The document summarizes the history of the Chasnala mine inundation accident that killed 375 workers in 1975. It describes the mine's location and coal seams. The accident occurred when a ventilation connection being driven punctured into old, flooded workings, allowing water to flood the underground mine. The immediate cause was driving the connection closer to an incline than permitted, violating the sanctioned plan. Blasting just before may have also contributed by bursting out the intervening coal block.

1. CHASNALA
MINE INUNDATION
27th DECEMBER,1975
375 PERSONS KILLED

2. HISTORY OF THE MINE
 Chasnala colliery situated on north bank of river
Damodar, at south eastern fringe of Jharia coalfield, in
the Sadar subdivision of district Dhanbad.
 Owned by IISCO (Indian Iron & Steel Company
Limited)
 Total area of about 902 acres.
 One major dyke about 27 metres thick runs North –
South within the property and several thin off shoots
from the major dyke met with.

3. No . of Thickness Parting
seams (Metres) (Metres) Remarks
17B 2.1 8-10 Developed through ten inclines up to a depth of 45 metres along
the dip. Abandoned in 1948. Waterlogged .
17A 2.1 70-80 Developed through fifteen inclines up to a depth of 75 metres
along the dip. Abandoned in 1948. Waterlogged.
17(Spl) 2.3 80-100 Developed and partially depillared by stowing. Being developed
and extracted at that time through inclines.
16 1.8-2 40-50 Virgin
15 2 2-3 Jhama(Virgin)
14A 2 40-50 Jhama(Virgin)
13/14 24 10-40 Developed through 1,2,2A,3(old) Inclines on west of the dyke,
and from 3,4 and HK Inclines on the west of the main dyke.
Working abandoned in 1949 which got waterlogged in due
course. Also worked through 1, 2, 3 quarries. underground
workings through 1 and 2 pits in I and II Horizons.
12 4-5 30-80 Mostly virgin, except a small old quarry on the outcrop side. Some
new workings have been made from No. 1 and 2 pits where it lies
close to 13/14 seam.
11/10 10-12 3 metres coal (rest Jhama). Developed in a small patch and
abandoned in 1948

4. HISTORY OF THE MINE
 Three quarries within the property, working the coal along the
outcrop
Name of the opencast Number of the Extent of the working
working seam worked
No. 1 quarry 12, 13/14 460 m along the strike & 60 m along the dip
No. 2 quarry 13/14 490 m along the strike & 60 m along the dip
No. 3 quarry 13/14 60m by 60 m
 The combined width of No. 13/14 seam is about 24 m thick and
gradient of about 1 in 1.5
 Worked through 4 inclines on the western side of the dyke 3
inclines on the eastern side of the dyke

5. HISTORY OF THE MINE
 West side inclines are numbered as 1, 3(old), 2A and 2.
 East side inclines are numbered as 3, 4 and HK incline.
 Workings on the western side of the dyke had been developed
in the pattern of levels going down to L –level.
 Workings on the eastern side of the dyke had gone down to
K – level.
 Various levels had been developed by Bord & Pillar system
 Workings were discontinued in and from April, 1949 and the old
workings through these inclines ( No.3, 4 and HK inclines) were
allowed to be filled with water

6. HISTORY OF THE MINE
 In 1958, the management entrusted Mr.N.Barraclough, a retired
chief inspector of mines to prepare the feasibility report.
 Project was undertaken with assistance from M/S. International
Construction Company, London.
 Method of mining proposed was horizon mining.
 At Chasnala, the datum of horizon no.1 fixed at 100‟ ( 30 m)
below MSL and that of horizon no.2 at 490‟ (150 m) below MSL.
Pit no Depth from surface up to Depth from surface up to
horizon no.1 horizon no.2
No.1 566‟ (172m) 956‟ (290m )
No. 2 566‟ (172m) 956‟ (290m)
No. 3 560‟ (170m) 940‟ ( 287m)

7. LATERAL PROJECTION OF THE WORKINGS

8. TO BE NOTED
 At the time of accident, 1st and 2nd horizons have got
workings only through pits no.1 and pit no.2. the horizons
were not connected to no.4 pit.
 Pits no.1 and 2 only going down to 1st and 2nd horizons of
the deep mine, workings through which had been
completely inundated. The two pits were situated 165‟
(50m) apart.
 Work in the mine was carried out in three shifts each of 8
hour duration. (7A.M to 3P.M, 3P.M to 11P.M, 11P.M to
7A.M). The inundation had occurred in 1st shift (7A.M to
3P.M) of 27th December 1975.

9. HISTORY OF THE MINE
 Dewatering of old workings through 3/4 inclines started in 1963.
 Dewatering continued till 2.4.1966 by when water level had
reached between E and F levels of old workings and on that date a
major subsidence took place resulted in collapse of roof of ‘A’
level right up to the S/F.
 On 17.5.1967 active fire was detected U/G between 3/4 inclines.
To deal with the situation the mouths of 3/4 inclines were sealed
off.
 The seals were broken on 26.9.1967 and then restricted
dewatering started. The level of water never allowed to fall
below ‘C’ level because of susceptibility to fire.
 As a result , in the new deep underground mine, the west side
workings had about 70 m head of accumulated water and the east
side workings had about 118 metres head of accumulated water
above K – level.

10. INUNDATION
The total quantity of water accumulated in the
old workings, was estimated to about 110
million gallons, out of which 30 -37 million
gallons went down the new deep mine resulting
in inundation.

11. ORGANISATION CHART
Chairman – Board of management
(Nominated owner under mines act)
H.BHAYA
General Manager (Materials)
A.C.LAL
Chief Executive (Collieries)
J.N.OHRI
Planning officer
Area Manager AGENT (Mining) Group Safety officer
(Appointed as agent under (Appointed as agent (Appointed as agent D.SARKAR
mines act) under mines act) under mines act)
S.K.BANERJEE D.SARKAR D.SARKAR
Manager
(Appointed as manager
under mines act)
R. BHATTACHARYYA
Safety officer
A.PRASAD

12. DESCRIPTION OF WORKINGS
 In 1971 permission had been obtained by the management to
drive into coal in horizon no.1 and make a gallery R-R3
( hanging wall gallery)
 Though they got permission for long drivage nearly
1000‟(300m) (R-R3), by 1973,only 200‟ (60m) was driven
towards east. (R-R1) and further drivage was stopped
 In the year 1971, a footwall drivage (T-T3) was also
proposed, but the proposal had been withdrawn in the same
year.
 In 1975, sanction was sought for making connection with H/W
gallery by F/W gallery (T-T2)
 It was proposed that the length of F/W drivage would be 200‟
and it would take sharp right angled bend towards south to

13. PROPOSED GALLERY DRIVAGE - I

14. PROPOSED GALLERY DRIVAGE - II

15. DESCRIPTION OF WORKINGS
 In 1975, after getting permission from DGMS, F/W drivage
commenced.
 But after this drivage has proceeded to length of 90‟ (27m), the
F/W drivage was stopped and a new ventilation connection
was started from H/w gallery and was made to a length of 67‟ –
70‟ (20 -21m). In the mean time, H/W gallery was also further
driven.
 Drivage was continued with the belief that the partition between
hanging wall of level – k and the footwall drivage in horizon no.1
is 90‟ ( 27m).
 But, the parting between the roof of footwall drivage and the
floor of the incline no.4 was only 1.5 – 1.8 metres.

16. DESCRIPTION OF WORKINGS
 When the ventilation connection, had progressed for a distance
of about 20m, the accident occurred. At that position, the face of
the ventilation connection was more or less below the then
existing end of No.4 incline.
 Coal between the roof of the ventilation connection and the
bottom of no.4 incline had been dislodged, making a connection
between no.4 incline and the ventilation connection, through
which water from the old workings of 3/4 inclines had rushed
down into the deep mine inundating it.

17. POSITION OF WORKINGS AT THE TIME OF ACCIDENT

18. POSITION OF WORKINGS AT THE TIME OF ACCIDENT

19. IMMEDIATE CAUSE OF THE ACCIDENT &
PERSONS LIABLE
 The accident occurred because the Ventilation
connection had been opened at a distance of only about
90 -100 ft ( 135 – 150m) from the east chimney
approach, instead of 200 ft (303m) at which it was
sanctioned (by DGMS) .
 As this is contradictory to the permission granted, the
persons who decided on driving this connection are
liable, even if the extent of the incline no.4 below K-level
is not known to them.

20. IMMEDIATE CAUSE OF THE PUNCTURE
 A hidden sill well above the roof of ventilation connection was
found to exist and this created a weak plane along puncture
point.
 During inspection it was noted that sockets were found on the
face. It would be legitimate to infer that some blasting had been
done just before the accident had occurred and it was this
blasting that had caused the intervening block of coal to burst
out under the pressure of water.

21. ETHICAL ISSUES
 INACCURATE PLANS BY SURVEYORS
 VIOLATION OF LAW BY MANAGEMENT
 LAXITY OF DGMS IN CONSIDERING
APPLICATIONS & GRANTING
PERMISSIONS

22. APPLICATION FILED IN 1971

23. PERMISSION GRANTED IN 1971

24. REASONS FOR STOPPAGE OF F/W
GALLERY IN 1971
Reasons given at the time of inquiry
 As that horizon was meant for material supply & ventilation, it
was thought that omitting gallery will have no effect in the
general construction of the mine.
 Uncertainty about „nothing cross cut‟ – extension of „nothing
cross cut‟ below K-level.
 Hanging wall of „K‟ level came almost vertically above on top
of the drivage of F/W of horizon no.1
#. It is clear that, they had thought of danger to horizon no.1 by
F/W drivage.

25. REASONS FOR PROPOSAL OF F/W GALLERY
DRIVAGE IN 1975
 To remove the blind ends of the H/W gallery.
#. The aforesaid reason is not clearly defined. The H/W drivage
was restarted in September 1975, before the permission had
been received for F/W drivage. Hence, the blind end was being
extended further towards east and the proposed drivage of
1975 even if completed could not have removed the blind ends
in H/W gallery. Moreover, the continued progress of the footwall
gallery towards the east would have brought the same danger
from „nothing cross-cut‟ that apprehended in 1971.

26. REASONS FOR STOPPAGE OF F/W DRIVAGE IN
1975 & STARTING VENTILATION CONNECTION.
 F/W gallery was hot & humid.
 Ventilation in the F/W gallery was sluggish.
 The ducting of fan which was suspended from the roof provided
obstruction in the roadway. Hence loaders faced problems while
carrying the buckets. So workers felt discomfort while working
there
#. Did they not anticipate the difficulty in ventilation while starting
the gallery?
#. In the inquiry it was told by the management that it was
possible to ventilate the F/W gallery with separate fan. If it could
have been possible, then opening a unplanned ventilation
connection as an alternative was not needed.
#. Calculations showed that size of Auxiliary fan and tubing were
adequate to ventilate both the headings simultaneously.

27. REASONS FOR STOPPAGE OF F/W DRIVAGE IN
1975 & STARTING VENTILATION CONNECTION
#. In the manager‟s diary there were no reference to be found in
ventilation & loader‟s difficulty in F/W drivage.
#. They got permission for driving 3m x 3m gallery and it is
reasonable to presume that no loading difficulty was expected.
#. Ventilation duct could have suspended from sides if there were
difficulty due to ducting being suspended from the middle.

28. APPLICATION FILED IN 1975

29. PERMISSION GRANTED IN 1975

30. CMR 127(5) - 1957
“No such working shall exceed 2.4 metres and there
shall be maintained at least one bore-hole near the
centre of the working face, and sufficient flank bore-
holes on each side; and where necessary, bore-holes
above and below the working at intervals of not more
than five metres. All such boreholes shall be, and shall
be constantly maintained, at sufficient distance in
advance of the working, and in such distance shall in no
case be less than three metres. These precautions shall
be carried out under the direct supervision of a
competent person specially authorised for the purpose.”

31. WHY ONLY CENTRAL BOREHOLE?
Refer DGMS sanction letter granted in year 1975
 They did not object to proposal as the development at the same
horizon was already being done and hence they felt that flank
boreholes were not necessary.
#.The F/W gallery to be driven was outside the area that had been
really „proved‟ during the earlier drivage. The BH pattern
approved in the year 1971 was not meant to intercept any stray
downward extension from old workings. But was designed to
check the parting between the old & new workings and all that
had been established was that the old workings were more than
15m above the horizon. No.1

32. WHY ONLY CENTRAL BOREHOLE?
 The common view point of all the officers ( from officers in zonal
office to Director General of Mines safety ) for requiring the
central borehole, in the face, was that if some geological
disturbance existed in front of the proposed F/W drivage, it
could be guarded against by a central BH in face
#.If the permission of rising boreholes was followed in the face of
the footwall gallery, it was very likely that the water in the
extended Incline no.4 would have been tapped much before the
F/W gallery had gone below the extension.
#.Though letter did not specifically refer to any relaxation, it did
amount to relaxation of the requirements of regulation 127(5) of
CMR 1957

33. SIZE OF THE DRIVAGE
 According to regulation 127 of CMR 1957, the
maximum size of the gallery can be 2.4m x 2.4m when
it is approaching the waterlogged workings where as
DGMS has permitted the gallery size of 3m x 3m
which was contradictory with regulation 127 and No
justification was given upon this decision.
#. Though it did not have any direct connection with the
accident as such.

34. VENTILATION CONNECTION – WHETHER NEW
LOCATION JUSTIFIED
 The management did not get permission from DGMS for
drivage of ventilation connection.
 At the time of inquiry, they told that the ventilation connection
which was opened in the distance which was opened at a
distance of 90‟ – 100‟ which was from east chimney
approach, fell within the scope of permission granted in 1975.
“Because it was being driven at the same level as the footwall and
the hanging wall galleries, and was not in anyway approaching the
old waterlogged workings” – Shri.J.N.Ohri

35. CONTRAVENTION OF CMR - 99
 The management claimed that they selected the location of
new ventilation connection in accordance with
CMR – 99 and the calculation was made based on “average
width of gallery”, whereas the values given in CMR – 99(4)
are based on maximum width of the galleries, and it does
not make any reference to average width.
 If CMR – 99 applies in the instant case, the size of the pillar
between east chimney approach and the ventilation
connection was smaller than the size required under the
regulation.

36. INADEQUACY IN REGULATION 127(4)
Regulation 127(4) – CMR 1957
“ Every application for permission under sub-regulation (3) shall
be accompanied by two copies of a plan and section showing
the outline of such abandoned or disused workings in relation to
the workings which are approaching the said workings and such
information as may be available in respect of the said
workings.”
 As per the above regulation, the extent of the old workings had
to be shown. The extent to which the new workings were to be
extended was indicated but it did not necessitate the outline of
the new workings which were to be made within a distance of
60m of disused or abandoned workings.

37. MISINTERPRETATION OF LAWS

38. MISINTERPRETATION OF LAWS

39. MISINTERPRETATION OF LAWS
 At that time, S.S.Prasad was Director General of Mines Safety
and H.S.Ahuja was Deputy Director General of Mines Safety
which entitled them the powers of Chief Inspector in the Mines
Act - 1952 and the powers of Inspector in the Mines Act -
1952, respectively.
 G.O. issued under section 83(2) of Mines Act, 1952 authorized
only the Chief Inspector to give Exemption under regulation 127
of CMR-1957.
 But the permission for F/W drivage, with exemption from
aforesaid regulation was granted by H.S.Ahuja who was entitled
not entitled with the powers of chief Inspector.

40. MISINTERPRETATION OF LAWS
#. H.S.Ahuja could not have sanctioned permission for F/W
drivage with relaxation from CMR 127(5),1957. He should
have referred the case to Chief Inspector (S.S.Prasad).
#.Management should have followed the CMR 127(5), 1957 as
the exemption was not sanctioned by Chief Inspector.
#.Exemption given under CMR 127, 1957 is to be exercised in
aid of requirements of safety .

41. PROBABLE REASONS FOR STOPPAGE OF F/W DRIVAGE IN 1975 &
STARTING VENTILATION CONNECTION.
BASED ON STATEMENTS FROM WITNESSES
J.KHAN – Mining Sirdar
LAKHAN MANJI - Loader

42. PROBABLE REASONS FOR STOPPAGE OF F/W DRIVAGE IN 1975 &
STARTING VENTILATION CONNECTION.
BASED ON STATEMENTS FROM WITNESSES
Premji Mandal – Mazdoor
 From the above statements, it becomes clear that they had
faced abnormal water seepage problem in F/W drivage and
they had stopped drivage. But no measures had been taken
by the management to deal with that and at the same time,
they had not communicated this problem to DGMS

43. WITNESSES GOING BACK ON THEIR EARLIER
STATEMENTS.
 It is a matter of regret that even 375 of the co-
workers, colleagues & officials of these court witnesses had
suffered a painful death in the accident, these employees of the
colliery had not thought fit to divulge the true facts before the
court.
 For Example,
In the case of J.Khan ( Mining Sirdar ), according to the
record, his statement had been read over and explained to him
in Hindi and on the face of record it appeared that he had
signed in English. But before the court he stated that the
statement was not read over to him before he had signed and
he had also gone back on his previous statement that he had
no knowledge of any difficulty of water in East district. It is
regrettable that an important official was not prepared to stand

44. WITNESSES GOING BACK ON THEIR EARLIER
STATEMENTS.
 Statements made by the persons in the course of statutory
inquiry under Mines Act were not made under on oath and the
court did not consider the previous statements as substantive
of the facts stated therein.
 Those witnesses had no respect for truth and had failed in
their duties to assist the court

45. CONCLUSION
Considering the situation of the East district of horizon no.1
in relation to the accumulation of water in the old 3/4
incline workings above the departure made from the
sanctioned plan in making the ventilation connection where
the accident had occurred, was in utter disregard for safety
of the mine and the accident must be considered to have
occurred due to the carelessness of the persons who
decided on that opening
(J.N.Ohri, S.K.Banerjee, D.Sarkar, R.Bhattacharya)