Flame Safety Lamp Part 3: Maintenance, Repair & Examination || Indian Minerology

A flame safety lamp protects you only when every one of its parts is in perfect order. A missing packing ring, a gauze choked with soot or a loose lock can turn a safety device into an open flame in a gassy mine. That is why the regulations spend so much effort on how the lamp is cleaned, repaired, examined and handled.

Flame Safety Lamp Part 3: Maintenance, Repair & Examination (Lamproom Rules & Regulations)

This is Part 3 of our flame safety lamp series. It covers the maintenance, repair and examination of the lamp: who checks it, what is checked, what the lamproom must do and what every user must do. We have written it in question-and-answer form, which makes it easy to revise for DGMS, Mining Sirdar, Overman or gas testing exams. If you missed the earlier parts, read Part 1: Construction and Development and Part 2: Parts, Types and Relighter first.

At a glance

Every lamp goes through five kinds of checks, including a detailed weekly examination every 7 days
Only competent persons appointed by the manager may examine lamps
A damaged gauze is never repaired. It is crushed and replaced
If a lamp is defective, never take it underground. Return it and get another
Never blow out a lamp when it is in gas. Carry it slowly into fresh air

Contents

The five examinations (Q1 to Q3)
Weekly examination and report (Q4)
Why so many checks, and checking on receipt (Q5 to Q6)
Cleaning and repair in the lamproom (Q7 to Q11)
Rules for using a safety lamp (Q12)
FAQs

Maintenance, Repair and Examination of the Safety Lamp

Q1. What arrangements for examining the safety lamp are required by law?

Answer: As per the Coal Mines Regulations, five kinds of checks are required:

Examination by the lamproom staff before the lamp is issued.
Examination by a body checker at the mouth of the incline or shaft.
Examination by the lamproom staff when the lamp comes back to the lamproom.
A detailed weekly examination.
A check by the person himself when he receives the lamp from the lamproom.

Figure 1: The five checks a safety lamp goes through.

Q2. Who can carry out the four kinds of examination listed above?

Answer: Checks (1) to (4) are carried out by a person appointed by the manager who has passed the examination for manager, overman, gas testing or lamp checker.

Q3. What does a body searcher (lamp checker) look for in a safety lamp?

Answer: Before anyone is allowed to take a safety lamp into an underground mine through the incline or shaft mouth, the body searcher (lamp checker) examines it and checks that:

No part is broken and all parts are properly joined.
The lock is fitted.
Packing is fitted above and below the glass. To test this, he blows above and below the glass while turning the lamp. If the flame flickers, the packing is missing or not fitted properly.
The wick moves up and down properly.
The lamp is clean, inside and outside.
The oil vessel is filled.

Q4. Who does the weekly examination of safety lamps, what is checked and what kind of report is written?

Answer: At least once in every 7 days, each lamp in use is examined in detail by a person appointed by the manager for this work. The person should hold a certificate of manager, overman, gas testing or lamp checker.

He examines all the parts of the lamp, then assembles it and examines the whole lamp. In his report he writes:

the numbers of the lamps that were found to be in good order;
for every defective lamp, its number, the type of defect and what was done to correct it;
a special remark, with his signature, if a lamp shows signs of having been opened in the mine or of having been damaged.

Sample report format (as per Regulation 155(4)):

.................... Colliery
Weekly Examination of Safety Lamps (as per Regulation 155(4))

Page No. ........................ Date ........................

I have carried out a detailed examination of all the safety lamps, in my capacity as the person appointed under the above regulation. The report is as follows:

1. Numbers of the lamps found to be all right: ..................................................

2. Details of the lamps found defective:

Lamp number	Type of defect	Action taken to rectify	Other remarks

Signature ........................ Date ........................

Q5. Why are so many different types of checks carried out on safety lamps?

Answer: A safety lamp is safe only when all its parts and safety features are in order. If it has a defect, it is simply a burning flame, which is a very dangerous thing to carry where there is gas. That is why repair, examination and correct use of the lamp get such strict attention.

Q6. How will you check a safety lamp when you receive it from the lamproom?

Answer: When you receive the lamp, check that:

Figure 2: The ten checks every user makes when receiving a safety lamp.

No part of the lamp is loose. Shake it by hand to check.
The gauzes, rings and packing above and below the glass are in place. Blow above and below the glass while turning the lamp. The flame should not flicker.
The lock is fitted. Try turning the oil vessel in the opposite direction to open it. It should not open.
The glass is not broken or cracked, and it does not turn when you rotate it.
The bonnet is not dented and has no holes. The pillars are not loose or broken, and all five are present.
The handle is firmly fixed.
There is no surplus oil sticking to the outside of the lamp.
The wick adjusting screw works properly.
The lamp has oil in it.
The lamp number can be read clearly.

Golden rule: If the lamp has any defect, do not take it into the mine. Take it back to the lamproom and get another lamp issued.

Q7. What should be kept in mind while cleaning and repairing oil safety lamps in the lamproom? (Regulation 157)

Answer:

1. Assembly. Every lamp must be cleaned and assembled properly. A defective or broken lamp must not be issued until it has been repaired.

Bonnet: Brush the inside clean to remove soot. The bonnet must have no holes, and no part of it should be dented in a way that touches the gauze. Bent or loose pillars must be corrected. Take care while assembling that no part is left out.

Gauzes: Clean soot from inside and outside each gauze with a brush. Check that no wire is broken and no hole is blocked. This inspection should be done with a magnifying glass in good light. Press the surface of the gauze lightly with a finger. If it slides down, throw that gauze away and fit a new one. While fitting, make sure no wire from the brush or other foreign matter stays attached (an iron-wire brush must not be used). The outer gauze, inner gauze, glass and bonnet must each be cleaned with the special brush made for them. A repaired gauze is never used.

Glass: Wipe the glass well. A dirty glass hides gas from view. Make sure it is not cracked or chipped anywhere, and turn it by hand to check that it is fixed tightly.

Packing rings: Fit asbestos packing rings above and below the glass, only one on each side, never more. The rings should be clean, dry and soft. (A good-quality ring may last 8 to 10 days.)

Retainer ring: Tighten it properly.

Oil vessel: After filling the vessel with oil, turn it upside down to pour out surplus oil. Cut the wick straight with scissors so that the flame burns evenly across its whole width. Move the wick up and down to check that the adjusting screw works, so that a full flame and a testing flame can both be made. Light the lamp to check, and recut the wick if needed.

Threads, lock and relighter: The threads of the bonnet and the oil vessel must be tight and the lock properly fitted. Try turning the vessel the opposite way to be sure it does not open. If there is a relighter, check that it works, and if the battery voltage falls below 2.3 volts, replace the battery. The handle must be strong, and there must be enough oil for the whole shift.

2. Broken parts. Defective gauzes, glass and other parts must not be kept in the lamproom, so that nobody fits them by mistake. A broken gauze must be crushed.

3. Spare parts. Buy spare parts only from the company that makes the lamp, so that the design and size are right.

4. Oil. Fill only approved oil: petrol or Esso Solvent 1425, or an equivalent.

5. Burn-in. Keep the lamps burning for a while before the shift starts.

Q8. What precautions are taken in the safety lamproom? (Regulation 158)

Answer:

No unauthorised person may enter the safety lamproom.
Nobody may smoke or light a fire in the lamproom.
If petrol or a similar volatile oil is used in the lamps, the following precautions apply:
- Cleaning, fitting and filling of the lamps is done in a separate room.
- No more than one day's requirement of oil is kept in that room.
- The internal relighter is not opened, cleaned, repaired or fitted on the table where lamps are cleaned, fitted or filled with oil.
- An adequate number of proper fire extinguishers is kept ready for use in the lamproom.

To understand why flame, fuel vapour and mine gas make such a dangerous mix, read more in our mine gases posts, including firedamp.

Q9. What should be done with damaged gauzes?

Answer: A damaged gauze should be crushed at once, so that it cannot be fitted again by mistake, and a new gauze should be fitted.

Q10. Under what conditions does a gauze become ineffective?

Answer: A gauze stops doing its job when:

holes appear in it, or the wires wear thin and the openings become larger;
soot collects and blocks the openings because of poor cleaning;
in a gassy atmosphere the flame grows long and burns for a long time, so the gauze becomes white hot;
only one gauze is fitted instead of two.

Q11. What can happen if the lamproom does not have enough safety lamps?

Answer: The same lamps will have to be issued in more than one shift. As a result, there will be less time for cleaning, maintenance and examination.

Q12. What are the rules on using safety lamps? (Regulations 156 and 38 of CMR 1957)

Answer:

Every lamp carries a number, which must be kept clearly readable as long as the lamp is in use. As far as possible, each person should be given a lamp with the same number every day.
A competent person appointed for the job keeps a correct record of lamps issued from and returned to the lamproom. The record shows the lamp number against each person's name.
If a person returns a different lamp from the one issued to him, he must give the reason for the change.
No unauthorised person may take a safety lamp from the lamproom himself or give one to someone else.
When a person receives a lamp, he must check that it is in proper condition. If he finds any defect, he must return it to the lamproom at once.
Nobody may wilfully damage a lamp, misuse it, or open or try to open the lock or the lamp.
If a person's lamp becomes defective, he must lower the wick carefully to put it out and report to his superior.
In addition:
- If a person carrying a lamp finds himself in inflammable gas, he must not throw the lamp and not try to blow it out. He should carry it low, close to the floor, slowly and without jerks, out into fresh air. If it cannot be taken to fresh air, he should put it out by smothering it or by dipping it in water.
- Take full care of the lamp in the mine. Do not leave it lying about, and if it must be left, hand it over to someone.
- Do not place the lamp on the ground. Keep it at least two feet (0.6 m) away from the reach of a pick, hammer or other tools.
- If it must be put down, hang it from a solid object instead of keeping it on the floor.
- Protect the glass from splashes of water so that it does not crack.

Situation	What to do	What NOT to do
Lamp in inflammable gas	Carry it slowly, low, to fresh air	Throw it or blow it out
Lamp cannot reach fresh air	Smother it or dip it in water	Leave it burning
Lamp becomes defective in the mine	Lower the wick, put it out, report	Keep using it
Defect found on receiving the lamp	Return it and get another	Take it underground
Need to put the lamp down	Hang it from a solid object	Place it on the floor or within reach of tools

Quick Revision Points

Five checks: before issue, at the mine mouth, on return, weekly (every 7 days) and by the user on receipt.
Weekly examiners need a manager, overman, gas testing or lamp checker certificate.
Flame flickers when you blow above and below the glass = packing missing or wrong.
Only one asbestos packing ring above and one below the glass.
Replace relighter batteries when voltage falls below 2.3 V.
Crush damaged gauzes. Never use a repaired gauze.
Lamproom: no unauthorised entry, no smoking or fire, a separate room for petrol filling, and fire extinguishers ready.
In gas: never throw the lamp or blow it out. Carry it low and slowly to fresh air.