242.

THE COLLIERY GUARDIAN.

January 30, 1914.

Spontaneous Combustion of Coal in Mines.

First Report of the Departmental Committee.

The Departmental Committee on the Spontaneous
Combustion of Coal in Mines have issued their first
report. The Committee consists of Mr. R. A. S.
Redmayne, C.B., H.M. Chief Inspector of Mines, Sir
Arthur B. Markham, Bart., M.P., Mr. C. E. Rhodes,
Mr. Frank Rigby, and Mr. Herbert Smith; and was
appointed in August, 1912, to enquire into the circum-
stances in which spontaneous combustion of coal occurs
in mines, its causes and the means of preventing it or
of dealing with it when it has arisen.

The Committee now report on that part of their
enquiry which relates to the danger to persons employed
in a mine during the occurrence of an underground
fire occasioned by the spontaneous combustion of coa^
or other carbonaceous material. Although they purpose
to continue their investigation in other directions very
much further—viz., in the direction of solving the
difficult problem as to the cause or causes of spontaneous
combustion and the means which should be adopted^
firstly in preventing the initiation, and, secondly, in
dealing with such fires when they occur—they feel that
they have taken sufficient evidence to enable them to
arrive at definite conclusions in respect of the question.
Comparative Liability to Spontaneous Combustion in

Mines as between Different Districts in the United
Kingdom.

The Committee have made enquiries as to the com-
parative liability to the occurrence of fires from spon-
taneous combustion in the different mining districts of
the United Kingdom, and based upon the reports of
such occurrences received by the inspectors of mines,
find the extend of the evil to be as stated below. It
would appear, however, from the evidence that it is
doubtful whether all cases of incipient fire are actually
reported, and that the number of fires is probably far
in excess of those reported.

In Scotland spontaneous heating is liable to occur
in the Fifeshire coalfield, in the Edinburgh district, in
Lanarkshire, and at Brora Colliery in the county of
Sutherland. During the period January 1, 1910, to
October 1912, 21 cases of spontaneous combustion have
come to the knowledge of the divisional inspector, viz.,
15 in Fife, two (at the same colliery) in the county of
Edinburgh, three (at two collieries) in Lanarkshire and
one at Brora.

Of the 15 fires in Fife, 11 occurred at collieries work-
ing the Dysart Main seam, the thickness of the workable
section of which is 23 ft. 2 in. Little or no fire-
damp is given off by this seam, but Mr. Walker (the
divisional inspector) says: “ As this seam is worked at
greater depths it will in all probability be not so
immune in this respect, and it will be necessary to take
further precautions.”

In the Northern Division instances of spontaneous
combustion are extremely rare. In the whole history
of mining such fires have been known to occur at only
three collieries in Northumberland and one in Durham.
At the collieries in which the fires have occurred little
firedamp is given off, though there are many “ gassy ”
(fiery) collieries in the coalfield, especially in the county
of Durham.

In the Yorkshire and North Midland Division,
spontaneous combustion occurs in some of the mines of
the Yorkshire, Derbyshire and Nottinghamshire coal-
fields, viz., at eight collieries in Yorkshire, at seven in
Derbyshire, and at 11 in Nottinghamshire. At many
of these collieries fires are of frequent occurrence,
and in Yorkshire, in particular, dangerous conditions in
respect of firedamp are liable to occur as the mines are
very gassy. Mr. Mottram (the divisional inspector)
says: “ the only instances I know of life having been
lost through gob fires are the recent ones at Bentley
and Cadeby (two collieries in Yorkshire). I have heard
that there was loss of life at Annesley colliery
(Nottinghamshire) in 1877. . . . The gob fires are
practically confined to the Barnsley Bed, in Yorkshire,
and to the Top Hard, Kilburn, and Silkstone seams in
Derbyshire and Nottingham.”

In Lancashire and North Wales, instances of
spontaneous combustion have occurred at about nine
mines in Lancashire of late years. The seams which
are most liable to be affected are the Ravenhead,
Wigan Four-feet, Wigan Nine-feet, the Doe coal, and
the Big Mine. Most of the mines in which the fires
occur are gassy.

In South Wales, fires due to spontaneous combustion
are reported to have occurred at 13 collieries (it is
•doubtful, however, whether one of the cases was due to

spontaneous combustion, and it is interesting to note
that the coal worked at this colliery is anthracite).
One occurred last year at a steam coal colliery, “ in
which,” says Dr. Atkinson (the divisional inspector),
“ cases of spontaneous combustion are extremely rare.”
The seams most liable are the Victoria and the Swansea
Five-feet or Llanelly Four-feet.

In the Midland and Southern Division fires
due to spontaneous combustion have characterised
the working of coal in both North and South
Staffordshire and in East Worcestershire for a great
many years, and the instances are countless. In North
Staffordshire they are liable to occur* in the Great Row
Cannel Row, Winghay, Rowhurst or Ash, Yard, Rag-
man or Rough Seven-feet, Hams, Ten-feet, Banbury,
Cockshead, and Bullhurst seams; and in South Stafford-
shire and East Worcestershire, wherever the “thick
coal ” is worked, and, to a less extent, in the New Mine
coal. In the Cannock Chase district they are liable to
occur in the Deep and Shallow coals in the Seven-feet
and Five-feet, and occasionally in some of the other
seams. They are numerous also in Derbyshire, Leicester-
shire and Warwickshire. They occur in the Moira
Main and Kilburn seams in Derbyshire, in the Upper
and Lower Main coals of Leicestershire, and in the
Rider or Two-yard, the Slate, and the Seven-feet coal in
Warwickshire. In Gloucestershire, spontaneous com-
bustion is of fairly common occurrence in the Coleford
High Delph, but fires from this cause occur also,
though to a less extent, in the Red Ash, Great Vein,
and Hollybush seams. In Somerset they have occurred
occasionally in the Ashton Great Vein, the Standing
coal, the Dungey Drift, and the Perrink seams; and in
Shropshire, chiefly in the Top or Double coal.

During the last 20 years 177 persons have lost their
lives through accidents caused by spontaneous combus-
tion in coalmines in the United Kingdom. Particulars
of these accidents are set out in the report.

Reports as to Heating.

Although this trouble has been a feature of such long
standing in South Staffordshire mining the Committee
cannot discover, either from searching the records or
from the evidence of witnesses, that it has been attended
with much danger from explosions of inflammable gas,
though deaths from poisoning or suffocation of persons
engaged in combatting the fires, and, in some few cases,
of others engaged in the ordinary work of the mine in
that part ventilated by the air current passing by or
over the seat of the fire, have occurred by reason of the
deleterious gases generated by the combustion.

The greatest danger from spontaneous combustion
occurs in mines which generate large quantities of fire-
damp. Fortunately mines characterised by both of
those features—generation of firedamp and liability to
spontaneous combustion—are not so numerous as those
in which only one or other exists. Thus, although the
number of “ gassy,” usually described as “ fiery ” mines
is very large, only in two districts are such mines liable
to spontaneous combustion to any considerable degree,
viz., in North Staffordshite and Yorkshire. On the
other hand, although a great number—we are well
within the mark in saying the majority—of the mines
in South Staffordshire and East Worcestershire are
liable to spontaneous combustion, few of them can be
termed gassy; in fact, so comparatively free from gas
are they that many of them are worked with naked
lights.

The fact that mines are now being worked to much
greater depths than in the past and the certainty that
still deeper mining will obtain in the future, with
consequent higher initial natural temperature, and
probable higher ventilating pressure, make it extremely
doubtful whether the comparatively favourable condi-
tions hitherto prevailing will continue. These observa-
tions apply to all districts.

Section 81 of the Coal Mines Act, 1911 (which re-enacts
as regards mines, section 5 of the Notice to Accidents
Act, 1906), gives the Secretary of State power to require
the notification of dangerous occurrences. By an Order,
No. 934 in the series of Statutory Rules and Orders of
December 22, 1906, under the Notice of Accidents Act,
1906 (which Order is continued in force by the operation
of section 126 (a) of the Coal Mines Act, 1911), the
Secretary of State included “ all cases of fire below
ground ” among the dangerous occurrences notifiable to
the inspector of mines. ,

From the evidence the Committee find that a state of
doubt exists as to what constitutes an underground fire,

and consequently at what stage of the spontaneous
heating notification should be sent to the inspector of
mines. Cases frequently occur when it is impossible
for the management of a colliery to say definitely
whether a fire is or is not in existence. Gob stink
may travel some distance from an inaccessible point in
the gob or goaf, and be detected in an airway or on the
edge of the goaf, and a fire may or may not result.
Fires have occurred, and only years afterwards has the
fact been discovered, e.g., when driving through an old
goaf.

The normal temperature of mines varies so widely as
between colliery and colliery that it would not alone be
a safe guide to give any fixed point on the thermometric
scale which would constitute a standard for abnormal
heating. The Committee think, therefore, that abnormal
heating, should be defined as a rise of a certain number
of degrees above the normal temperature of the air in
main return airway of the seam being worked at the
point of discharge into the upcast shaft, and that a safe
minimum to take would be 20 degs. Fahr., but with
the additional safeguard that on the temperature of any
accessible part of the mine attaining 110 degs. Fahr,
the fact should be reported to the inspector of mines.
They are of opinion that notification should be sent to
the inspector of mines:—

(1)	When gob-stink, smoke, or any other sign of
combustion is observed;

(2)	When the temperature of the air in an acces-
sible part of a mine is 20 degs. Fahr, above the
normal temperature, as hereinbefore defined, or where
the temperature at such place attains to 110 degs.
Fahr.

(3)	When any flash has been observed coming from
any pack or waste.

They further recommend that as soon as any work is
commenced for the purpose of discovering or combatting
a fire or anticipating fire, the inspector should be
notified of the fact.

The Withdrawal of Workmen.

Section 67 of the Coal Mines Act, 1911, makes com-
pulsory the withdrawal of persons other than those
engaged in enquiring into or in removing danger, from
the mine or anyplace in the mine fsund dangerous.
Some doubt has existed as to whether the occurrence
of a fire underground, even in a gassy mine, constitutes
a dangerous state within the terms of Section 67 of the
Act, seeing that the danger cannot be said to have
actually arisen in the workings, though it may arise at any
moment. Some mining engineers maintain that on the
occurrence of a fire a place in a mine is not dangerous
unless inflammable gas is actually present in dangerous
quantity—the possibility, or likelihood even, of such an
occurrence not constituting such a state as to render
compulsory the withdrawal of persons.

In most cases it is necessary that when once abnormal
heating has been discovered in a mine, some persons
should be employed at or near the seat of the heating,
to prevent, if possible, it reaching a state of incan-
descence, or to combat the fire once it has occurred.

The number of . persons who should be engaged in
combatting a fire in a mine must [depend entirely upon
the circumstances surrounding each case, and it is quite
impossible for us to lay down any useful limiting
conditions in this respect; the persons so employed,
however, should be as few as practicable, for even if the
fire occurs in a non-gassy mine, the operations attending
its extinction are of a more or less dangerous character
by reason of the poisonous gases evolved by the
combustion.

As to that part of the question which relates to the
persons employed below ground, other than those whose
presence may be necessary for dealing with actual or
incipient fires, much evidence has been taken. The
Committee realise that what is a dangerous or serious
occurrence in gassy mines is usually attended with
comparatively little danger in mines where gas seldom
occurs or occurs only in small quantity, e.g., when
J per cent, of inflammable gas has never been found in
the airway. For instance, in the South Staffordshire
coalfield, most of the mines are not at all gassy,
explosions are rare, and never extensive. What danger
may exist from a rib or gob fire in such mines is rather
that of poisoning or suffocation by the products of
combustion, a danger practically limited to the persons
on the return side or in the immediate vicinity of the
fire, and not affecting those on the intake side, especially
if they are far removed from the seat of the fire.

Having carefully weighed all the evidence the Com-
mittee are of opinion that:—

In mines in which safety lamps are used, whether
in pursuance of the Act or of any Regulation or
Order under the Act, or in mines in which one quarter
per cent, of inflammable gas has been found in the