Shuttle Car

Shuttle cars are vehicles used in underground mining, especially room-and-pillar and longwall mining, to haul away muck.^[1][2]

[edit] History

The first shuttle car was manufactured by Joy Global in 1939. It was powered by onboard batteries supplying current to a DC motor. This design proved to be unsuitable due to a lack of power from the batteries, and was replaced by a system using trail-behind cables to supply DC current. These cars provided a constant power source and a comfortable ride; however there were still unsolved issues. While descending a gradient, DC motors could not control the speed of the shuttle car, so mechanical brakes were required. As well, under heavy loads the DC components would overheat. DC motors also require frequent maintenance.^[3]

These limitations cued the adoption of AC motors in shuttle cars. AC motors have more power and torque, making them better suited to handle heavy loads. AC motors are able to slow the vehicle when going downhill, eliminating the need for mechanical brakes. But AC motors could not provide as smooth of a ride as DC motors did. So in the mid 1970’s, shuttle cars came to market with combination AC/DC power systems. These cars used trail-behind cables to supply AC current to the car’s conveyer, the pump, and other onboard peripherals. They were able to supply DC power to the wheels by running AC power through an onboard converter. The end result was a smooth ride without overheating problems. This would remain the industry standard until 2003, when Joy Global launched their OPTIDRIVE AC VFD system. OPTIDRIVE uses regenerative braking to keep brakes cool and to hold speed when going down hills. With OPTIDRIVE, Joy shuttle cars can achieve 6 miles (9.6 km) per hour, the maximum allowed by international regulations.^[4]

[edit] How it Works/Features

Shuttle cars are heavy-duty, rubber wheeled, low profile vehicles used to haul refuse in underground mining operations.^[5]Because they operate in limited ventilation underground environments, shuttle cars run on electrical power to avoid exhaust emissions. Shuttle cars are available with optional features such as service jacks, foam filled tires, power take-off systems, and remote controls.^[6]

[edit] Common Manufacturers

• Brookeville Equipment Corporation
• Fletcher Mining Equipment
• Joy Mining Machinery
• Phillips Machine
• Sandvik

[edit] References

1. ↑ room-and-pillar mining. Britannica.com [September 23, 2009].
2. ↑ Shuttle Cars. Joy Mining Machinery [September 22, 2009].
3. ↑ Joy Mining Machinery Ships 500th OPTIDRIVE Shuttle Car. ThomasNET.com [September 22, 2009].
4. ↑ Joy Mining Machinery Ships 500th OPTIDRIVE Shuttle Car. ThomasNET.com [September 22, 2009].
5. ↑ room-and-pillar mining. Britannica.com [September 23, 2009].
6. ↑ Shuttle Cars. Joy Mining Machinery [September 22, 2009].