Page 150 - Advances In Productive, Safe, and Responsible Coal Mining

134 Advances in Productive, Safe, and Responsible Coal Mining

Fig. 8.16 EW node about 3850ft inby the portal and the nearest secondary EW node.

Fig. 8.14 shows location details for a pair of FMNs in the area 3200ft inby the por-
tal on the primary EW. These nodes provide links in long straight tunnel segments
with no major obstructions. Fig. 8.15 shows the FMN on the primary EW 3850ft from
the portal. The nearest FMN on the secondary EW, also shown, is located between a
set of air lock doors. The inby pointing antenna associated with the node is positioned
inby the airlock.
Fig. 8.16 shows the terminal portion of the EW test area. The 90 degrees corner of
the primary EW is about 4400ft inby the portal. There are two BCN locations in the
area of the corner. The primary EW FMN is at the corner with two antennas directed at
right angles, inby and outby. The secondary EW FMN at the corner has three antennas
configured for 25%/25%/50% power split. The 50% portion is directed outby toward
the airlock (backward “D” symbol at the lower right of the figure). One of the two 25%