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July/August 2017 www.coalage.com 17 longwall mining continued "We gained the ability to run full shield au- tomation at that time," Colaw said. At the same time, they installed a quad, color-integrated lighting system. "We worked with Cat on the first design in the U.S. as far as laying out the color scheme and what each would be used for," Colaw said. "We use yellow strobes to pre-warn for conveyor starts. We also monitor AFC current and strobe a yellow light around the shearer area when they approach an overload condition. The displays on each PMCR will show a percentage of AFC load at any time. A blinking red light indicates automated shield movement or the push of the stageloader. A solid red light indicates manual movement. A green light indicates a lockout for shield maintenance, which is very useful for the maintenance personnel, as it's easy to see up and down the face." A blue light indicates information is available on the display. "We will flash a blue light every five shields up and down the face," Colaw said. "If a shield fails to ad- vance, the blue light will indicate the fault and the miners simply check the Cat PMCR to read the information about the fault." The Cat PMCR allows full shearer-initi- ated roof support advance, including gate- end turnarounds, wedge cuts, bank-push, and batch advances. "Once we installed the system, we were really motivated to start using the automation," Colaw said. "It's be- come a standard for us at the mine now." The Joy shearer is equipped with pitch and roll sensors, arm inclinometers, and cowl and haulage encoders. The primary form of communication is fiber, which has been installed inside the trailing cable, with a backup secondary ethernet BPLM system. The ASA system with recorded roof and floor targets automatically posi- tions the trailing ranging arm to accurate- ly cut the floor profile. "We have upgraded the hydraulics on the shearer to increase the turnaround times in the gates," Colaw said. "We also use AFC load monitoring and speed zones. It's an enhanced version of the external feedback. Instead of having a set hard percentage of slowdown, we let it fluctuate through an algorithm." Joy worked with Tunnel Ridge to devel- op gate-end programs that stop the shear- er at a fixed point in the headgate and at adjustable points in the tailgate. The tail- gate uses a Joy Dynamic Chain Control management system (DCM), which com- municates to the shearer and lets it know its position. "When we are mining into the gates remotely, the operators do not have to worry about where to stop," Colaw said. "We let the program handle it." The shearer is also equipped with vid- eo and sound. "We have a microphone inside the shearer," Colaw said. "It's very useful. We can listen to the drives. When- ever we break out on the gate ends, you can hear the drives release. There are eight cameras and two lights on the shearer. We developed the camera housings, mounts and sprays, and positioned them on the shearer for the best visual clarity." The Command Center When automated operations began in ear- nest, Tunnel Ridge needed to determine a location for the Longwall Command Cen- ter. Colaw and his team reviewed several options to physically place the command center. "We considered the beltline, belt heads, outside, on the face, etc., but we re- ally wanted to put it with the 'mule train,'" Colaw said. "We sketched out what we wanted it to look like and now we have a patent-pending design. The initial con- cept was developed in-house and, in the end, it didn't differ that much from the original design we sketched out." The Longwall Command Center has a positive pressure, climate-controlled fil- tered atmosphere. It has Internet Protocol (IP) phones for the outside world and radio communications with multiple channels to communicate with face personnel and out-by miners. The command center has a Joy display, a Cat display, a mine monitor display, several camera displays, a longwall profile graph and the foreman's computer. "The Joy display and the other op- erating displays are all real time," Colaw said. "The operator has a good indication of what's happening on the face at any time. The foreman's computer allows pro- duction foremen to log information and maintenance foremen to see parts books." The command center is rail-mounted with an adjustable top, which allows it to be transported easily underground. Outside, Tunnel Ridge has construct- ed the Longwall Command Room. Using larger screens, it displays much larger images from the cameras and the other screens and graphs. "We have enhanced the views," Colaw said. "These two com- mand units have worked very well for us." Automated Operations Typically, when the longwall is running, one shearer operator is on the face up- wind from the shearer monitoring activity, while the other operates the shearer from the command center. They switch during lunch time. "The shearer operators use different screens in the command center to run the automated system," said Kyle Faykus, automation engineer for Tunnel Ridge. "The maintenance people look at a different set of screens to troubleshoot systems. The Joy screen reports on the AFC status as far as the TTT couplings (fill, drain and temperatures), solenoid states, speeds, as well as the DCM (target stroke, sys- The current Longwall Command Center (right), which is rail-mounted, does not differ a whole lot from the original version the engineers sketched (left).