GURPS Spaceships Design Spreadsheet

[ericbsmith]

Originally Posted by DaltonS

That's what I thought. (Glad it wasn't from some Pyramid article I'd missed.)

Everything described in the Optional Rules is my original creation, with the exceptions being the Escape Pod, Drop and Stealth Capsules (which came from the Designers Notes) and the Vehicle Dock which was nipped from RPK's Traveller rules and included mostly because of the complexity of the rules covering it. There are a lot of rules there that are modifications of older rules, such as Cargo Hold Collapsible Fuel Tanks, but those come indirectly from 3e material and needed rewriting for the Spaceships rules. Even the pods needed some redesigning, as the original designers notes allowed them to be fired from a 32cm (12 inch) missile launcher. I don't know about you, but firing a 4-man escape pod through a 32cm missile tube sounds like a good way to spaghettify the occupants.

Originally Posted by DaltonS

I think a rational supposition would be performance might increase if a Large or Front Standard Module was detached from a single forward facing surface, but not if a Center Standard Module was deployed due to the structural concerns of connecting front and rear sections.

That sounds pretty reasonable. However, keep in mind that the original Traveller Modular Cutter basically had a Large Module. It just had a forward command deck which helped clamp the modules in place, but by weight it was at least 50% module (up to 70% depending on the exact module) and by volume 60%.

There are also concerns about detaching small or tiny modules. A ship can carry a number of these and detaching a number of them can compromise structural integrity, making it difficult to do high acceleration maneuvers.

Originally Posted by DaltonS

Ah, but I was talking about Force Screens, not armour. I suppose this would depend on whether the screen was spherical or conformal and the ship's general shape; if the overall length of the ship was reduced, a spherical screen could apply its energy to a smaller surface area thus increasing dDR, while if the screen was conformal, it would depend on the ratio of exposed surface areas with/without the module.

I'd missed that you were talking about Force Screens. I would say that dDR doesn't change unless you have the Adjustable option on the screens, in which case you can Adjust the screens away from the part of the ship that is no longer there to reinforce the part that is. I'd probably allow x1.5 dDR across the two remaining sections if a Standard module is detached; x2 dDR across the remaining section if a Large module is detached (the later is basically the default rule).