locarno24 said:
Equally, a naval has a fundamental limitation - it has to float. Nothing prevents any traveller starship being fundamentally a solid block of bonded superdense with some small holes milled out of the middle - even the awkwardness of inertia, as the gravetic M-Drive (which apparently doesn't care how heavy you are as long as you're small enough) supports armouring warships up into ironclad mobile bunkers.
Like any ship today or previously, the 'eyes' and 'ears' of the ship are far more vulnerable than their heavily armored main weapons. Sure, you may have a fully capable warship with intact armor, but if you lose your sensors you now have an armored worthless piece of junk floating around. Though the Traveller combat system doesn't take this into account because it's not designed too (nor is the ship combat system).
locarno24 said:
In fairness, 'protected' is a relative term - that'd mostly be the compartmentalization stopping a shell wreaking damage much outside the impact area, but I doubt even the main belt stopped dead shells that heavy very often - that must be...what? a 16" shell? 18"?
The rule of thumb for armored combatants was to have armor capable of resisting the same caliber shell they carried. Though this rule wasn't always followed, as the
Iowa class ships were armored to resist 14" shells (which was the original caliber they were to be fitted with) and they had 16" main armament. The follow-on
Montana class were to be all-gun 16" armed battleships armored to withstand the same caliber shells. The Navy was aware of the 18" of the Japanese BB's, but instead of developing an entire new class of gun, they simply plonked on a 4th turret, giving the
Montana a 12x16" set of main guns to the
Yamato 9x18" main battery.
The other thing about armor is you have to factor in construction techniques, not just thickness. I found this excellent article (http://www.combinedfleet.com/okun_biz.htm) on armor design of battleships that goes into a lot of detail in regards to how the various navies built and implemented their armor schemes. Properly manufactured and built, an armored warship can take a massive pounding before it starts to lose it's combat capabilities.
And, as it's been pointed out many times, it's not a fair comparison of water naval ship design to spacecraft design due to the differences between fighting in a vacuum vs. fighting using a surface fleet. Water makes a helluva difference in what and why you do things.
Today's unarmored warships aren't really a good comparison to yesteryear's armored ones.