I have installed and maintained scales for wieghing trucks slightly smaller ( 150-250 ton avarage load ) . I realy don't know if they are electric drive or hydrolic drive . I will ask tomorow .
I do know that most articulating trucks of this size ( yes there are some that will bend in the middle ) are hyrdolic drive .
All modern train locomotives use this same way to get about ( diesel engin drives a genarator that drives traction motors at the wheels ) . I can't even imagen the size of a drive shaft to pass that much power(3650-horsepower engine) , it would have to be HUGE !!!!!! I bet it has Allmost as much torque as Bruces 57
If you think about it the way this truck drives is VERRRY enviromently friendly , no messy trans fluid dripping every where . And BELEVE me these folks ARE worryed about the EPA messing with them !!!
Oh 2 more points , these trucks are assimbled on site , and the mirrors are sorta an after thought , useless , most have video cameras built in to a HARDENED housing in the back .