[GURPS Spaceships] TL11´´ Scout Corvette ('' denotes limited superscience)

[Peter Knutsen]

This is a TL11 Scout Corvette, for a limited superscience space opera setting.

Among the deviations from the official rules are:

1. Overall Armour Modules. Spend one mass-module and get 1/3 the dDR (round down) over the entire ship.

2. XL Sensor Arrays. You can spend 3 mass-modules to get an extra-large sensor array. It functions, in all regards, as the one from a ship one SM larger: crew requirements, sensor strength, monetary cost. As with a normal array, there's no need for Power Points (it comes with a built in power plant slice, just like most other modules).

3. Stealth is much more expensive in this setting, especially for larger ships. I really, really, really dislike the consequence of the default GURPS rules (from Vehicles, GURPS Traveller or GURPS Spaceships) that all military ships are totaly stealthed as a matter of routine:

3a. Normal Stealth subtracts (TL-8)*2 from detection rolls, and has a cost multiplier, applied to the cost in the table on page 30, equal to SM-4 squared. Thus for an SM+8 ship, the cost multiplier would be x16.

3b. Radical Stealth subtracts (TL-5)*2 from detection rolls, ahd has a cost multiplier of SM-2 squared. Thus for an SM+8 ship, the cost multiplier would be x36.

4. A house rule not used in this design is a ship may fit more than 3 ECM modules, but can only benefit from 3 at a time. Any extras are just redundancy in case to combat damage. (The "only 3 modules" limit in the PDF has always struck me as really stupid. I mean, what happes if a ship fits a fourth? Does the universe cease to exist?)

5. Stardrives give +0.5 FTL rating per module at TL9, +1.0 at TL10, +1.5 at TL 11 and +2.0 at TL12. They use no fuel, but require power as per the default rules.

6. AM fuel has 1/12 the listed cost.

Scout Corvette

TL11¨¨
Size: SM+8
Hull: Unstreamlined, 35 meters long (compact shape)
dST: 70
dHP: 70
dDR: 10/10/10
Hnd: -1
SR: 5
Accel.: 1.5G
Delta-V: 1260 miles per second
FTL rating: 3.0
Stealth modifier: -12
Stealth mod. (w. Cloak[!]): -22

Cargo: 35 tonnes.
Crew: 7
Passengers: 8
Life support: Total (includes food)

Front:
[1] Overall Armour, TL11 Diamondoid unstreamlined, gives dDR 10 to each section, 10 M$.
[2-4] XL Multipurpose Sensor/Comm Array (combines Tactical and Science Array, as per page 15), Array level 11, zero workspaces (1/3 fractional workspace), cost 60M$
[5] Hangar Bay, 30 tonnes capacity, can launch all in 1.5 minutes. 1/10 workspace if using fractional workspaces, cost 100 k$.
[6] Control Room, 4 Control Stations, (1/10 workspaces), rating 8 backup sensor/comm array, Complexity 9 computer, cost 2M$.
[C!] Cloaking Device, (1/10 workspace), -10 to detection when active, cost 30M$.

Mid:
[1-3] Habitat, 8 cabins with total life support, plus 1 briefing room and 1 sickbay without total life support. 3M$ (3/10 workspaces).
(3 cabins for crew, 1 cabin for captain, 4 cabins for passengers.)
[4!] Secondary Weapon Battery, 3x3cm VRF gauss guns for point defence with 3000 shots each, 35 tonnes cargo. (3/1000 workspace), 1.8M$
[5-6!] Stardrive/TL11, FTL rating +1.5x2, (2/10 workspace), cost 20M$
[C] Antimatter Power Plant, provides 4 Power Points for 20 years, (1/10 workspaces), cost 20M$.
(Note that 4 Power Points are (slight) more than enough to power all power-hungry modules continously.)

Rear:
[1] Engine Room, 1 workspace, cost 300k$,
[2-4] Fuel tank, 3x50 tonnes of AM-boosted hydrogen, provides a base of 3x360 miles per second delta-V, cost 900k$ (not including fuel),
[5] Module split in half
[5a] Fuel tank, 25 tonnes of AM-boosted hydrogen, provides a base of 180 miles per second delta-V, cost 150k$ (not including fuel).
[5b] AM Plasma Torch, 0.5G acceleraion (360 mps per fuel tank), (5/100 workspace), 5M$
[6] AM Plasma Torch, 1G acceleration (360 mps per fuel tank), (1/10 workspace), 10M$

Total module cost: 171.3 M$
Total workspaces: 6.4 (including the 4 control stations in the control room)

Design options:
Radical Stealth (house rule), cost 72 M$, subtracts -12 from detection rolls.

Total cost of ship, without fuel or auxillary craft: 243.3 M

Fuel tanks: 3.5
Delta-V multiplier: x1
Delta-V per fuel tank: 360 miles per second
Total delta-V: 1260 mps
Cost of fuel: 1 M$ per tonne (note this is a house ruled cost reduction)
Fuel amount: 175 tonnes
Total cost for fuel: 175 M$

Total cost of ship plus 1xfuel: 418.3 M$


The Hangar Bay can contain 30 tonnes, which would be one SM+5 ship of some kind, although I quite like the idea of 3 SM+4 mini-boats instead, each 10 tonnes. Given that this is a hugely and expensively stealthed Scout Corvette, with power and life support that can last 20 years (if it conserves delta-V), the auxillary craft should be some kind of stealth boat(s) with streamlining. I haven't designed it/them yet, though.

I think perhaps one SM+4 Mini Scout Fighter with stealth, one SM+4 armoured troop landing boat with stealth and some weapons useable to suport ground troops (and, if at all possible, 1 sickbay), and one SM+4 intrusion landing boat with radical stealth (and maybe even a Cloaking Device). All streamlined.

Either way, auxillary craft should use the same kind of reaction mass as the Scout Corvette, so that they can refuel from its tanks. (In general, the idea of antimatter drives doesn't sound very stealthy to me, but this is a space operatic setting.)

This is a very expensive ship, quite possibly some Special Forces colonel's wet dream come true, able to go places and do stuff that the opposition would usually prefer to not have done.


The idea for a Scout Corvette originated in my own simple Point-Based Spaceship Design System. I haven't published it yet (it needs to be documented), but the GURPS writeup ended up deviating quite a bit from the original's stats.

[Diomedes]

Originally Posted by Peter Knutsen

I really, really, really dislike the consequence of the default GURPS rules (from Vehicles, GURPS Traveller or GURPS Spaceships) that all military ships are totaly stealthed as a matter of routine:

Actually, GURPS Spaceships makes Stealth of distinctly limited utility:

Originally Posted by GURPS:Spaceships, p.45

-2*(TL-4) if using a stealth hull unless the target has signature modifiers of +5 or more.

The only power plant that has a modifier of less than +5 is the fuel cell. An antimatter reactor is +7. An antimatter plasma torch is +10, so unless this ship is drifting, she'll be visible all over the solar system, and with her ∆V and acceleration, I doubt you designed her to coast in transfer orbits.

[Peter Knutsen]

Originally Posted by Diomedes

Actually, GURPS Spaceships makes Stealth of distinctly limited utility:

That's not very space operatic.

[Diomedes]

Originally Posted by Peter Knutsen

That's not very space operatic.

I figured that's what the cloaking device was for.