November 5, 1915.

THE COLLIERY GUARDIAN.

929

ally stretched the ropes to near breaking, but in all
cases it was the eyebolts which fractured, and not the
rope.

After all attempts had been made to overcome the
downward creep of the setts it was decided to try whether
concrete walls, built up on the existing concrete
stringers to such a height as to form both a support and
anchorage for the caps, would solve the difficulty. The
unusually large clearance of 24 in. between the tracks
made it possible to put in fairly thick walls, and thus
made for the success of the idea. By planing down the
wide tread rear skip wheels of 5 in. to 3 in. tread, and
altering the headgear tip, it was possible to make these
walls 15 in. in width.

In the meanwhile the first caps put in hand had been
subjected to pressure and movement, and were pushed
out of alignment. These, for the sake of speed, were
left as they were, and concrete piers were built up under
them. When the concrete was set, and advance was
again possible, the new caps were fastened to these caps
by hanging bolts, and also anchored back by wire ropes
fastened to every sixth cap. Where possible, the caps
were further supported by means of 10 in. by 8 in.
diagonal struts off the footwall of the shaft pending the
setting of the concrete.

These first concrete piers or walls fractured somewhat
under the strain, but as they were extended down the
shaft they soon became strong enough to catch up and
hold the strain, and have held up since then most satis-
factorily.

The caps, after being jacked into position, were sup-
ported by temporary 10 in. by 6 in. legs. Two legs only
were necessary, one at each end. A centre leg would

PERMANENT CAPS

.Hardwood slip

^Hardwood corbel
I onr G jshboard

-Crushboard
Z5W«'

Temporary

Figs. 7 to 13.—D kt ails

of Method Employed in Recovery and Support of Central Incline.

have added to the difficulty of swinging the caps into
position. It is, however, an easy matter to put in a
centre leg and move it to a fresh position when neces-
sary, should the pressure on the cap make an additional
leg advisable.

Figs. 7 to 13 show the position of these temporary
legs and the 3 ft. track laid down. The legs rested on
the edge of the concrete stringers and the permanent
rails, the foot being cut so that the pressure was taken
up by the rail as well as the concrete. When in this
position the legs formed the uprights for the housing
of the concrete boxes.	x

The end walls vary in width according to irregularities
of the side of the shaft, but all others are 15 in. wide.
The walls are 5 ft. in height, surmounted by a 15 in.
by 12 in. by 6 in. crush board, on which the caps rest.
Rails (45 lb.), 5 to 6 ft. long, are set in the concrete 1 in.
below where the caps are to lie. These rails project
12 in. above the wall, and take the sliding thrust of the
caps, and act (through being embedded in the con-
crete) as bearers supported off the footwall alone. To
prevent the rail from crushing into the caps, hard wood
filling pieces were inserted between the two.

The west end of the caps was cut so as to form a scarf
joint with the east end of the caps to be put into the
western portion of the shaft. To increase the bearing
portion of the caps at this end, they rested on hard
wood corbies set out 2 in. from the wall, while these
crush boards were reduced to 4 in. in thickness.

It is, of course, necessary when using such an unyield-
ing substance as concrete for the legs on which the caps
are carried, to supply some form of cushion to take up
the crush, as otherwise the caps would themselves be
damaged, and thereafter, when the limit of their com-
pressibility was reached, the concrete might tend to split
and slab off the edges. To prevent this, and the need-
less replacement of the caps themselves, which would be
expensive, 6 in. Oregon pine crush boards were laid on
the top of the concrete under the permanent caps, and
these, as they crush, and before their spring is gone,
will be renewed by jacking up the cap and substituting
a new crush board. The hard wood filling between the
back of the cap and the 45 lb. rail bearer tends to spread
the crushing action of the creep down the shaft over a
larger area than if the cap pressed directly against the
rail, and so also prevents damage to the cap.

The concrete was mixed on the surface as required,
and sent down to the work in small drums of about
0-6cu.ft. capacity, placed in the drill trolley. The
mixture found best was 3| parts washed mine rock,
screened through l|in. screen, 1| parts washed road
sand to 1 part of quick-setting Pretoria cement. The
whole was thoroughly mixed dry, the water only being
added immediately before being sent down.

The surface of the concrete stringers was stepped,
chipped, and well watered, to ensure a good joint with
the wall, while the ends of the separate sections put in
were dovetailed and left roughened to provide for good
contact with the following sections. The walls followed
as close as possible to the advancing face, but sections
of concrete were never made less than 6 ft. in length.

The concrete had set sufficiently in 24 hours to allow
the boxing to be removed. After another two to three
days the 6 in. crush boards were put in between the
walls and the caps, and the walls allowed to take the
weight.

The walls were extended a distance of 40 ft. above
and 45 ft. below the fall, making a total length of 180 ft.
The wall below the fall was put in hand, and had set
before the travelling setts holed, and was used for sup-
porting the lower portion of the fall when cutting through
the girders at the bottom of the cave, the weight of the
permanent caps at holing being taken up on the three
lower walls, thus allowing of the removal of the anchor
ropes, etc., while the last section of the concrete walls
to be put in was setting.

The accident occurred on December 19, 1914, and
hoisting was re-commenced on February 19, 1915. The
shaft was therefore hung up for two months or 62 days.

The first 10 days were employed in doing preliminary
work and the work connected with getting the pumps
restarted.	v

All difficulties were overcome without accident to life
or limb. A start with the recovery of the remaining
three compartments may be undertaken shortly.

Grimsby Coal Exports.—The following is the official return
of the quantities of coal exported from Grimsby during the
week ending October 29:—Foreign : to Aarhus, 2 tons;
Dieppe, 302; Esbjerg, 947 ; Banders, 2,155; Treport, 2,398.
Coastwise: To London, 550 tons; and Yarmouth (Isle of
Wight.), 195 tons; a total of 5,804 tons to foreign ports, and
745 tons coastwise, compared with 16,573 tons foreign and
360 tons coast wise in the corresponding week of last year.

Mine Valuation Problems.—A bulletin lately issued by the
State of Wisconsin entitled “ A Study of Methods of Mine
Valuation and Assessment,” by W. L. Uglow, discusses
the treatment of royalty and interest upon working capital,
neither of which, he thinks, can equitably be considered as
an addition to working costs, and both should, therefore,
come wholly out of profits. The methods of valuation pro-
posed by the author are applicable only to mines of short
life. He discusses the following in detail, viz. :—(1) The
Finlay ad valorem method which calculates the value of a
mine as the present value of the average annual profits that
may be expected to be obtained during the life of that mine,
setting aside an annual sinking fund instalment, the total
amount of all of which instalments, at the end of the
estimated life of the mine, wrill amount to the present
value; (2) the Arizona method, which takes the value of a
mine for the purposes of taxation as represented by one-
eighth of the gross production of the previous year, four
times the net profit of the previous year, and the value
of the improvements; (3) the Colorado method, which takes
the value as one-fourth of the value of the gross output of
the preceding year, unless the net exceeds one-fourth of
the gross, in which case the net output is taken to be the
assessable value; (4) the equated income method, which
takes the value as the present value of all future profits,
these latter being taken as equal to the actual profits of the
preceding year, excluding royalty, interest, and amortisation
charges, assuming the same average length of life for all
the mines of a district. The last-named method is favoured
by the author, who insists upon the fact that mining pro-
perty is a wasting asset, and should not, therefore, be taxed
on the same basis as ordinary real estate.

COAL MINING ORGANISATION
COMMITTEE.

DIGEST OF THE EVIDENCE.

(Continued from page 877.J

Mr. W. House.

Evidence was given on April 24 by Aid. William House,
president of the Durham Miners’ Association, and vice-
president of the Miners’ Federation of Great Britain.
Respecting absenteeism, he said he had the conviction that
the figures in the returns that had been supplied had been
a sort of wholesale percentage, including both the compensa-
tion cases and the bond fide sickness. He thought that if
an appeal were made to the men to put in a more regular
attendance at the collieries, even at considerable discomfort
to themselves, it would be successful. In fact, appeals that
had already been made had borne fruit. His own experi-
ence was that up to very recently the rank and file did not
realise the gravity of the national situation. He pointed
out that in Durham there were some very deep pits, and
some of them were very hot. A man had to be very strong
and robust indeed if he could follow up coal getting in these
hot mines for five and six days a week. Since the war
broke out a good many collieries had been closed. Six,
seven, or eight had been absolutely closed, and at the large
collieries several of the seams had been closed, while the
other seams had been continued. If you go back to the
beginning of this war, our large collieries were working
only one or two days per week. He was told that although

11	days a fortnight had been the rule for many years, some
of the large collieries on the East Coast had never worked
on the Saturday, they had never been asked to work on a
Saturday for a considerable length of time, but they were
asked to work on the previous Saturday, and they did so.
Therefore, there was a considerable reserve there. If things
got desperate and men were appealed to in the proper spirit,
they would be quite prepared to go the other Saturday,
too. Some of the pits in Durham were winding coals the
whole 24 hours, and the coal hewers were completely
employed. The division of mine labour in Durham was
very complex, and any interference with the system would
be unsettling, and would be resisted unless they could
satisfy the people that it was absolutely necessary. The
further west they went, the smaller the pits and the less
number of coal-getting shifts per day. But there was a
single colliery in Durham where they were working a single
shift of coal getters. Some went back to the 10 hours,
which meant there were still the two shifts of coal hewers.
Half of the boys went down at 6, and the remainder at
8, which meant they could keep on drawing continuously for
the 10 hours, but there were still two shifts of hewers.
Probably 85 per cent, worked three shifts of hewers. The
only men who could do any shift work would be the men
who happened to be in the third shift. Any wholesale
suspension of the Eight Hours Act in the North would be
a very upsetting thing. With regard to the boys in
particular, they had learned to appreciate the Eight Hours
Act, and they would be the most difficult folks to get away
from it.

Witness had one suggestion to make. The great difficulty
in that county was to get boys. He had been chairman of
the District Education Committee ever since its inception,
and he thought if this wholesale change were brought about,
there was room for a sort of relaxation of some of the very
stringent regulations, or in other words the red tape might
be relaxed a Httle bit. Many useful boys could be got, say,
at about 13 years and 10 months of age. The parents came
to them and said : “ He has been in Standard VII. for

12	months; he is merely marking time.” Yet if he was
a day under 14 he must continue to attend schooL Has

. committee instructed him that he might exercise some dis-
cretionary power in special cases of that kind. In these
cases the older brothers had gone to the front, and the
father was a weakly man; the cost of living had gone up,
and they said : “ We cannot live,” yet this boy must simply
mark time at school, whereas he could be doing useful work
for the next month or six weeks. There were scores of such
cases. If the boys who had a month or two months to go
could be liberated, they would be of the greatest possiole
service to the mine managers. His suggestion was to take
the standards of education and age, both into account. It
had been difficult work even to get the examinations held;
25 per cent, of the boys would be 14 before they knew
whether they had passed or not. In Durham, before you
could sit for the liberating examination, they had now to .
be six months in Standard VII. It used to be Standard VI.

Mr. Pease suggested that if these boys were liberated a
little earlier at the present time, some additional arrange-
ments could be made so that they could be given a special
advantage later on with regard to their education.

Witness said, of course, there were always the evening
classes and that kind of thing; but if the boy had passed
Standard VII. and wras going straight into the mine, or
on to the pit head, he did not see that they need trouble
much more about him.

Mr. House said in Durham the 11 day pits and the 12
day pits would be pretty well divided, but if the actual
working was meant, there were very few 12 day pits that
had been working 12 days. They could work 12 days if
they were asked to. Every one of the Bolckow collieries
could work 12 days, and he was not av^are that one of
them had worked 12 days yet. The 12 day pits were coking
collieries, and it was recognised that they would want coal
for the coke ovens regularly. They had had most complaints
as to absenteeism from the east pits. Witness said there
was no absolute compartment between wages and prices;
but there was a pretty well understood relationship; 1| per
cent, for every 2d. was the rule, but that had been very
frequently departed from of late years, both ways. There
was no scale and no maximum or minimum. Witness
agreed that if they could liberate some of the bigger boys,
both underground and above ground, it wrould increase the
supply of putters. These boys could be employed at the
surface for a month or six weeks until they were 14, and ,
they would liberate boys at the surface for down below; but
when they were talking of boys, they got that disturbing
element of the boys acting together. A great deal of the
shortage that was then felt was due to the facilities for
getting coal away in the first months of the war not being
rapid. He was not aware that any of the collieries had
stopped for want of raihvay facilities, or anything of that
kind, but the war had affected five or six where they were
closed down, and most of them were permanently closed.
All they said was that they could not afford to go on.
They wTere old places, and evidently losing money. There
were certain collieries which wTould have great difficulty in