CRB2e pg 159, critical hits. neither sensors nor computers get disabled in just one step short of a massive critical/multiple criticals. As far as I'm concerned the armor can be just as distributed around as the computer/sensor grid. Nothing says it has to be concentrated in one spot unless you design it that way. As far as the Enterprise goes, I blame *lazy* scriptwriters for the computer going down just as badly as they do the shields. I'm going to go with bridge armored bulkheads cover critical computer components and basic sensor sensor functions, advanced sensors must be armored separately. The tonnage for armor can be considered to be redundant circuitry, protected conduits, or whatever. Now that I think about it, the particular design I was working on has everything reinforced/armored, I could just take volume left after calculating armor and use that to figure bulkheads tonnage.