Standards of Illumination in Underground Coal Mines – DGMS Guidelines & CMR 2017

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🏗️ Detailed Notes

1️⃣ Introduction

Proper illumination in underground coal mines is essential for safe operations, visibility, and accident prevention. Due to poor natural light, artificial lighting is required in all working places, travelling roads, haulage roadways, and pit bottoms. Lighting in coal mines must comply with Regulation 146 of the Coal Mines Regulations, 2017 (previously Regulation 149 of CMR 1957) and relevant DGMS circulars.

2️⃣ Objective of Illumination Standards

Ensure safe working conditions for miners.
Prevent accidents caused by poor visibility.
Enhance inspection and supervision efficiency.
Reduce eye strain and fatigue.
Support safety compliance with DGMS norms.

3️⃣ DGMS Legal Framework

Reference	Description
CMR 2017 – Regulation 146	Requires adequate and suitable lighting in all parts of the mine where persons work or travel.
DGMS (Tech.) Circular No. 18 of 1975	Specifies standards for illumination and measurement methods.
DGMS (Tech.) Circular No. 08 of 2002	Prescribes illumination levels for underground and opencast mines.
IS: 6665 – 1972 (Reaffirmed 2016)	Code of Practice for Industrial Lighting (used as reference).

4️⃣ Standard Illumination Levels (as per DGMS & IS: 6665)

Location / Area	Minimum Illumination (Lux)	Remarks
Working faces / faces under operation	5–10 lux	Adequate for manual work.
Travelling / haulage roads	2–5 lux	Uniform lighting needed.
Pit bottom / shaft station	20 lux	White light recommended.
Pump rooms / mechanical rooms	20 lux	Continuous lighting required.
Workshops / repair bays	100 lux	Shadow-free lighting preferred.
Control rooms / sub-stations	150 lux	Must meet industrial standards.
Refuge chambers / shelters	30 lux	For reading & resting comfort.

5️⃣ Types of Lighting Systems

Type	Description
Cap Lamps	Personal portable lamps for miners (LED type with rechargeable batteries).
Fixed Lighting	Installed in main entries, pit bottom, and work areas.
Flameproof Lighting	Used in gassy seams or hazardous zones.
Emergency Lighting	Battery-powered backup for outages.

6️⃣ Flameproof & Intrinsically Safe Fittings

All lighting fittings in gassy seams (Degree-II & III) must be flameproof as per BIS/CMRI/DGMS approval. Fittings should bear DGMS approval number and be maintained by a Competent Electrical Supervisor. Lighting voltage: Normally 110V or 220V AC/DC, depending on the installation.

7️⃣ Measurement & Maintenance of Illumination

Measurement Procedure: Conducted using a digital Lux Meter. Measurement taken at 1 metre above floor level. Minimum 5–10 readings per area averaged. Recorded in Illumination Register (Form IV), signed by Manager & Electrical Engineer.

Maintenance Practices:

Regular cleaning of reflectors and glass covers.
Replacement of burnt-out lamps immediately.
Proper alignment of lights to avoid glare and shadows.
Monthly illumination surveys to ensure compliance.

8️⃣ DGMS Recommendations

Maintain minimum 10 lux at working faces.
Ensure uniform lighting (avoid dark and bright spots).
Provide emergency lighting in critical areas.
Monthly verification of lux levels (Note: text originally said Quarterly, but Monthly is standard practice).
Only DGMS-approved electrical fittings to be used.

⚡ Quick One-Liners (Revision Points)

Regulation 146 of CMR 2017 governs lighting in coal mines.
DGMS Circular 18/1975 sets lux levels.
Working face requires minimum 10 lux.
Pit bottom illumination – 20 lux.
Cap lamps – LED type preferred.
Flameproof fittings mandatory in gassy seams.
Lux measured at 1 m above floor.
Record maintained in Illumination Register.
DGMS-approved fittings only allowed.
Uniform lighting prevents shadows and glare.

🧠 Descriptive Model Question & Answer

Q. Describe the DGMS standards of illumination in underground coal mines and how illumination is measured and maintained as per CMR 2017.

Answer:
As per Regulation 146 of the Coal Mines Regulations, 2017, every mine must provide adequate and suitable lighting in all working places, approaches, and travelling roads. DGMS (Tech.) Circular 18 of 1975 and IS: 6665 – 1972 specify the required illumination levels. At least 10 lux illumination must be maintained at working faces, 5 lux at haul roads, and 20 lux at pit bottoms.

Lighting must be flameproof in gassy seams, and fittings must have DGMS approval. Illumination is measured using a Lux Meter at 1 metre above floor level and recorded in the Illumination Logbook. Maintenance includes regular cleaning of lamp fittings, replacement of bulbs, and verification of lux levels. Adequate illumination enhances visibility, safety, and operational efficiency in underground coal mines while preventing accidents.

🎯 25 MCQs – Standards of Illumination

Q1. Illumination in coal mines governed by:

A. Reg. 146, CMR 2017 B. Reg. 147, MMR 1961 C. Reg. 150, CMR 1957 D. None

Q2. DGMS Circular prescribing illumination levels:

A. 18/1975 B. 08/2002 C. 06/2019 D. None

Q3. Minimum illumination at working faces:

A. 10 lux B. 20 lux C. 5 lux D. None

Q4. Haulage roads require illumination of:

A. 2–5 lux B. 10 lux C. 20 lux D. None

Q5. Pit bottom illumination standard:

A. 20 lux B. 5 lux C. 50 lux D. 100 lux

Q6. Unit of illumination:

A. Lux B. Lumen C. Watt D. Candela

Q7. Flameproof fittings are required in:

A. Gassy seams B. Surface workshops C. Offices D. None

Q8. Equipment used to measure light intensity:

A. Lux Meter B. Anemometer C. Manometer D. Voltmeter

Q9. Measurement height for illumination:

A. 1 metre above floor B. 2 metres C. 0.5 metre D. None

Q10. DGMS-approved lamps are:

A. Flameproof B. Open type C. Decorative D. None

Q11. Illumination Logbook verified by:

A. Manager & Electrical Engineer B. Clerk C. Overman D. None

Q12. Cap lamp used by:

A. Every underground worker B. Manager only C. Surveyor only D. None

Q13. Flameproof equipment certification given by:

A. DGMS/CMRI B. BIS C. NLC D. None

Q14. Workshop illumination required:

A. 100 lux B. 10 lux C. 20 lux D. 50 lux

Q15. Emergency lights are:

A. Battery-powered B. Diesel-powered C. Solar only D. None

Q16. Lux Meter readings taken at:

A. 1 m height B. 2 m height C. Eye level D. None

Q17. Regular illumination survey frequency:

A. Monthly B. Annually C. Quarterly D. None

Q18. Poor illumination can cause:

A. Accidents B. Eye strain C. Fatigue D. All above

Q19. Reflectors should be cleaned:

A. Regularly B. Yearly C. Once a decade D. None

Q20. Cap lamps now mostly use:

A. LED B. Filament C. Gas flame D. None

Q21. Flameproof light approved by:

A. DGMS B. Company C. OEM only D. None

Q22. In degree-II seam, lighting must be:

A. Flameproof type B. Open type C. Decorative D. None

Q23. Lux is equivalent to:

A. Lumen per square metre B. Joule per second C. Watt per hour D. None

Q24. Emergency lights provided in:

A. Pump houses & main roads B. Manager’s office C. Weighbridge D. None

Q25. Proper illumination ensures:

A. Safety and productivity B. Darkness C. Delay in work D. None

🔗 Internal Linking Suggestions

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CMR 2017	CMR 2017 Part 2 - Working & Supervision Rules

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