Personaly I have no doubt that a nuke would effect a citadel, though it would have to be detonated properly to do so, a detonation directly above the citadel (most nukes use an airburst to maximise thir damage no normal, earth structures) may gut the upper interior with that expensivce dark...
I dont know the command, so do this...
look at the boat
pen console
type "ent_setname boat" and press enter
type "ent_fire boat " dont press enter, instead press the down arrow until you find somthing that looks like it would put a gun on the bat then press enter.
Repeat if...
In my game when the gas tanks exploded griggs jumped ibnto the explosion just to show how tough it is. THen he, while on fire, but he didnt care becasue he's that toucugh. Walked up to a zombie and allowed it to slasg him in the face to show his toucghness before systematicaly blowing the heads...
I dunno about you guys but i'm gonna pull the BS card on this one.
Either way, it's not realy a mech at all, just an outrageously innefecent wheeled vehicle. Note it's feet "roll" across the ground.