822

THE COLLIERY GUARDIAN.

October 16, 1914

watered. This method of bricking between the girders
also keeps them, to a great extent, from “ buckling ”
when under great pressure, and, therefore, being of
uniform section and strength, each girder is held in its
position, and, thus combined, they resist pressure very
much more effectively than timber.

This method is carried on chiefly on the main haulage
roads (intakes). In the return airways the girders are
combined together, so to say, with what we term
“ stretchers.” These are props cut to the required
lengths to fit between the flanges, according to the dis-
tances apart the girders are set, and are fixed in—one
on each side at the foot of the girders, one on each side
about the centre, and one on each side of the fishplates.
We aim to have these stretchers put in systematically,
and as near as possible in line with one another. These
stretchers are also used on the main haulage roads prior
to the bricking; when 13 ft. girders are used, four of the
stretchers being put on each side.

When a roadway is secured with “ double timber ” it
is often the case that the strength and resisting power cf
the “ collars ” varies considerably, with the result that
the weaker ones break and give way. This often brings
about heavy falls of roof on our main roadways, result-
ing in the loss of a day’s coal from a district. These
troubles and risks of falls are avoided by the use of
girders. This the writer has proved, and has no hesi-
tation in stating : he has seen collars 12 in. to 16 in. in
diameter breaking in less than a week’s time after
having been put up, and the same result after renewals
time after time. At a cross measure drift of about
250 yds. in length, rising 1 in 6, from the Old coal seam
to the Black Vein seam, great trouble was experienced
in keeping it open when timber was used. It was as
much as three sets of timbermen could, do to keep it
open for work, the gradient adding to the contention,
owing to the difficulty experienced in dealing with the
traffic of the rubbish from the repairs; but it was so
arranged that often one set, and often two sets of
repairers were “ doubling ” where required, while the



X

' v-- ■

■- ■ ■

Mi,

Fig. 7.







others would require the rope to deal with the rubbish
from where they had been “ cutting out ” for re-opening.
Nearly three years ago it was decided to secure this drift
with 9 in. girders. They were set at distances varying
from 18 in. to 2 ft. 3 in. apart, and bricked in between
along the whole of its length, all possible force being put
on to get them in. Since the work is completed, with
the exception of 28 girders which have been changed
owing to the heavy squeeze, there have been no further
repairs.

In another part of the colliery great trouble was experi-
enced in keeping open a long length of rope haulage road
in the Old coal seam, large French timber being con-
tinually broken in a few days after being put in, making
it very difficult and costly to keep the district open. Here
again, long lengths of 9 ft. girders were put in, and
although th Black Vein seam was being worked imme-
diately above this district from another pit, the girders
have given every satisfaction. They have been subject
to very severe tests, as shown in figs. 7 and 8, but,
nevertheless, the roads stand good. At some portions
the area of the roadway, owing to the great squeeze, has
decreased from about 60 sq. ft. when the girders were
put up to about 40 sq. ft., roughly speaking; through the
effects of the enormous squeeze to which the girders in
this particular district have been subject, the area of the
roadway has been reduced to about the size of a road
secured with 7 ft. girders.

It will be seen that even under these extraordinary
circumstances the conditions of the roadway afford
sufficient space to comply with the requirements of the
Coal Mines Act, 1911, as regards room between one side
of the road and the side of the plane.

When we first used the girders, they were set up
against the ground with simply a wedge here and there
where there was room, but they buckled quickly, that
is, where set up in strong ground, but when put up
under the same ground, with a layer of timber at the
sides and over the girder they have stood very much
longer without any sign of buckling. When subjected

to heavy weight the tendency has been for the centre
point of the girder to push in a direction parallel to the
roadway. This is especially noticeable in the 13.ft.
sections on double partings. In some instances, owing
to the immense pressure, the bolts and fishplates snap
off, but the flange of the girder becomes firmly
embedded in the timber (laggings), and being tied with
the brickwork between them, it is surprising how they
keep in position.

The requirements of the Mines Act to keep places of
refuge every 10 yds. has a somewhat evil effect on the
girders. The space of 3 ft. 6 in. width left for the man-
holes divides the girders into sections of 9 yds. in length,

p

t

Fig. 8.





and thus has a tendency to reduce the good effect which
would otherwise be obtained by having a long length of
girders supporting each other. A method adopted to
give the best result is to set two girders close together
on each side of the manhole, have them ‘‘ strutted ”
firm at the foot, and also at a height of 6 ft. from the
ground. The manhole is then secured with two pairs of
timber. Owing to the height the hole has to be kept
clear (6 ft.), the girders can only be stayed on one side,
and when heavy weight comes on, the girders bend
inwards towards the manhole, with the result that the
width of the entrance is reduced.

Comparative Cost.

To open a roadway with timber to an area of 60 sq. ft.
the average cost is as follows :—Labour, 16s. to 20s.;

Fig. 9.

«

material, 7s.—total, 23s. to 27s. per lineal yd. The 9 ft.
arching girders give practically the same aiea
(59-8 sq. ft.). The cost of setting these up at distance:;
of 2 ft. 3 in. apart in average ground, with, say, 1 ft.
or 18 in. packing over the laggings, would be as follows :
Cost of girders, say 18s.; timber, 5s. 7d.; taking out
ground, erecting and packing girders, and dealing with
the rubbish, 20s.; cost of brickwork, 6 ft. 6 in. high,
8s. 2d.; labour, 4s.—total, £2 15s. 9d.

The Seven feet section (many hundreds of yards of
this section have been put in return airways at the fol-
lowing cost) :—Taking out ground and dealing with

rubbish, erecting and packing rings at Ils. per yd.;
girders, 3 ft. apart, 12s.; timber, 4s. 7d.—total, £1
7s. 6d. per yd.

The Thirteen feet section, re-opening double partings :
Taking out ground, fixing and packing girders at £2
per yd.; girders set 18 in. apart, .£1 IBs. 8d.; timber,
9s. Id.; bricks and mortar, 9s. 7d.; mason, 5s.—total,
£4 17s. 4d. per yd.

Compared with arching, the difference is more strik-
ing still. The standard size of arch for main roads
adopted at these collieries gives a roadway 8 ft. high
by 8 ft. wide, with an area of about 57 sq. ft. Side
walls, 18 in. thick in brickwork, arch three rings thick
in brickwork. The cost of taking out ground and deal-
ing with rubbish, £2 5s. per yard; materials, £2 11s. 7d.;
labour putting in arch, 19s. 6d.—total, £5 16s. Id.

It will be seen by the above figures that the cost of
girders set in their place is a little over twice that of
setting the timber, but while the first cost is all in
favour of the timbered roadway, it must be remembered
that the girdered roadway will stand equal to several
settings of timber. Thus the loss and inconvenience
caused by the roads being continually under repair is
avoided where girders are used. We have had lengths
of arches 8 ft. by 8 ft. with three rings of bricks set on
roadways (adjacent to portions secured by 9 in. girders.
The bricks in the arches have been crumbled so badly
that portions of the arches had to be taken out, whereas
the girders are standing, buckled.

Hundreds of yards of 9 ft. girders have been erected
18 in. apart on main haulage roads where the roof had
fell several yards high. The method at first adopted
was to pack the girders to a height of 9 ft. to 12 ft., and
then cog the remaining space up to the roof, but the
effect was, when the squeeze came on, that the girders
gave way in the crown, as shown in fig. 9. It was then
decided to fill up the whole space over the girders with
rubbish, and to do this as many as five stages have been
used so that it may be thoroughly packed up to the
roof. This method has given better results than when
the space was partly packed, and then cogged to the
roof.

Of course, when this extra work is done it incurs
additional cost to the figures given above.

The girders can be used with advantage in very steep
roads. Some time ago a “ roof ” 68 yds. in length was
driven from one seam to another for ventilation pur-
poses. This was driven at an angle of 45 degs., and
secured throughout the whole length with 7 ft. girders
set 2 ft. 3 in. apart, and strutted between with wooden
stretchers, as previously described. These are doing
their work satisfactorily, although near the face .of the
working of the seam wherefrom the “ roof ” was driven.

To have such useful effect from this method under
such extraordinary circumstances is a good proof of their
utility. We have nearly 4,500 yds. of roadways (intake
and returns)’secured with girders, resulting in improved
haulage roads, and increased quantity of ventilation.
Our intention is to continue with this method.

I have mentioned that the average weight of the
girders is about 27 lb. per yd. I consider this weight
suitable for the two smaller sections, viz., the 7 ft. and
5 ft. 6 in., but, from the experience we have had, it
would be very advisable to have the sections of 9 ft. up
to 13 ft. made stronger, say from 32 to 341b. per yd.

OBITUARY.

Mr. Albert Cliffe, mining engineer, of 5, Beech-grove,
Southport, late of the firm of Messrs. Grimshaw, Son and
Cliffe, of St. Helens, passed away last week.

The death took place at Barrow, last week, of Messrs.
James A. L. McDougall, of Ironworks-road. He was a
partner in the firm of Messrs. Burnip and McDougall, oil
and grease manufacturers, and was one of the pioneers of
the oil trade at Barrow Docks. He was 43 years of age,
and eldest son of the late Capt. Alexander McDougall, of
the Allan Line.

The death took place somewhat suddenly, on Saturday
morning last, at his residence, “Blackamoor,” Astley, of
Mr. John Holland, J.P., who was a well-known leader in
coal-trade circles, being president of the Leigh and District
Miners’ Association for several years. He was in his
sixtieth year.

The death occurred last week of Mr. Benjamin Hardy, of
Holmfirth, coal merchant, the oldest tradesman in the
town. He was 88 years of age. He had a remarkable
degree of use of all his faculties, and was in active business
operations within a week of his death. He was one of the
leading figures in public movements in the district half-a-
century ago. He was a director of the Holmfirth Gas
Company. He leaves two sons and two daughters.

Grimsby Coal Exports.—The official returns for the week
ending Oct. 9 show that a total of 13,175 tons of coal were
exported to foreign ports. Exports were as follow :—To
Bergen, 1,496 tons; Christiania, 2,100; Gothenburg, 1,567;
Halmstad, 1,635; Malmo 2,303; Nexo, 701; Oxelosund,
1,750; Rotterdam, 533; and Ystad, 1,090. No coal sent to
coastal ports. The coal exported during the corresponding
period last year totalled 20,696 tons foreign.

Institution of Mining and Metallurgy. — The opening
meeting of the 24th session, provisionally arranged for
Thursday, October 15, has been postponed. Due notice will
be given when the date has been definitely fixed. A large
number of members have joined the Naval and Military
Services. With, a view to the preparation for publication
of a complete list, the secretary will be glad to receive the
names (and rank, unit, etc.) of all members who are serving
at home or abroad.