December 27, 1918.

THE COLLIERY GUARDIAN.

1351

to stiffen the tie beams by interposing a column under-
neath, and this proved satisfactory.

In the course of the discussion, Mr. Bentham said
there was a big vibration of pit headgear, especially
when the cargo began to retard the motion. Had Mr.
Taylor formed any idea whether reinforced concrete
headgear would withstand the vibration for a very
long period of time? It was known that timber head-
gears had been standing 50 years and upwards. Was
the reinforced concrete going to stand like that? If
it had not already been done vibration tests should be
made. The author had suggested that the bending of
the tie beams in the Glasgow Corporation coke bunkers
was due to the coke bridging between the tie beams
because it was in large pieces. He thought that was
not correct. In every bunker of that kind, where the
material ran down, there was a side pressure, which
increased as the size of the material became less.
The smaller the grain, the smaller the coke, the greater
was the pressure or friction on the side. This side
pressure tended to carry the tie beam down. He
thought it was fairly satisfactorily settled that that
was the cause of the bending.

Referring to Mr. Bentham’s criticism, Mr. Taylor
said in the case of a bin containing grain the pressure
on the side walls was due to the angle of repose of
the material actually upon the side walls. In the
case of the time beams, he mentioned there was no sur-
face for the pressure to exert itself upon to any large
extent.

A NEW REVERSAL FAN.

By J. Fox.

Arrangements for reversing the ventilating cu>rents
of a coal (or any other) mine in case of a fire, or large
outflows of noxious gases, have been strongly recom-
mended by members of‘the Royal Commission on Coal
Mines. This very important point has received the
attention of Dr. J. S. Haldane, who in a paper on the
possibilities of rescue work in connection with mine
fires and explosions of gas and air, laid great stress
upon the quick reversal of the ventilation in many < as°s
as the best means of reducing the loss of life in such
disasters.

The fan now under consideration (see illustration)
affords quite a simple and effective means of carrying
out Dr. Haldane’s suggestion: to reverse or keep
reversed (if already done so by an explosion) the

Arrangement for Reversing Air Current in Fan Drift.

ventilation of any district or mine. Owing to the great
simplicity of the arrangement this, could be effected by
anyone in charge without fear of failure, and without
entering either the fan drift or fan house.

In following the description given, it will be seen that
the change from an exhaust to a blowing ventilation is
simplicity itself.

Every mining man knows that the reversal of any
system of ventilation requires very great consideration
before it is decided upon, and must be worked out and
experimented upon under normal working conditions, to
find out what would take place (and what should Im done)
under abnormal conditions, so tint there should be no
doubt about its action when taken. If the above pro-
visions were in use it would not require a very competent
person to decide to move a lever, and so reverse the
current. The arrangements work as follow :—

A marks side doors fixed in the fan walls and only
requiring to be opened immediately before the reversal
of the ventilation is to take place. To reverse the

ventilation open the doors A, then turn the winch
handle B three and a-half times, this at once actuating
every part of the reversal gear in a complete ratio. By
’’ using the sliding front C the covering is lowered, by
^the same movement, into the chimney of the fan D,
and the same process gradually brings across the
junction doors E, to the sides of the two former inlets,
thus at once closing up the original intakes of the fan.
Moreover, the doors E, in passing from the junction
centre of the fan drift, at once give a clear passage for
the reversed air through the doors A, the sliding front
C, the junction doors E, and on into the former
upcast shaft. All the various changes are made in one
operation by turning the winch.

As mentioned above, it is well known that in most
explosions of gas and air, there is a reversal of the air
current; and by actuating the winch, as described, it
would be most simple to keep the reversed cun ent in that
condition, so as to clear the foul gases out of the mine
before making any change in direction; for if the
air were restored to its normal course before the deadly
gases were thoroughly diluted or cleared away, the latter
would be sent back into the workings and claim a second
lot of victims, who have, perhaps, only just survived the
first deadly current from the one explosion.

It is most important that energy should be directed
to affording some means that will get rid of the deadly
gases that are al way s given off from the disastrous
accidents always imminent in coal mines, and the
quicker the gases mentioned above are diluted or cleared
away, the fewer will be the casualties.

In support of the arguments put forth above
concerning the loss of life through CO, the chief
product of such disasters, the following figures, obtained
after the Hulton Colliery disaster, may be quoted:—

Cause of Deaths.

CO responsible for ............ 220	deaths.

Effects of explosion ........... 54	,,

CO and explosion................ 61	,,

Asphyxia.......................   2	„

Other causes..................... 7	,,

344

Much the same results were found in many disasters,
including Maypole, Hamstead and Whitehaven. It will
be seen that the largest loss of life is caused by CO,
and to minimise these risks it is quite feasible to alter
the fans at present in use, and in all new undertakings
adopt such reversal fans as will do what is described.
This will enable a better control of the ventilation,

which, under the old order of things, often got the
upper hand.

The author has had experience of fires in mines where
the victims have lost their lives through the effects of
CO, and it was through experiences of this kind that
the protected device here described was designed.

Messrs. John Davis and Son (Derby) Limited are ex-
hibiting at the Manchester British Scientific Products
Exhibition examples of their aural and visual winding
engine and haulage plane signals, lamps, electric blasting
apparatus, surveying instruments, self-registering water
gauges, etc.

American Coal for Holland,—The Ministry for Foreign
Affairs, U.S.A., announced that the United States has
granted permission for the export of 100,000 tons of coal
:o Holland. Five Dutch ships received permits to sail
immediately with cargoes of coal.

MANCHESTER GEOLOGICAL AND
MINING SOCIETY.

At the meeting of the Manchester Geological and
Mining Society held on December 17, Mr. Orchard
in the chair, a discussion took place on Prof. Hard-
wick’s paper on “ The Training of Students in C.oal
Mining, with special reference to the scheme of
the .Engineering Training Organisation ” (Colliery
Guardian, December 6, 1918, p. 1187), which in the
absence of Prof. Hardwick was read by Mr. Sydney
Smith, the hon. secretary pro lent.

Sir John Cadman, in a written communication,
suggested the provision of ample opportunity, by
scnolarships, etc., for the aspiring underground
worker to pass freely to the higher grade of manager
or mining engineer, and he also outlined schemes of
training co be followed with that object in view.

Mr. Pickup said employers in the future would do
well to realise more than they had done in the past
the advantage of a higher standard of education
amongst their officials. Aspiring students must be
encouraged and assisted to pass from the local classes
to the district colleges, from those to the university,
and a complete co-ordination of the whole system of
mining education from the bottom to the top should
be attained. In the past the importance of technical
education in mining had not been sufficiently realised,
and the industry had suffered from that, especially
m comparison with others. They must get away from
the apathy of the past, and wherever ability was
found give free scope to it. The day of unscientific
mining was passing; in the future the industry would
be of much greater complexity and difficulty, and a
higher technical education for those controlling it
would be necessary. The day was now all but over
when the qualifications of a principal were that he
had been brought up underground and was therefore
thought to be sufficiently trained. The industry had
often been carried on at a low standard of efficiency;
it must now’ give proof of its belief in the value of
highly trained men by giving them adequate support,
moral and financial, and it must encourage students
in sufficient numbers to meet not the demand merely,
but the real needs of the industry. The problem
was how to produce a sufficient number in each of
the different grades. In the first place, the workman
would obtain his principal education at a public
elementary school, and after he had reached the
highest standard and commenced work at 14, he should
continue his attendance at continuation classes under
the new Education Act until he was 16 years old. The
necessary facilities must be provided, and he could
take in those two years the preliminary technical
courses as arranged by the local education authorities.
In considering the training of the classes from which
colliery officials would be drawn, it was necessary to
distinguish between one who was rising from the
practical side and one who was coming direct from
school. In other branches of engineering, institutions
were free to make such regulations affecting educa-
tion as they deemed best, but in coal mining regard
must always be had to the provision of the Coal Mmes
Acts respecting firemen, under-managers, managers
and surveyors, not only with regard to the subjects
for examination and the standard to be attained, but
also with regard to the practical work which was an
essential qualification for these certificates. The
workman who desired to become a fireman would begin
to specialise early. While attending his daily work
he would take the first and second years’ mining
courses at the local mining classes, and he would pass
the Home Office examination for the fireman’s certifi-
cate at 25 years of age. The promising student who
desired to become an under-manager would take at the
local mining classes the third and fourth year mining
courses as provided by the local education authori-
ties. He would be still attending his daily work. At
23 years of age he would pass the Home Office exami-
nation for the second class certificate of competency
as an under-manager. The student whose aim was to
become a manager would take, while still attending
his daily work, the eight years mining course, either
at the local mining classes (where facilities were avail-
able) or at the district mining college. He would
pass the Home Office examination for the first class
certificate of competency as a colliery manager at 23
years of age. County and local authorities should
encourage the most promising students to go forward
from the local classes to higher studies at the district
colleges, paying the fares and fees for a certain
number. The scholarships should also be increased in
number and value so that it would no longer be
possible for a boy to be prevented by financial reasons
from receiving a university training. It should be
made clear to all that there was no position to which
a capable student might not reasonably aspire. The
training of colliery mechanical and electrical engi-
neers was outside the scope of the present discussion.
Candidates for these positions would be prepared by
taking the usual mechanical and electrical engineering
courses, both theoretical and practical, which were
necessary to qualify them for their future work. The
str dent who came into the mining profession direct
from a public school would be well advised to matricu-
late before leaving, in order to obtain entrance to the
university. If he desired to become a surveyor he
might enter upon his career direct from school
through a regular pupilage with a mining surveyor
or at a colliery, or he could take the day courses in
surveying at a mining college. He would pass the
Home Office examination for the surveyor’s certificate
as soon as he was qualified and able to pass, or he
might take it at the same time as the examination
for the first class certificate. It was, however, to the
university or to the technical college of university
rank that the industry must look for the adequate
Draining of the future managers of the largest con-
ferns, agents, mining engineers and inspectors. The
manager of a large colliery had great responsibilities.
He must be able to initiate, consider and decide upon
proposals for working seams that had hitherto been