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Armata Response 1: Myrmidon MBT

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Usually, the Russians tend to make things that are rugged, ugly, and simple. See, the AK-47, the Mosin-Nagant, and the T-34. They work. But they are hardly innovative. Every so often though, they surprise everyone and come up with something new. In the 60s, it was the T-64, which introduced a production tank with composite armor and an autoloader. Last year, they did it again with the T-14 Armata, the first production1 tank where the crew are all in the hull and the turret is unmanned.

Why would they do this? Well, we’ve got some fancy electrics now, and if we physically isolate the crew from the ammo, then we maximize safety and survivability in the event of a catastrophic penetration of the ammo compartment. It also means that we can minimize the protected volume for the turret, so we can reduce overall tank weight. Much as I hate to admit it, tank experts in West Germany, the United States, and the Soviet Union all agreed that this was the way forward, even if it meant sacrificing visibility from the top of the turret with the Mark I Eyeball. Guess it’s time to suck it up and embrace the future.

So, the Russians have unveiled their fancy new Armata armored vehicle family, and it seems to be a pretty good one. We could upgrade existing hardware to match, or discuss the use of attack helicopters as tank destroyers. But the Tank Destroyer Doctine was a failure in World War II, and Fishbreath would never let me hear the end of writing up attack helicopters so darn much. Plus, it’s much more fun to write up a symmetrical counter, a new MBT of our own: the Myrmidon.

The Russians are trying to make the Armata a family of heavy combat vehicles. However, I don’t think this is a good idea. While commonality of spares is great, commonality of chassis is irrelevant and useless from a maintenance cost perspective (which is by far the bigger cost over the lifetime). Plus, it’s a false economy, since the HIFV and probably the SPH will be front-engined, but the T-14 MBT is rear engined, so that’s going to drive up design costs and force compromises. And Heavy IFVs are expensive–too expensive to buy in the desired quantity. The GCV was cancelled for cost reasons. The US Army also looked into the heavy IFV/heavy APC concept when they were designing the Bradley, but felt it was too costly. And the basically-unarmed Namer is almost as expensive as the Merkava IV. Further, giant vehicle families encourage gold plating, which leads to cost overruns, which leads to a budget kill of the project. So we’re just going to make a new tank. We’ll have other designs for IFVs and SPHs and the like forthcoming as separate designs.

In terms of engine, we’re going to put it at the back like normal people, but otherwise we’re going to be a little different. This is a bit of a throwback in that we’re going to build the ultimate combat tank, not some excessively tall MRAP thing for COIN. Which means we need the best possible engine performance. We oughtn’t neglect the mobility part of the firepower/protection/mobility triad. So we’re going to take a gas turbine engine design, because nothing beats the acceleration of a turbine. Nothing. Specifically, we’re going with the Honeywell LV100-5, originally intended for the cancelled XM2001 Crusader program, and an M1 Abrams re-engine project. This little engine weighs just 1,043 kg, develops 1,500 horsepower, is 25% more fuel efficient than the Abrams’ AGT-1500 at speed, and is 50% more fuel efficient than the AGT-1500 at idle. It also has 43% fewer parts than the AGT-1500, which already has many fewer parts than a comparable diesel engine. It also requires much less cooling volume than a diesel. With the newer high-temperature ceramic turbine blades and the full authority digital engine controls, we can get the gas turbine down to diesel-ish fuel consumption levels. At least for older diesels, or diesels that care about performance. We still get unholy amounts of torque, easy cold starts, and the ability to run on just about any flammable liquid that you can run through the injectors. We could probably get an even smaller engine, but I try to keep these designs at least a bit grounded so that Fishbreath doesn’t complain too much.

I guess we’re moving from back to front on this design walkaround. We next come to the turret section, right in the middle. The turret is completely unmanned, but still has plenty of modular armor. We can’t get away from that, since we’re not stupid. An unarmored gun is vulnerable to mission kills from machine gun fire and shell splinters, plus just about anything heavier. It does no good to put the crew in perfect protection if the tank can’t do its job. So, we still have turret armor, we just have a lot less armored volume to worry about. We have the main gun, the coax gun and its ammo supply, the autoloader assembly, which is mostly behind and below the main gun, a bunch of data cables for targeting systems, and the electric motors needed to move everything. That’s it. So we can make our turret pretty freaking small. Most of its mass will be composite armor modules. The main gun is a 120 mm L/55 smoothbore, that wonderful Nato standard. A few changes from what you might see on your bog standard Leopard 2A6 though. First, there’s no bore evacuator, because the autoloader doesn’t care about fumes, and Cylon-OSHA isn’t a thing we have to deal with in Borgundy. Second, the chamber and recoil system are designed with future, higher-pressure rounds in mind, just in case upgrades to ammunition are needed. Third, we’ve got the necessary data interfaces built in to let us use smart rounds like the Israeli LAHAT gun-launched ATGM or the KSTAM top-attack round from South Korea. It has the usual muzzle reference sensor, muzzle cant sensor, crosswind sensor, and muzzle velocity sensor. It’s stabilized in two axes, with an active damping system to reduce barrel vibrations.

The autoloader is worth discussing here, since it’s a good part of how we’re keeping armored volume down. Rounds are stored in a vertical carousel, point-down. The carousel has a capacity of 60 rounds. The autoloader can load at a rate of about twelve rounds per minute, it can extract unfired shells, and it can eject duds (or spent case bases) out a rear hatch in the turret. This is also used for reloading the carousel. There’s no other access to the carousel without removing the turret. It’s a pain, but there’s nothing to be done about it. The autoloader scans a barcode on each round as it’s loaded in the carousel, so that the stores management system can keep track of how many rounds of each type are loaded and where they are in the carousel. Each round is stored in its own canister to minimize the chance of a catastrophic explosion. Finally, the carousel is designed to safely vent such an explosion away from the crew compartment.

The coaxial machine gun is the usual FN GPMG in 7.62×51 mm, with 4,500 ready rounds and a heavy barrel, since it’s not easily accessible without pulling armor modules. The magazine for the coax gun is accessible through a roof hatch for reloading.

Now, we come to the crew compartment. Here, we have the driver, tank commander and gunner, sitting at their stations. The driver is seated on the vehicle’s left, the gunner is seated in the middle, and the commander is seated on the vehicle’s right. All crewmen have their own hatch to allow for a rapid exit. Hatches are very thick, and are power-opening. The gunner has a single vision block for emergency uses; he does not have the option to operate turned out. The driver and commander have five vision blocks with associated thermal viewing units, and may perform their duties when turned out. The driver has a separate hull mounted thermal viewing unit, capable of 1x and 4x magnification for searching or resolving obstacles. He also has thermal-capable cameras to provide view to the sides and rear. He can cycle through these views on his internal monitors.

The commander can also view through the driver’s thermal cameras on his monitors. In addition, he controls an independent thermal sight mounted atop the turret. This sight is capable of 3x, 6x, 13x, 25x or 50x magnification, and is a third generation3 imaging system. The commander’s independent sight has an Nd:YAG laser rangefinder. The commander can match gun bearing to his sight bearing automatically with the push of a button, and he can fire the main gun (or the coax gun for that matter) himself if he wishes. The commander’s sight is, of course, fully stabilized. Slaved to the sight is a biaxially-stabilized remote weapons station, mounting a 12.7mm M2A1 HMG with 400 ready rounds.

The gunner’s sight is a copy of the commander’s; he has the same 3x/6x/13x/25x/50x magnification options, the same Nd:YAG laser rangefinder, and the same third generation thermal imager. His fire control computer is capable of automatically tracking targets. The gunner’s sight is biaxially stabilized like the main gun. The gunner’s computer can select round types and display remaining quantities of available ammunition by type. The gunner’s sight also integrates the laser guidance system for gun-launched ATGMs with semi-active laser homing guidance like the LAHAT. There’s a second, backup, sight mounted just below the main gun with fixed, 8x magnification and a stadiametric rangefinding reticle, and the gunner can also pull this view into his displays.

Hull armor is necessarily sturdy. Around the crew compartment and ammo stowage area, the sponsons contain only armor, and the thick glacis is sloped 82 degrees4 to maximize effective thickness. This is also the minimum angle for long rod penetrators to have a reasonably significant chance of ricochet, which further enhances survivability. The crew compartment has a thick bulkhead aft to divide it off from the ammo compartment. It also has a thick spall liner to minimize damage in the event of a penetration. NBC protection, plus heating and air conditioning, are provided.

In terms of electrics, the fire control system can do automatic target tracking, and can pull in information from encrypted line-of-sight, frequency-hopping, tactical radios as well as satellite tracking data if available. Information includes the vehicle’s position, positions of other friendly vehicles, information on known or suspected enemy positions, and information on terrain and obstacles. Information from ground surveillance aircraft5 can also be pulled into the network. For more traditional means of data gathering, there’s an external telephone provided on the hull to allow nearby infantry to talk directly to the crew.

Looking to the flanks, we come to the suspension. There are seven roadwheels per side. The suspension is a controllable hydropneumatic system, so the Myrmidon can lean and adjust ride height. Ground clearance is adjustable from 14 cm to 74 cm. I would love an actively damped suspension like the early-90s Williams F1 cars used to have, but the heaviest things those have been put on is a CV90, which, as we’ll soon see, is quite a bit lighter than the Myrmidon. We do have a dynamic track tension system though to keep the optimal tension on the tracks without requiring manual adjustment. The flanks are protected with heavy side skirts that contain composite armor. These can be supplemented with reactive armor cassettes, especially useful for operations in built-up areas.

Let’s talk active protection. Alas, it will drive the cost up, but all the cool kids have one on their tanks, so we should too. Plus, it saves us the trouble of trying to protect the sides and top of the tank from something like a Hellfire missile. The first part is seeing the missile coming, and the easiest way to do that is with small radars. Naturally, we locate these around the turret to provide an all-around view, like the systems on the Merkava Mark IV or the K2. This data will also be available for the crew so they can counterattack. If a launch is detected, the crew has the option to swing the turret towards the launch, presenting the thickest armor and simplifying return fire. The crew can also trigger smoke grenade dischargers to throw up a smoke screen that contains thermal obscurants. We will also integrate the Israeli Trophy hard-kill system. Trophy has successfully intercepted a number of high-end Russian anti-tank weapons, including the Kornet, the RPG-29, and the Konkurs. Field tested is excellent. We’ll be keenly interested in Rafael’s follow-on system.

Now let’s get down to the figures for dimensions and a cost guesstimate. The hull is 8.7 meters long, and is 3.657 meters wide with the skirts detached. We’re constrained in width by the need to fit on road and rail transporters. Fuel is stored in the aft section of the sponsons, on either side of the engine compartment, below the engine in an “inverted saddle” arrangement, and around the ammunition carousel. The fuel tanks are built with a heavy internal baffle structure to increase their protective value. 1,500 L of fuel are carried internally. A pair of 200 L fuel drums can be carried, one on either side of the turret, in quick-release brackets. Obviously, these shouldn’t be mounted in areas where heavy combat is expected. We reckon the Myrmidon would tip the scales at about 57 tonnes.

Let’s talk cost. How bad will this tank be? Well, we’ve kept it simple above. Hull construction is of welded steel; unlike on my Thunderbolt design workup, the Myrmidon uses no special techniques to reduce weight. Armor does have wonderful things like super-hard steel and depleted uranium, which is going to up the cost a bit. We’ve got plenty of nice electrics, but nothing that hasn’t been done before. Even the autoloader was done before in the late 80s as part of the M1 TTB project, and the LV100-5 engine was worked up for the Crusader artillery project. Uralvagonzavod claims that the Armata will come in at about $4 million, but we’ll see how that works out for them. Russia also claims they’ll order 2,300 T-14s. Again, color me skeptical. To be frank, I don’t believe a figure of $4 million dollars for the T-14, and some analysts reckon a rather higher figure, something more like $8 million. So, we can’t use a direct comparison. The K2 Black Panther is pretty similar to the Myrmidon in terms of complexity and electronics fit. The configuration is somewhat different in that the K2 is traditionally configured. On the other hand, the South Koreans aren’t ordering a lot, and we plan6 a big, Russian-sized order to equip our armored divisions. The K2 comes in at a bit over $9 million per unit. We reckon we can come in under $8 million.

1.) Well, production-ish. Like many other projects in Putin’s Russia, there’s a lot of question as to how many of these are actually going to get made. They’re not making many PAK FAs for example, and they may or may not make many T-14s. That said, the one in the Great Patriotic War Victory Parade was a pretty complete pre-production or low-rate initial production model, which is a lot farther than anyone else has gone with this.
2.) More precisely, tactical “idle”, which is actually 60% of max RPM, because throttle response on a gas turbine is terrible. The torques are outrageous though, again because turbine.
3.) i.e. it’s a dual band (MWIR and LWIR) imaging unit.
4.) From the vertical. Duh. Measuring armor angle from the vertical makes more intuitive sense to me, since a measure of 0 degrees–completely vertical–conveniently equates to a line of sight thickness multiplier of 0.
5.) e.g. JSTARS
6.) If the Russians can do it, so can we. We’re totally ordering something like 2,300 Myrmidons.

Milspec Challenge

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Here’s one that came from Fishbreath. I’m a big AR-15 guy, and he suggested I spec one out as if I was going to issue it. So here goes. An issue AR-151, Parvusimperator-style.

We’ll start with the receivers. Both upper and lower receivers should be forged from 7075-T6 aluminum. Forged to keep it simple. The forging process is cheaper than the billet manufacturing process, and marginally stronger. Win-win. We’ll focus on the lower receiver and its components first.

The trigger group is a safe/semiautomatic/fully-automatic one. The AR-15 trigger group allows for a three-position selector without some serious modifications. The reader might wonder, ‘why not three round burst?’ My response is ‘why bother?’ The three round burst is the latest in a long line of devices designed at the urging of girly-man bean counters to force soldiers to not “waste ammo”. In the 1870s, the US Army didn’t issue the Winchester repeating rifles to the cavalry because the soldiers might waste ammo. Bolt action rifles around the turn of the 20th century had a magazine cut off, because soldiers might waste magazine after magazine of bullets. Both decisions were proven wrong. Discipline must be taught; it cannot be enforced by weapons. You might not always need ammunition, or fully automatic fire, but when you do, you really need it. So safe/semi/auto is the trigger group we’ll use. We’ll also specify an ambidextrous selector switch.

The receiver extension should be 1.14 inches in diameter, and should have six position detents on the underside. This part may also be called the “buffer tube” but it’s better to think of it as an extension to the receiver that gives more room for the bolt carrier to decelerate. It should be held in place by properly-staked castle nut. This will ensure that the castle nut will not back out on it’s own, but can be removed by an armorer if necessary. In terms of buffer internals, we’ll use chrome silicon wire springs (something like the Springco Blue model extra power spring) and an H32 weight buffer.

As for the stock, we’re going for the Crane3 SOCOM-pattern stock. This is heavier and sturdier than the standard collapsible stock, and comes with two waterproof storage compartments. These are perfect for storing batteries for the various issue electrics that will get attached to the carbine, as well as small bottles of lubricant to keep the gun running. It’s a convenient place to store some lubricant to make sure it’s available when needed.

There are a few other gubbins we need to specify. We’ll specify an ambi bolt catch and an ambi mag catch. Installing these in a convenient manner will take some reworking of the lower, but it can be done. Knight’s Armament and several of the fancy billet receiver companies have already done this. I’m not overly particular about most other small parts. Appropriate aluminum pins, etc. are fine. The one other thing to call out is the pistol grip. I hate the A2-type grip, so that’s right out. It’s too small and it has a pointless nubbin in a stupid place. Fortunately, there are lots of alternatives out there, and almost all of them are better. I’m a fan of the TangoDown BG-16 grip, as it fits the hand better and doesn’t have a stupid nubbin on the front in the wrong place, so let’s go with that.

That takes care of the lower. Onto the upper. We’re going to call for a 14.5″ barrel. Why 14.5″? Because it’s a military standard with lots of available data, and it’s shorter and handier than a 20″. This is a general issue carbine, so barrel length is going to be a compromise. Plus, that hot deathray M855A1 ammunition is designed around a 14.5″ barrel. It will have a 1:7 twist rate4 and a lightweight profile. Why a lightweight profile? Because I don’t see a point to anything heavier. A lightweight barrel was perfect for full-auto ambush drills in Vietnam. A lightweight barrel will take something like 900 rounds before it fails, and that’s if you reload as fast as you can and never stop firing. That’s about three times a basic ammo load for the average soldier. This is more than adequate for a select fire carbine. It’s not a support weapon built for sustained automatic fire. The barrel should be made of 4150 chrome molybdenum steel. And yes, Virginia, it will have a chrome lining.

The gas system should be a carbine-length one, or about seven inches from the receiver to the gas block. Again, this is the standard on a 14.5″ barreled gun. The gas block should be a low-profile unit held onto the barrel with a pair of taper pins. This is the most secure method of securing a gas block to a barrel. It should also have a bayonet lug at the front, since the length is right for a bayonet. And bayonet fighting teaches a lot of good things to troops, plus it’s occasionally very useful on the battlefield. Just ask the British. For they bayonet lug to work, the gas block has to be as long as a front sight block, but this isn’t hard to do.

For handguard, we actually want a 9″ long unit, even though our specified gas system is only 7″ long. This will cover most of our low profile gas block, giving us more room for a grip and accessories, but still let us access the bayonet lug. We want a quadrail handguard, because picatinny rails are the standard accessory mount. There are some alternatives out there, namely keymod and mlok, but they don’t totally replace the picatinny rail. We see no reason to adopt two mounting systems, so we’ll stick with the picatinny. I went back and forth quite a bit on which handguard design to call out here. I’m rather fond of the notion of a monolithic design, where the rail and upper are one continuous piece. However, this is generally heavy, and doesn’t let us change the handguard out at all. One of the joys of the AR design is just how modular it is. We’re using a very different handguard design than my father would have found on an AR-15, and we’d like our sons to be able to apply their own wisdom. So let’s skip the monolith, cool though it might be. We want a durable design though, and since we’re covering our gas block, we’ll need something tube-style, i.e. free float. No mall ninjas, we’re not getting a free floated barrel for accuracy benefits. It’s a service carbine. Don’t kid yourself–no one cares about tiny group improvements. We just need it to work with our gas block system. We’ll take the Daniel Defense DDM4 rail, in the 9″ length. This is an off the shelf product, just like everything else on our list. It’s lightweight, sturdy, and easy to install. It will still let us access the bayonet lug, but give us plenty of room for lights and lasers as needed. It also has quick detach sling swivel sockets built in, which is convenient. Saves us a part.

So far, so good. There are a few more notes that we’ll make for the upper. The muzzle device should be a three-pronged-style flash hider, since these seem to work the best. It should also be a suppressor adapter. Since we haven’t specified a suppressor, we won’t specify a muzzle device. But a good example would be the Surefire SF3P, which would work with Surefire’s excellent line of suppressors.

You may have guessed we’ll be using a “flat-top” or “A3-style” upper receiver, and you’d be right. That’s prime optic mounting real estate. And we’ll have the standard folding dust cover on there too. Yawn. Tell me something interesting, you say? Fine. We’re specifying our uppers to not have a forward assist. Why? Because it’s a stupid, useless, protruding, weight-adding piece of junk. Get rid of it. It makes the design simpler. It makes the design lighter. It’s how Stoner originally intended it to be. And stupid Army was wrong to insist on such a device. If you’re in a situation where you need to force the bolt closed, then your gun is FUBAR, and unsafe to use. Any case so screwy that you have to force it into the chamber because the buffer spring won’t do the job has no business in your gun. Yes, you can force a fucked-up, bulged case into an M1903, M1 Garand, or M14, but that doesn’t make it a good idea. Or even a military requirement. The M1918 BAR has no such capability, but troops loved the BAR all the same. Look, when both John Moses Browning and Gene M. Stoner don’t think it’s needed, it’s not needed.

Didn’t see that coming, did you?

Now for the guts of the rifle. But first, the charging handle. Surprise, the stock one is fine. It doesn’t need ambi anything. It’s already ambi. It’s on top of the freaking gun, for crying out loud. Fine as is.

Anyway, the guts. Or, more specifically, the bolt carrier group. We’re going to call out somewhat nonstandard parts here. No, we’re not going to retrofit a piston. There’s already one there. It’s inside the carrier, you dumb idiot. We’re going to use a specialty bolt carrier and bolt, specifically the Lewis Machine and Tool Enhanced Bolt Carrier and Enhanced Bolt. Why? Well, let’s take a look at our system, here. We have a shorter gas system length than Stoner originally specified, so we’re getting more gas pressure than Stoner originally designed around. The M193 ammunition that was originally used had an average chamber pressure of 52,000 psi. But we’re calling for something like M855A1, which takes advantage of more consistent modern powders to increase the average chamber pressure to 63,000 psi, which of course means more gas pressure for the system. Plus, we like suppressors, which means yet more gas pressure. What does all this gas pressure mean? Well, it means we’ve got more velocity on the bolt, which increases the likelihood that the bolt will try to unlock to early, which puts a shear and bending load on the bolt lugs. Surprise, this is bad for bolt life. The Enhanced Bolt Carrier has more vents and a revised cam path to reduce pressure and slow unlocking of the bolt. The revised bolt has a different extractor, using two springs instead of one, which is designed to give longer spring life. The lugs are redesigned for added strength as well. The end result is a longer-lasting system. Plus it’s a slightly not-stock part, so I’m not just picking a rifle off the rack here and calling it good.

So how is the rifle issued? Well, it comes with an issued optic, which we haven’t chosen yet. But there will be an optic. There will be a two-point, quick-adjust sling. More convenient than a standard carry strap type sling that your grandfather had on his M1 Garand. There are three rail panels issued. I prefer the Tango Down units, but the exact model isn’t very important. Just something so that the picatinny rail doesn’t cut your hands up after lots of campaigning. The rifle is also issued with a set of folding back up iron sights. Specifically the Troy industries M4-style front and their standard (non-dioptic) rear sight. The rear sight is “A1 style”, i.e. it’s has two apertures, but is not adjustable for elevation. Nor should it be. It should be durable and simple. It should be zeroed and kept safely in reserve. It should not be complicated. It is a backup sight on a carbine, not iron sights on a National Match rifle. Keep it simple.

The carbine is issued with iron sights and optic fitted and properly zeroed. Since we’re not dumb, our weapons racks are designed to hold the carbines with optics mounted, so soldiers can trust that the carbine they draw from storage has a good zero.

Some of you may be wondering what I would do if you made me get an AR-15 that I couldn’t piece together as above. What if you had to buy something off a shelf, all-up, Parvusimperator? Simple. I’d call Knight’s Armament Corporation, and ask if they give a bulk discount on large carbine orders. So there. Smartass.

1.) I’ll be using AR-15 as the generic term here, so as not to sound like I’m specifying brand or model details. Also, the AR-15 designation came first.
2.) 5.6 oz weight.
3.) NSWC Crane designed, produced by LMT and B5 Systems.
4.) I.e. one complete rotation in seven inches of travel

Skypirates: a zeppelin aircraft carrier construction ruleset

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Every zeppelin which has played a major role in Skypirates to date (so far, only Inconstant and Arys, where parvusimperator’s characters are based) has been designed in accordance with a fixed set of rules. We appreciate the verisimilitude this lends proceedings, for one; for another, we just really like rules for designing things. Ask parvusimperator about tanks or IFVs sometime1.

But not now. We have zeppelin rules to cover. I believe parvusimperator, to whom I owe the credit for these, believes he originally stole them from some Germans2, which is apropos. They were designed for tabletop RPG rules system Savage Worlds, which I wholeheartedly recommend if you’re looking for something opposite GURPS on the fun-GURPS axis. In traditional RPG fashion, round in the least favorable manner unless otherwise stated.

These are primarily construction rules. They were borrowed for a Savage Worlds campaign that never happened, and so the portions of the rules pertaining to acquisition and combat were never really fleshed out. If you want to use them, you’ll have to do some innovation. (If you do, let us know! We’ll put them up here for the benefit of posterity.)

Hulls

Length(m)    Width(m)    Hexes     Lifting/Payload (t)
300                50      6x1                 425/275
350                60      7x1                 670/435
400                65    8x1.5                1000/650
450                75    9x1.5                1425/925

The listed payload assumes helium as a lifting gas, military-spec internals (protected against enemy fire), and a single keel, and is 65% of the lifting capacity, rounded to the nearest 5t. For hydrogen lifting gas, add 5%. For civilian-spec internals (not protected against enemy fire), add 5%. For triple keels in the style of USS Akron and USS Macon, which permit internal engine mountings, subtract 5%. (That is to say, the maximum payload achievable is 75%, using hydrogen lifting gas and civilian internals, and the most durable build achievable is helium, milspec, and a triple keel.)

Take the product expressed in the Hexes column, and write it down as your hex-volume.

Engines
1 ton & 1 crew (slow diesel engine),
3 tons & 1 crew (normal diesel engine),
5 tons & 2 crew (fast diesel engine)

One engine pod is needed per every hex a zeppelin is long, rounded down to the nearest even number.

Gun Turrets
1/2 ton & 2 crew for cal. 30 MG
1 ton & 2 crew for cal. 40 and 50 MG
2 tons & 2 crew for cal. 60 and 70 MG
2 tons & 1 crew for flak cannon

Machine guns may be single or double turrets. Their requirements are the same, excepting acquisition costs. Turreted flak emplacements may only hold a single gun. Add a +3 modifier to shock rolls for the gunshield.

Bow/Stern Turrets
2 tons & 2 crew for cal. 60 and 70 MG
2 tons & 1 crew for flak cannon

The bow/stern mounts can hold one gun mount or one rocket mount or one aerial minelayer. Only one thing.

Broadside Guns
2 tons & 2 crew per gun

Each gun deck may mount up to six guns per side, and are retractable. Five rounds are stored at the mount; more are brought up from the holds. Broadside guns may be directed from the bridge for firing at zeppelins or ground targets within the guns’ effective range. The gun crews may fire under local control when attacking aircraft.

Broadside guns are typically flak guns, in similar calibers: usually between three and five inches (76 to 127 mm).

Bomb Rack
5 tons & 1 crew

Some military zeppelins mount bomb racks on the underside of the hull. It mounts eight hardpoints’ worth of bombs. It may not be used to fire rockets. Bombs must be accounted for in cargo. Bombs are released from the bridge.

Rocket Rack
10 tons & 2 crew

Rocket racks provide eight hardpoints for aerial rockets. Bombs may not be dropped from rocket racks. Rocket racks may be placed at the bow or stern, or to replace broadside guns. Ammunition must be accounted for in cargo. They are fired under local control.

Control Room
[Length of hexes of the zeppelin / 2] tons and [Length of hexes of the zeppelin] crew
The bridge includes a chart room and a radio room. Sometimes, military zeppelins place these rooms separately. Civilian zeppelins always place them in the control gondola.

Cabins
1 ton & 1/4 crew

Crew are required only for passenger cabins. Accommodations aboard a military zep do not require crew.

For your one ton, you may have any one of the following: one luxury cabin (for one person, a first-class passenger or senior officer), one suite (each person requires one ton of accommodation; a suite for five people weighs five tons), one double cabin (aboard a passenger zeppelin, tourist class), one quadruple cabin (economy class), or one cell for up to eight prisoners.

Crew Rooms
2 tons & 1 crew

For your two tons and one crew, you may have any one of the following: one extra chart room, one extra radio room, one kitchen section (one section required for every ten cabins), one dining room section (one section required for every ten cabins), one lounge (suitable for ten tourist or economy class passengers, or two first-class passengers), a library (which may be expanded), an arboretum (which may be expanded), an observation deck, a briefing room or flight command center, or a science laboratory (which may be expanded).

Aircraft
We have a set of aircraft design rules which are not reproduced here. It suffices to say, for the remainder of this post, that zeppelin-borne aircraft come in airframe sizes ranging between 4t and 15t, and their weight in tons is their size for the purposes of these rules.

Internal Skyhooks
[3*size] tons & 5 crew

A traditional docking hook used to launch and recover planes: the skyhook drops planes out the bottom of the zeppelin, and extends into the air below the bottom of the zeppelin to recover them. Each skyhook may launch or recover one plane per round. The size specifies the largest plane that may be launched or recovered.

External Skyhooks
[2*size] tons & 1 crew

Skyhooks mounted outside the zeppelin’s hull, frequently used for emergency exits or as emergency landing spaces. Each may hold one plane, its maximum size specified by the skyhook’s size. The pilot gains entry to the zeppelin by means of a small ladder. Moving large cargo between an external skyhook and the zeppelin’s interior is impossible.

Launch Bay
[5*size] tons & 15 crew

Launch bays are used in the largest military zeppelins. Each may launch two planes per round, but may not be used to recover aircraft. The size specifies the largest plane that may be launched.

External Refueling Rig
[2.5*size] tons & 3 crew

Refueling rigs are external skyhooks with plumbing to refuel docked planes. Each plane may be refueled in one round. (It therefore takes a three-round cycle: recover in round one, refuel in round two, launch in round three.) Otherwise, they function as external skyhooks.

Hangar
[ size of air wing ] tons & 1 crew/10 tons

The size of the air wing refers to the sum of its weights. The hangar is an internal space in the zeppelin with room for parking, access to the launching systems, and facilities for refueling and rearming planes, as well as stowage for aircraft stores. Any zeppelin with a launch bay or an internal skyhook must have a hangar.

Repair Bay
[2*size] tons & 5 crew

Repair bays contain tools and equipment for disassembling, maintaining, and repairing planes. A hangar and an internal skyhook are prerequisites. The size specifies the largest plane which may be serviced.

Provisions
1/2 ton food/water/etc. per person per month.
1 ton per plane per combat sortie. (Includes fuel and ammunition, as required.)
1/2 ton per plane per non-combat sortie. (Includes fuel only.)
1 ton of ammunition per zeppelin gun of any type.

Engine Speed

Engine          Fuel/day (tons)  Speed (hexes)   Speed (mph full/economy)
Diesel, slow      Volumehex / 5              1                     50/10
Diesel, normal    Volumehex / 2              2                     65/15
Diesel, fast          Volumehex              3                     80/20

For travel, engines can be run at full speed, consuming the listed amount of fuel per day. They may also be run at economy speed, using the second number in the speed column and consuming half the listed amount of fuel per day.

Fuels
Engines may be fueled by blaugas, gasoline, or diesel, which are identical for our purposes. (Zeppelins which run gasoline engines may share fuel with the air wing.)

Cargo Hold
[any size] + 2 tons

The two tons are for handling equipment, and do not count toward capacity.

External Cargo Platform
[any size] + 2 tons

Smaller freight zeppelins sometimes use an external platform mounted under the hull. These are much cheaper for a given capacity, and may also be used as an emergency hangar for small planes. The cargo capacity is 1.5 * size. The two tons are for handling equipment, and do not count toward capacity.

Cargo Winch
[2 tons + cargo weight] & 2 crew

A cargo winch lowers a section of the cargo hold floor beneath the zeppelin, which may be used to easily load cargo without the use of ramps or slings.

With modifications, the platform may be used as an emergency landing point. Add one ton to the mechanism. The winch’s rated capacity must be twice the size of the plane. A plane making an emergency landing on a cargo platform loses its engines.

Zeppelin Harpoons
[5 + length in hexes of largest zeppelin which can be towed] tons & 4 crew

Intended to tow disabled zeppelins for repair, pirates sometimes modify the towing mechanisms to serve as grappling harpoons.

1. Or just read his posts here.
2. As he said, “IIRC, ja.”

2014A: Project Carius (The Thunderbolt MBT)

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To beat the Red Army, you need numbers. Thus holds conventional wisdom as well as the experiences of Napoleon’s Grande Armee and Hitler’s Wehrmacht. You. Need. Numbers. Borgundy doesn’t have those. Can’t really get them either, because conscription is gone, and there’s no use trying to go down that road again. Can’t borrow numbers, because the NATO big cheese, America, has a bunch of other commitments in other parts of Europe, not to mention Asia and the Middle East. So, like all powers stuck at a quantitative disadvantage, we’re going to go for a qualitative edge. Hence, Project Carius, which has yielded Thunderbolt, the most powerful tank…in the world. Let’s take a tour.

Sorry, no flash photography.

MAIN GUN
We’ll start with the main gun, both because it’s a striking aspect of the tank, and because it’s where I started in the design. Most modern tanks use a 120mm gun if they’re good friends with America, or a 125mm gun if they’re good friends with the Soviet Union. Thunderbolt’s main gun is a 140mm L/47 smoothbore. L/47 means its barrel is 47 times longer than it is wide. It’s built for high-pressure rounds, and APFSDS-T rounds from it will go clean through the turret face (i.e. the thickest armor) of any current tank. It’ll laugh in the face of 1,200 mm of RHA steel. If we can hit it, we can kill it. Other less interesting but nonetheless important features of the gun include a protected bore evacuator and a thermal sleeve.

The aforementioned APFSDS-T rounds are somewhat problematic. To get the desired performance, each round is a one-piece unit (no separate propellant charge) that is 1.5 meters long and weighs 40 kg. This mandates the use of an autoloader, rendering crew size debates academic. The large round size also makes internal ammunition arrangements difficult. We’re also very concerned with survivability–we’re building a main battle tank, not a tank destroyer. To maximize crew safety, we’re going to take a page out of the Abrams design and store our main gun ammo in the bustle, beneath blow-out panels. The idea is that we won’t be able to perfectly protect the ammo from enemy fire, so accept the vulnerability and direct the blast outward, away from the crew. Then, we’re left merely with questions of mechanical layout and capacity. Our autoloader system will use a pair of side-by-side, electrically-driven horizontal carousels, each containing 18 rounds. The carousels are isolated from the crew compartment and each other by bulkheads, with small doors that open automatically for rounds to pass through. Rounds are indexed electronically by barcodes, allowing the computer to know how many rounds of each type are remaining. Blow out panels are above each carousel compartment. The twin carousels provide some measure of redundancy, allowing the tank a chance to continue fighting if one carousel is compromised. Other available round types include HEAT and a gun-launched ATGM. This missile insures that the Thunderbolt gives up no range to the Soviet AT-11 Sniper GL-ATGM.

OTHER GUNS
The Thunderbolt has formidable secondary armament as well. Instead of the usual coaxial general-purpose machine gun, the Thunderbolt mounts a 30mm Bushmaster II Chain Gun. This was chosen to maximize stowed kills and increase the number of targets that could be engaged without the use of the main gun. The Bushmaster II is electrically driven, making it phenominally reliable. It’s dual feed capabile, and is compatible with all standard NATO 30x173mm rounds.

The commander’s roof machine gun is a pretty conventional affair. We have an M2-HB mounted in a remote weapons mount, slaved to the commander’s independent sighting unit. This is pretty typical for modern tanks.

SENSORS AND FIRE CONTROL
The Commander normally observes the battlefield through his independent viewing unit. He has the option of using either day or thermal imaging modes, with 3x, 6x, 13x, 25x, or 50x magnification. He has his own laser rangefinder, as well as optional stadia rangefinding reticles for HEAT or APFSDS rounds on higher magnification settings. The commander can pass targets to the gunner and have the turret automatically turn onto target, or receive targets from the gunner and have his viewing unit turn to the target for additional observation. The commander can also override the gunner and slave the turret to his sighting unit for aiming purposes. He can fire the gun if desired. Additionally, the commander can see the view through the gunner’s sight on his monitor. The commander’s sighting unit has an auto-scan mode if the commander wishes to keep an eye on the monitor while doing other tasks. As a backup observation system, he has eight periscopes arrayed around his hatch to observe the battlefield.

The gunner observes the battlefield and targets on it through his roof-mounted panoramic sight. He also has day or thermal imaging modes, with 3x, 6x, 10x, or 20x magnification. The gunner’s sight also has a laser rangefinder, as well as optional stadia rangefinding reticules for both ammo types. The gunner’s backup sight is an 8x telescopic sight that has been boresighted to the main gun. It can also be used to verify that the gun is clear of an obstruction. Thermal imagers for both the commander and the gunner are dual band units (MWIR and LWIR).

The driver has the usual trio of periscopes providing a reasonable field of view while buttoned up. The center periscope is a combination thermal viewer unit that gives him the ability to operate at night without lights. Additionally, a thermal backup camera is fitted to aid in backwards maneuvering.

The Thunderbolt uses fiber optic cables and a data bus to coordinate information for the computer system. In addition to the aforementioned sensors, the Thunderbolt is equipped with the usual set of crosswind sensors, muzzle reference system, and cant sensors. The fire control computer will automatically compute lead for a firing solution on a target. It is also capable of automatically tracking a target. The computer system can interface with the datalink to share data including position information, maps, planning details, and targeting data with other nearby vehicles. Position data for the current tank is determined by the inertial navigation system, GPS receiver, and a north-finder unit. This data is shared so the crew can view locations of nearby friendly units. Relevant information about status of the tank is also displayed to the crew on the internal monitors.

ARMOR
Actual armor composition and configuration is classified, and details have been removed by the War Office’s Directorate of Secrets Protection. Here’s what they’re willing to let us share. The armor structure has been designed to be fully modular around the turret and hull front. These modules can be easily removed (with a convenient crane) for replacement of damaged modules in the field or simplified upgrades of armor in the most important areas. The turret face armor is a massive 1.3 meters thick, and side armor is approximately 50 centimeters thick. Armor modules on the turret face include depleted uranium. Other materials used include titanium diboride, titanium-aluminum alloys, triple-hardness steel, and nano-crystalline ceramics. In order to allow for a turret face built like the Rock of Gibraltar but not put the Thunderbolt into the realm of stupid-heavy tanks like the Maus, we’ll also need to make some effort to reduce weight. A critical part of this effort is the widescale replacement of RHA steel with titanium aluminum alloys in structural components of both the turret and the hull. This will provide very significant weight savings for no loss in structural strength or protection.

OTHER PROTECTION
A few other protective systems are of note. First, as is almost obligatory for a modern tank (or a modern refit of an older tank), the Thunderbolt has a spall liner to protect the crew from fragments of hull knocked loose by a hit. There’s the usual modern Halon-gas based fire suppression system for the engine compartment to put out flames as well. Finally, the GALIX system of smoke grenade/decoy launchers have been liberally placed about the turret. These can fire smoke to obscure the tank (and it’s IR signature) from an enemy or incoming missile. These can be fired manually by the crew, or automatically from the laser warning system or missile approach warning system. Finally, the Thunderbolt is also equipped with Rafael’s Trophy Active Protection system. This uses a series of small radars mounted around the turret (also used for missile approach warning notifications for the crew or GALIX cueing) to detect an incoming missile, which is then neutralized by a shotgun-like blast. This provides added defense against large ATGMs.

ENGINE
This took me quite a while to work out. Gas turbines have come a ways since the AGT-1500, and there’s also the French hyperbar V8X to consider. And then there’s everyone’s default choice, the relatively compact MTU MB 883 V-12 diesel. We’re going to go with that V8X. The V8X is basically a hybrid engine that starts life as a rather overbuilt V8 diesel engine, and then went in search of more power. An ordinary diesel engine designer would add one or more turbochargers at this point, but not SACM. Instead, they hooked a mini gas turbine up to the blowers rather than using a tap on the exhaust. Et voila! Massive amounts of extra pressure in the cylinders (a whopping 32.1 bar mean effective pressure). All the power one needs to drive his tank of choice (1,500 hp), along with great torque. Plus, unlike a conventional turbocharger, there is no turbo lag. The massive boost pressure is available immediately, even at idle. The little gas turbine engine can also function as an integrated APU, saving most of the space and weight of a separate installation. Additionally, the V8X has no trouble starting in the cold, unlike conventional diesels. The V8X has somewhat increased fuel consumption, especially at idle, due to the little gas turbine, but it is not as bad as a regular gas turbine. Also, since it does not require the big recuperator or the additional reduction gearing, the V8X powerpack is smaller than the gas turbine powerpack.

SUSPENSION
The Thunderbolt is designed with an advanced hydropneumatic suspension system. This was chosen because of reduced weight compared to a conventional torsion bar suspension, plus the ability to reduce hull height over a torsion-bar-equipped hull. Hydropneumatic in-arm units are also somewhat easier to replace than torsion bars. Furthermore, the suspension is centrally controlled, allowing the tank’s crew to adjust ride height, or provide additional incline/decline to the main gun. This will allow them to use the terrain more effectively.

VITAL FIGURES
Crew: 3 (Driver, Commander, Gunner)
Weight: 65 Tonnes
Cost: $14.2M