The H Series wheel tractor-scrapers include the 621H single-engine, open bowl machine, the 623H with elevating scraper and a single engine and the open-bowl 627H with twin engines and all-wheel drive. Capacities are 24 cu. yds. for the 621H and 627H, and 23 cu. yds. for the 623H. The 621 is also available in a push-pull configuration for the first time.
The Cat C13 engine in the tractor produces 407 hp, 18% more power compared to the G Series predecessors. The C9.3 on the 627H scraper produces 290 hp, an increase of 19%. The new torque converter coupled to the scraper engine is designed to put more power to the ground. The 8-speed planetary powershift transmission hardware is the same as the G-Series unit, but new controls and software drive greater performance.
The H Series offers three new integrated technology options. Sequence Assist uses integrated software and position sensing cylinders to automate many of the tasks an operator performs when loading, hauling and dumping. The operator simply sets preferences for bowl and apron height and pushes a button to ready the machines for loading, then hauling, dumping and return to cut. The system automatically sets the cushion hitch, bowl height, apron, ejector and elevator.
Load Assist is available on the 621H and 627H models. It builds on Sequence Assist by loading the bowl with the push of a button. As the machine enters the cut, the operator can activate Load Assist so the system takes over control of the cutting edge height, limiting tire spin based on integrated sensors and GPS technology to ensure consistent and full bowl loads. The operator is responsible only for the throttle and steering. This helps get operators up to speed quickly.
"Contractors can achieve 85% to 90% efficiency level from all operators," says John Gerhold, Caterpillar product manager. "Running a scraper no longer requires the same level of operator experience."
Cat Grade Control is available on all three models and is designed to work seamlessly with Sequence Assist and Load Assist. The optional system is available from the factory and fully integrated into the machine.
Other H Series features include:
- 21% larger cab with Cat Advanced Ride Management System to dampen vibration and prevent end-stroke shock loads
- Multi-function hydraulics enable the operator to operate the apron, ejector and bowl height control at the same time for faster cycle times
- Optional Work Area Vision System (WAVS) provide views of the cutting edge, right side and rear of the machine
- Cushion hitch configuration with a high-pressure and lower pressure
- 33.5-mph top speed (loaded)