Caterpillar has met the strictest Tier 4 emissions standards with the Cat 794 AC mining truck.
The 290-tonne 794 AC truck features the Cat C175-16 diesel engine. It is equipped with an exhaust aftertreatment system using a selective catalytic reduction system (SCR), which uses diesel exhaust fluid to reduce emissions of nitrogen oxides.
Caterpillar selected the SCR solution due to its “robust and reliable” Tier 4 final emissions compliance without sacrificing engine performance.
In field testing, of more than 20 million operating hours, the Tier 4 pilot trucks matched the performance and productivity of the Tier 2 equivalent versions of the 794 AC.
The modular SCR design is adopted from other Cat production machines, and boasts easy serviceability with readily accessible components.
It is aligned with truck preventative maintenance intervals to maintain high availability, according to the original equipment manufacturer.
Caterpillar conducted an on-site performance study of the 794 AC Tier 4 final trucks in a copper mine, and measured no loss in performance or productivity compared to the Tier 2 equivalent 794 AC trucks.
The Tier 4 trucks also delivered lower operating costs by reducing fuel consumption. The trucks have completed more than 10,000 hours of operating time in North American mines.
Caterpillar is using the same exhaust platform to progress its European Union Stage Five certification.