Terra Cat is proud to have partnered with OceanaGold Macraes on a major project to resurrect three Cat 789C trucks.
When the trucks were first parked up in 2014 or 2015, each truck had accumulated about 65,000 to 70,000 frame hours since being delivered new to Otago’s Macraes mine in 2002. The 789D model superseded the 789C, and Macraes operates a C and D series truck fleet.
Since being parked, the three trucks had slowly been stripped of much of their componentry and parts, leaving them exposed to the elements, says Mining Account Manager David Baillie.
They resembled outback wrecks more than useable haul trucks! However, Cat trucks are built to be rebuilt and are known for their durability and for delivering multiple lives.
After an initial review and assessment on site, we found the trucks’ core frames were in good condition and well suited for repair and rebuild.
The first truck was recovered from the Macraes site and taken to Terra’s Christchurch workshop, where it was stripped back to a bare frame for a full evaluation. This inspection found the frame was in good condition overall. The decision was made to rebuild, and upgrade to a 789D high horsepower powertrain.
The rebuild started with repairing the frames, including replacing the torque tube assembly. The front frame rails were extended to better support the front walkways and to provide additional protection to the bottom of the radiator and cooler group.
The major change to the powertrain was the upgrade to the engine. The 789C trucks use a 1,900 horsepower 3516B (69 litre) engine, featuring a jacket water aftercooler system. This was replaced with a Cat Reman 789D 2,100 horsepower 3516C (78.1 litre) high displacement engine with an air-to-air aftercooler system.
These engines meet higher emission standards and offer improved efficiency.
The torque converter, transmission and other powertrain components were rebuilt by Terra’s Component Rebuild Centre in Christchurch to match the engine output. The rebuilt powertrain meets Cat-certified standards and is supported with a ‘like new’ warranty. To match the rebuilt powertrain, all the other systems on the truck were rebuilt or replaced including pumps, lines and hoses, cylinders, suspension, and wiring. This was completed with refurbished cabs.
Through the rebuild process, and once assembled, the trucks go through extensive testing at Terra Cat. They’re then returned to Macraes where new wheels and tyres are fitted. New lightweight truck bodies have been installed giving a reduced empty truck weight, allowing them to optimise the payload.
Onsite testing has proven the value of the rebuilds with excellent performance and a like-new feel to the truck
The second rebuilt truck was returned to the site in May, with the third truck scheduled for later this year.