In 2019, FLANDERS completed the first DC to AC conversion on a dragline in Australia at BHP Billiton Mitsui Coal’s (BMC) South Walker Creek mine. After several months of digging, the mine is reporting a significant increase in production due to improvements in machine availability numbers and dig rate. Furthermore the operators are very pleased with the smooth operation from the Flanders Control System and there is evidence of a reduction in boom stress alarms.

FLANDERS pioneered DC to AC dragline upgrades to help surface mining operations transform older machines into high-producing assets that require less maintenance. These upgrades combine four key FLANDERS dragline technologies:

• Liquid-cooled, excavator-duty AC drives that reduce drive maintenance by half
• FLANDERS AC motors—specifically for draglines—that yield 110% peak power over OEM
• Advanced FREEDOM control system with Active Front End (AFE) technology
• INVISION condition monitoring, which increases machine uptime by enabling timely predictive maintenance

This Marion 8050 marks the 5th large walking dragline converted to AC by FLANDERS. The company pioneered the first purpose-built DC to AC dragline upgrade for a customer in North America. This was back in 2012 for a 50 year old Bucyrus Erie 770 at Armstrong Coal’s Lewis Creek mine in Western Kentucky.

Conversion from DC to AC reduces costs with energy efficiency gains; while power gains of 30% are possible with FLANDERS M Series motors. There is also 80% less electrical maintenance with FLANDERS AC upgrades. The FLANDERS R&D team developed the first liquid-cooled AC drive for draglines. Liquid cooling reduces noise and heat levels in the house and makes it possible to place electronics in a sealed enclosure, eliminating the need for dust filters and corresponding maintenance. This AC dragline drive system is 92-93% efficient, compared to ~80% for DC systems, reducing cost per tonne by lowering electricity costs of running the dragline. With little to no market stomach for very high cost new draglines, these types of upgrades are likely to be a major focus for operators going forward.