Got the outline frame completed after about two weeks of game time - and this time I remembered to fit the wheels before adding too much weight 
I hope 14 wheels will be enough because there will be no easy way to add more later!
The rest of the framework will be filled in with extra light frames, but I need to find more electric vehicles to scavenge them from. So far I’ve dragged 4 electric cars, one tour bus(!), two APCs and five Humvees to my base, and I am slowly breaking them up for parts. This will take some time…