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THE COLLIERY GUARDIAN.

June 26, 1914.

The Killiiigworth Colliery (New South Wales) Explosion.

By JAMES ASHWORTH.

From a paper read before the North of England Institute of Mining and Mechanical Engineers.

A very serious disaster occurred in 1902 at the Mount
Kembla Colliery (New South Wales), causing the death
of about 130 persons. The experts and others who were
called to give evidence were only agreed on one point—
that there had been a heavy fall of roof rock in a large
goaf. The experts called by the colliery company
propounded a theory originated by the present writer.
This theory was fully explained in an article published in
the Colliery Guardian* in explanation of the 1901 explo-
sion at the Talk-o’-th’-Hill colliery, North Staffordshire,
and was to the effect that the disaster was due to a heavy
fall of roof, causing sudden air percussion. This article
was most unjustly criticised by the Commissioners. In
the end the Commissioners held that it was an explosion
of firedamp, although they had absolutely no evidence on
which to base such a verdict.

Since then another New South Wales mystery (the
subject of the present paper) has been recorded, namely,
the explosion which occurred at Killingworth Colliery
about 5.15 a.m. on December 7, 1910. At the time of
the explosion only one man was on the works at the
surface, and an untethered horse was in the underground
stable, which was situated near the bottom of the upcast
shaft. The man (Watkins) had as his duty the firing-up
of the boilers and the starting of the ventilating fan
engine, which had been standing since the previous
afternoon. Watkins said that he started the fan a little
after 4 o’clock, and that at 5.15 he heard a sharp report,
which made him think that one of the boilers had burst.
The Commissioner in Appendix B of the report says
that Watkins’ idea that it was a boiler explosion was
natural; but, as. that was his first impression, it raises
the question whether the explosive outburst did not in
its very inception come from the dierction of the boilers,
which from his position would be the B or upcast shaft.
Watkins further stated that when he looked towards the
downcast shaft he saw a cloud of dust, and then ran
away, and that, whilst he was running, there was a
rumbling sound behind him and a cracking as the
materials thrown up the shaft struck the headgear.

The first man to see the explosion was Featherstone,
and he at the time was dressing to go to work at another
mine. He heard a grumbling noise for about 10 or 12
secs., and on going to the door saw what he thought was
smoke coming from the mine; he said that there was a
second explosion, three or four minutes after the first.
He saw smoke gradually rising from the pit, there was
smoke over the poppet-heads, and it seemed to die away
in about two minutes before the second explosion.

On the previous day one cage was left at the surface
landing and the other about 14 ft. above the bottom. The
dust thrown out of the shaft was neither coked nor burnt.
When the dust cleared away, it was seen that a huge
mass of material, weighing from 10 to 11 tons, had been
thrown up the shaft. Probably no such evidence of
enormous force was ever before demonstrated by a
colliery explosion.

The management assumed that a gob-fire, which had
previously been walled off, had broken out in one section
of the workings, and had originated the explosion. As
the mine itself had been laid off for some time, it was
decided to close both shafts and smother out the sup-
posed fire. Later on when the mine was re-opened it
was absolutely proved that there never had been a
gob-fire.

During the re-opening very careful records were taken
of the indications of force and fire throughout the mine.
All the witnesses were agreed that the evidences of force
were mainly towards the bottom of the downcast shaft.

The evidence given by various witnesses before the
Royal Commissioner has been summarised. Mr. Ernest
Humble, the manager, said there must have been an
explosive mixture of gas and air in the first place. Mr.
Duncan McGeachie, the superintendent of the colliery,
said that the Borehole seam (in which the explosion
occurred) was worked on the bord-and-pillar system, and
was about 61 ft. thick throughout the mine. Only about
5| acres had been pillared, and this area was sealed off on
account of incipient heating in June, 1908. The seam of
coal is clean, and has a roof of soft brittle shale, 30 in.
to 14 ft. in thickness. Above this shale is the Young
Wallsend coal seam, which is dirty, full of brass, and
very gassy. Practically all falls of roof extended up to
the Young Wallsend seam, and after the explosion no
less than 200 falls were counted. The body of the horse
found in the stable was uninjured and unburnt. The
upcast shaft was a very wet one, and nothing was forced
up the shaft. A small pipe at the foot of the shaft was
displaced, and the steam pipes were broken in one or
two places. Mr. McGeachie said that he would not like
to give a definite opinion as to the cause of the disaster,
nor as to where it originated. He was of opinion, how-
ever, that the explosion was largely due to coal dust,
started by a pocket of gas, but he did not suggest how the
gas was ignited. If it had been an explosion of pure gas,
it would have been “ a puff and over.”

Mr. John McGeachie found the indications of heat in
the cul-de-sacs very severe indeed, and the force out-bye.
He thought that the primary forces had their origin
in the neighbourhood of the downcast shaft. He
imagined, however, that the point of origin might have
been in the Majuba district. He had not seen anything
which would account for the explosion.

Mr. A. A. Atkinson, Chief Inspector of Mines, said
none of the falls exceded 20 ft. in height. There was an
absence of the most likely causes, and he was quite
unable to state the actual or probable cause. In his
opinion a flame ignited a mixture of firedamp and air,

•* Vol. Ixxxiii., 1902, p. 389,

and then raised a cloud of dust which carried the flame
throughout the pit. It had been shown that the explo-
sions occurred simultaneously in the workings on
different sides of the pit, which was impossible to
conceive, and thus forced materials up the shaft into the
headgear. Two distinct forces, an inward and an out-
ward, were indicated. He thought the locality of the
ignition of less importance than the discovery of its
cause. He attached no importance to the match theory.

Mr. D. A. W. Robertson, the general manager of the
Metropolitan Colliery, said that never before had the
investigation of a colliery explosion been so thorough, and
yet so barren in its results. With great diffidence he
gave the West Wallsend narrow bords as the place of
origin. A distinct feature of the explosion was that the.
force had proceeded outwards from every district.
Unlike most explosions which only last a few seconds,
this one lasted for .at least five minutes. As a cause of
ignition, he suggested the falling of the strata on a skip
and the resulting sparks.

Mr. William Humble, inspector of mines, thought that
matches were a likely cause of the ignition of an explo-
sive mixture in the West Wallsend narrow bords. A
double force was evident throughout the mine. Mr. J.
T. Tennant, inspector of mines, said that a few windows
in the fan engine house were broken, the covering of the
upcast shaft was blown off, together with a cage standing
on it, part of the fan drift was blown out, some of the
brickwork over the fan fell in, and two blades of the fan
were broken. The mine was a labyrinth of contrary
forces, but he was inclined to say that the starting point
was in the Main Dip district. On pages 155 to 166
of the report will be found most valuable information
for every student of colliery explosion and air
compression phenomena. The field having been thrown
open to anyone to enunciate a theory supported by the
known facts, the writer has already had considerable
correspondence with the New South Wales authorities on
his theory that the Killingworth explosion originated at
the top of the B or upcast shaft. He has also made the
following suggestions—first, that the engineer whilst oil-
ing the fan shaft ignited an explosive mixture which
was coming up the upcast shaft; secondly, that flame
from the spontaneous combustion of oily waste in the
fan drift, or around the inside shaft bearing, had ignited
an explosive mixture; thirdly, that a stream of sparks had
been caused by the fan blades striking the brickwork,
and had thus ignited an explosive mixture of air and gas.
Mr. A. A. Atkinson, however, thought that the two last-
mentioned suggestions were possibilities, but that the
first one was disproved by Watkins’ evidence.

On the main point as to the possiblity of there being
an explosive mixture of firedamp and air in the mine, all
the witnesses gave their opinion that this could not have
been possible, and yet they were all agreed that the
initiatory conditions necessitated the presence of an
explosive mixture somewhere to fire the coal dust, and
that the main force radiated towards the downcast shaft
bottom. They also agreed that whenever a heavy fall
of roof occurred, the force went up to the Young
Wallsend seam, and brought down large quantities of
gas. There were 200 of these falls counted, but their
sequence was not indicated. The most likely possibility,
therefore, seems to be that the explosive mixture
originated from one or more big falls, and thus might
have travelled, only slightly diluted, to the point where
it was fired, which the writer suggests was at the top of
the upcast shaft.

The writer is most deeply impressed by the damage
to the fan housing and drift by the effect of the explosion
on the materials at the bottom of the downcast shaft, by
the time during which the force continued in the down-
cast shaft, and finally by his recollection of an explosion
which he saw at the Burley Pit in North Staffordshire
many years ago. This latter demonstration of force was
up the downcast shaft, and not up the upcast, and as at
Killing worth the ignition was in the upcast. In all its
principal features therefore it resembled the Killingworth
explosion. Some of the witnesses called before the Royal
Commissioner evidently had some suspicion that the
explosion might have originated at the fan, or in the
upcast shaft, but they resolutely set their minds to accept
only that evidence which tended to prove that the
explosion did not originate there. That they did not
exhaustively digest the whole of the available evidence is
quite clear. Thus, Featherstone whilst dressing heard
the first sound, and saw the first smoke; he also saw
the smoke clear away, and heard the second sound,
which was probably due to the crash of the materials
thrown up into the headgear from the pit bottom; he also
saw the black smoke or dust rising from the colliery.
Further, it must be noted that every man who arrived at
the works before smoke and dust had ceased coming out
of the downcast shaft said that no smoke was then
coming out of the upcast. The stable where the horse
was killed was fed with fresh air, and was surrounded
by return airways; consequently, any pressure developing
in these airways would be distributed evenly all round
the stable, and thus would prevent any force from
crossing from one side of the stable to the other. Further
than that, the overcasts were blown into the haulage
ways, and therefore as soon as the flame passed these,
the fine coal dust on the haulage ways became involved.
By following this probable sequence of events, it will be
found that the continuously-increasing force of the explo-
sion, as it gathered headway, passed inbye, whilst at
the same time it found an outlet through the downcast
shaft. Eventually the force became so great that it
lifted most of the material and coal skips, with the cages

and ropes, and jammed the whole lot into a tangled mass
in the headgear. In these conditions it will be realised
that the upcast shaft,.being at first under pressure from
the primary ignition with a downward direction of force,
then became the downcast, and the air was thus
reversed.

In further confirmation of this argument, the explorers
found that a wooden beam from an overcast in the Main
Dip district was so forcibly ejected from the return into
the intake, that it was forced through the ends of a skip
on the haulage way. This instance of force also tends to
show that at this point the force in the return airway was
in advance of. that from the ignition of coal dust on the
haulage way. The fact that the development of force
continued for so unusual a length of time proves incon-
testably that it was the result of flames travelling on
every main roadway towards the coal faces, and not in
the opposite direction. This was also proved by the
recorded extremely intense pressures which were found
to have been produced in the cul-de-sacs and other places.
The direction of the force (as stated above) is further
confirmed by the fact that there was little or no indica-
tion of “ back-lash,” and thus the accumulated pressure
just died away quietly after the flame had reached the
coal faces.

No samples of dust appear to have been taken for
analytical and microscopical examination, but had such
been obtained from the fan drift and various points in
the mine, it is most probable that the mystery would
have been more readily cleared up. In reference to
Watkins’ evidence, the Royal Commissioner remarked
that “ Watkins’ idea that it was a boiler explosion was
natural, but, as it was his first impression, it raises the
question whether the explosive outburst did not in its
very inception come from the direction of the boilers,
which from his position would be the B [upcast] shaft.”
Featherstone also said ‘ ‘ that the cloud of dust seemed to
die away in about two minutes, and that was before the
second report was heard.”

In conclusion, the writer would suggest that the
information afforded by the Killingworth explosion of
the forces developed by explosive mixtures of gas, air,
and coal dust, be applied to the unravelling of the point
of origin of the more recent explosion at Senghenydd.
In both cases the point of origin has been placed near
the bottom of the downcast shaft; but, assuming for a
moment that such was the case, then it becomes plainly
evident that the forces at Senghenydd were not developed
similarly to those at Killingworth. In the Killingworth
case the force was cumulative, whereas at Senghenydd it
was of much shorter duration, and the effects on the
mine were of a totally different character. The compari-
son will probably therefore, lead at least some students of
explosive phenomena to conclude that the point of origin
of the Senghenydd explosion was not at the lamp-relight-
ing cabin, but inbye at some point such as the one in the
Mafeking district known as ” William Williams’ place.”

THE LOHDOBS COAL TRADE.

Thursday, June 25.

The London coal trade during the past week has been of a
very quiet character. The issue of lowest summer prices has
not as yet led to any appreciable increase in orders at the
depots, although enquiries as to the time of delivery, etc.,
from the various customers anxious to lay down their usual
cellar stock tend to make merchants take a more hopeful
view of the near future. At the moment supplies under
contract, coupled with the difficulty of finding sufficient work
for their own wagons, prevent merchants from taking advan-
tage of any cheap lots offered by collieries or. factors, and
in consequence the holders of stocks at various railway
sidings are quoting prices well below the colliery quotations.
For the time of the year the colliery position appears to be
strong, with only an occasional spot lot being offered, mainly
in the cheap qualities. Contracts, especially, for the best
brights type of coal, are receiving more attention, and it is
reported that a fair number have been renewed on the basis
of last year’s prices. The cheaper qualities, such as stove
and kitchen cobbles, have not as yet had much serious atten-
tion paid them, as the attitude of the buyer at present is to
buy from time to time as the occasion demands, rather than
to saddle himself with what he considers high-priced coal.
The current business for Silkstones is somewhat slow, but
prices are holding together, although some of the Yorkshire
qualities are offering at a specially low price just now—
probably due to anticipated difficulties to find suitable
vessels at the ports. Best brights find a ready sale, and also
the second quality Derby brights, but house nuts, bright
kitchen coals, and also stove qualities are in poor demand,
and prices are weak. The best qualities of steam find a
ready sale, and prices are steady, but the second grade quali-
ties are inclined to be easier owing to a poor enquiry. Small
nuts and slacks just about hold their own, both demand and
output being light. The issue of the results of some of the
large contracts recently tendered for again reveal the fact
that merchants are prepared to run their wagons and cart
coals at prices which are cut to the very last fraction, in
order to secure regular work winter and summer, thus again
emphasising the very keen competition set up by the gas
stoves, especially during the summer months. The seaborne
market remains very quiet, with little or nothing offering,
and prices are returned as unchanged. Only seven cargoes
have been reported as entering the Thames so far this week—
all contract coals. Gas coke is almost neglected, but the
make being small, prices do not show much change. Prices
still vary to an extent, rendering satisfactory quotations
impossible.

From Messrs. Dinham, Fawcus and Co.’s Report.

Friday, June 19.—The seaborne house coal market was
quiet again to-day—a part cargo of Yorkshire was sold, but
price not available. Cargoes, 21.

Monday, June 22.—There were no cargoes of either
Durham or Yorkshire seaborne house coals on offer at to-day’s
market, which remained quiet. Cargoes, 29.

Wednesday, June 24.—The seaborne house coal market
was exceedingly quiet to-day, with no cargoes offering.
Cargoes, 7.