When the shearer reaches the headgate, the coal face will be straight, all shields except the headgate will be advanced, and only the tailgate shields will have pushed the conveyor, as shown below. The picture below shows the longwall state when the shearer reaches the headgate. Full-Web Cycle – Step 2 – Shearer at HG
After reaching the HG, the system is ready for the shearer to travel back towards the TG, remove any bench of coal and grade the floor. Again, the operators can stay on the HG side of the machine to avoid exposure to dust. Following the shearer, the conveyor will push as determined by SRB parameter “H->T Push Stroke”. This will usually be set to 100. The picture below shows the longwall state as the shearer cuts back towards the tailgate. Full-Web Cycle – Step 3 – Cutting Head to Tail
The full push will follow the shearer all the way to the TG until the entire conveyor is pushed. The picture below shows the longwall state when the shearer reaches the tailgate. Full-Web Cycle – Step 4 – Shearer in Tailgate
When the shearer reaches the tailgate, it will again be a full-web in the coal. The coal face has one snake (at the tailgate), the shields are straight and the conveyor is completely pushed on the entire face. The longwall is in the same state as the Initial Position picture shown previously. The system is ready for the shearer to go back to the headgate and repeat the entire cycle. © Caterpillar
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