, but let’s continue all the same. Lethality is a pain to talk about, because it’s not readily derivable from a number. For small arms though, you armchair physicists out there can shut up about kinetic energy–momentum is a better zeroth-order proxy for lethality. But that’s not a very useful proxy; it’s only good if you want a number to play with. Reality isn’t nicely quantifiable–it’s complicated. Gel tests are better, especially since the no-good treehuggers will get mad at us if we try to do more pig testing. Anyway, the idea of gel (a proxy for flesh) is that we want a cavity that is deep and wide. Deep, because (if you recall your high-school anatomy course), your heart is not on the skin, and we may have to shoot through things that are in the way (arms holding a weapon in firing position, gear carried on the vest, etc.) We want it wide because we want the best chance of damaging something important, like the heart or the central nervous system. Were we civilians hunting, say, wild hogs, we’d choose a nice, controlled-expansion soft- or hollow-point bullet. This would give us great expansion and penetration, and thus plenty of dead hogs (and tasty bacon!). But soldiers are forbidden by various treaties and conventions to not use such bullets. So let’s move on. The best we can hope for is that the SCHV bullet will hit the target in such a way that it will tumble rapidly, losing velocity. If the initial impact velocity is high enough (usually, above 2,700 feet per second for most standard military ammunition) the tumbling will cause the bullet to tear itself apart. Even though this is a tiny bullet, this causes some really nasty wounds. If you can only get tumbling out of your bullet, that still makes for a big, destructive wound channel. The worst case (well, from the perspective of effectiveness–it’s still pretty sucky.), is the “ice pick” case, where the bullet goes straight through, minimizing the wound channel size.
So now we get to the historical cases. In Vietnam, complaints about the M-16 were generally about issues with maintenance. No complaints about lethality were heard–in fact the lethality was praised by the troops, and damned by the red cross. In Afghanistan, the Russian 5.45mm earned similar praise from the Soviet troops and infamy from the mujahedeen, who called it the “poison bullet”. In Somalia, and again in Afghanistan complaints started to come up occasionally about lethality issues. Now, the skeptics among you might have some issues here. Can a soldier, who may not have an optic with magnification, be sure of how many hits he scored and where? Were these hits really center of mass shots? Did he hit at all? And why were the complaints not universal? Why were some soldiers, often in the same units, totally satisfied with the performance of their 5.56 rounds? Further, in Afghanistan, many would point out the longer engagement range as further proof of the failures of the 5.56. However, the Soviets had no complaints from their 5.45mm rounds. So what’s different? Well, we have a bunch of asinine restrictions on fire support missions in Afghanistan that prevent timely assistance to infantry. And, to no one’s great surprise, eventually the enemy figures this out and exploits it with snipers attacking infantry. In Vietnam, the enemy tried to get as close as possible because they feared our artillery. We can also note two more issues with the “5.56 is crap” theory here. First, if 5.56mm was so useless at range, why would SOCOM make the Mk 12 SPR in 5.56mm? Special forces can pick their gear–why would they use such a weapon if it is so ineffective? And use it they did; SOCOM units registered plenty of long distance kills with the Mk. 12. Second, if we are using Afghanistan as our instigator for change, we’re saying that we are expecting to fight more wars in that sort of terrain. Even if I wasn’t designing a force around a conventional war, I would find this a dubious proposition. I might be more swayed by arguments in favor of preparations for urban warfare in that case–but those would almost certainly favor shorter range rounds.
We’ve established that 5.56 can be an effective round at longer ranges. Something to note here is that the choice of the bullet itself for long range shooting is a little different from the NATO usual M855. The Mk. 12 is usually used with Mk 262 rounds, which are match bullets designed for their long range performance. I’m sure the shooters among you are thinking that I’ve cheated by looking at match rounds. To them I grunt, Belichick-style. They’re missing the point. I can choose whatever rounds I want to disprove the claim that “5.56 is useless at range”. If that claim was true, then I could load whatever rounds that I please, and should get the same piss-poor results. If the argument is that using basic service rounds I’ll get poor range performance, then I would say, did you miss all of those earlier paragraphs? Scroll up, actually read them this time, and come back. I’ll wait. Bullet design is pretty important, and I’m just not a big fan of M855. Given the choice, I actually prefer Vietnam-era M193, since it fragments more reliably. M855 is sort-of-armor-piercing, with a steel cap, but not a steel core. It’s not super helpful, except for telling you which Level III plates are cheap and lame. Soft flak vests can be dealt with by just about any 5.56 with its high velocity, and hard plates will need the fancy, tungsten-cored M955. And we can totally do better than your father’s M193 with modern bullet design. Something more like M855A1 (don’t let the designation fool you–it’s really an entirely new round) or Mk. 318 SOST. The key is getting a bullet that will tumble upon impact regardless of the nature of this impact (so minimize the impact of “Fleet Yaw”), and both of these bullets do this. M855A1 also takes advantage of modern, more consistent, less temperature sensitive propellents to up the chamber pressure. We can get away with this, because said modern powders won’t dramatically increase pressure in a hot bore. I’d prefer bullets themselves that use proper lead (because the “environmentally friendly” bullet gripe is dumb), but the example is good. The point is that these are excellent examples of effective, good 5.56 rounds, and SOST has gotten rave reviews in the ‘Stan. So we can find “infantry grade” rounds that are plenty effective at infantry distances.
So now we come back to those “6.x” intermediate rounds. Specifically, I’d like to look at 6.8 SPC and 6.5 Grendel, because those actually exist. While they’re somewhat handicapped by having to fit in an M4 magazine, this means there’s no weapon weight penalty, and it keeps the ammo weight about as low as we can. However, we’re still paying quite the weight penalty–each loaded magazine weighs about half again as much as a comparable 5.56 mag (with a 30 round magazine for each case). What does this weight/higher cost of ammunition get us? Well, 6.8 SPC was designed to explicitly give us better terminal performance than 5.56, and it delivers, even when we compare modern, fancy rounds. But these modern, properly designed rounds certainly give us nothing to really complain too much about in 5.56, in a lighter, cheaper, more controllable package. So there’s no reason to switch (and SOCOM agrees with us–they’ve basically got rid of any plans that they might have had to switch over). 6.8 SPC at least delivers what it claims to out of a standard carbine barrel. Out of a long (24″) barrel, 6.5 Grendel delivers phenomenal ballistic performance, but if you put it in a regular carbine barrel, performance suffers. There are also as yet unsolved issues with stuffing a longer tracer round into that case, or trying to make it work in a belt-fed weapon. Some might say that this doesn’t matter, but if you’re actually trying to have one cartridge to rule them all and any hope of reducing weight like proponents claim (do the math though–you fail), you’ll need to replace a full power round like 7.62 NATO in the support weapon role, which means belt fed. And that’s if you buy into bulky drums for the squad machine gun–I don’t. So the Grendel doesn’t deliver the goods on a perfect intermediate cartridge round either. Are 6.x rounds good? Sure. For military use, do they have advantages over 5.56 that offset the penalties of cost and weight? No.
So, the infantry will continue to carry light, reasonably effective 5.56x45mm NATO rounds. Next, we’ll choose a carbine to launch it.
Whereas, Fishbreath is neither a lazy shirker nor a poltroon; and Whereas, Fishbreath is nevertheless a busy man; and Whereas, Parvusimperator ought not escape the difficulty of deciding on things (or at least writing articles to justify those decisions),
Be it resolved that Fishbreath demands to see the following things from Parvusimperator:
1. His choice for a short- to medium-range air defense system, bearing in mind that he cannot buy Russian; 2. His choice for an APC; 3. His choice for an anti-tank rocket (i.e., for the AT specialist in a rifle squad), and an infantry-portable ATGM (for a proper AT team). 4. His 25-year, $250 billion procurement budget, as submitted to Borgundy’s legislature. (In the spirit of fairness, I’ll come up with one, too.)
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