**General Principles**

When it comes to One Year War mobile suits, the situation with their specs is really chaotic. Over the years, various sources -- Sunrise, Gundam Century, model kit manuals, the Entertainment Bible series, Hobby Japan's Gundam Mechanics books -- have proposed a huge range of different numbers for these vintage machines. (The recent MS Encyclopedia further muddies the waters by listing Sunrise-approved specs in its color pages and Gundam Mechanics specs in its black-and-white line art section.)

Even if we attempt to narrow things down by using the official anime specs as a guideline, it doesn't help much. In particular, the thruster layouts of the Zeon mobile suits are listed differently for pretty much every show. In Gundam 0080, the specs of the Rick Dom II and Gelgoog Jaeger include only their backpack and skirt thrusters. The specs for Gundam 0083 generally include only backpack and foot thrusters, and the total thrust of the Rick Dom II and Gelgoog Marine is about half of their Gundam 0080 analogues. The vintage machines in Gundam ZZ aren't even internally consistent; the Dowadge's thrust comes almost exclusively from its skirt and calf thrusters, while the ReGelgu's specs only list thrusters in its backpack and shoulder binders, suggesting that the thrusters in its skirt and legs -- which provided the entire propulsion of the original Gelgoog -- don't do anything at all!

As far as total thrust is concerned, I think I find the numbers from Gundam 0080 the most convincing. Gundam ZZ demonstrates pretty conclusively that vintage machines like the Dowadge and Gelgoog can fly for short periods under Earth's gravity, and in the animation, these older machines don't seem to handle any worse than the "modern" ones of the Zeta Gundam era. The notion that the Rick Dom II has 110,000 kg of thrust doesn't distress me; it's absolutely jam-packed with rocket engines, and I have no problem believing it has the same thrust-to-weight ratio as the Rick Dias.

Before we get into specific cases, I'll suggest one other rule of thumb. According to Entertainment Bible 1, the Guntank weighs 80 tons and has 88,000 kg of thrust, and the MSM-10 Zock weighs 229 tons and has 253,000 kg of thrust. Both of these machines have virtually no leg motion to speak of, they're both capable of launching vertically upwards using their thrusters alone, and they're both credited with 1.1 gees of thrust. This seems like a useful benchmark for things like the Dom series, but more on that later.

**Case Study: MS-06R Series**

As a warmup, let's look at the MS-06R High Mobility Type Zaku II. There are basically four sets of published figures to work with here:

* The old MSV kit manual says that the backpack thrusters of the standard MS-06R produce 218 tons of thrust apiece, and the six leg thrusters contribute 45 tons each. (This is based on the specs from Gundam Century, in which the regular Zaku's backpack thrusters are rated at about 105 tons each.)

* Entertainment Bible 1 says that the R-1A type has a total thrust of 49,800 kg. Its base and full weights are also listed as 61.8 tons and 76.8 tons respectively. The former figure was revised to 56.8 tons in recent editions of the MS Encyclopedia, which also claims that the R-2 type has a base weight of 58.2 tons.

* Hobby Japan's Gundam Mechanics series credited the MS-06R-1A with 52,000 kg of thrust. The R-2 type is listed as having 60,000 kg of thrust, and its base and full weights are given as 49.5 tons and 75.0 tons respectively.

* And finally, the original Master Grade MS-06R-1 and R-2 model kits included backpack stickers which read "hp 49,700kg" and "hp 56,200kg" respectively. It's not obvious whether we should read that as an electrical power output in horsepower or as a thruster output in kilograms, but the number for the R-1 is suspiciously close to the specs from Entertainment Bible 1, so I'll assume the latter.

**MS-06R Thruster Specs**

Looking at all these conflicting figures, the ones from Entertainment Bible 1, the MS Encyclopedia, and the MG kits appear to be the most "official". The thrust-to-weight ratio, however, seems to be really low for a rocket-boosted high-performance machine. So it stands to reason that this is probably a Gundam 0083-style figure that only includes the thrusters in the backpack and the soles of the feet, omitting the rocket engines in the legs.

So how powerful are those foot thrusters, anyway? We can find an answer by consulting Gundam 0083, which tells us that the MS-06F2 Zaku II has four 3,100 kg thrusters in its legs -- two in the calves, and two on the soles of its feet. If we subtract out the foot thrusters, then the contribution from the backpack would be: 49,800 - 6,200 = 43,600 kg. Which breaks down to two

**21,800 kg**thrusters. Which is

*exactly*one-tenth of the figure in the MSV kit manual! What a handy coincidence!

In this case, can we just divide the rest of the MSV thruster outputs by ten? I don't see why not! After all, the specs for the MS-06G Zaku II in the current MSV-R series say that its very similar leg thrusters have an output of 3,500 kg each, so

**4,500 kg**for the leg thrusters of the R-1A type seems perfectly reasonable. This gives us the following...

Thruster output: 21,800 kg x 2 (backpack), 3,100 kg x 2 (feet), 4,500 kg x 6 (legs)

By another uncanny coincidence, this comes to a total of

**76,800 kg**. So if the full weight spec from Entertainment Bible 1 is still valid, then the R-1A type has a thrust-to-weight ratio of exactly 1.0.

What about the R-2 type? Well, if we take the output listing on the backpack of the MG kit and subtract the standard foot thrusters, we get: 56,200 - 6,200 = 50,000 kg. Which means that each backpack thruster is rated at

**25,000 kg**, a nice round number. As for its leg thrusters, these are a new design that was apparently repurposed from the abandoned MS-11 project, and so we can only guess. However, they should be at least as powerful as those of the R-1A type, and so this machine would have well over 80,000 kg of thrust in total.

**MS-06R Weight Specs**

I'm not sure how much I want to get into weight specs here, since these are really all over the map. But in Zeta Gundam and Gundam ZZ, we're given detailed weight specs complete with a "mass ratio" figure, which we can use to figure out how many tons of propellant each machine carries. The difference between base weight and the "unfueled" weight would be the optional carried weapons, and in the Zeta and ZZ specs this almost always turns out to be a nice round number (which suggests that these weapon payloads, and thus the full weight spec, are actually just estimates).

The Hizack, which is based on the MS-06R series, has a base weight of 38.7 tons, a full weight of 59.6 tons, and a mass ratio of 1.33. That's a difference of 20.9 tons between the base and full weight, and using the mass ratio spec, we can break it down into 6.0 tons of weapons and 14.9 tons of propellant.

If the MS-06R-1A has a base weight of 56.8 tons and a full weight of 76.8 tons -- which seems to be the current official line -- then that's a weight difference of 20.0 tons. Hypothetically, we could break this down into 5.0 tons of weapons (one notch below the Hizack) and 15.0 tons of propellant (virtually identical to the Hizack).

The R-2 type, meanwhile, is said to have 18% more propellant than the R-1A version. Based on the above figures, this would come to roughly 17.7 tons. Add that to the base weight of 58.2 tons, and the same 5.0 tons of weapons cited above, and we get a full weight of 80.9 tons. We could round this up to 81.0 tons if we aren't too picky about hitting that 18% figure, and it would go up or down slightly if we adjust the weapons-versus-propellant breakdown for the R-1A type. But it's also possible that the R-2 type has a higher weapons payload -- after all, it uses the same bazooka as Dom-series machines like the Dowadge, which carries 6.0 tons of weapons -- so the figure should perhaps be in the ballpack of

**82 tons**. This still gives the R-2 a slightly better thrust-to-weight ratio than its predecessor, although we know from the MSV background info that its performance isn't quite as high as that of the Rick Dom.

Speaking of which: Next time, the Dom series!

-- Mark