Caterpillar launch new 777G dumptruck
Redesigned G-Series rigid truck features new technology for high production and fuel efficiency
BUILDING on the legacy of performance, reliability and long-term durability established by Cat 777 models since 1977, the design of the new 777G focuses on productivity, fuel efficiency and enhanced visibility as well as operator comfort, convenience and safety.
Replacing the Cat 777F model, the new 777G off-highway truck has a rated payload of 89.4 tonnes and a standard-body volume (SAE 2:1) of 64.1 cubic metres. It is powered by a Cat C32 ACERT engine that delivers 765kW (1,025hp) and meets US EPA Tier 4 Final as well as EU Stage V emission standards.
The engine incorporates a number of fuel-conservation features, including: Auto Neutral Idle, which allows the 777G transmission to intermittently shift to neutral when the truck is idling in a forward gear to avoid stalling the torque converter and increasing engine speed; and Engine Idle Shutdown, an operator-selected feature that stops the engine when the truck idles in park for more than a pre-set interval.
In addition, speed limiting provides an alternative to gear limiting the 777G by allowing the truck to travel at a more fuel-efficient engine speed and in a more efficient transmission gear, whilst Advanced Productivity Electronic Control Strategy (APECS) transmission controls boost fuel efficiency by maintaining momentum and speed on uphill grades during shifts.
The 777G also features two operating modes: Standard Economy saves fuel by reducing engine power by 0.5–15%, based on the fleet and economic conditions at a particular site; whilst Adaptive Economy automatically evaluates the power rating needed to meet baseline requirements – full power is applied when needed, and reduced power is applied when appropriate.
The efficiency of the new truck’s performance is further enhanced by 7% more engine torque and an increase in top speed.
The 777G features a redesigned cab that is easier to enter/exit and comes with a new operator seat on the left and a more comfortable trainer seat on the right. A new console with an integrated hoist-and-shift lever enhances convenience, as does more interior space for storage.
The truck’s design also provides improved visibility of both the work area and instrumentation, whilst overall visibility can be further enhanced with an optional object-detection system. For convenience, the cab spec includes a powered left window, automatic temperature control, throttle lock for long uphill grades, and a 50% reduction in interior sound level compared with previous models.
Operator safety is a primary factor for the 777G, with roll-over and falling-object protective structures integrated into the cab’s design. Laminated glass is used in the front and left windows, and emergency egress is provided via a right-side hinged window. A ground-level engine-shutdown switch is readily accessible, and a secondary steering system is provided in the event of the primary steering system failure.
Powerful wet-disc brakes are used at all four corners and provide parking brake and slope-holding capability. Brake life can be extended with an engine brake, whilst a brake-wear indicator facilitates timely maintenance. Automatic retarding adds to positive control on downhill grades and a new steering-sensitive traction-control system assists when ground conditions deteriorate.
The 777G’s major structures are designed for long-term durability in harsh operating conditions and engineered to allow for more than one powertrain life cycle. Box-section castings are used strategically in high-stress areas, whilst a new front frame design increases the approach angle on ramps and grades, and a heavy-duty rear-axle housing allows increased lubrication and filtration of critical components.
The dual-slope body option, designed for optimum material retention, has a heaped capacity of 60.2 cubic metres, whilst the flat-floor X body option has standard heaped capacity of 64.1 cubic metres. Rubber or steel liners are available for both bodies.
For serviceability, fluid-fill and extraction points are grouped for convenience and all check points are located at ground level and lighted for night access. Moreover, a master disconnect switch, engine lock-out switch, and hydraulic lock-out switch provide added convenience when servicing the 777G.
