Following its acquisition of the Unit Rig truck line as part of the Bucyrus deal, Caterpillar has revealed some of its plans for the range. Principally, the key development is the launch of two new Unit Rig models, both with a fully integrated Cat power train – the 4400D AC (240 short tons) and the 5300D AC (320 short tons). The 5300D is an all new truck which will compete directly with the popular Komatsu 930E. These trucks will be assembled going forward in the Decatur facility as opposed to the existing Unit Rig factory in Acuna, Mexico, though this will stay operational as the fabrication centre. A 4400D AC is expected to be delivered to a copper-gold mine in Mexico in the next few months, though MT4400 trucks with Cat engines are already operating in the country.

The 320 short ton 5300D AC has 2,750 and 3,500 hp power options to optimise performance. It also has four corner wet disc brakes with blended mechanical and dynamic braking for increased operator confidence along with Cat AC drive, Cat drive system and a Cat C175-16 engine. On the 4400D AC features include a new radial retard grid that improves the right hand view; along with improved access and egress, stored energy dissipation at shut-down, and a door sensor warning for park brake application. The model has increased productivity over the previous MT4400, and has “best-in-class retarding”, an integrated Cat drive system & control software, a Cat 3516C HD engine and Cat AC drive system as well as Cat rear wet brakes.