OM3070 Operation - Section 30 Operating Instructions Page 30-23 LINE STATUS SIGNAL MARKINGS The line status signals will show the following colors to indicate line status: TRAFFIC CONSIDERATION FOR TROLLEY LINE OPERATION Trucks operating on trolley assist will travel faster than trucks unable to operate on trolley, most support equipment and some maintenance equipment. Because of this speed difference, trucks operating on trolley assist will actually be able to overtake some slower moving vehicles if allowed.
To maintain the highest level of effectiveness and efficiency of the trolley system, it is important that all personnel oper- ating equipment in the pit area react properly to trol- ley assisted haulage equipment and be aware of the proper procedures to allow faster moving haulage trucks to overtake the slower moving vehicles when possible. Ready for haul traffic - green Not ready for haul traffic - red Trucks operating on trolley assist may be rejected from a trolley assist line for several reasons. They include: 1. System current overload - The trolley system is capable of power output to a certain rating.
If too many trucks are using a section of line at one time, this rated power output may be exceeded and the section of line will automati- cally de-energize, rejecting the haulage units operating on that section of line. 2. Overloaded truck - If a truck is overloaded, the power required to transition to trolley assist may be too great for the truck's electrical control sys- tem, which would cause the truck to not accept trolley assist or reject from trolley after the truck is on trolley.
APPROACHING SLOW MOVING VEHICLES IN A TROLLEY ASSISTED TRUCK As trucks operating on trolley assist approach slower moving vehicles, the truck operator must begin to reduce the trolley truck speed by notching back on the trolley control. Operators must be looking well enough ahead to begin speed reduction before the truck gets too close behind the slow moving vehicle (less than 100 feet). 3. No throttle signal - If, at any time while on trolley assist, the operator releases the throttle pedal, the truck will reject from the line and the panto- graph will lower immediately. The truck's electri- cal control system will switch the truck back to the diesel mode. NOTE:
Haul trucks must continue to maintain minimum following distances between equipment or vehicles of 100 feet uphill or on the level, and 200 feet downhill. 4. Electrical system malfunction - The truck is equipped with systems that monitor the status of the trucks trolley control system. If any abnor- mal condition is detected in the electrical sys- tem, the electric control system will lower the pantograph, and switch the truck back to the diesel mode. If a slower moving vehicle, traveling in front of a trol- ley assisted haulage truck, does not take the required action allowing the truck to overtake, the truck will reduce speed adequately to maintain proper following distances.
If proper following dis- tances cannot be maintained while operating on trol- ley assist, and the slow moving vehicle does not, or cannot, take the required action to allow overtaking, the trolley assisted truck will switch back to diesel mode, if necessary. If a truck is rejected while the operator has the throttle fully depressed, the transition back to a diesel mode will be smooth and the operator will notice the truck speed decrease from trolley speed to diesel speed. The truck will not stop and the operator can proceed up the ramp. If the operator releases the throttle pedal, the truck will stop in either mode.
If the slower moving vehicle takes the necessary action to allow the trolley assisted truck to overtake them, the trolley assisted truck will notch forward to obtain maximum speed and overtake the slower moving vehicle as quickly as possible.