Page 164 - Advances In Productive, Safe, and Responsible Coal Mining

146 Advances in Productive, Safe, and Responsible Coal Mining

Fig. 8.31 TSP and predicted TSP for a location in the primary EW.

Table 8.6 Predicted and measured metrics for the primary EW
location in Fig. 8.31
Location Type AA SDA 90% CD AEV ACR

844 Primary 402 215 550 h220,19i 251
844 Primary 193 125 370 h146,13i 140

Fig. 8.32 TSP and predicted TSP for a location in the primary EW.

Table 8.7 Predicted and measured metrics for the primary EW
location in Fig. 8.32

Location Type AA SDA 90% CD AEV ACR
199 Primary 119 99 336 h 6,2i 119
199 Primary 103 66 220 h59,1i 64

Stationary handset tests were performed in order to understand the variation in cal-
culations of the tracking system’s location under static conditions. The data show that
there is a general variation of roughly 200ft in a direction following the escapeway, or
400ft in either direction. The 400ft of variation is still 1/5 of the 2000-ft guideline set
by MSHA. For both primary and secondary EW, a tracked device can be located in the
general area of its actual location. A description from the tracking system could be
relayed to a miner underground and at walking speed they would have encountered
the tracked device within minutes, assuming a search along the escapeway.