December 11, 1914.

THE COLLIERY GUARDIAN.

1219

of the face to indicate any alteration in the movement
of the air. At two o’clock the fan was stopped, and
at 2-1 there was an appreciable reduction in the air
current noticed; at 2’2 the long paper streamers fixed
to the roof at the face of the ripping had come to rest;
at 2*16 the fan was re-started, and the paper streamers
showed signs of moving quickly, extending out with
the breeze. Samples of the air for analyses were taken
at the coal face, 2 ft. above the floor of the seam, every
four minutes for 20 minutes. The experiment gave the
following information :—

Barometer at surface—12.45 p.m., 29 80.	No. of sample.	Time taken.	1 Analyses. ;		Remarks.
			Inflam- mable gas.	Oxy- gen. i	
		p.m.	I Per c.	Per c.	
Hygrometer Beadings:—	t i				( At face of Wm. FisheFs gate.
p.m.	1	l.DV '	0'65	20’64	< Conditions normal; fan running.
12.45—At surface—wet, 57; dry, 67.	2	2.4 i	5’25	19’54	At face of Wm. FisheFs gate. Fan stopped.
3.12—Pit bottom—wet, 55|; dry, 61b	3	| 2.8	10’29	18’48	Do.	Do.
1.30—Bottom of No. 4 Slant—wet, 57;	I 4	; 2.12	9’41	18’65	Do.	Do.
dry, 59.	: 5	; 2.16	30’45	13’99	Do.	Fan re-started.
1.50—At face of Wm. FisheFs gate—	i 6	i 2.20	5’82	19’64	>	Do.	Do.
wet, 58; dry, 60.	' 7	2.20	3’63	—	1 At coal-cutter.

The experiment showed that gas accumulated rapidly
after the fan was stopped, and that the gas in the face
at Wm. Fisher’s gate was diluted down from 30*45 per-
cent. to 5*82 per cent., or roughly about one-fifth, four
minutes after the fan had been restarted. Gas accumu-
lated at this place would, on its way to the return air
course, envelop the coal cutter, and the percentage at
the coal cutter after the lapse of the same period (four
minutes) was 3*63 per cent. Assuming that the gas at
the coal cutter, which was only 20 yds. away, had been
similarly diluted during the same period, it follows that
the percentage of gas there before it was diluted was
five times 3-63 per cent., or about 19 per cent. This,
amount would be diluted down to the explosive point,
and would, for -a time, remain explosive.

This experiment was subsequently repeated 14 day:;
after the explosion in the presence of Profs. O'Shea and
Armstrong, of the University of Sheffield, for the
further information of the management when the
inspectors were not present, and the details
of this second experiment were set out in a report by
Prof. O’Shea, which was given in evidence at the
inquest. A point of difference between the two experi-
ments was that on the first occasion the change over
took place from the steam engine to the gas engine,
whilst in the second experiment the change was from
the gas engine to the steam engine, as on the day of
the explosion. The results obtained, however, were
equally remarkable and confirmatory, notwithstanding
the fact that the faces had been longer standing,
whereas the first experiment was nearer the day of the
explosion when the face had been freshly exposed.

In view of (a) the defective coal cutter, (b) the
liability to accumulation of gas on stoppage of fan, (c)
the point of ignition traced by the inspection of the pit,
and (d) the preliminary enquiries at the pit, the follow-
ing sequence of circumstances was disclosed, and in
the absence of any one of these circumstances the explo-
sion would not have occurred :—

(1)	Men were, on the day of the explosion, staying
at work longer than usual.

(2)	Whilst the men were at work, the ventilating
fan was stopped for 16 minutes, causing the ventila-
tion to cease, contrary to section 29 (1) of the Coal
Mines Act, 1911.

(3)	Gas accumulated in consequence in the cutting
side of Wm. Fisher’s gate.

(4)	The electrically-driven coal cutter was running
at the moment, when a wave of gas in explosive
quantity passed over it, due to the restarting of the
fan.

(5)	There was a defect in the coal cutter, which
rendered it capable of igniting gas when it was work-
ing, contrary to General Regulation 132.

The inquest into the cause and circumstances attend-
ing the death of the victims was held by Mr. P. P.
Maitland, H.M. Coroner for the Honour of Pontefract
and the West Riding of Yorkshire, and the jury
returned an unanimous verdict in the following form :—

“ Wharncliffe Silkstone Colliery Company.

‘ ‘ The 12 men lost their lives by an explosion of coal
gas on May 30, 1914, caused by the stoppage and
restarting of the fan with a defective coal cutting
machine running at the face causing ignition, and
the jury are of opinion that the whole of the manage-
ment have been very negligent, but not criminally
so.”

To this verdict the following rider was added ::—

” The jury trust that the Home Office will give
instructions so that the management may be more
careful in the future.”

Messrs. Pope and Mottram believe that the conclusion
as to the site and cause of the explosion arrived at by
the jury was the correct one.

Owing to the arrangements existing at the colliery
for driving the fan, it was apparently found necessary
to change over from gas to steam engine about once a
week, so that the valves and other parts of the gas
engine might be cleaned and examined. After detailing
the arrangements for stopping the fan, it is stated that
the manager was a party to these arrangements, and
communicated them to the under-manager, Fearnley,
as each change of time was decided upon. Fearnley,
in turn, so he says, communicated them to the deputies,
at the same time instructing them that during the

stoppage the workers were not to be allowed at the
coal face. But these instructions once given were not
repeated for each stoppage, and on the day of the explo-
sion, through misunderstandings, they were not carried
out. Fearnley was, however, in the pit in No. 2 level
at the time of the explosion, and he knew the time for
the stopping of the fan. It was his duty, under General
Regulation 41, to give such directions as might be
necessary to ensure the safety of the persons employed.
This, unfortunately, he failed to do.

According to air samples taken by Government

inspectors and by the colliery officials previous to the
explosion, 1| per cent, of inflammable gas was not
present in the general body of the air current, and
four days after the explosion, when the fan was running,
a sample of air taken in the general body of the air
current showed, by analysis, only 0-65 per cent, of
inflammable gas to be present.

This disaster emphasises, says the report, once again-
the immense importance of the proper and systematic
supervision of electrical apparatus. The electrical coal
cutter which was in use at the No. 2 level face was not
flametight. The joint between the commutator box
cover and the body of the machine was defective. There
was at one place a gap or aperture in the joint measur-
ing | in. long by about y^in. wide at one end, tapering
to nothing at the other, and there was a second gap or
aperture of lesser dimensions. There was external
indication of the larger aperture. Mr. Hudspeth
described it as very obvious, and it was noticed at the
first inspection after the explosion. In consequence of
this, “ the cover was lifted off, and it was at once
evident that the aperture extended to the inside of the
motor casing.” The second aperture was discovered at
a later inspection. There were other features' about the
machine (certain rough and ready repairs) which came
under considerable criticism, but Mr. Nelson, in his
evidence, dismissed these as possible sources of
ignition.

The apertures were the result of some ill-usage of the
half-moon plate, a portion of the motor case which had
to be removed when an armature was taken out of or
put in the machine. Mr. Blake Walker thought the
half-moon had been hammered into position every time
an armature was put in, and with an ordinary hammer.
He did not think that the machine men would ever have
had instructions not to use a metal hammer, and he
further stated that he did not think the machine men
would attach much importance to the injury if they
saw it.

It ought not to have been possible for the coal cutting
machine to have got into the condition and be worked in
the condition in which it was found. It would have
imposed no serious burden upon the electrical staff in
addition to the routine weekly inspection, which the
evidence showed to have been carried out, to have
inspected the machine thoroughly for flameproofness
after ■ every time it was opened out for replacing an
armature, and had this been done on the occasion when
the new armature was-put in on the morning of May 29,
it is believed that the defect in the cover would have
been seen. The removal and replacing of an armature
was a job of several hours’ unpleasant work, and for it
to be undertaken, as it was in this case, by the machine
man himself (who was paid at piece rates for the coal
cut) without any supervision or subsequent inspection as
regards safety by the electrician before the machine was
restarted and put to work, seems to be wrong.

Much greater strictness should have been observed,
however great the confidence reposed in the machine
man. The condition of this machine strongly suggests
that the deceased man was not fully alive to the import-
ance of absolute flameproofness or to the risks attending
the neglect of it, and the evidence given at the inquest
has impressed Messrs. Pope and Mottram with the great
desirability of such a simple precaution as an examina-
tion for safety after each change of an armature by an
electrician having duties of inspection underground.

The fact of men being at work at the coal face during
the temporary cessation of ventilation in the mine on
the afternoon of the explosion indicates that the dis-
cipline of the mine was seriously at fault through lack
of definiteness in the orders given and cohesion among
the officials concerned. The persons more or less con-
cerned in the matter are Mr. Blake Walker, Mr. Wroe,
Mr. Mairet, Mr. Fearnley, and the deputies, Slack and
Clayton.

The report calls attention to breaches of specific
statutory duty and of the Regulations as follow :—

Failure to Produce Adequate Ventilation.—It is clear
from the circumstances of the disaster, and from experi-
ments subsequently made, that the effect of stopping
the fan was to cause a serious accumulation of gas in
the working places leading to a violation of section
29 (1). Not only wore no measures taken by those in
authority to ascertain what would be the results of
stopping’the fan, but it is obvious that in the case of a
gassy mine, such as this is, those in authority should

have taken the most scrupulous care to see that the
men were, in fact, out of the pit before there was any
interference with the ventilation. The agent who
authorised the stopping of the fan does not appear to
have consulted at all with the manager as to the
arrangements to be made, and the manager, on his
own account, appears to have done nothing more than
give the under-manager a general instruction, verbally,
to have the men out.

Electricity (Defective Apparatus). — Events have
shown that the coal cutting machine which the jury
found to have been the cause of the explosion had not
been “ worked and maintained ” on the day of the
accident, so that there was “ no risk of open sparking.”
It was part of Otway’s duty, as the foreman electrician,
to see that the apparatus was properly worked and
maintained, and this he failed to do. It was proved
that it formed no part of the discipline of the mine for
an electrician to inspect the coal cutter after vital parts
of the machine had been changed, and before the
machine was again put into use, and it did not appear
that the manager had brought home to the minds, either
of the electricians or the drivers, the great importance
of maintaining the apparatus in safe working condition.

Failure to Comply with Section 33, with regard to the
Construction of Safety Lamps.—As indicated earlier,
there was in use at the colliery a greater proportion of
unapproved oil safety lamps than of approved lamps.
The contention put forward by the Wharncliffe Colliery
owners is that they did their best to comply with the
Act, and that the failure lies with the manufacturers,
who did not meet their demands. The number of safety
lamps ordinarily in use at the colliery was 2,072, and
up to the time of the explosion the company had
ordered 1,050 lamps, leaving 1,022 lamps still to be
ordered. Of the 1,050 lamps ordered or reconstructed,
700 had been received and were in use, and the manu-
facturers were 350 short of completing the order they
had received. The first order given to the lamp makers
by the colliery owners was for 100 lamps on December 2,
when it would be known that 2,000 approved lamps
would be required to fulfil their obligations under the
statute. In these circumstances, and in view of the
fact that orders in sufficient quantity to comply with
the Act had not been given on May 30, 1914, the opinion
is expressed that the owners, agent, and manager have
failed to carry out section 33 of the Coal Mines Act,
1911.

SOUTH WALES INSTITUTE OF
ENGINEERS.

The ordinary general meeting of the South Wales
Institute of Engineers was held at the Institute. Cardiff,
on Thursday, December 3. 1914. The chair was
occupied by the President (Mr. Henry T. Wales.)
■ The Chairman announced that the council had
elected Principal Griffiths president of the institute for
the session 1915.

Principal E. H. Griffiths, D.Sc , F.R.S., said he
interpreted the action of the council in electing him
president as an endorsement of tbe view he had always
tried to emphasise—tbe closest possible union between
pure and allied science.

The following were elected office bearers for the
session 1915:—Vice-presidents : Mr. William Stewart,
Caerleon, Mon.; Mr. John Fox Tallis, Newport, Mon.;
Mr. J. Dyer Lewis, H.M. inspec oi- of mines, Swansea.
Members of council: Mr. William Thomas, Oakhill,
Aberdare; Mr. Westgarth Forster Brown, Cardiff;
Mr. David E. Roberts, Cardiff; Mr. T Allan Johnson,
Cardiff; Mr. Trevor F. Thomas, Cardiff; and Mr. W.
Gascoyne Dalziel, Bath.

Among new members elected to the institute were :—
Lieut.-Col. C. S. Denniss, general manager, Cardiff
Railway Company; Mr. Alaric Hope, M.Inst.C.E., chief
engineer, Cardiff Railway: Mr. W. A. Brown, general
manager, Aberthaw and Bristol Channel Portland
Cement Works, Aberthaw, Glamorgan.

Arching in Collieries.

Discussion was resumed of the paper on this subject
submitted by Mr. Robert G. Clarke.

Mr. J. Fox Tallis said in many cases reinforced
concrete could be used to great adv antage underground,
but where the job was of repairing ordinary l oads in
collieries it did not appear to possess the advantages
which were secured by using curved girders. In bad
ground curved girders in short lengths could be put in,
rendering unnecessary the large opening that would be
required for concrete arching and the packing. The
author had not given them comparative costs as between
concrete arching and curw d girde» s. Such information
would be valuable. By putting in girders they had to
take out much less ground, and they could be quickly
installed. Walled in between girders with special
bricks, a very strong arch was obtained, and a good road
was made which could always be watered and practically
rendered dust-proof.

Mr. W. O’Connor was glad the author of the paper
had arrived at a conclusion which he (Mr. O’Connor)
came to many years ago—that any kind of soft packing
around an arch, unless under exceptional circumstances,
was a mistake. In all cases they should endeavour to
cut out the ground as sparingly as possible, and to fill
up with solid masonry pack. The timber.ng and
shuttering should be made sufficiently strong to resist
any squeeze, thus allowing the masomytime to set in
its proper shape. With regard to the use of girders
formed into an approximate arch shape, he thought
they seemed tn be well adapted to the purpose in main
roads, but he was opposed to filling in with brickwork
as against concrete. There could be no question which
was the superior material. The brickwork, even where
specially shaped bricks were used, was liable to become