The new Cat C2 Series articulated dump truck range includes the 314-hp (234-kW) 725C2 and the 367-hp (274-kW) 730C2 and 730C2 EJ with ejector-type body. Rated payloads are 26.5 tons (24 tonnes) for the 725C2 and 31 tons (28 tonnes) for the two larger models. Standard automatic traction control ensures efficient operation of the new models, which advance the design of predecessor models with increased productivity, lower operating costs and added rimpull/retarding capability, while retaining the long-term durability, high availability, high resale value and optimum rental margins of previous models, according to the company.
Engines in all three models are available that meet or are equivalent to world emission standards: U.S. EPA Tier 2/EU Stage II, Tier 3/Stage IIIA or Tier 4 Final/Stage IV. A diesel particulate filter and selective catalytic reduction system provide exhaust aftertreatment for Tier 4 Final/Stage IV models.
The Cat 6F/1R power-shift transmission electronically modulates clutch engagement pressures for smooth, positive shifts and incorporates the Caterpillar Advanced Productivity Electronic Control Strategy (APECS) system. The APECS system improves acceleration, maintains torque converter lock-up (and ground speed) during shifts, provides automatic speed holding, and modifies shift points to match operating conditions. Net benefits include high productivity, optimum control and increased fuel economy.
For controlling downhill speed, the 730C2 and 730C2 EJ employ an engine-compression brake that provides 60 percent more retarding force than previous models. The 725C2 uses a fluid retarder with four operating modes. Both systems effectively manage speed and minimize service brake application for extended brake life.
All three new C2 Series models feature full-time, six-wheel drive and are equipped with wet disc clutch locks in the cross axle and inter-axle differentials. Automatic, on the go application of the locks is fully proportional, engaging only the required amount of lockup to maintain traction in adverse conditions – with no input from the operator. Also, new for the C2 range is all-axle wet brakes. The sealed system prevents the ingress of debris and extends brake life.
The new models also feature field proven major structures that ensure long-term durability in severe applications. The front frame incorporates box section longitudinal beams, and the rear frame uses a four-plate box construction to reduce stress points. The hitch retains its durable two-piece construction, using a cast-steel head bolted to a hard wearing, forged steel tube that maintains a tight, trouble free connection between the frames.
Three-point, oil/nitrogen front suspension and walking-beam rear suspension effectively absorb haul road impact to allow safe, high speed travel. The newly design dump body, using high strength Brinell HB450 wear resistant steel for added resistance to impact and abrasion, features a diverging flow design that promotes clean dumping and minimizes material carry-back. The body top rail design reduces material spillage in the loading area, and a fully welded front bumper and full-width belly pan provide enhanced machine protection.
To promote safe operation, the cab features integral ROPS/FOPS construction. An electro-hydraulic secondary steering system automatically activates in low pressure situations. The park brake is spring applied, hydraulically released. External switches for fuel cut-off and electrical disconnect are easily accessible outside the machine.
An electric hood, which is raised and lowered via a switch in the cab, provides ample access to routine service points, and the rear of cab mounting of the radiator (using long life coolant) allows easy access for cleaning. The cab tilts for access to the transmission, drive shafts and hydraulic components, and an electrical service center in the cab provides a power port, diagnostic connector, and Cat Data Link connector. Extended drain intervals for engine oil and hydraulic fluid lower maintenance costs, as do adjustment-free wheel bearings.
The optional Cat Production Measurement system brings payload weighing to the cab, helping operators work more productively and accurately. The integrated system calculates payload values using sensors located on the walking beam suspension and shows when target weight is reached, thus maximizing payloads and productivity, while reducing overloading that results in premature wear.