Caterpillar says customer feedback at every stage of development drove the design of its new feller buncher models, the 563C and 573C.
In terms of power, the new C7.1 ACERT engine is said to deliver more power and burn less fuel than previous models. Power is delivered where and when it is needed as a result of PowerDirect Plus, new technology that optimizes machine efficiency and productivity.
“Operators will have better performance in all functions on both steep and flat ground,” said Matt McDonald, Caterpillar Forest Products, Product Performance Engineer. “Simultaneous lift-tilt and lift-steer functions are significantly faster than major competitive machines. Saw recovery time is also significantly faster.”
New technology was incorporated into the C7.1 to ensure that changes to meet Tier 4 emissions requirements would not reduce uptime or shorten service life. Cat says productivity was not affected by the Cat Clean Emissions Module and its active regeneration process. The system can regenerate during operation with no impact on machine performance.
The engine was placed at the back of the machine for better weight distribution and balance between the front and rear axles, providing the C Series with "unprecedented stability—even when carrying big timber on steep or uneven terrain,” said McDonald.
The center articulation joint is positioned between the front and rear axles to facilitate tire tracking. That, combined with the benefits of the rear engine position, offer an advantage in agility.
According to Cat, the C Series is the first wheel feller buncher that can be serviced standing on the ground, including fueling. “No more climbing up on the machine, dragging a fueling hose to fill the tank,” McDonald said.
Hydraulic oil also is added at ground level with a standard electric hydraulic oil-fill pump and a quick coupler hose stored on the machine. Oil is pumped through the filtration system before it enters the tank, safeguarding the hydraulic system.
The tilt cab and large hinged doors on three sides and at the bottom of the engine compartment provide ground-level access to the engine; hydraulic pumps; and all key components, including fuel, air and oil filters, drive belt, hydraulic hose connections, water pump, AC compressor, alternator, and starter. Short hoses and electrical wires that are bulkheaded between systems also contribute to the ease and safety of servicing.
Robust box section frames and a field-proven center hitch design provide a solid foundation. A dual-pad pump drive, steering cylinder mounts, and chrome-plated lift arm and tilt link pins are examples of design changes built into the C Series to increase machine life.
Fast and smooth multi-functioning is due to a high-performance control valve. “We put the control valve and hydraulic pumps through extensive lab ‘torture’ tests that simulated the most brutal logging conditions and environment,” McDonald said. “The tests verified a significant increase in the service life of the control valve and pumps.”
In designing the C Series, special attention was focused on keeping the machine cool and free of debris. The machine is segmented into separate compartments that are pressurized to prevent debris from entering. The pressurized airflow keeps electronics, sensors, and other key components cool during long workdays.
A high-capacity cooling system and on-demand reversing fan keep the machine running at the proper operating temperature, optimizing performance, durability, and fuel efficiency. The oversized, hydraulically driven fan spins at a slower speed overall and only turns as fast as needed to maintain proper hydraulic and engine temperatures. It automatically reverses every five minutes of run time to keep the cooling system free of debris.
The cab is centered between the axles for a smooth ride. The standard air suspension seat with neck and back support and new high-capacity HVAC system add to operator comfort. A clean three-piece front windshield, large rear windows, and skylight give the operator a 360˚ view, including the rear tires.
Additional functions include Control Adjustability to customize the machine operation for each operator, Terrain Selection Mode to optimize performance on hills or flat ground, Creep Mode to improve machine functionality particularly in first thinnings, and Road Steer Mode for high-speed transport of the machine. These functions, combined with complete electrohydraulic controls, provide the operator with a smoother machine, increasing productivity.
New work tools have been developed to meet the increased capabilities of the C Series wheel feller bunchers, including the new SH-56B, featuring Caterpillar’s patented Strait Grip bunching finger and no-pinch-point tower. “The SH-56B keeps bunches tightly compressed and straight, providing excellent productivity in thinning applications,” said McDonald. “It also optimizes skidder and loader efficiency because the stems are well organized.”