A program for equipment dealers and customers in Chattanooga, Tenn. was the venue for Komatsu America (www.komatsuamerica.com) and Komatsu Mining Systems (www.komatsumining.com) to unveil several upgraded machines to the U.S. market this spring. Two wheel loaders, a large excavator, a mobile crusher and three tracked dozers are particularly suited to the aggregates industry.

Large and small wheel loaders Upgrades-from dash-2 to dash-3 models-at both ends of the wheel loader size spectrum include larger buckets, greater horsepower, quieter operation and larger, more comfortable cabs.

Komatsu Mining's WA800-3 wheel loader, which has been sold in other countries, made its U.S. debut. Equipped with a 14.4-cu-yd bucket and standard boom arms, the loader has a 15-ft 6-in. dump height. Optional high-lift arms, used with a 13.1-cu-yd bucket, provide 17-ft 11-in. dump height, enough to load all 100- and 150-ton trucks on the market, according to Komatsu.

The WA800-3 is powered by a 808-hp Komatsu 12-cylinder diesel engine that meets all EPA Tier 1 regulations, the company said. Steps and a platform on the left side of the engine provide access for all daily maintenance. An air cleaner extension, power train guard, high-pressure in-line filters and pre-lube starter are standard. Automatic transmission and Lincoln automatic lube system are optional.

A steering wheel, joystick steering and kick-down switch also are standard. All four wheels have hydraulically actuated, wet multi-disc brakes.

Near the other end of the wheel loader spectrum is Komatsu America's WA250-3 Avance Plus. Upgrades to this dash-3 model include 180 degrees swing-back doors, reduced noise level, pilot hydraulic controls, increased power (to 131 hp) and increased bucket size (to 3 cuyd).

It comes with a standard, electronically controlled automatic transmission that has four forward and four reverse speeds. The wheel loader's sealed wet disc brakes have hydraulic actuation.

Mining backhoe and shovel Komatsu Mining's PC1800-6 excavator, currently available in a 15.7-cu-yd backhoe configuration, is expected to be available as a front shovel by the middle of this year. The machine is powered by twin diesel engines with a combined 908 hp.

The PC1800-6 features Komatsu's new Vehicle Health Monitoring System, which includes self-contained diagnostics, a preventive maintenance scheduler and machine performance history.

The excavator offers three working modes to adjust machine performance to working conditions. In addition, a boom selector provides two operating modes. Each main hydraulic pump has a dedicated, high-pressure in-line filter. An independent circuit controls swing functions.

Dozers and rippers Komatsu's D475A-3 and D87E-2 tracked dozers were introduced to the U.S. market at the spring event and its D375A-3 was reintroduced with an improved design.

The 52,885-lb D87E-2 has a 230-hp turbocharged diesel. A two-speed geared steering module maintains full power to both tracks during gradual turns, the company said. There is a conventional clutch-brake for pivot turns. The steering system is coupled to a three-speed torqflow transmission and torque converter with six forward and six reverse gears, all shifted with a single transmission control lever.

The dozer is available with a 9.2-cu-yd semi-U blade.

Changes to the D375A-3 dozer, effective with serial number 17501, are in response to customer feedback, Komatsu said. Improvements to operator comfort and machine serviceability include:

* seven-roller undercarriage, providing a longer effective track length;

* wider cab with more interior space and vertical front windows to minimize dust accumulation;

* servo valve to provide better steering control;

* adjustable positions for the steering lever and left armrest;

* greater air conditioner capacity and relocated ducts; and

* larger hole in the cab floor for access to hydraulic and powertrain components.

The D475A-3 dozer has a 860-hp diesel to provide the power to push a standard 45-cu-yd blade or optional 58.9-cu-yd Super Dozer blade for special applications.

Another option is the Track Shoe Slip Control for ripping applications. This system governs power from the engine by monitoring theoretical speed and actual speed, then adjusting for the difference, the company said. The adjustment decreases track spinning, which improves both track life and traction.

Fuel consumption and emissions are improved, according to Komatsu, due partly to a new electronic governor coupled with new dual after-coolers and a lock-up torque converter.

Komatsu's BR500JG-1A expands its line of mobile jaw crushers. Weighing 126,000 lb, the track-mounted crusher operates by two hydraulic motors with belt drives, one on either side of the crusher. This improves drive-system durability and provides better machine balance, according to Komatsu.

A two-stage grizzly feeder, turned on and off by remote control, moves rock from the hopper into the 30- Yen 42-in. jaw crusher. Crusher capacity ranges from 93 to 507 tph at discharge settings of 2.8 in. to 7.8 in., respectively, according to the company.

The crusher is built on Komatsu's PC400 tracked excavator undercarriage and powered by a 306-hp diesel engine.

Transporting the BR500 over the road requires removal of the crusher and hopper. The main tracked body can be hauled on a 30-ton lowboy. Disassembly and reassembly each require half a day, Komatsu said.