Friday, May 21, 2010

GURPS Ultra-Tech Vehicle Design

Alternate Title: Modern Tanks in Spaaaaace.

So, after years of planning and sacrificing the lives of many Bothans, I managed to infiltrate Kromm's secret laboratory and discover the release date of the GURPS VDS: Turns out, it'll be shortly after the Cabaret Chicks on Ice give a performance in hell.

Soooo, I've given up on the VDS.  I mean, yeah, it'll come out, and when it does, I'll buy it, but there's no point in waiting around for something that's not going to be out in years, especially when I want to run Space Opera now.  Now, several old veterans of GURPS, including the inestimable Rev. Pee Kitty, have declared that "You can just make up the stats for vehicles" by deriving them from real-world stats, and this certainly seems to be true.  However, this only works for "real world" vehicles, and we want to design, for example, contragravity gunships toting nanocomposite armor and gauss HMGs.  So how do we go about that?

Well, for one thing, 90% of the vehicles we want are really just real-world vehicles updated into an Ultra-Tech world.  For example, in G-Verse, we expect to see tanks, so how hard is it to take an Abrams, figure out its stats, and then figure out what it might look like in a UT environment?

With this in mind, I began part 1 of this process: Deriving real world stats.  For our example, we'll be using the Eurocopter Tiger Gunship because it looks sci-fi to me.  First, we take a look at the GURPS Vehicle stats:

ST/HP: According to GURPS, powered vehicles (ie, all the vehicles we'll be using) have identical HP/ST, therefore, all we need to do is derive the HP.  The formula is found in the tables in the back: The cube root of the loaded weight times 4.  This is consistent with all the vehicles I've found.  The Tiger has a loaded weight of 6.5 tons, or 13,000 lbs, which gives us an HP (and thus ST) of 92.  Easy.

Next we have Hnd/SR, how maneuverable and stable the craft is.  There's no easy way to derive this, so I just estimate.  Assuming the Tiger is the same as most Helicopters, this gives it a +2/2.  However, the Tiger seems to be able to pull things like loops, so I'll give it a +3/2 instead.

Next, we have HT, which seems to be a guess.  Standard vehicles have a 10, unreliable have a 9 or even an 8, whereas reliable vehicles have an 11 or 12.  The Tiger seems to be hardened with multiple redundant systems, so I'll give it an 11.

Move is divided between acceleration rate and top speed.  The later is easy: Take the top speed in MPH and divide by 2.  That gives you the Yards Per Second aka "Move."  Acceleration rate is harder for me to find, so I just stole the standard helicopter acceleration rates, giving us a 3/90

Loaded Weight and Load are easily found on Wikipedia.  In this case, we have 6.5 tons and 3 tons of load.

The Size Modifier is the longest dimension, +1 if it's an "elongated box" like a tank or a car, or +2 if it's a cube or a sphere.  In this case, a helicopter is a very long vehicle (14 yards at the longest), so I won't add the +1, and simply give it a SM of +5.

Occupancy is easily derived from Wikipedia: 2 (and sealed).

DR is kinda tricky.  Generally, you look for the "RHA value," which is basically armor given in the equivalent of "inches of steel" and you multiply that by between 50 and 70.  In this case, they simply tell us that the Tiger is capable of stopping rounds from a 23mm Autocannon.  I could only find 20mm and 25mm Autocannons, and they had 6dx3 and 6dx4 damage respectively.  Averaging them out to 6dx3.5 gives us an average damage of 75, and we make that the Tiger's DR.

Range is easily found on Wikipedia.

Cost is tricky.  I'm making a rough stab and guessing that a modern dollar is worth half as much as a GURPS dollar, giving us a cost of about $15.5 million for a Tiger.

Finally we have hit locations and notes, and that's pretty easy to figure out on your own (it has small glass windows, runners, rotors, weapon mounts, an independent turret)

So, the result:
TL 8
ST: 92
Hnd/SR: +3/2
HT: 11
Move: 3/90
LWt: 6.5
Load: 3
SM: +5
Occ.: 2S
DR: 75
Range: 500 mi
Cost: $15m
Locations: 2gH2Rt2X
Now, that's all well and good, but we want a TL 10 contragravity gunship swooping around.  We simply take the above, and modify them by comparing them to other vehicles that have similar technologies.

ST remains the same (We lower it to 90 for ease).  Contragravity vehicles seem to typically have +3/3 Hand/SR, so we give our gunship +4/3.  We improve the HT to 12 for the improved reliability of a TL 10 device.  Contragravity vehicles generally have an acceleration of 10, and the top speed varies.  We could leave it at 90-100 to reflect standard helicopter tactics, but Vertols and Tactical Tilt-Rotors (its main competition) have a top speed of 200, so we give it that.  LWt and Load remain the same.  We ditch the long tail and come away with a SM of +4.  We reduce Occupancy to 1 (we don't need a gunner).

DR is a little touchy: We find the equivalent DR in GURPS Spaceships (looking at TL 8 Metallic Laminate) and then adjust upwards to fit with the equivalent DR in GURPS Spaceships for a TL 10 armor (in this case, Nanocomposite).  That gives us double DR: 150.  That makes it about as tough as a guy in power armor.

We ignore range (a fusion engine means it can fly forever).

Finally, we have cost.  The armor is about 5 times as expensive, so we take the previous cost of the armor (about $300k according to Spaceships) and replace it with the cost of our new armor (about $1.5m).  Then we add up all the components we want:

A Gauss HMG in each “gun pod” to either side of the gunship ($88k)
A Gauss Minigun in the “chin turret” ($44k)
MLAWS in each “gun pod” on either side of the gunship ($46k)
Fusion Generator ($200k)
Complexity 9 Hardened Microframe computer ($20k)
Holographic Crew Station ($10k)
Inertial Navigation System (+5 navigation) ($5k)
Large Radar (200 miles)($100k)
Sensor Turret (Hyperspectral, 20x mag (+4), 20 mile LADAR) ($300k)
Medium Radio (200 mile range) ($1k)
IR Cloaking (-6) ($6k)
Radar Stealth (-6) ($6k)
Now, we're removing old guns and electronics, so we should strip those costs out, but prices tend to inflate with time, and our gunship is more maneuverable and reliable than a Tiger, so we'll simply lean towards pricier rather than cheaper, and add everything atop the cost of the Tiger.  This gives us a total cost of about $25m, which is comparable to the cost of things like the Tactical Tilt Rotor.

And there you have it, a complete Contragravity Gunship, ready for play.  I'll make some more and post them in my G-Verse page.
Contragravity Gunship "Raptor"
TL: 10
ST: 90
Hnd/SR: +4/3
HT: 12
Move: 10/200
LWt: 6.5
Load: 3
SM: +4
Occ.: 1S
DR: 150
Range: NA
Cost: $25m
Locations: g2Rrt2X
Related Posts Plugin for WordPress, Blogger...