Abstract
The objective of this research was to develop and test a fail-safe device that would provide positive indication of track switch point position and be suitable for application in contemporary underground coal rail haulage systems. The effort was divided into four phases as follows: (1) evaluation, (2) design, (3) fabrication and surface testing, and (4) underground installation and testing. The results are described in section 2 of the report and a sequential listing of the 53 steps employed in developing the system is Appendix A.