Modular Ship Design for GURPS Space

GURPS – Generic Universal RolePlaying System

Modular Ship Design for GURPS Space

by David R. Jackson (RANGER)
Playtest Draft 3-1-89

Module Placement

Below TL11, reactionless and reaction engines must be placed at the "rear" or "bottom" of the spaceship. At TL11+, or any TL that uses the stardrive as maneuver engines, there is no requirement for placement of engines.

The deck plans, shown below, can also be used to be a model of how modules can be put together for Emods. The view would be a front cross section and each hex would be a module.

      7 modules                       9 modules           1 module
                                        ___
         ___                        ___/   \___
     ___/   \___                ___/   \___/ 6 \___
    /   \___/ 5 \              /   \___/   \___/ 5     \___/ 8 \___/              \___/   \___/   \___/        ___
    /   \___/   \              /   \___/ 8 \___/   \       / 2     \___/   \___/              \___/   \___/   \___/       \___/
        \___/                  /   \___/   \___/                                  \___/   \___/   \___/
                                   \___/   \___/
                                       \___/

The numbers in each module are the minimum number of module docks required for a frameless ship using these configurations.

  1 module: 2 – top and bottom.
  7 or 9 modules: 2 – top and bottom.
                  3, 4, or 6 – for the number of sides in contact with
                   other modules.

The above gives an easier layout for frameless ships.

Modular Deck Plans

For non-streamlined modules, the modules are hexagonal-shaped "cans." To avoid the problems that are normally caused by angular divisions of spaces, most modules have compartments of rectangular divisions, with the "waste" triangles used as services routing and accessways.

most SF that features artificial gravity (and most Science Fantasy, then) orients a spaceship's motion like earthbound vehicles: you travel *forward*. Having the hexagonal cross-sections means that the ship travels *up*. Of course, it doesn't make one whit of difference in space. In fact, that orientation may make the most sense. Before agrav, having the thrust at the bottom (not back) of the craft gives you some psuedogravity, at least enough to get the job done. Even after true agrav is developed, the up-down orientation will be familiar to spacers, therefore retained.
related to the previous point, engines and other large components aren't long, they're tall. Also, the airlocks at the ends of the modules will be on the ceiling and floor of their respective decks.
if we're going to have hexagonal cross-sections, they might as well be as convenient as possible. In TFT there were things called megahexes (a "circular" cluster of seven hexes); larger cousins of the megahex make good floor plans.
to standardize the module size as much as possible, they should be designed 1 deck. Using 3.12 yd decks the best sizes are 100 cy and 250 cy. Actually, the decks have some thickness so there isn't quite that much space in the 100 cy module and slightly more in the 250 cy module.

For larger displacement modules you just add multiple decks. Example: a 1500 cy module would either have 6-250 cy decks or 15-100 cy decks.

                 ___
             ___/   \___
         ___/   \___/   \___
     ___/   \___/   \___/   \___
    /   \___/   \___/   \___/       \___/   \___/   \___/   \___/
    /   \___/   \___/   \___/       \___/   \___/   \___/   \___/       37 hexes, 100 cy,
    /   \___/   \___/   \___/   \       deck ht. 3.12 yds.
    \___/   \___/   \___/   \___/
    /   \___/   \___/   \___/       \___/   \___/   \___/   \___/
        \___/   \___/   \___/
            \___/   \___/
                \___/

           Flat to flat cross section.

           ______________
          |              |
          |      XY      |                  X _ A Human is about 2 characters
          |______XY______|                  X   tall.

          |<<-- 7 yds. -->>|
                                           XY – approx. width of 1 hex.

                       ___
                   ___/   \___
               ___/   \___/   \___
           ___/   \___/   \___/   \___
       ___/   \___/   \___/   \___/   \___
   ___/   \___/   \___/   \___/   \___/   \___
  /   \___/   \___/   \___/   \___/   \___/     \___/   \___/   \___/   \___/   \___/   \___/
  /   \___/   \___/   \___/   \___/   \___/     \___/   \___/   \___/   \___/   \___/   \___/
  /   \___/   \___/   \___/   \___/   \___/     \___/   \___/   \___/   \___/   \___/   \___/
  /   \___/   \___/   \___/   \___/   \___/   \  91 hexes, approx. 250 cy
  \___/   \___/   \___/   \___/   \___/   \___/     actually 245.89 cy.
  /   \___/   \___/   \___/   \___/   \___/   \     decks still 3.12 yds
  \___/   \___/   \___/   \___/   \___/   \___/     tall.
  /   \___/   \___/   \___/   \___/   \___/     \___/   \___/   \___/   \___/   \___/   \___/
      \___/   \___/   \___/   \___/   \___/
          \___/   \___/   \___/   \___/
              \___/   \___/   \___/
                  \___/   \___/
                      \___/

           Flat to flat cross section.

           ______________________
          |                      |
          |          XY          |       X _ A Human is about 2 characters
          |__________XY__________|       X   tall.

          |<<-----  11 yds ------>>|
                                           XY – approx. width of 1 hex.

General modules may be attached to any module dock.