Reduction of Roof and Side Fall Risks in Coal Mines – DGMS Guidelines & Support Systems

Accidents Due to Roof Fall During 2014 – DGMS Report, Analysis & Safety Measures

🏗️ DETAILED NOTES

1️⃣ Introduction

Roof fall is one of the most frequent and deadly hazards in underground coal mines. DGMS statistics show that more than 40% of fatalities in underground coal mines occur due to falls of roof or sides. The main causes include poor support installation, delayed setting of supports, weak strata, and insufficient supervision. Relevant provisions are found in Regulation 99 to 104 of the Coal Mines Regulations, 2017 (CMR 2017).

2️⃣ Case Summary (Example)

Date of Accident: [Example: 12 June 2014]
Location: Depillaring district, underground coal mine
Fatalities: 4 persons (1 Overman, 3 loaders)
Nature of Accident: Sudden roof fall during coal extraction
Extent of Fall: 5m × 4m × 1.5m thick

3️⃣ Probable Causes (Based on DGMS Findings)

Inadequate or delayed support installation.
Violation of Systematic Support Rule (SSR) approved by DGMS.
Presence of cleavage planes or weak roof strata not detected earlier.
Improper withdrawal of supports in goaf area.
Absence of roof monitoring instruments (tell-tales).
Lack of supervision during change of shift.

4️⃣ Relevant Legal Provisions

Regulation	Description
CMR 2017 – Reg. 99	Support of working places
CMR 2017 – Reg. 100	Withdrawal of supports
CMR 2017 – Reg. 101	Systematic Support Rules (SSR)
CMR 2017 – Reg. 102	Precautions during depillaring
Mines Act, 1952 – Sec. 23	Duties related to mine safety / Notice of Accident

5️⃣ Lessons Learned

Strict adherence to Systematic Support Rule (SSR) approved by DGMS.
Roof examination before each shift by competent person.
Immediate reporting of any roof crack or sagging.
Regular use of tell-tales, extensometers, and monitoring tools.
Training of miners on roof hazard recognition.
Proper supervision by overman during coal extraction.
Ensuring no work below unsupported roof.

6️⃣ DGMS Recommendations

DGMS advised all mine managers to conduct special safety drives focusing on roof support practices. A review of SSR was mandated, especially in depillaring panels. All future roof monitoring must include instrumented observations and risk-based classification of areas. DGMS Circular No. 02/2016 on roof fall prevention reiterated these standards.

⚡ QUICK ONE-LINERS

Regulation 99–104 of CMR 2017 cover roof & side support.
Roof fall accounts for ~40% of coal mine accidents.
SSR must be DGMS-approved.
First support must be set within 1 m of the face.
Resin-grouted bolts provide quick anchorage.
Tell-tales are used to monitor roof movement.
Withdrawal of supports only after permission (Reg. 100).
Roof fall prevention is part of Code of Practice (COP) for ground control.
DGMS Circular 02/2016 covers roof safety.
Roof fall often occurs in depillaring.

🧠 DESCRIPTIVE QUESTION & ANSWER

Q. Discuss the DGMS guidelines and lessons learned from the fatal accident involving four persons due to roof fall in an underground coal mine.

Answer:
A fatal accident occurred in an underground coal mine where four persons lost their lives due to a sudden fall of roof during depillaring operations. Investigation by DGMS revealed that roof support installation was inadequate, and the Systematic Support Rule (SSR) was not followed strictly. The roof strata were weak, and tell-tales were not installed for early detection of movement.

Key Findings: Supports were not installed immediately after extraction; Roof inspection by the competent person was not thorough; Supervision during shift change was poor.

Regulations Referenced: CMR 2017, Reg. 99–102 (Support, SSR, Withdrawal); DGMS Circular 02/2016 (Roof fall control measures).

Preventive Measures: Follow SSR strictly; Use tell-tales in all depillaring panels; No work under unsupported roof; Provide roof bolting in systematic grid pattern; Regular roof safety training.

Conclusion: Strict adherence to support regulations and effective supervision can prevent recurrence of such tragic accidents. Every miner must understand that roof safety is life safety.

🎯 25 MCQs – Roof Fall Accident & DGMS Safety Rules

Q1. Which regulation of CMR 2017 deals with roof support?

Solution: Regulation 99 of CMR 2017 specifically covers the support of working places.

Q2. SSR stands for:

Solution: SSR is the acronym for Systematic Support Rule, a key element in roof control.

Q3. Tell-tales are used for:

Solution: Tell-tales are instruments specifically designed to detect and indicate movement or separation in roof strata.

Q5. Roof fall commonly occurs during:

Solution: Depillaring operations inherently destabilize the roof strata, making them high-risk areas for falls.

Q6. DGMS circular for roof fall prevention:

Solution: DGMS Circular No. 02/2016 specifically addresses measures for preventing roof fall accidents.

Q7. Roof support must be:

Solution: Timely installation of support after exposing fresh roof is crucial for preventing falls.

Q8. Minimum roof support inspection frequency:

Solution: Competent persons like Overmen/Sirdars are required to inspect the roof at the beginning of each shift.

Q9. Unsupported roof area is:

Solution: Working or travelling under unsupported roof is extremely dangerous and strictly prohibited.

Q10. Withdrawal of supports requires:

Solution: Regulation 100 of CMR 2017 outlines the procedures, permission, and supervision required for withdrawing supports.

Q11. Roof fall hazard mainly due to:

Solution: The inherent geological weakness of the roof rock (strata) is a primary contributing factor.

Q12. Roof bolting spacing depends on:

Solution: Geotechnical assessment of the rock quality (like RMR) determines the required bolt density and spacing.

Q13. SSR approval authority:

Solution: Systematic Support Rules must be formally submitted to and approved by DGMS (Regional Inspector).

Q14. Roof fall accident reporting under:

Solution: Regulation 9 of CMR 2017 specifically deals with the notice of accidents in coal mines.

Q15. Roof monitoring device:

Solution: Tell-tales are common, simple instruments used specifically for monitoring roof movement.

Q16. Overman responsibility:

Solution: Examining the roof and sides of working places is a primary statutory duty of the Overman/Sirdar.

Q17. Roof fall leads to:

Solution: Roof falls are a major cause of serious and fatal injuries in underground mines.

Q18. Depillaring involves:

Solution: Depillaring is the second and final phase of bord and pillar mining, where the coal pillars are extracted.

Q19. DGMS stresses on:

Solution: Training workers to recognize and respond to roof hazards is a key preventive measure emphasized by DGMS.

Q20. Roof fall mostly occurs in:

Solution: The layered sedimentary nature of coal measures often makes them more prone to roof instability compared to hard rock metal mines.

Q21. Roof bolt type used:

Solution: Resin-grouted bolts are a common and effective type of roof support used in modern mining.

Q22. Support withdrawal order given by:

Solution: Withdrawal of supports is a critical operation requiring authorization from the Mine Manager or designated competent person.

Q23. Roof fall hazard prevented by:

Solution: Adherence to approved support rules (SSR) and effective support methods like bolting are primary preventive measures.

Q24. DGMS mandates tell-tale frequency:

Solution: While the exact SSR dictates spacing, installing tell-tales at regular intervals (like every 10m) at critical locations like junctions is a common guideline.

Q25. Main cause of roof fall fatalities:

A. Unsupported roof B. Water C. Light D. Dust E. None

Solution: Working or being present under roof areas that are not adequately supported according to regulations is the direct cause of most roof fall fatalities.

🔗 INTERNAL LINKS

Related Topic	Read More On...
Strata Control	Strata Monitoring in Longwall Workings
Safety Management	Integrated Safety Management Plan (SMP)
DGMS Circulars	DGMS Tech SOMA Circular No. 03 of 2024
CMR 2017	CMR 2017 Part 2 - Working & Supervision Rules

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