November 17, 1916.

THE COLLIERY GUARDIAN.

955.

MIDLAND INSTITUTE OF MINING, CIVIL
AND MECHANICAL ENGINEERS.

The meeting of the Midland Institute of Mining,
Civil and Mechanical Engineers, held at the Danum
Hotel, Doncaster, on Saturday, November 11, with the
President (Mr. C. C. Ellison) in the chair, was largely
attended.

The President, in opening the meeting, said it was
his painful duty to ask those present to pass a vote of
condolence with several members and their relatives.
Just recently, one of their past-presidents (Col. T. W. H.
Mitchell) had lost his eldest son at the front; Mr. G. H.
Peake had also lost his son; and Mr. W. H. Ball, of
Dalton Main, had lost his. Col. J. R. Shaw, one of
their associate members, and Mr. G. H. Barraclough, a
member, late of Rotherham Main, had both died within
the past few days.

The resolution was carried.

New Members.

Mr. Herbert Gent and Mr. George Wilshaw were
elected members of the institute. They were both pro-
posed by Mr. G. H. Barraclough, and seconded by
Mr. E. W. Thirkell.

Making a Shaft Upwards.

Mr. G. Blake Walker read the following paper :—

It is found desirable occasionally to carry up a staple
pit (or blind pit) to a higher seam, and the only practi-

Fig. 1.—Plan of Scaffold used in Elevating.

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Fig. 2.—Plan of Rectangular Boxes A and B
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cable means of doing this is from below. As it is a
difficult and somewhat dangerous undertaking, a short
account of such a piece of work recently successfully
carried out at Wharncliffe Silkstone Colliery may be of
interest.

Some 20 years ago a shaft or staple pit was sunk from
the Parkgate seam to the Thorncliff e Thin seam, a dis-
tance of 30 yds., for ventilation purposes. , The shaft
was 10 ft. in diameter, lined with brickwork, with the
top arched over. Two years ago it was desired to con-
tinue this staple pit to the Fenton seam, 20 yds. above.
The writer consulted Mr. Fred Walker (sinking con-
tractor), of Doncaster, who suggested the plan adopted.

An excavation over the arching over the staple was
opened out, and room was made for a strong scaffold
well secured at the sides, as on this scaffold a consider-
able amount of the excavated material would have to
rest.

The scaffold was built up of two cross girders
measuring 14 ft. long by 10^- in. deep, and four cross
girders 12 ft. by 10| in. A hole about 1ft. square was
cut out of the crown of the arch at the point C (fig. 1)
for the centre line. The centre having been fixed, the
girders were laid and levelled, and a wood crib, to carry
the brick walling was laid on the girders and secured in
position.

Two holes, marked A and B (fig. 1), were then cut
out of the arch, over which two rectangular boxes,
measuring 2 ft. 9 in. by 2ft. Bin, inside,

* Paper read before the Midland Institute of Mining
Civil and Mechanical Engineers.

carried up as the excavation proceeded. The boxes
were formed of 9 in. by 3 in. deals, and were scarf-
jointed. They were nailed together, and four planks
were put on at a time. They were further stiffened by
racking pieces in the corners.

The rock was blasted out in the usual way, the boxes
being protected by old timber, and part of the excavated
material was packed round the boxes, and levelled up
as the work progressed. The surplus material was cast
down the box B, and fell to the bottom of the staple pit.

*	The box A was fitted with ladders, by means of which
the men had access to their work.

As each 3 ft. of rock was excavated, another length of
boxing was added to A, B, and C, and securely packed
round with the fallen material. The walling was then
carried up, and the working floor raised. The height of
the excavation above the filled portion of the shaft was
never more than 7 ft.

As there was a good pressure of air, the ventilation
was always ample. The work proceeded without any
special incident, and with no accident.

After the Fenton seam had been passed through, an
arch was turned over the pit, and the shaft then cleared
of material down to the scaffold. The girders were then
taken out, and the shaft walling of the lower staple built
up to the crib carrying the walling of the upper part.
This had been previously underpinned at four points.

The work was carried out by Mr. Fred Walker, under
the supervision of Mr. Jonathan Wroe (manager) and
Mr. Joshua Rawlin (under-manager). The cost was £15
a yard.

Discussion.

Mr. T. H. Mottram said sinking upwards was not a
very frequent occurrence in that part of the world, but

•	in parts of Scotland it was often resorted to, not only for
blind pits, but also (in Fife, he believed) some very
large pits had been sunk upwards, sinking simul-
taneously from the surface in order to save time. In
Scotland, they usually went in for rectangular shafts,
with partitions. One of the partitions was filled up
with dirt, and others were left open for ventilating
purposes.

In reply to a question by Mr. J. H. W. Laverick,

Mr. Jonathan Wroe said the shot-firing was carried
■ out in the usual manner. Not more than one shot was
fired at a time, and the length of the holes was not more
than 1 yd. Safety was the principal thing con-
sidered. If they had bored holes 2 yds. deep, and
brought down material in tremendous quantities, there
might have been a collapse. The deputy examined
every shot, both before and after, and all the stuff that
was loosened by one shot was pulled down before the
next was fired. The boxes were covered by pieces of
wood raised sufficiently high to form a bridge, so that
the debris would not fall through the boxes into the
bottom. All the stuff had to be pulled up in a bucket,
or with a rope lashed on to the brickwork. In order to
keep the ventilation going, buntons were put in from
the bottom to the place where the new work began,
and planks fastened to them, so that the shaft was
divided into two portions : one for the dirt which came
down the dirt box, the other being the place where the
men went up. They also had a rope running down the
staple, and some ladders up one side, and these had to
be protected. The ventilation was coming in at both
sides of the pit, and, as pointed out in the paper, there
was a box at “A” to take the fresh air in. Boxes were
laid, from the in-bye side of the ventilating doors
separating the return from the other districts, to the
bottom, taken up to the commencement of the sinking,
and carried through right up to the top. Owing to the fan
being only 1,000 yds. away, they had plenty of ventila-
tion in the place. For cleaning out the debris, they
made arrangements ‘to have a hole through the girders
at the bottom, so that everything could be extracted.
The centre line seemed to be the most important thing.
It was suggested that they should take the centre lines
up the two boxes, and measure them off from the top,
which could be done very well; but they thought that
the boxes might get knocked out, or collapse, and so
they took a special box up for the centre line alone.
When the work was completed, they were only about
1| in. out of the centre. The job was a good job when
finished, and the staple pit of 50 yds. was now in opera-
tion, and working remarkably well.

Mr. John Gill asked if there was any trouble from
the rising of the crown of the arch owing to side
pressure.

Mr. Wroe said the arch was left in for that purpose,
and the girders were secured on independent walls, so
that they were amply safeguarded for any extra weight
that might come on to the top of the arch. That was
one of the points which required some attention at the
commencement. If they had depended entirely on the
arch, it might have collapsed.

Mr. A. C. F. Assinder said he had discussed, with an
experienced sinker, a proposition somewhat similar to
the one described. That gentleman sank upwards
25 fms. by setting two buntons across the pit, and
dropping the dirt from the top, filling up the middle of
the shaft altogether. He got a very good ventilation in
that way. The price that he gave was very much lower
than Mr. Walker’s; the speaker believed, £10 eper
fathom, not including brickwork. When the .sinking
was finished, the dirt was withdrawn from the bottom,
and the brickwork carried right from the bottom.

Mr. H. F. Smithson said that at the colliery with
which he was connected they were working seams 30yds.
apart, and they had had occasion to put up four or five
staple pits, using two different methods. One was to
box off about a third of the space, to put buntons across
as they went up, and batten across. He forgot the
size of the battens, but it was probably about 7 by 3,
or 11 by 3. The large side of the pit was always filled
with muck, while in the small side they put ladders,
and took air pipes up for ventilation. The top was
naturally flush level with muck, and was protected by
putting flat sheets over the top of the small side when
they were firing shots. The other method adopted was
the carrying of a scaffold up. The contractor had a
false scaffold, and a scaffold that he was working off.'
He always had his pit clear, and he dropped the muck
from the top to the bottom. One of the advantages of
the method adopted by Mr. Walker was that he had a
way in and a way out. If the box with the ladders in
got crushed in, or anything of that sort happened, the
men might be able to get down the other box. With
regard to the cost of Mr. Walker’s sinking, it certainly
seemed to be rather high. (Mr. Walker assented). He
should be inclined to agree with the figure that Mr.
Assinder had put forward. In his own case, the shafts
were 10 ft. diameter, and he did not think they cost
more than £7 10s. a yd., including walling, where they
did the walling up. He thought this was an advantage,
because it acted as a certain amount of protection
against the sides pushing that way. Without the wall-
ing, there was a chance of getting pressure in the middle,
which might lead to the collapse of the boxes.

Mr. Walker said he did not think there was any like-
lihood of the boxes squeezing in, in the case of the
Wharncliffe Silkstone- work, because the walling pre-
vented any pressure from the sides. The only pressure
would be from the packing. The advantage was that
the men always had the floor to stand on. They were
never more than 7 ft. from the roof, and were just as
safe as in an ordinary working place. In answer to
several questions, Mr. Walker added that the price
included everything, material as well as labour. The
place was a most awkward one, right away in the
returns, and they had no main road to it. He admitted
that if the work had been done in a different place, it
ought to have cost less. In the out-of-the-wray place
where it was done, everything was twice as expensive
as it ought to have been. The work was done in war
time—two years ago.—Replying to Mr. J. Ford, Mr.
Walker said that there was such a powerful ventilation
that nothing remained of the gases from the explosions;
everything was blown out immediately. They were on
the main return, and could have just as much air as
they liked, and he dare say they had a couple of inches
water gauge.

Mr. Wroe said the covering of the boxes was not
directly over the top of them, but about 2 ft. above, so
that the ventilation was always open when the shots
were fired, and by the time the men got there every-
thing was as clear as could be. There were no effects
at all from the explosions.

The President said what seemed to be one of the
very important things about the pit under discussio'i
was that there was an upcast and a downcast. If they
had had no ventilation, and they had got the place full
of gas, they would have had to adopt some mechanical
means for removing that gas. He should like to know
how many yards of shaft had been driven in the way
described. It seemed to him that if they bricked as
they went along, they could go a lot further than if they
went on the principle adopted by Mr. Walker. To make
a shaft at anything like £10 a yard, would be very much
more economical than driving a drift of, say, 1 in 3, if
these shafts could be driven at anything like a reason-
able rate. But if they had to make one of these shafts
where the ventilation was anything like sluggish, he
supposed they would need a special blowing fan, or
would have to use compressed air. He concluded that
the timbering in the shaft was done in the ordinary way,
with rings.

Mr. Walker : You kept on walling up as you went.
There was never anything to support.

Mr. S. J. Rayner asked if the boxes were fastened
together in any way, or simply rested on the top of each
other; and, also, how the inspector, or deputy, knew,
when he went up the ladder, whether there were any
pieces of loose stuff resting on the top, or on the rungs
themselves. He also thought it would be an advan-
tage to state the number of shifts worked, instead of
the cost, because, after all, it was the work done which
told, and not the amount of money spent on it.

Mr. Walker said fig. 2 showed how the boxes were
fastened together. They were scarfed to begin with,
and then supported at the corners. The boxes never
moved during the whole time. They never had any
trouble with them, from the bottom to the top.

Mr. Wroe said they were mortised and tenoned, and,
to strengthen them, a corner piece was fastened in.
The timbers, which were placed about 2 ft. above the
boxes, were long enough to prevent anything from fall-
ing on to the top of the boxes: neither could there be
anv overhanging pieces, as only one shot was fired at a
time, and the debris was cleared off after every shot. In
reply to Mr. Assinder, Mr. Wroe said there was nothing
to prevent them from firing more than one shot at a
time, but they did not want to have the contractors