The recipient of the 10SC32AA was Massey Energy’s Voyager mine in Kentucky which took delivery of the unit last month. Voyager is operated by Massey subsidiary Martin County Coal.

The Optidrive AC with VFD was introduced to the market in the US spring of 2003 and is now in use underground in 10 countries including the US, UK, Australia, China and South Africa. In 2008, nearly 100% of Joy’s new shuttle cars shipped were Optidrive units.

The company’s introduction of the Optidrive shuttle car brought with it a faster top speed (from four miles per hour to 6mph), the international standard, which it said can potentially increase mine production by as much as 10% – or the equivalent of five extra loads per shift.

“Optidrive was a major breakthrough in applying AC variable frequency drive to shuttle cars and has resulted in significant increases in power, speed and productivity,” Joy engineering technologist Doug Anderson said.

“Mine performance studies have shown Joy shuttle cars with Optidrive AC VFD have less motor maintenance when compared to haulage vehicles having AC/DC drives or DC drives, primarily because DC traction motors have brushes that must be replaced about every six months,” Anderson said, adding that the maintenance costs of these Optidrive shuttle cars are typically lower than AC drives with soft start.

The original engineering manufacturer said both new and rebuild shuttle cars now possess the AC VFD feature.