That's freakin' BIG. Do you have any links with pics?
All that was actually assembled was the chassis
The engineers working on it were mostly right out of college & had read all of the BOLO series by Keith Laumer& the Hammer's Slammers books by David Drake, they were a bunch of sci fi junkies
A lot of the development was coordinated by FMC/United Defence, GE & CAT used a bunch of the data to punch the AC locomotives up to 6000 HP
They were also considering a railgun instead of the 30 cm gun.