When designing the new R1700 XE battery-powered load-haul-dump (LHD) machine, Caterpillar relied upon its long history in designing electrified machines and power generation components and solutions.
This included more than 350 patents spread across such products as the electric-drive D7E and D6 XE crawler dozers, the 988K XE wheel loader and the 794 AC and 795F AC mining trucks.
The R1700 XE program also uses components from the Cat Microgrid solution. For underground mining, the electrification experience was backed by the development of a proof-of-concept machine where Caterpillar converted a conventional mechanical Cat LHD into a battery-electric platform.
Battery-powered LHD machines have the potential to impact the economics of underground-mining and the capability of opening new mines.
The benefits include reducing ventilation infrastructure requirements and costs; generating less heat and dust that must be removed with additional air conditioning; and lowering the overall operating costs of the mine.
For a battery-electric driven LHD to achieve these benefits, it must balance high production capability with extended run times between battery charges.
Caterpillar has chosen to make its new R1700 XE the company’s first battery electric platform while using fast, onboard charging to facilitate high production levels. The new Cat R1700 XE will be positioned and engineered to accomplish these critical design parameters.
The Cat R1700 was introduced last year as a redesign providing customers with productivity improvements. The improvements mainly come from the machine’s new electro-hydraulic system, which saves fuel and provides a 65 per cent increase in lift force – leading to improved digging performance in the pile.
The R1700 XE combines these new features with a Caterpillar-developed lithium-ion battery operating and charging system.
The company’s MEC-500 charging system allows rapid, on-board battery charging with little to no impact on existing electrical infrastructure. The MEC-500 charging system eliminates battery handling during recharging, as well as its potential safety hazards, and the requirement to maintain change-out battery inventories.
The creation of the R1700 XE was achieved alongside the testing of the new MEC 500 charging system. Both developments went through substantial testing at Caterpillar’s Peoria Proving Grounds, followed by weeks of operation and testing at a customer mine in Canada.
Results were impressive, according to Caterpillar. Compared with base-line numbers for a diesel-powered R1300, the battery-powered model exhibited more than a 10-fold decrease in total energy costs; nearly an eight-fold decrease in generated heat; a significant reduction in noise at the operator’s ear; and instant torque from the electric motors. As well, the machine testing resulted in reduced dust levels, attributed to not having a conventional diesel-related radiator fan and reduced tire wear.
Caterpillar has used the insight gained from its proof-of-concept testing to design the R1700 XE and the MEC-500 charging system as a safe, profitable and productive option for mines transitioning to electric fleets.