All axles on the tractor pull and the front and rear axle steer. The trailer is a nightmare of hydrolic hoses, air lines and stub axles. The rear axles on it steer also......I never saw one with more than a hundred miles on it that didn't run as crooked as a three legged dog.
For what the military paid for one HETT system they could have bought three civilian rigs that would have done the job better.
By the way, they cannot legally haul an M1 tank on US highways due to the weight distribution.