wuzak
Captain
Depends - if you're talking something like a long milling machine, all you have to do is get it un-leveled and it would render it unusable. Assembly jigs are also precision made and any disruption of their foundation or un even movement could throw them out of tolerance.
I would say you would have to do more than get it unlevelled.
You would have to get it to bend - I suppose you mean that will happen under its own weight.
Still, how close to teh machine would you have to explode a bomb to unlevel it?