The history of coal mining in the region of Assam dates back to the later part of the 19th century by the erstwhile Assam Railway and Trading Company (AR&T). A Civil Surgeon, Dr. John Barry White, while founding the Assam Railway and Trading Company played a very significant role in the early development of Assam’s mineral resources including the opening of the Makum Coalfields. Mr. George Turner, a mining engineer from South Staffordshire, also played an important role to transform the jungles and coal outcrops in the area into prosperous collieries in a few years time. Skilled practical miners were first brought from abroad to train Indian Workmen in the “South Staffordshire” method of wining thick coal seams.
The first mining of coal was started in 1882 at Ledo by Railway’s Engineers, when the erstwhile AR&T Company was laying its own Meter Gauge line. In order to increase the output of coal, the following collieries were started: at Tikak (1884), Namdang (1896), Tirap (1904), Baragolai (1909), Tipong (1924) and Namdang Dip (1904). The establishment of these mines were of great importance to the Tea Industry of Assam which hitherto was dependent upon wood fuel. Some indication of the nature of the Makum Coalfields are interpreted in the words of George Turner in 1895:
“Coal has been proved in these hills over the whole length of the Company’s area, and as coal of very nearly similar description is found in the hills twenty miles eastward and thirty miles westward, there can be no doubt of the existence of a large coalfield. The coal in the hills is found at various heights from Zero in the plains lip to 1000 feet above them. The hills conform in longitudinal direction with the strike of the rocks, although they do not form a continuous ridge, being cut through several streams. The coal has a high dip towards the hills, the average being about 1 in 3, but sometimes it is as high as 1 in 2”
All these erstwhile company mines were Nationalized on 1st May, 1973 and vested with the Central Government of India. At present, the entire coal production of North Eastern coalfields comes from Makum coalfield of Margherita Area, comprising of six mine of which Tipong, Ledo/Lachit Khani and Baragolai are underground mines (temporarily suspended due to DGMS violations) and Tirap, Ledo and Tikak are opencast mines. Both productivity and safety in these mines had improved significantly after nationalization.
Coal mining in Assam in extremely difficult. The area represents a typically folded and faulted mountain belt of Tertiary strata bounded by thrusts. the problem frequently encountered are steep inclination of coal seams, complex seam structure like inter-banding, irregular with thickness variations. The seams are highly gassy,susceptibility to spontaneous combustion, friable coal and poor roof and floor conditions.. The Chief Inspector of mines, in his annual report of 1929 referred to these coalfields as being “where the worst natural conditions of all the coal mines in India have to be faced.”
Certain methods of Underground Coal Mining in Makum Coalfields:
- Bhaska Method: Blocks of inclined and thick coal seams are developed on Board and Pillar System. The junction of a level gallery and a dip-rise gallery is then widened and heightened by drilling and blasting to form a dome shaped void which is self supported. The dome is kept on widening and heightening till the roof coal starts caving down automatically. As in this method the recovery is low it is no longer practiced.
- Tipong Method: Very similar to the Bhaska method of mining in the Tipong Method, between two sub levels, a funnel is made in coal along the dip-rise gallery which is kept unsupported. Then a slot is cut from Hanging Wall to Foot Wall along the dip-rise direction with a limited width to provide a free face. Towards outbye of the slot, rings of drill-holes are made and blasted to make the broken coal flow onto the funnel.
- Descending Shield Method: A Coordinated effort with engineers of erstwhile USSR, this method was introduced in 1983-84. A Shield of timber beams, reinforced with Steel, is made and placed horizontally from Hanging Wall to Foot Wall and coal is blasted below the same to make it flow downward. The Shield descends downward making a canopy above the work-persons face. This practice has been discontinued now.
- Flexible roofing method: Here, in place of a shield, artificial roofing is made out of MS-strips and wire netting which is hinged at the Hanging Wall at the top of the panel. Blasting and loading is done below artificial roofing. Roof rocks cave down over the artificial roofing and do not get mixed with the blasted coal. Likewise, the whole block is de-coaled below the artificial roofing.
The History of Coal Mining in Assam is put up on an elaborate display at India’s only Coal Museum at Margherita where visitors get to experience the thrill of underground coal mining. Also put up on display are Steam Locomotives built by W G Bagnall of Stafford in the late 1800’s. Operational Steam locomotives of the likes of ‘796’ and ‘DAVID’ are to be found at Tipong Colliery. The Open cast mining experience can be enjoyed at Tirap Colliery that practices the traditional Shovel-Dumper style Open-cast Coal Mining and is a located a little while away from Margherita.
Jungleideas welcomes you to India’s North East to witness the History of Coal Mining at Makum Coalfields, Margherita, the State of Assam, Incredible India!
Map of Coal Deposits across the Sates of North East India in Assam, Meghalaya, Arunachal and Nagaland