November 24, 1916.

the colliery guardian.

1009

MIDLAND INSTITUTE OFM1NINC, CIVIL
AND MECHANICAL ENGINEERS.

(Continued from page 956.)

Fuel Economy at Collieries.

There was also a further discussion on Mr. F. F.
Mairet’s paper on “ Fuel Economy at Collieries.”
(Colliery Guardian, July 21, 1916, p. 114.)

Mr. W. H. Chambers, who was asked by the presi-
dent to re-op^n the question, said it was difficult to go
into the question of colliery consumption, and the
economies that could be effected, at the present time,
when the collieries were not working to anything like
their capacity, but were producing an output perhaps
not much more than half of what it ought to be. He
would prefer that the matter be deferred until they
could return to normal conditions. Then he intended
to go pretty fully into it.

The President said Mr. Chambers’ remarks were no
doubt very much to the point, but, at the same time, if,
by any improvement, which they could make in their
existing plants, they could bring about the slightest
economy in the use of coal, he thought it was very
important to consider the matter. He knew of several
instances where considerable economy had been effected
by using washed fuel instead of dirt. He believed there
were gentlemen present who could give figures to prove
that using washed coal in these abnormal times had
given them considerable advantage in labour and
economy.

Col. Rhodes said he was connected with a small
colliery in Derbyshire where they were troubled with a
good deal of water. They only got about 300 tons a
day best. During the month of July they burnt no
less than 1,400 tons of fairly respectable coal under their
four boilers, the chief trouble being that they*had an out-
burst of water, and a good deal of pumping to do. All
they could manage to do was to let one boiler off at
the week end, clean it as best they could, and get it
going again on the Monday morning. By spending
.£600, they put down another boiler, and they could now
have one boiler off all the week, and clean it thoroughly,
so that they got round them all in three weeks. In
October they only burnt 800 tons instead of 1,400; they
got more coal and pumped not less water. Probably
other people would get equally striking examples if they
went in for similar measures on a large scale. They
might not save 50 per cent, of their coal, but if they
could save 5 per cent, it would be something.

Mr. T. Beach said since the paper was written he had
been carrying out some experiments, and had changed
over from rough slack to washed smalls. Before making
the change, they had a good deal of trouble with the
firemen, and the percentage of consumption was, in his
opinion, excessive. The change had more than fulfilled
his prophecies. He was nowT absolutely certain that the
cheapest way was to bum in their boilers the best stuff
they could get hold of. The power companies always
burned washed smalls, with the smallest percentage of
dirt, and it stood to sense that if the colliery companies
followed their example, they would be on the right lines.
He was not prepared to give actual figures, but he
could say that the percentage of colliery consumption
had been reduced over 1 per cent. They had no trouble
whatever with firemen, the ashes were reduced by 50 per
cent., and, at the same time, a very considerable
economy was being made. He was certain that people
.who were burning rough stuff would do better to send
everything to the washer, and put coal and not muck
into -the boiler fires.

Mr. R. Nadin said he had some shares in a small
colliery near the one to which Col. Rhodes had referred.
It was a very old concern, having been going over 100
years, and part of the engines were rather antiquated.
When he left, they were getting about 700 tons a day
from a shaft 7 ft. in diameter. They had some fairly
good boilers, and were compressing steam at 50 lb. They
were burning an enormous amount of their output.
Shortly before he left he suggested to the directors that
it would be a good thing to compress at a higher pres-
sure, and put in reducing valves, to allow the antiquated
engines to have their steam at a less pressure. They
did so, and compressed steam at 1001b., which saved
an enormous amount in boiler fuel. He thought it was
at the old collieries where savings could be effected, if
things such as Mr. Rhodes suggested, and reducing
valves, were put to work. At the colliery with which
he was now connected, they were winding pretty well
as fast as they could wind. They were running some-
what short of steam, and, rather than put in a new
boiler, they had fitted the old range of boilers with
mechanical stokers, and by so doing had managed to
keep their steam at a decent pressure—between 90 and
100 lb. This had enabled their underground haulages to
get a better pressure from compressed air. Their con-
sumption now was a low one (about 2-} per cent.),
chiefly, he considered, through getting their electrical
power from the power company..

Mr. J. H. W. Laverick said it seemed to him that
the whole question resolved itself into one of £ s. d. He
had tried washed fuel, and had given it up. He had
plenty of boiler power on his reduced output, and fairly
good chimney draught, and under those circumstances
he preferred to burn inferior stuff that did not give
eatisfaction to one’s customers, and to send away stuff

that did give satisfaction. When he got out the cost
per ton of making these experiments, he found that
there was really nothing in it. It depended, of course,
on what they charged the boilers for the different kinds
of fuel, but he found that there was not a tenth of a
penny per ton in it, and so he went back to the
unwashed fuel.

Mr. W. H. Chambers said his experience was a good
deal similar to that of Mr. Laverick. They only used,
for consumption at their collieries, coal that went
through a 4 mm. mesh. That stuff was absolutely
unsaleable, and contained about 15 'or 16 per cent, of
ash, and 20 per cent, of water, taken away from the
washers. The result of taking that out had enhanced
the saleable value of the other size, that went through
a | in. mesh, to a considerable extent. It was very
saleable indeed, suitable for firing marine boilers, for
ship hunkering, and he got very good results and a very
good price for it. For treating the -stuff that they used
themselves, they put down a Craig’s washer, but found
that the expense of washing the stuff exceeded the
benefit that they derived from the process. They had
to do something with the dirt, and they found that by
burning it in bulk under the boilers they got more water
evaporated than they did if they burnt only what
remained after it had been treated at the washer. They
evaporated something like 4| lb. of water per lb. of coal
weighed in—dirt, water, coal, and everything together.
They had a central condenser, and condensed all their
steam.

Mr. John Gill said he must also plead guilty to going
in the wrong direction. At the colliery where he was
they had two seams of considerably inferior coal, some
of it mixed with dross. Until a few years ago, all this
stuff was tipped in large heaps. Occasionally it fired,
with the result that they got a huge blaze, and were
threatened with trouble. The stuff was not saleable at
all. So they put in a crusher, and now they crushed it
and burnt it under the boilers. They had not increased
the number of boilers, nor the number of firemen. Cer-
tainly they had had more ashes to empty, but they burnt
less good fuel than before.

Mr. W. H. Humble said he was fortunately not con-
nected with any very old collieries, but with one that
was practically new, and which had a fairly low per-
centage of colliery consumption. In laying out Bull-
croft Main, with a view to a low consumption, they kept
the main steam pipes, in fact, all the steam pipes, as
short as possible. They only used steam in the wind-
ing engines, and exhaust steam in the mixed-pressure
turbines. They had an adequate supply of boilers. He
did not believe in running with a few boilers, because
they were liable not to get the best out of their fuel, half
of which probably was taken off the fine before it was
properly burnt. They used washed coal. He dare say
that if they were to start on dry slack, with 20 per cent,
of dirt in, they would probably want more boilers. At
present they had eight—six under steam, and two spares.
Their consumption at present was 1-8 per cent, of the
output. They put water into the boilers at 75degs.,
which sounded pretty poor. They used to put it in at
boiling point, but, owing to the system they adopted,
they found they were getting grease in from the heaters,
and they had to give it up. They were now putting
down a Weir feed heater and Green’s economisers, with
a view to getting the water up to at least boiling point.
When they got these to work, he thought that probably
their consumption would come down to 1-5 per cent,
again. With regard to the cost of consumption, they
charged their washed small, and washed singles, which
they fired with, at 10s. 6d. The washery settlings, of
which they used about 50 tons a week, they charged at
5s. The cost came out at l|d. If anyone would like
to see the plant at any time he would be welcome. He
thought the great secret at any new place was to keep
down the length of the steam pipes. He once made a
test at a small colliery in South Wales, along with
Parsons’ expert, and they found it took a boiler 30 ft.
long by 9 ft. diameter to keep the steam pipes warm.
That test was followed up on three consecutive Sundays,
and he thought it was perfectly accurate.

Gol. Rhodes thought that one or two of the speakers
had missed Mr. Beach’s point, which he took to be
that, if they had a washery at their colliery, and washed
the small, it was a great deal easier to go on washing
the small, and—assuming they had no inferior fuel—to
burn washed small in their boilers, than to take the
trouble to separate the rough slack out from the screens,
send it round to the boilers, and then have the ashes to
cart away. They had to cart the muck away some-
where, and Mr. Beach carted it away direct from his
boilers. The speaker was assuming, of course, that he
had no inferior stuff to begin with. That was the way
in w’hich they worked at a good many collieries. They
used inferior stuff as far as it would go, and eked it out
not with rough slack, but with washed stuff.

Mr. R. Claytor said his company and Mr. Humble’s
were practically the same, but he received complaints
about high consumption. Mr. Humble’s explanation
had helped him a great deal. While that gentleman
used washed slack, he (the speaker) used the rubbish.
He thought that explained a lot, and he was very
thankful to Mr. Humble.

Mr. Humble said his strong argument in favour of
washed slack was that they managed with fewer men
in the fire hole. That was the chief reason they went
in for washed slack. They were turning out between

19,000 and 20,000 tons a week. They had only three
men in the fire holes, including ash wheelers, with two
coal turning shifts. He thought that was something in
favour of washed coal. They would want considerably
more men if they were burning slack with 20 per cent,
of dirt in.

The President said that, to those who were accus-
tomed to old pits, it was horrible to hear Mr. Humble
say he was going to get down to 1-5 per cent, colliery
consumption. Of course, circumstances altered cases.
Some people had no washers, and some people had so
much dirt that it choked the washer they put it in.
Another point which most of them had experienced at
one time or another related to the bad top coal, which
could not be sold. Very likely that coal had been
included in their price lists, and, if the seam was, say,
5 ft. thick, the men had been allowed to send out 5 ft.
of coal, or, at any rate, they were being paid for 5 ft.
If they were now to say, “We will not have this coal
up; we will use washed coal,” they would have to pay a
certain increase on the tonnage rate to the men in the
form of allowances, in order to let them cast that back
into the gob. That was a case where it was probably
better to send the stuff out of the pit and make the best
use of it. There was no doubt that the labour question
was of very considerable importance, especially at the
present time, since the Eight Hours Act came in, and
the higher rate of wages. He thought they all knew
that, if they did not press their boilers, and fired with
washed stuff, they did not have the fine door open half
as much; there was nothing like the amount of cleaning,
and there was not the tremendous loss due to cold air
getting into the flues; and also that the boilers lasted
considerably longer under those conditions than they
did when they were fired with bad stuff and very hard
pressed. At Wharncliffe Silkstone, the colliery con-
sumption used to be, he believed, about 10 per cent.,
but it had been brought down to 3*5. He knew that
many people had found fault with Mr. Blake Walker
for putting down a new plant at an old colliery which
had not got a very great life. He thought Mr. Walker’s
pluck had been justified. By putting down gas engines
he had reduced the colliery consumption to 3*5 per cent.,
and those who knew what the place was, the years it
had been going on, and the amount of water that had
to be pumped, would, he thought, agree that that was a
really wonderful result. The difficulty which colliery
engineers had had to face had been very often a great
deal due to want of education on the part of the
directors, who had not had the pluck to find the money
for improvements. Of course, it was no use saying
they ought to find the money, if they were next door to
bankruptcy. But if concerns would only make a much
greater exertion to find the money for their engineers to
deal with the serious question of colliery consumption,
many a pit would have made handsome dividends on
what could have been saved. Mr. Beach had told them
how he had reduced his consumption. At a recent
meeting in London, Mr. Asquith spoke forcibly on absen-
teeism, which he said could be reduced by 5 per cent.
They were told that a great deal of the trouble was due
to want of management, and that the managers were as
big sinners as the men. He did not quite agree with
Mr. Asquith, but if they could increase their saleable
coal by 1 per cent., it would be a very large tonnage all
over the country. Even Mr. Humble, at probably the
best place they could find in Yorkshire, was looking for-
ward to a reduction of 0*3 per cent. If he could do that,
what could some of them do who had older plants to
deal with?

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AMERICAN v. BRITISH WORKERS’ OUTPUT.

Sirs,—Some time ago, in a paper read before the
North of England Institute of Mining and Mechanical
Engineers, the writer endeavoured to explain why, in
the coal mines of America, the output per man was so
much higher than in Great Britain and other countries,
but he was met by the argument that conditions were
different, that the roofs of British mines were bad, the
seams gaseous, etc.

Mr. Samuel Hare, a mining engineer in the county
of Durham, appeared to be particularly hard to convince
that there was room for improvement, and on that
account I will now quote a recent statement by Mr.
Edward D. Page, author of “ Morals in Modern
Business,” Page Lecturer at Yale University, who
writes :—

We are making munitions in Connecticut, paying wages
twofold and threefold higher than abroad, and delivering
the finished product to our British cousins for less than
they can make the same goods in their own workshops.
And so it is that America’s prime contribution to world
progress is machine efficiency and economy of labour. . . .
For as far ahead as we can see, our workpeople will get
the highest wages paid anywhere, because we know how
to make them the most efficient, and efficient labour is
always wrell paid.

I will now ask Mr. Hare to describe the conditions
which prevent the introduction of Connecticut methods
in Birmingham or Newcastle-on-Tyne.

Delagua, Colorado, U.S.A.	Samuel Dean.

October 30, 1916.