super-heavy vehicles

mmm, I think this would be of interest for any vehicle type, with suggested limits. Say, greater than 2700 tons for chemical rockets? greater than 200,000 tons for watercraft? 75 tons for air plane? 25 tons for helicopter?

Maybe. I'm having trouble figuring out how to clearly categorize such.

Changed the base description to just say something vague like 8 times as large&heavy as one would expect such vehicles to be, that should be fairly well applicable to most things. Chose multiplier of 8 as baseline as it would mark very clear difference. The vehicles should be identified by subtype, like assault helicopters should be considered separate of cargo helicopters.