The objective of this program was to design, fabricate, install, and test a pneumatic braking system for 10-ton mine haulage cars that complies with the intent of the Coal Mine Health and Safety Act of 1969, Public Law 91-173, sec. 314. The program dealt with a braking system capable of automatic operation in the breakaway mode and as a manually operated parking brake for five 10-ton coal mine cars. The program borrowed on data, concepts, and designs originated in another Bureau of Mines contract report. Based on the use of standard truck brake control components, the advanced concepts produced a well-performing brake system consistent with reliability and low overall cost.