Company Announcement - The new class leaders in the respective 75 and 90 tonne class, Caterpillar’s latest generation Cat 374F L and Cat 390F L hydraulic excavators build on the legendary performance of the D-Series and come to market with key enhancements in terms of safety, ultra-fast truck loading cycle times, fuel efficiency, and longer-term downstream availability. These new units replace the Cat 374D L and Cat 390D L hydraulic excavators launched globally in 2010 and are designed to meet diverse production tasks ranging from mining, quarrying and road construction to large-scale earthmoving projects. F Series models are being rolled out to the southern African market from the fourth quarter of 2014. Delivering power on demand, the Cat 374F L is equipped with the Cat C15 ACERT engine, and the Cat 390F L with the Cat C18 ACERT unit. These engines models, which were also fitted on the previous D-Series machines, have been further refined by Caterpillar’s research and development team. They consume significantly less fuel thanks chiefly to two new built-in features: automatic engine speed control; and automatic engine idle shutdown.
Automatic engine speed control lowers rpm according to production demands; whilst automatic engine idle shutdown turns the engine off when it has been idling for more than a specified amount of time, which can be preset via the in-cab monitor. Operators can also switch between high power and economy mode. High power is best suited to hard digging conditions. Net power on the Cat 374F L is 353 kW (ISO 9249) and hydraulic power 311 kW (compared to 355 and 302 kW for the Cat 374D L), whilst engine rpm (operations and idle time) are down from 1 800 to 1 600. This results in an approximately 5% saving in fuel consumption and a 3% productivity gain: an estimated 8% plus fuel saving improvement overall. A similar 8% plus fuel gain is anticipated for the Cat 390F L. Net engine power (ISO 9249) and hydraulic power on the new model is 391 kW and 341 kW (compared to 390 and 323 kW on the Cat 390D L). Engine rpm (operations and travel) are down from 1 800 to 1 700, with an approximately 5% productivity improvement and a 3% fuel consumption saving. A major contributor to these machine efficiency results is Caterpillar’s introduction of the Adaptive Control System valve, a further advance on the previous generation’s Proportional Priority Pressure Compensation system. “The new ACS valve takes the PPPC system a step further and has been designed to intelligently manage restrictions and flows. It opens slowly when your range of joystick lever movement is small and opens rapidly when movement is high,” explains Barloworld Equipment group product manager, Johann Venter. “More specifically, it puts flow exactly where you need it, when you need it, which means you will experience much smoother operation, greater efficiency, and ultra fast swing speed gains in hard digging and truck loading.” (Barloworld Equipment is the Cat dealer for southern Africa.)
On the F-Series, major components like the pumps, the main control valve and oil tank are placed closer together so shorter tubes and lines can be used, which results in less friction loss, reduced pressure drops, and more power to the ground. Auxiliary circuits also enable the fitment of a range of work tools, such as hammers, grapples and rippers that are quickly interchangeable with the fitment of a hydraulic quick coupler.
The new side-by-side cooling system is completely separated from the engine compartment to reduce noise and heat. Plus it features easy-to-clean cores and a new variable-speed fan that reverses to blow out unwanted debris that may accumulate during the work day. In terms of ground engagement, in the field the new F-Series comes equipped as standard with the new Cat Grease Lubricated Track 4 (GLT4) undercarriage: their track links protect moving parts by keeping water, debris, and dust out and grease sealed in, which delivers longer wear life and reduced noise when travelling. Meanwhile, the integrated Cat Positive Pin Retention 2 (PPR2) system prevents looseness of the track pin in the track link, which reduces stress concentrations and eliminates pin walking for increased service life. Optional three-piece guide guards help maintain track alignment to improve the machine’s overall performance when travelling over varied ground conditions and gradients.
The factory integrated Cat Grade Control system provides depth and slope guidance, enabling operators to cut or fill to exact target elevation, saving money on fuel and materials. Real-time bucket tip positioning through the standard cab monitor guides the operator to grade. For added functionality, machine owners can upgrade to AccuGrade™ 3D. The key benefit of this system is that it provides 3D bucket tip position and elevation guidance, indicating precisely where to work and how much to cut or fill.