GURPS Spaceships and Traveller

[Rupert]

Originally Posted by AlexanderHowl

Without a hull, you would not have mass for cargo doors, air locks, and the other free systems of the spacecraft. Of course, you could instead have a structural component equal to SM-1, but it is just easier to assume that all of the mass of the free systems are part of the armor. I do think that there should be a Reinforced Structure component though that would give Damage Reduction equal to (number of Reinforced Structure components × 2).

SS10 makes it clear that armour is not required - it has rules for how much protection the hull of unarmoured ships gives (DR3 for unstreamlined, and DR2 for streamlined). It also gives out a certain number of airlocks 'for free', landing gear in certain cases, small built-in power systems to run those systems that don't require huge amounts of power, and assorted other pieces of structure that turn a pile of components into a working spaceship.

Now, for my Traveller game I have it that spaceships built to normal standards need to have dDR on each section at least equal to that given by a system of Steel Armour, because Traveller spaceships have always been pretty robust, and are expected to manage things like accelerate at 1-6G for up to half a week without worrying about interplanetary dust, etc. I allow armour to be installed as smaller systems, and also to be 'spread' so that armour in one section can protect both that section and any adjacent, or to be spread over the whole hull (dividing dDR by the number of sections covered).

[Agemegos]

Originally Posted by AlexanderHowl

Without a hull, you would not have mass for cargo doors, air locks, and the other free systems of the spacecraft.

Unless the necessary mass were included as part of the relevant systems (air locks in habitats, cargo doors in cargo holds etc.) the way that the rules say they are.

[Rupert]

For what it's worth, here's how I'd do the Azhanti High Lightning:

TL11, SM+13 (300,000 tons), unstreamlined.
[Front]
1x Diamondoid Armour (dDR200)
1x Comm/Sensor Array, Tactical
1x Major Battery, Particle Beam, fixed forward
1x Fuel Tank, Liquid Hydrogen, 15,000 tons
1x Smaller Systems:

1x Habitat, 600 cabins (includes 50-ton, SM+8, Nuclear Damper)
1x Refinery, 1,500 tons/hour (Ice, Water, GG atmosphere to liquid H2)
1x Cargo Hold, 5,000 tons

1x Defensive ECM

1x Control Room

[Centre]
1x Diamondoid Armour (dDR200)
1x Other weapons, turrets, centre
2x Fuel Tank, Liquid Hydrogen, 15,000 tons
1x Hanger Bay, 10,000 tons fighters and assorted small craft, 1,000 tons/minute.
1x Force Screen, Heavy, Meson Screen

[Rear]
1x Stardrive Engine, Jump-5

1x Diamondoid Armour (dDR200)
2x Fuel Tank, Liquid Hydrogen, 15,000 tons ea.
1x Hot Reactionless Engine, 2G
2x Super Fusion Reactor, 4PP ea.



A meson screen is a Force Screen that only affects Meson Guns (Ghost Particle Beams). Exactly what DR they should have I'm not yet sure. In High Guard having a Meson Screen at all meant near-immunity to non-spinal Meson Guns. But even the best screens have iffy protection against high-end spinal mounts. Looking at major weapons and heavy screens, and assuming that the weapon should be able to generally cause disabling hits, but not usually destroy a system outright, dDR of 1/3 listed (rounded down) seems about right. As bay weapons are, by the standards of big cruisers and battleships, rather small even a light screen on a cruiser should defend against them.

The refinery takes 40 hours to refine a full fuel load, but as in canon the AHL uses four fuel shuttles (400 DTons, or either 1,000 or 3,000 tons each - the latter causes problems with hanger space) to gather and shuttle fuel, it's probably not a major choke-point in normal refuelling operations.

The hanger size works well if the 'light fighters' are taken to be 100 tons (which works for them being 15 DTons, as given in Supplement 5), as they take up 6,000 tons, leaving 4,000 tons for the shuttles. If Supplement 9 is used, there no longer room for the shuttles, and in either case there's no room for the various other small craft listed.

CT has no exact equivalent to Defensive ECM systems, but they can stand in for sandcasters and repulsors, and they're also simply really important to not dying to missile strikes in SS.

One trick (involving a house rules) would be to make the second reactor smaller, and assume that a 1/3rd size reactor normally good for 4PP can provide one full-sized PP. That frees up rwo smaller systems, as the ship only needs 5PP in combat operations. These can be used for another Hanger Bay for the missing small craft, more cargo capacity, or extra armour. Also there's quite a lot more cabin space than the crew needs, so over 1,000 tons can be steerage cargo, or it could be further sub-divided and the mass used for hangers, armour, more guns, etc.

Obviously, systems can be moved round - the layout above is rough.