The Akasha Colony wrote:Anacasppia wrote:Out of curiosity: why then are progressive upgrades of the T-55, T-62, T-72, and T-80 considered very much viable? T-90 is case in point. I'm guessing that its because the designs of these tanks still have room and potential for additions without overburden.
Because all of these are more modern than a 1948 tank, and the T-64 and T-72 which form the foundation of the current T-80 and T-90 are significantly newer. Even then, they're reaching the limit of their upgradeability, which is why the Russians want something closer to a clean slate design. The older T-55 and T-62 hit the limit of their upgradeability long ago, which is why they've been replaced in Russian service and in the service of most militaries that can afford to do so.
That's not actually true.
We'll take the T-55, for example, which is little different structurally from a T-54, and thus a T-44. You can upgrade virtually anything on a tank, simply by replacing it. Especially older tanks, which are little more then steel boxes, things can be removed, moved, changed, etc. All you need to ensure is a) volume, and b)strength. Volume can be changed fairly easily, even without cutting steel (And you can do that too). Strength is less an option, but can be added also, but it is limited by the weight of the vehicle, and itself limits the weight of the vehicle, so it is not so much changed IRL.
The reason you replace vehicles over time is not so much upgradability, but wear and tear, and suitability. A tank will only be useful for so many years of use before it needs to be scrapped because the hull or turret or other major parts are so worn they are unable to continue on without serious fatigue. At this point, you need a new hull, new turret, new whatever. So then you can either build the old hull and upgrade, or build a new hull with the upgrades already in it. If you do the latter, you have a new tank!
Engines, fuel, suspension, weapons, systems, fire control, even crew placement, can all be changed fairly easily.