I just re-watched both parts of Year of Hell yesterday, and I had forgotten how much damage Voyager takes. Are the Krenim's chronitonic torpedoes not particularly strong, other than the fact that they can cut right through regular shielding? Otherwise, I don't see how Voyager could have been as intact as it was towards the end of the episode. I mean, it took much less for an old Klingon Bird of Prey to cause a warp core breach in Generations after their disruptors tore through the Enterprise's shields. Voyager still was able to function after numerous attacks, and even was able to go to warp after it was heavily damaged.
Starfleet ships seem to be build out of super stable material. They even can crash against hard mountain rock or fall onto the ground of a planet without being completely pulverized. With todays materials crashes like these would leave only small chunks scattered around in a large area. In Star Trek the rock breaks, not the ship, when hit.
They're made of a special alloy called Plotanium, the properties of which vary depending on the needs of the story. Or possibly melted down Nokia phones.
Unfortunatly the interior of Starfleet ships are made out of Explodium, just look at all those consoles that blow up.
Didn't they come up with "transverse bulkheads" which allowed the ship to be utterly shredded while remaining functional? It's because in the Star Trek Universe, nobody ever invented fuses.
Late in the second part there was a wonderful overhead shot of Voyager limping along, huge black scorch marks all over the primary hull and lights flickering intermittently. The state-of-the-art limousine had wound up looking like a rusty oil truck. With regards to structural integrity - look at the exact moment Janeway rams Voyager into the weapon ship. The latter stays remarkably rigid until it actually explodes. The former crumples as if made of tin foil.
Voyager has a stamp just below the shuttle bay. It's very hard to make out...you must look closely. It reads, "Made in the U.S.A"
Akin to us never seeing people in Voyager step into a restroom, I imagine that Voyager has repair robots that do a lot of the structural and outer hull fixing. It makes perfect sense. Having people being solely responsible for something that should be automated is counter-intuitive to technology at this point in time (24th century). It's the only way I can fathom to explain how Voyager will go from episode to episode always starting "fresh and clean" as if it just left a starbase from a maintenance and repair visit. Ideally, it would've been smart for the producers to make sure more serious damage would leave repair scars that would continue throughout the show, lending to continuity. But no... it's the magic of repair robots!
Well, obviously I know that it fits the plot, but I was trying to figure out an in-universe explanation for it.
Structural integrity field, the transverse bulkheads they installed to seal off the damaged sections of the ship, power reroutes around abandoned damaged portions, and the deflector dish I'm sure all help to keep her going. Although in the last battle it's clear there wasn't much left to her. Even Torres scoffed at Janeway's notion of taking Voyager into combat, noting that there was barely enough of the ship functioning to get there. No phasers or shields to speak of.