Caterpillar's milling and loading advances

178 Caterpillar is broadening the range of applications for its PM200 milling machines as well as offering a new tracked loader model. The PM200 milling machine can now be fitted with a 2.2m wide milling drum for special wide cutting applications. The new 2.2m drum is said to offer high efficiency and productivity by reducing passes. Making fewer passes will also help cut fuel consumption. The standard 2m drum however best suits duties in urban applications and milling tasks that require a high degree of manoeuvrability and precision. The PM200 weighs in at 30.9tonnes when fitted with the standard 2m rotor package and its weight increases to 31.5tonnes when the optional 2.2m drum package is installed. There is also an optional dust-reduction package available for PM200 machines equipped with the 2.2m rotor option. This includes an additional water pump as well as additional spray bars located inside the rotor housing and conveyors.

Caterpillar also continues to develop its tracked loader range with the introduction of the 973D. This 28tonner completes the firm's D-Series and features load-sensing hydraulics, joystick steering and a new operator's station with a tilting cab that offers good access for maintenance. Productivity is improved due to the more efficient hydraulics as well as a drive-train that provides 10% more power than the previous 973C model. The machine retains the Cat C9 engine, hydrostatic drive, single-fabrication mainframe, Z-bar loader linkage and oscillating undercarriage from the earlier generation model but benefits from a load-sensing hydraulic system with a new closed centre design. Key to the hydraulics is a variable-displacement pump that supplies the precise volume of oil required for the load on the system, cutting fuel consumption and also leaving more engine power to drive the tracks. The system also allows better simultaneous functions of lift, tilt and travel.