Wanne can be crank case, oil sump, etc, but this compound does not seem to exist. The sentence is: "die verstärkte Fahrzeugwanne sorgt für die Sicherheit der Insassen"
Erklärung: See reference for an example of usage in this context.
But then the Hummer/Humvee isn't a tank - in combat it wasn't supposed to be driving around where it could get shot at with heavy weapons. Armored doors and floor pan were added (the basis of the level two kit) for those situations where small arms fire was likely. It was never intended the Hummers would be taking RPG fire, or large calibre artillery shells (which form the basis of a lot of IEDs).
Erklärung: See reference for an example of usage in this context.
But then the Hummer/Humvee isn't a tank - in combat it wasn't supposed to be driving around where it could get shot at with heavy weapons. Armored doors and floor pan were added (the basis of the level two kit) for those situations where small arms fire was likely. It was never intended the Hummers would be taking RPG fire, or large calibre artillery shells (which form the basis of a lot of IEDs).
The translation workplace 
Zustimmung (Netto): +3