Excavation Department of NCL is responsible for maintenance management of HEMMs alongwith operation of Draglines deployed at different projects of NCL. The brief introduction of state-of-the-art HEMMs is given below:(Population of HEMMs has been taken as on 25.04.2020)
1. Draglines:Dragline, is largest earth moving machinery, used for removal of overburden, consists of a large bucket, which has teeth, which is suspended from a boom with wire ropes. The bucket is maneuvered by means of a number of ropes and chains. The bucket is positioned above the overburden to be excavated. The bucket is then lowered and the dragrope is then drawn so that the bucket is dragged along the surface of the material. The bucket is then lifted by using the hoist rope. A swing operation is then performed to move the bucket to the place where the OB is to be dumped. The dragrope is then released causing the bucket to tilt and empty. During its operation of digging and placing the overburden to another placed machine remains seated at the same place. At present NCL is having total 23 nos. of Draglines working at different projects of NCL.
2.ShovelsShovels are used for excavating overburden and Coal. It has bucket consisting of teeth which dig the material and load it to Dumpers. NCL is having 118 nos. such Excavators bucket capacities ranging from 1.2 Cum to 20 Cum.
3. Surface Miner:Surface Miner is used to extract Coal by cutting it in small size. It consists of a drum having cutter on its periphery. Drum rotates and Surface-miner keeps moving ahead, leaving behind the cut coal. Then this coal is loaded in dumpers using loader and transported to dispatch point. So, by using surface miner drilling and blasting are not required to be done in Coal patch. In this way it also helps in clean, safe and environment friendly Coal Mining. Since Size of Coal particles extracted by Surface miner is small so further crushing is also not required. NCL has 04 Surface Miner.
4. Dumpers:Dumpers are high capacity off the road trucks, used for transportation of Coal and Overburden from point of Excavation/ digging to dumping point through haul-roads. NCL has the 556 nos. Dumper of capacities varying from 85T to 190T (205 Short tons) Dumpers. In 2020 & 2021total 92 number of 190T (180-200 class) dumpers are to be supplied to different projects of NCL. 8 Dumpers Out of 92 are on trial basis.
5. Dozer: Dozer equipped with a blade used to push large quantities of soil, Coal, sand, rubble, or other such material during. Dozers are of two types Crawler and Wheel mounted. NCL has 176 numbers of Dozers Capacity from 280HP to 860 HP.
6. Crane:Crane is a type of machine, generally equipped with a hoist rope, wire ropes or chains, and sheaves, that can be used both to lift and lower materials and to move them horizontally. It is mainly used for lifting heavy things and transporting them to other places. NCL has 75 number of Crane ranging from 3 Tonnes to 120 Tonnes.
7. Loader:Loader is a heavy equipment machine used to move aside or load materials into or onto another type of machinery (such as a dump truck, conveyor belt, feed-hopper, or rail). There are many types of loader, which, depending on design and application, are called by various names, such as front loader, front-end loader, pay-loader, wheel loader etc. NCL has total 16 nos. loaders.
8. Grader:Grader is earth moving equipment used to maintain haul road and light vehicle road in mines. It is auxiliary equipment that helps in smooth movement of Dumpers and other light vehicles in mines. Better quality of haul road augment the life and performance of tyres fitted in HEMMs. Generally a long blade is fitted in the machine and placed between front & rear wheels creates flat surface during the movement of Grader. NCL has 57 numbers Grader and all are of 280 HP Capacity.
9. Drill:Drill is a heavy equipment machine used to move aside or load materials into or onto another type of machinery (such as a dump truck, conveyor belt, feed-hopper, or rail). There are many types of loader, which, depending on design and application, are called by various names, such as front loader, front-end loader, pay-loader, wheel loader etc. NCL has total 16 nos. loaders.
10. Water Sprinkler:Water Sprinkler is equipment to sprinkle water to suppress the dust. This is done to increase visibility, reduce air pollution. This is basically a truck carrying a water tanker. Water is sprayed into the atmosphere through small pipe openings fitted at the outer periphery of backside of tank. Population of Water Sprinkler at NCL is 64 numbers.