Caterpillar has brought the single-engine 651 wheel tractor scraper back to market with powertrain, control, hydraulic and structural upgrades to improve productivity and ensure a high return on investment. The unit features a 33.6 cubic metre (44 cubic yard) heaped capacity and 46.4 tonnes (52 tons) rated capacity. The new WTS shares the same bowl design and many components as the 657, which gives companies with mixed fleets the opportunity to stock fewer repair parts and reduce costs.
The scraper's new Advanced Productivity Electronic Control System (APECS) fully integrates the transmission and engine drivetrain to provide smooth and responsive shifts, allowing the 651 to move more material faster. Its electronic clutch pressure control features advance shift control logic for smoother speed and directional shifts, while part throttle shifting controls transmission shifts for smoother shifting between gears. Preventing loss of momentum during shifts, the shift torque management system carries higher torque through shift points.
Its single engine design features the Cat C18 engine powering the tractor with 469 kW (629 hp) and meets EU Stage V/U.S. EPA Tier 4 Final emission standards. The design gives the 651 the ability to work with a Cat D10 or D11 push dozer for ultra-fast load times, even when working in abrasive or rocky conditions. With its 8-speed transmission reaching a top speed of 56.1 km/h (34.8 mph), this WTS delivers fast cycle times.
Boasting the same, larger cab as the 657, the 651 improves operator comfort and delivers easier ingress/egress. Relocation of the heating, ventilation and air conditioning (HVAC) system to below the cab plus steering column and pedal repositioning help to improve visibility.
The scraper's new high-pressure steering system requires significantly less steering effort, reducing fatigue and improving productivity further into the work cycle. Improvements to the hydraulics include an electrohydraulic implement system for improved multifunction capability and a short throw for the T-handle implement control. Cat advanced ride management eliminates end-stroke events of the seat suspension cylinder. Three camera locations for the optional Work Area Vision System (WAVS) show the cutting edge, right side and rear of the machine on a 178-mm (7-in) in-cab colour display.
Auto-stall, new for the 651, assists in warming up the transmission oil faster when working in colder ambient temperatures, so the machine is quickly ready for work.