Every time a serious mine accident happens, one question follows: was it a surprise, or were the warning signs already there? Mine inspectors see the warning signs every day. In July 2007, the Director General of Mines Safety (DGMS) listed a set of serious deficiencies that his officials had found during inspections of coal mines and after recent major accidents, and suggested remedial measures to avoid more of them.
In this post we go through all 22 deficiencies and the remedies in plain language, explain the technical terms and add a short quiz. It is useful for students and professionals preparing for DGMS, Mining Sirdar, Overman and Manager exams, and for anyone who wants to understand what good mine safety management looks like in practice.
- Many accidents trace back to routine lapses: stowing lag, poor supervision, uncalibrated instruments and unmaintained equipment
- Problems are grouped into six areas: ground control, gas and fire, inundation, supervision, training and access
- The remedies are practical: provide the equipment, do the inspections, keep records, train people and give managers real authority
1. Ground Control and Extraction
1. Stowing lag
What was observed: One of the main causes of mine accidents is a huge stowing lag in mines. Several depillaring permissions granted by DGMS had been withdrawn because of it.
Remedy: Contracts for the supply of sand should be made foolproof. Even mines near rivers were short of sand. Top management should personally watch sand contracts and renew them on time.
In simple words: When pillars are extracted, the empty space (goaf) is filled with sand, called stowing, to support the roof. If the filling falls behind extraction, that gap is the stowing lag.
8. Roof bolting
What was observed: The quality of resin capsules had deteriorated, anchorage testing of grouted bolts was not done regularly and overall workmanship needed improvement.
Remedy: Use good-quality capsules, test the anchorage of bolts regularly and improve the quality of work.
9. Line of extraction
What was observed: In many depillaring districts, the line of extraction approved in the permission was not followed. Supervisors did not realise how important it is, and goaf-edge supports were not provided as required by the Systematic Support Rules (SSR) in some mines.
Remedy: Follow the permitted line of extraction strictly and provide goaf-edge supports as per the SSR.
15. Coring machine
Remedy: Provide one core drilling machine to each Area to determine the Rock Quality Designation (RQD) of the roof strata above the workings. RQD is a measure of how fractured the rock is, which tells you how well the roof will stand.
2. Gas, Fire and Explosion Safety
4. Calibration of methanometers
What was observed: Methanometers were not being calibrated regularly, and most of them were out of order.
Remedy: Calibrate them regularly and keep them in working condition. A methanometer that reads wrongly is worse than none, because it gives false confidence. Read more about methane in our post on firedamp.
5. Flame safety lamps
What was observed: Mining sirdars were often found not carrying flame safety lamps underground, and so could not prepare a testing flame.
Remedy: Sirdars must carry proper flame safety lamps and know how to use them. See our series on the lamp: Part 1, Part 2 and Part 3.
22. Life of safety lamps
What was observed: Most of the flame safety lamps in the mines were very old.
Remedy: A recent circular had fixed the life of a new flame safety lamp at 5 years.
6. Area-level testing labs
What was observed: Area-level gas testing laboratories were not maintained well enough for proper analysis of air samples.
Remedy: A gas chromatograph is a very useful instrument for accurate and speedy gas analysis. It also helps to judge whether a fire is advancing or dying down, even on the spot. Such equipment should be provided in all companies.
7. FLP features of electrical equipment
What was observed: The flameproof (FLP) features of electrical equipment were not maintained properly, and in most mines log books were not kept. Defective electrical equipment can cause a major accident.
Remedy: Maintain FLP features and keep proper log books.
13. Stone-dust barriers
What was observed: Stone-dust barriers were far from satisfactory in most Degree II gassy mines.
Remedy: Build and maintain stone-dust barriers properly. They help stop a coal-dust explosion from travelling.
16. Nitrogen plants
Remedy: CIL may consider setting up a liquid nitrogen plant in every fiery Area so that mine fires can be dealt with effectively.
2. Stemming
What was observed: Some mines were using only dry sand filled in polythene bags as stemming material, instead of a mixture of clay and sand in the right proportion. This is unsafe because the poly bags are highly inflammable.
Remedy: Use a clay and sand mixture in the correct proportion for stemming blast holes. For more on blasting precautions, try our Mining Safety MCQ series.
3. Inundation Prevention
14. Burnside boring apparatus
Remedy: Provide one machine to each Area for advance drilling, so that the danger of water inrush (inundation) from underground sources can be avoided. Drilling ahead of the workings tells you whether there is water or a waterlogged area in front before you cut into it.
4. Supervision and Manpower
3. Back-shift inspections
What was observed: Supervision in the back shifts was lagging.
Remedy: Senior executives should give special thrust to inspections in the back shifts.
20. Back-shift inspections and roster duty on holidays
Remedy: To make sure back-shift inspections are really done by senior officials, the Chief of the Internal Safety Organisation (ISO) should coordinate them, and records of these inspections should be kept.
21. Pre-shift inspections
Remedy: After holidays, the Assistant Colliery Manager (ACM), Safety Officer or Manager should inspect all faces before work starts and record their condition. A duty roster for inspections during holidays should be prepared and followed.
19. Shortage of statutory manpower
What was observed: There was a significant shortage of overmen, mining sirdars and surveyors.
Remedy: Make up the shortage to improve supervision. The statutory officials are the people who actually see the faces every day.
18. Authority of managers
What was observed: The status of managers had deteriorated.
Remedy: Mine managers should be given due authority. A manager carries the legal responsibility for the mine, so the authority has to match it.
5. Training and Contractors
10. Contractual work
Remedy: Safety norms should be written into work orders when contracts are awarded. Workers employed by contractors should be trained, and they should get medical facilities, welfare amenities and personal protective equipment (PPE). Local eligible people around the mines can be given proper training so that contractors have trained manpower, as was done in NCL.
12. Vocational training centres (VTCs)
What was observed: Most vocational training centres were not functioning properly. A posting to a VTC was treated as a “shunting post”, and officers working there lacked motivation.
Remedy: Make VTCs work properly and make a posting there respected and motivating.
6. Access and Travel
11. Manriding systems
Remedy: Provide manriding systems in all underground mines that have a long and tiring travelling road to the worksite, especially where the worksite is more than 1.5 km away. Tired workers reach the face late and less alert.
17. Approach road to mines
Remedy: Keep the approach road to the mine in good condition so that rescue teams, ambulances and officials can reach it easily in an emergency.
7. What the CIL Chairman Said
The observations were discussed with the Chairman of Coal India Limited, who agreed that managers play an important role in safety and that their authority and status need to be restored. In summary:
- The GM or CGM may be authorised as “Agent”, and managers may be of at least M-1 grade. A final decision was to be taken soon.
- Managers should take responsibility and carry out their statutory duties properly, and should not be intimidated by outside pressures such as gheraos.
- All mines were advised to send an Action Taken Report on the DGMS suggestions.
He made these further points:
- A Management Information System (MIS) for safety should be developed by the ISO and Safety Department. If the stowing lag in a depillaring district goes beyond the permissible limit, production from that district should be stopped.
- The ISO and the Safety Department should collect regular feedback from mines and intensify inspections.
- All mines should get adequate safety support irrespective of productivity and profitability. Safety budgets should be scrutinised, safety spending should show up in the monthly cost sheet, and every effort should be made to use 100 percent of the allocated funds, especially capital funds.
- To strengthen the ISO, CIL was considering a separate Safety Cadre.
- Advanced technology should be used to reduce human error in judging impending danger, particularly in underground mines. A timely warning of roof falls and an audio-visual warning system for monitoring strata behaviour would help greatly, and IITs and other scientific institutions should be approached for research on such technology.
All 22 Points in One Table
| No. | Area | Deficiency | Remedy in short |
|---|---|---|---|
| 1 | Stowing | Huge stowing lag | Foolproof sand contracts, timely renewal |
| 2 | Blasting | Dry sand in poly bags as stemming | Clay and sand mixture in right proportion |
| 3 | Supervision | Weak back-shift inspections | Senior executives to inspect back shifts |
| 4 | Gas | Methanometers not calibrated | Regular calibration and repair |
| 5 | Gas | Sirdars not carrying flame safety lamps | Carry lamps and prepare testing flame |
| 6 | Gas | Poorly maintained area testing labs | Provide gas chromatographs |
| 7 | Electrical | FLP features and log books neglected | Maintain FLP and keep log books |
| 8 | Roof support | Poor capsules, no anchorage testing | Quality capsules, regular testing |
| 9 | Depillaring | Line of extraction not followed | Follow permission, provide goaf-edge supports |
| 10 | Contractors | Safety not built into contracts | Safety norms, training, PPE, welfare |
| 11 | Travel | Long walks to the worksite | Manriding where distance exceeds 1.5 km |
| 12 | Training | VTCs not working properly | Make VTCs effective and respected |
| 13 | Explosion | Poor stone-dust barriers | Build and maintain barriers |
| 14 | Inundation | No advance drilling arrangement | Burnside boring machine per Area |
| 15 | Strata | No coring facility | Core drilling machine per Area to find RQD |
| 16 | Fire | Limited fire-fighting capability | Liquid nitrogen plant in fiery Areas |
| 17 | Access | Poor approach roads | Keep roads in good condition |
| 18 | Management | Reduced status of managers | Give managers due authority |
| 19 | Manpower | Shortage of overmen, sirdars, surveyors | Fill the vacancies |
| 20 | Supervision | Back-shift and holiday inspections | ISO to coordinate and keep records |
| 21 | Supervision | Pre-shift checks after holidays | ACM, Safety Officer or Manager to inspect and record |
| 22 | Gas | Very old flame safety lamps | Life of new lamp fixed at 5 years |
Key Lessons
- Most deficiencies are about basics: equipment kept working, inspections actually done, records written and people trained.
- Supervision matters in every shift, including back shifts and holidays.
- Safety needs money and time that are protected from production pressure.
- Managers need both responsibility and authority.
- Technology can reduce human error, but only if it is kept in working order.
Check Your Knowledge
1. Which hazard is described as stowing lag?
A. The delay in issuing lamps
B. The gap between pillar extraction and filling the void
C. The time taken to reach the worksite
D. The delay in training
Show Answer
B. The gap between pillar extraction and filling the void
2. Why is stemming with dry sand in polythene bags unsafe?
A. Sand is too heavy
B. The sand is too fine
C. The poly bags are highly inflammable
D. It takes too long
Show Answer
C. The poly bags are highly inflammable
3. For which distance to the worksite were manriding systems recommended?
A. More than 500 m
B. More than 1 km
C. More than 2.5 km
D. More than 1.5 km
Show Answer
D. More than 1.5 km
4. What was the life fixed for a new flame safety lamp by the circular mentioned?
A. 5 years
B. 2 years
C. 10 years
D. 15 years
Show Answer
A. 5 years
5. A Burnside boring apparatus is used for:
A. Roof bolting
B. Gas testing
C. Advance drilling to prevent inundation
D. Stowing sand
Show Answer
C. Advance drilling to prevent inundation
Frequently Asked Questions
Who observed these deficiencies?
Officials of the Directorate General of Mines Safety (DGMS) during mine inspections, discussed by the DGMS in July 2007.
What does ISO stand for here?
Internal Safety Organisation, the safety body within the company that inspects mines and collects safety information.
What is RQD?
Rock Quality Designation, a measure of how fractured the rock is. It helps judge roof strength.
Are these observations still relevant?
The details of rules and company practice have changed, but the underlying lessons about supervision, maintenance, records and training remain valid.
For more notes on mine gases and safety, browse our mine gases posts, the gas testing exam posts and the Mining Legislation MCQs, or visit the Indian Minerology homepage.
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