Date of the Accident – 18.3.1973
Owner – Indian Iron & Steel Co. Ltd.
Number of persons killed – 48
Place – Jharia Coalfield
A firedamp explosion occurred in 14 seam workings at about 8 p.m. on 18th March 1973 in which 48 persons were killed. It was a predominantly methane explosion. Coal dust took very little part in it. Participation of coal dust in a big way was averted because adequate stone-dusting had been done and stone-dust barriers had been provided which operated successfully to arrest the spread of the explosion.
14 seam is a gassy seam of the third degree. Methane emission from the seam was measured in June 1972 and was found to be 6 m3/min which gave an emission rate of 13.45 m3/t of daily output. All electrical apparatus installed in the seam were of flameproof construction. 18th March, being a Sunday, was the weekly day of rest. The next day (19th March) was also a holiday on account of the “Holi” festival. Items of work which could not be done on working days were normally detailed for execution on Sundays and holidays. Such work included checking and maintenance of heavy items of underground equipment, extension of conveyors, erection of stowing barricade, attending to stowing ranges, checking and re-setting of supports, etc. On this occasion, as two consecutive non-working days were available, a major item of work, namely, installation of a shaft cable from 16 seam inset to 14 seam, was also taken in hand.
The cable laying job was planned in consultation with the Agent, Senior Manger and Senior Engineer. According to the programme, the cable was to be put on a special cable reel kept in the cage at J-3 pit-top in the first shift. For transferring the cable to the reel, the two air-lock doors at the pit-top had to be kept open and the main ventilator on J-3 shaft was to be stopped for about 11/2 hours. As the Senior Manager was on leave, permission to stop the fan for 11/2 hours was obtained from the Acting Manager.
The work of transferring the cable to the special reel took longer time than expected and the fan was kept stopped for 3 hours from 1030 hrs to 1330 hrs The fan was re-started at 1330 hrs but shut down again at 1410 hrs, that is, after working for only 40 minutes. No evidence could be gathered as to the circumstances under which the main fan was again stopped at 1410 hrs or who ordered the stoppage.
The second shift started at 1600 hrs. 87 workers were deployed in 14 seam for routine maintenance jobs and 10 workers were engaged for the cable laying job. Nobody bothered to verify whether the main fan was working or not. The fan continued to remain shut down till 2010 hrs, that is, for 6 hours. As a result of the shut down of the main fan, there was practically on ventilation in the 14 seam workings. The explosion occurred at about 2000 hrs. The fan log book showed that the fan was re-started at 2010 hrs. No evidence was available as to who ordered the re-starting of the fan.
The prolonged stoppage of the fan resulted in accumulation of methane in the rise side galleries. While the main fan had stopped, the auxiliary fans continued to run and re-circulation of air by the auxiliary fans must have helped in forming a uniform methane-air mixture in the workings.
Source of ignition
In order to determine the source of ignition, the Court adopted the process of elimination. From among the different possible sources, the Court ruled out shotfiring and sparks produced from coal-cutting machine on the ground that as it was a rest day, no coal-cutting or shotfiring had been done. Underground fire and naked flame were eliminated on the ground that the rescue teams (which went into operation immediately after the explosion) had not found any evidence of an underground fire or any naked light or anyone smoking. None of the parties to the inquiry had suggested with any seriousness the possibility of a damaged flame safety lamp or cap lamp as the source of ignition. The Court was left with two other possible causes, namely, frictional sparks and sparks from electric apparatus.
The management’s contention was that the ignition was caused by frictional sparks produced by a roof girder falling over a metallic chute. The management had put forth the theory that the stoppage of the main fan was not responsible for the disaster to any significant extent. According to them, there was a release of large volume of gas consequent to a roof fall. The gas was ignited by a frictional spark caused by a steel girder falling on a steel chute.
After examining all the evidence available and taking opinion of scientists from CMRS, the Court concluded that the management’s postulation was far-fetched and founded on imponderables and was therefore untenable. The roof-fall was more likely to be a result of the explosion rather than its cause.
The investigations carried out by DGMS indicated that the probable cause of ignition was a spark from an electric apparatus. During the course of investigation after the explosion, officers of the DGMS had found a drill panel lying in an open condition in the affected workings. The front cover of the drill panel had been opened out and kept on the ground. The incoming PILCDWA cable had been pulled out from the terminal box and the drill panel thrown over 1 m from its original location. Dead bodies of 3 electricians and a helper with severe burn injuries were found lying near the drill panel. Accordingly, it was concluded by the DGMS that the site of ignition was near the drill panel. The direction of travel of the flame and the violence caused by the shock wave (as evident from the deposition of soot and devolatised coal as well as from a survey of the position of fallen roof supports and displaced machinery) also pointed to the drill panel being the starting point of the explosion. Subsequent investigations on the drill panel by CMRS had confirmed that work on the drill panel was being done without cutting off the power supply.
The Court agreed with the findings of the DGMS.
Violation of Rules and Regulations
CMR-132(2): The main ventilator was stopped in the second instance at 1410 hrs without any authority from the Manager.
CMR-134: The standing order in the event of stoppage of the main ventilator was as follow:
(a) In the event of stoppage of the main mechanical ventilator, all persons present belowground shall be withdrawn from the working places to the nearest main intake airway and at least 270 m from the nearest working face (or to the downcast shaft bottom if it is less than 270 m from the nearest working face).
If the ventilator is not re-started within a period of one hour from the time of its stoppage, all persons shall be withdrawn from the workings belowground. However, officials and persons engaged in supervisory duties, pump attendants and persons employed in essential and urgent repairing work may be permitted by the manager (or, in his absence by the senior official of the mine) to remain belowground if he is satisfied that the places where those persons are to work or to pass are adequately ventilated during this stoppage of the ventilator and gives an order in writing to that effect.
(b) The Engineer shall arrange to have the electric current cut off from all apparatus belowground except from such apparatus as are located in the main intake airway at a distance of more than 270 m from the nearest working place.
In this instance, neither of these requirements was complied with.
CMR-137(1): this sub-regulation state:
Every auxiliary fan:
(a) Shall be installed, located and worked in such a manner that:
(i) a sufficient quantity of air shall, at all times, reach it so as to ensure that it does not re-circulate air; and there is no risk of the air which it circulates being contaminated by any substantial quantity of inflammable or noxious gases or dust.
In this case, the first provision was violated by the stoppage of the main ventilator and the second by the continued operation of the auxiliary fans re-circulating the inflammable gas emitted from the headings they ventilated.
CMR-140(4) which states:
“Whenever there is any interruption of ventilation by the stoppage of any mechanical ventilator, including an auxiliary fan installed belowground, the official incharge of the mine or part shall immediately take precautionary measures including withdrawal of men, if necessary, against dangers that may arise out of non-compliance with the provisions of Regulation 130 to restore the ventilation in the mine or part”
In this case, neither were the men withdrawn nor was any attempt made to enforce the standards of ventilation as provided under Regulation 130.
IER-126: provides that electricity should be cut off
(i) during the period required for examination or adjustment of the apparatus which would necessitate the exposing of any part liable to open sparking; or
(ii) if in any part of the mine, the percentage of inflammable gas in the general body of the air is at any time found to exceed 1.25%.
The disconnection and re-connection of the supply shall be noted in a log-sheet and reported to the Inspector.
This was not complied with.
IER-122(e)(ii) : stipulates that the cable end should be efficiently sealed so as to prevent diminution of its insulating properties.
In a few cases which were inspected, the cable terminal boxes were not found to be filled with cable compound, thus violating the provisions under the above rule.
Mines Act-S-48(4) & (5) & Mines Rule-78(1) & (2): Four workers of the contractor who had actually gone down 14 seam were not shown as present in Form-C register.
- The circumstances leading to the explosion clearly indicated a lack of knowledge on the part of mine officials about their duties and responsibilities under the Regulations and. Standing Orders. For instance, the engineering staff did not realise that the main fan could not be shut off for any length of time without specific permission of the Manager. There was also a good deal of confusion about the respective responsibilities of the Acting Manager and the Assistant Manager when the former was away from the colliery in the afternoon.
- It is therefore recommended that all senior and supervisory officers who have duties and responsibilities laid on them by the Regulations and Standing Orders should be made fully aware of them. This task should be taken in had by the senior management.
- The Regulations should require that the permission to stop the fan should be obtained in writing from the Manager or a person authorized by him.
When the fan stops for reasons outside the control of the management, the fact of the stoppage should be recorded in the fan register and initialed by the Manager in token of his having been informed.
- On the day of the accident most of the senior officers claimed that they were off duty. To correct this situation, a regular roster of officers who would be on duty on weekly days of rest and holidays should be prepared. The concerned officers should be told clearly what their duties and responsibilities are for that day. The officers on such duty should be suitably compensated for the additional workload.
- The safety set-up for the mines needs a complete reorganisation. At present the safety officer and ventilation officer function as direct subordinates to the manager and very often they are employed on production work.
The safety set-up should be organized on the pattern of internal audit. A separate cadre of safety and ventilation officers should be created. Every Area should have an Area safety officer and the colliery safety officer should be under his administrative control. The safety officer should function as the principal advisor to the manager on safety matters. However, the manager should remain in complete operational charge of the mine and it would be for him to decide whether or not to accept the advice of the safety officer. At the same time the safety officer should have the right to report direct to the Area safety officer who himself should be a direct subordinate of the Technical Director.
- There is a need to re-define the functions of the DGMS by placing emphasis on three aspects of their duty, namely:
a) to set standards of safety;
b) to advise production authorities on specific practices adopted by them; and
c) to bring to the notice of the production authorities, through regular inspections, the standards of safety actually followed in the mines.The DGMS should function more as consultants, friends and advisors rather than as prosecutors and enforcement agents.
- To create interest and a feeling of involvement in safety matters among workers and supervisors, Pit Safety Committees should be activated.
- To take care of power failures resulting in stoppage of the main fan and other essential services, alternative arrangements of power supply should be made, at least for highly gassy mines.
Small thermal power stations of 50 MW each may be set up at strategic points in the coalfields.
- In this case the supervisory staff was not alert enough to detect the presence of gas with flame safety lamps. A more reliable system would be to install recording methanometers at important places in the mine.
Similarly, air-velocity meters should also be installed to provide continuous record of the quantity of air flowing through each district.
- While the rescue services acted with commendable speed and efficiency in the present case, there is no doubt that difficulty of communication prevented the rescue authorities to reach the mine even earlier than they did. Therefore more feeder stations should be opened, particularly, near large and gassy mines.
The possibility of using lighter breathing apparatus and manufacturing them in the country should be explored.
Self-rescuers should be introduced on a compulsory basis. If the miners had been provided with self-rescuers, they could have at least saved themselves from carbon monoxide poisoning and some more lives would have been saved.