Phelps Dodge Mining is eager to replace engines in its 793B and C haul trucks with Caterpillar's 3516B High Displacement (HD) diesels. Nine of 14 trucks at its Bagdad copper mine are already changed, and the new engines are using 10 to 15 percent less fuel.
The 3516B HD - with single-stage turbochargers and no wastegate - responds to throttle input more quickly than the short-stroke 3516B and has an improved torque curve.
While it's true that the HD engines are a ready cure for head-leakage problems that plagued the 793's original engines, the retrofits are not economical based on downtime savings alone. Many of Phelps Dodge's 793Bs must be wired for Cat's VIMS electronic controls to run the new engines.
"It's the production advantages and fuel economy we're after," says Kenny Hill, strategic commodity manager. "In some cases, we're seeing clear evidence of a 50-percent rate of return on the investment"
Refitting Cat 793 haul trucks with Cat's 3516B HD diesels has cut fuel consumption by up to 15 percent and improved productivity.