Also "башня" stands for slang "head" here.
More precisely it means "tank's turret" which is associated with "head" and "commander" (brain) inside it.
Common slang phrases: "оторвало/снесло башню" as for "gone mad" and similar. May be almost poetical "this bottle of vodka was as strong as armor-piercing shell. There was nobody alive in the turret after strike.".