Caterpillar says its new 988G wheel loader incorporates innovative design features to maximise productivity and durability in the toughest conditions - and is a larger, more powerful and more productive replacement for the 988F II.

''The 988G handles buckets ranging from 6.3 to 7.0 cu m and can easily load 36- to 63-metric tonne off-highway trucks. It has the versatility of a materials handler and is highly productive in stockpile work as well as face loading," a company spokesman says. ''The most apparent innovation is the fabricated box boom which replaces the traditional steel plate lift arms used on most wheel loaders. The new boom and linkage geometry work together for increased breakout and lift forces, increased dump clearance and improved sight lines to the bucket corners. The box-section design has superior torsional strength for long life.''

Other key improvements are an increase in horsepower by 10 per cent and increased torque rise by 24 per cent; an electro-hydraulic control system to reduce operator effort and a larger cab. These innovations maximise productivity in quarry, mining, earthmoving and load-and-carry applications, he says.

Elaborating on these features, he continues: ''The structures of the wheel loader combine the use of robotic welding, box sections and castings in critical high-stress areas. Robotic welding ensures consistent welds, and castings increase strength by spreading loads and reducing the number of parts.

''The fabricated box boom spreads stresses over the full length and perimeter of the boom. The boom resists twisting and prevents stress paths that can lead to cracking. Forked ends on the boom increase reliability. Also, the new boom and dual bucket links work together for increased breakout force, higher lift capacity and improved operator viewing.

''The dump clearance of the 988G exceeds the dump clearance of the High Lift 988F II by 12 inches, and the breakout force of the 988G is 20 per cent greater.

''The six-cylinder, turbocharged and aftercooled Cat 3456 electronic unit injection (EUI) diesel engine creates 475 net horsepower (354 kW) and has torque rise of 42 per cent. It is a proven high-pressure, direct injection fuel system that electronically monitors operator demands and sensor inputs to optimise engine performance. Efficient fuel management helps provide quick response, high productivity and exceptional service life. The engine cooling system design isolates the advanced modular cooling system (AMOCS) and hydraulically-powered fan from the engine compartment. The design cools more efficiently and allows the hood to be sloped for improved sight lines.

''The electronically-controlled Caterpillar planetary, power shift transmission has four speeds forward and three speeds reverse. The impeller clutch torque converter enables the operator to use the left brake pedal to modulate rimpull from 100 to 20 per cent for reduced tyre slippage. To further adapt the machine to the underfoot conditions, the rimpull control system allows the operator to select from four preset maximum rimpull settings other than 100 per cent. Rimpull settings available in first gear are 90, 85, 75 and 65 per cent.

''The 988G is equipped to stop as well as go. Axle-shaft mounted, oil-immersed and oil-cooled multiple-disc brakes are adjustment-free, fully hydraulic and completely sealed. Disc face grooves allow cooling for fade resistance and long service life.

''The electro-hydraulic control system increases hydraulic efficiency and enhances operator comfort through low-effort fingertip controls. The two-position main hydraulic pump is controlled by the electronic control module, which adjusts hydraulic flow during the loader cycle. The control system strategy results in faster hydraulics and greater lift forces.

''The 988G has load-sensing steering that directs power through the steering system only when needed. Steering and transmission control is integrated into a single, joystick controller. The STIC control system reduces operator effort and facilitates smooth operation.

''The loader has several electronic systems available as attachments. The electronic monitoring systems II (EMS II) monitors machine functions and provides warnings when appropriate. The system also aids troubleshooting. An optional payload control system tracks and displays bucket load data, and an optional ride control system uses a hydraulic system to cushion the boom when carrying loads.

''The new cab features a spacious volume of 3.18 cu m and provides outstanding viewing area, improved ventilation and interior sound levels lower than 77 decibels. Automotive-style accommodations include a cup holder, storage bin and space for a large lunch cooler. Intermittent, wet-arm windshield wipers improve viewing in adverse weather.

''Finally, the Cat Comfort Seat replaces the previous Contour Series Seat. The air suspension seat is six-way adjustable to allow the operator to tailor the seat for optimum control and comfort.''