[Spaceships] Missile shield vs. ramming: two questions

[Polydamas]

Originally Posted by Agemegos

The OP didn't actually express a thought about force screens: the "Missile Shield" setting switch to which he referred is an optional rule regarding defensive fire by beam weapons against ballistic warheads and ramming ships. It's in GURPS Spaceships 3 on page 35.

Ok. I do not have money to buy any of the later volumes in Spaceships, and in my view for questions like this, it is always better to start with the real world ("on the back of an envelope, how would large spaceships work?") and worry about how to model it later.

Two common phenomena in naval architecture are big for the sake of big ("mine is bigger than yours!") and ships which have to serve multiple functions (the galleons of the Indes were treasure transports and armed to fight off filthy heretical pirates; an American aircraft carrier is a base for land operations and a weapon of naval warfare). Both can be reasons why there are ships bigger than a rational in-game analysis would justify, let alone our amateur analysis through the foggy mirror of the rules on a lazy Sunday.