Motors & Drives Information

Haul truck capacity breaks through 300.ton mark; are 400-, 450, or even 500-ton trucks just around the corner?

"Too much is never enough" is a phrase that fits the rigid frame mine haul truck market. Over the last 30 years, haul truck size has grown remarkably and as the trucks have grown, the development time between each new generation of giants has shortened.

The newest vehicles, haul trucks in the 320- to 360-ton capacity range, are clearly the new benchmark, which begs the question: are 400-, 450- or even 500-ton monsters around the corner?

While no manufacturer appears willing to go that far, most agree that, based on past experience, it is plausible that such trucks may eventually be seen rumbling around mine sites, given some advances in the technology of tires, engines and drivetrains.

"Manufacturers cannot build larger capacity trucks just for the sake of building a larger truck," said Glen Carlson, senior product specialist at Komatsu Mining Systems. "The end goal is always a higher efficiency more economical truck."

The beginning of the dramatic growth spurt in haul trucks began in the mid-1960s. Prior to that, mechanical drive trucks were the standard and they grew appreciably from 27 to 35 tons in the 1950s to 60 to 70 tons by the end of the decade.

But in the '60s came d.c. diesel electric drives, a technology borrowed from locomotive markets, and truck size, which grew incrementally before then, began to advance in leaps and bounds, from 85 tons to 200 tons and more by the end of the 1970s. By the mid-1980s, 240-ton haul trucks were the standard. Mechanical drive configurations also grew, mirroring their electric drive counterparts.

As early as 1973 Terex developed a three-axle, 350-ton hauler, but the drivetrain and tire technology didn't allow it to operate effectively and economically, rendering it an interesting aberration.

Until 1996, that is, when Komatsu Mining Systems introduced the Haulpak 930E, a 320-ton a.c. electric drive truck. More recently, Liebherr has introduced its T282, 360-ton diesel a.c. electric truck (see story elsewhere in this issue). In addition Caterpillar has unveiled its latest entry in to the haul truck market, the mechanical drive 797 haul truck, which has a rated capacity of 360 tons and later this year, Terex Mining Systems will introduce a 340-ton truck, the MT5500.

# posted by Medical Information : 3:56 AM