The Cat 527 Skidder is designed and built specifically for log skidding applications. The 527's extended track roller frame and weight-forward bias make it well suited for mountainous and soft underfoot logging operations. The skidder's ergonomic and spacious operator's environment allow for increased comfort and production. The 527's standard forestry guarding and undercarriage design ensure the durability required in logging applications. Both Cable and Swing-boom Grapple configurations are provided to suit a wide range of skidding applications.
The Cat 3304 DIT turbocharged diesel engine powers the 527 Skidder. This field-tested engine supplies the 527 with an ample 123 gross kW (166 gross horsepower). A direct-injection fuel system uses adjustment-free fuel injectors for efficient, accurate fuel metering and reduced emissions. The 4-cylinder allows the 527 to consume less fuel in medium or low-load situations.
The 527 is designed for log skidding applications in high ambient temperatures and steep or muddy environments. The 527 features a very large capacity cooling system with a high volume fan providing maximum airflow and modular cores that can be replaced individually, thus reducing maintenance cost. Twin transmission oil coolers help maintain proper operating temperatures while extending the life of key transmission components.
The 527CA 3304 DIT engine is coupled to a high capacity skidder-type torque converter and a 3-speed powershift transmission, which transmits more engine torque to the track for higher drawbar capability and fuel efficiency. The torque converter functions to match engine power to skidding and traction load requirements, to minimize track slippage and to maximize drawbar pull in poor underfoot conditions. Ultimately, this reduces operator exertion and improves machine productivity.
A skidder-type torque converter is an efficient converter designed to transmit more engine torque to the track for higher drawbar capability. In contrast, a bulldozer-type torque converter is designed to absorb some of the engine torque, which allows the tractor to better handle the highly variable loading typical of dozing applications.
The 527 track roller frame and undercarriage system deliver superior balance required of skidding. The track roller frame extension places rear idlers beneath grapple/winch loads, improving skidder balance and performance. Having more track under the load greatly enhances the tractor's balance and ability to handle large loads, and reduces the potential for track spin to lower track wear and increase productivity.
All of the 527 track options consist of D6R-sized heavy-duty components to deliver maximum undercarriage life. The use of D6R undercarriage prolongs the life of key undercarriage components including: rollers, idlers, sprocket segments, pins, bushings, track links, and shoes.
The Elevated sprocket design provides the 527 with 71.2 cm (28 in) of ground clearance; and clutch-brake steering give the 527 the required agility and ability to maneuver in severe underfoot conditions.
Minimized Ground Disturbance
The extended track roller frame increases the track-to-ground contact area and decreases the ground pressure. This increases the 527's flotation and provides maximum performance and maneuverability in soft underfoot locations. Increased flotation also reduces the environmental impact, enabling the 527 to operate in site-sensitive applications.
Proper track selection depends on operating conditions. The 560 mm (22 in) and 610 mm (24 in) tracks are designed for firm underfoot conditions or for situations that do not require maximum flotation. The wider 760 mm (30 in) tri-link track option lowers ground pressure and is suited for soft ground conditions.
The 124 gross kW (166 gross horsepower) and a torque converter driveline provide a 49 percent torque rise and a drawbar pull of 30 276 kg-force (66,746 lb-force). This pulling power enables the 527 to overcome drag loads created during skidding.
The combination of tractor balance, torque converter drive train and high drawbar pull enable the skidder to offset the weight and overcome drag loads created during winching situations. The 527 winch is a durable and productive tool that delivers an impressive 31 388 kg-force (69,200 lb-force) of line pull.
Swing Boom Grapple
The 527's superior balance and extended track roller frame provide a superior platform for grapple skidding. The machine's weight distribution and longer undercarriage combine to offset the weight and pull of grapple loads and to keep the front of the tractor on the ground. The tractor's balance and pulling ability are most evident in uphill skidding applications, poor underfoot conditions, and side-slope skidding. With a swing boom attachment, the 527 needs less maneuvering and positioning to reach downed timber delivering high productivity, and less ground disturbance.
The 5P Power Angle Tilt (5P-PAT) blade is a highly versatile tool that allows complete blade adjustment from the operator's compartment. The ability for the operator to angle and tilt the dozer while operating is a significant performance and productivity enhancer. The operator can hydraulically adjust angle and tilt on the go, to focus the 527CA weight and horsepower on tough digging spots, effectively increasing the 527 digging forces to that of larger tractor. Further, hydraulic angle and tilt allows precise placement of material for faster doze cycles, and more efficient terracing and pioneering.With the knowledge of industry expectations gained since the introduction of the 527CA, Caterpillar designed a 527 PAT dozer specifically for Asian market requirements. It combines the control advantages of the 5P-PAT, with the durability and ease of material casting performance of the MA. The new 527 PAT dozer provides machine width coverage when fully angled, but will not compromise the 527's balance and stability in adverse terrain maneuvering. With appropriate dozer width, improved cutting edge angle and moldboard curvature, combined with the performance advantage of hydraulic angle and tilt, the 527 PAT dozing capabilities can be raised to equal the industry standard D6G.
Two cab options are available on the 527. Both cabs are designed for operator comfort and operation ease. The 527 open ROPS canopy includes standard rear, front, and side screens as well as screened doors. The side and rear screens are mounted on the outside of the ROPS structure for increased canopy area.The enclosed ROPS certified cab is ergonomically designed with a focus on operator comfort and convenience. The ROPS certified cab is isolation mounted to reduce sound and vibration and features standard air conditioning, heater, air pressurizer, and air filter to provide a comfortable operating climate.
The 527 features a state-of-the-art closed-center, variable-flow, pressure-compensating hydraulic system for braking, steering, and blade functioning. The variable displacement piston pump draws power from the engine only when steering, dozer, brake, or grapple actuation demands flow and/or pressure.
Auto-grab Grapple Hydraulics
All grapple-equipped 527s feature the Auto-grab hydraulic system, which helps maintain a secure grip on grapple loads and reduces the potential for dropped timber.
A single-lever blade control manages all blade functions including height, angle and tilt and a single-lever grapple control allows for simplified operation and reduced operator fatigue.
Less service time means more working time. Major components are made as modules and most can be removed without disturbing or removing others. Ground level access provides convenient servicing to most filters and lube points. Centrifugal prescreener removes large debris before it reaches the internal air cleaner, significantly increasing engine protection. Spin-on fuel and engine oil filters save changing time. Radial seal air filters are easy to change, reducing air filter maintenance times. 24-volt electrical system delivers increased electrical power for engine cranking, lights and engine diagnostics.