They have more bearing surface of the drum and prevent friction between adjacent turns of the rope. It properly guides the rope on the drum.

The wires and strands in regular lay cable flow in opposite directions while the wires and strands in lang lay cable flow in the same direction. Lang lay cable is great for lifting, hoisting, and push-pull applications, while regular lay cable outperforms in situations where bends are required

6 indicates number of strands in the wire rope and 19 indicates numbers of wire in a strand.

Lang lay ropes provide better abrasion resistance than regular lay steel wire ropes. It also provides better bending fatigue resistance than regular lay steel wire ropes

In percussive drilling, due to the constant percussive action the rock gets crushed and also results in chipping. 

In coal mines, the overlying strata or coal is hard so the drilling method is Rotary Percussive drilling as it provides more drilling power then only rotary or Percussive drilling 

The Crawler mounted drill is a self-propelled drill with arrangement of crawler drive. 

Dozers are fitted with hydraulic cylinders, which allow more precision in the blade’s operation so it operated by hydraulic force

The ripper is the long claw-like device on the back of the bulldozer. Ripping is a technique of loosening the land soil or breaking up hard soil rocks before the final excavation 

A diamond drill bit is a very effective tool for drilling hard materials. These bits get their extra cutting power from little pieces of diamond powder embedded in them