230

THE COLLIERY GUARDIAN

August 2, 1918.

sub-station switchgear, of much larger capacity, of
commercial dimensions.

Mr. B. Welbourn, M.I.E.E., was pleased to see
that the author, with his wide experience, was in
favour of the growing practice of earthing the neutral.
The advantages of this were more apparent with this
when automatic protective apparatus was used, and
when high voltage cables were installed. The author
apparently had a preference for V.B. cables. It
would be useful to know what was the E.H.T. pres-
sure at which he had used it, and over what period.
It was claimed, and was capable of proof, that paper-
insulated lead-sheathed cables could be worked at
higher temperature than V.B. cables. The maximum
temperature on the conductor advised by the makers
for V.B. cables was less than 120 degs. Fahr., whereas
paper-insulated cables could be worked, if required, up
to 175 degs. Fahr. This was a most valuable property.
There were numerous cases where the ultimate load
could not be correctly forecasted, and where over-
heating might occur. The author did not mention
that the cost of bitumen cable in normal times was
usually higher than for the corresponding paper cable.
This was a matter of increasing importance in the
dear-money period which must follow the war.

Mr. Chris. Jones having made partial reply to the
discussion, further consideration of his paper was
deferred.

A Modern Colliery.

Opening the discussion on the posthumous paper of
the late Mr. George Hann, describing the Britannia
Colliery, Pengam (Colliery Guardian, July 26, 1918,
p. 173),

The President pointed to the fact that the whole
of the colliery was electrically driven, there being
no boilers and no horses,, thus (he added) dispensing
with the luxury of hauliers and stokers, both of them
unreliable quantities. The sinking of the pits, if not
a record, was certainly an expeditious piece of work.
To put down two shafts of 21 ft. diameter, 730 yards
deep, in two years and seven months, having regard
to the quantity of water to be dealt with, was a highly
creditable achievement. In erecting main arches at
the bottom of the pits, Mr. Hann appeared to have
overcome the squeeze that took place at the bottom
of deep shafts. Although there were fewer conveyors
at work in South Wales than there were some years
ago, yet Mr. Hann had found them efficient, as was
evidenced by the quantity of coal worked at the
colliery—by the yield per yard of face. The author
was silent as to the cost of his conveyors, but when
they took the quantity of coal sent out per man, they
must come to the conclusion that the cost worked out
at a satisfactory figure. An important feature was
that 90 per cent, of the timber was withdrawn, a
large portion of it for use again. They all knew
what a difficult matter it was to get their workmen
to draw the timber out of the gobs. Mr. Hann’s
system of packing was also new to the district, and
had proved successful in his case.

Mr. William Stewart said with regard to Mr.
Hann’s adoption of main arches for the shaft bottom,
and obviating squeeze, he (the speaker) had the
privilege, recently, of visiting a colliery that had been
most ably laid out by the ex-president, Mr. Hugh
Bramwell, who had adopted a ferro-concrete system
of arching with success. In his electrification scheme,
Mr. Hann had done everything to provide against
difficulty arising from the current being cut off, being
supplied by several feeders. Where this was not
possible, some other alternative means of power must
be provided, and usually this was steam. The great
economy that had been accomplished at the Britannia
Colliery in the use of pitwood was a revelation, and
was an example which they would all wish to follow
where practicable.

The discussion was adjourned.

Argentine Coal Mines.—Owing to the scarcity of coal
brought about by the war, the Argentine Government is
taking active measures to utilise coal deposits in that
country. The principal difficulties are the scarcity of
mining machines and the distance of the mines from exist-
ing railways. The San Julian mine is more favourably
situated as regards transport. Most of the mines will
start with small equipment, which will be increased accord-
ing to the yield obtained.

Annual Meeting of Manchester Coal Merchants’ Associa-
tion.—The annual meeting of members of the Manchester
and Northern Counties Coal Merchants’ Association was
held on Tuesday last at the Coal Exchange, Manchester,
the president, Mr. John Parry, in the chair. The chairman
said the committee had been exerting themselves in the
interests of the merchants and the coal trade generally,
and although they had not always succeeded in obtaining
all they asked for, they had met with a fair amount of
success. It was now incumbent on collieries and rail-
ways to notify the wagon owner if his wagon was used
without his knowledge. With respect to the calling up
of men engaged in the coal trade, he thought the Ministry
of National Service had met them in a generous manner
with regard to exemption. The officers and retiring com-
mittee were re-elected, and the meeting empowered the
committee to proceed with the projected scheme of federa-
tion of the whole of the Lancashire and district associa-
tions. The meeting also passed the following resolution,
and ordered it to be forwarded to the Coal Controller:
“ That this meeting of members of the Manchester and
Northern Counties Coal Merchants’ Association emphati-
cally protests against the action of the Coal Controller in
sending full supplies of coal to London and the South,
whilst the whole of the shortage caused by the withdrawal
of large numbers of miners from the pits for military
service, the immediate delivery of coal to the Allies, and
the effect of the influenza epidemic has had to be borne
by the residents in the North.”

TWO NEWCOMEN ATMOSPHERIC
PUMPING ENGINES.*

By Gerald T. Newbould.

The two engines in question pump water from the
Barnsley Seam workings of Earl Fitzwilliam’s col-
lieries, and are situated about five miles apart, the
“ Westfield ” engine being at Rawmarsh, near Rother-
ham, and the “ Old Elsecar ” engine at Elsecar, near
Barnsley.

No written information is available of their early
life, and it is not known who made or erected them;
but it is believed the following dates are correct: 1787
(Elsecar) and 1823 (Westfield). The Elsecar engine
must be one of the very oldest still working, and very
few atmospheric engines would be erected after 1823,

Fig. 1.—Valve Gear, Plug Tree and Front
of Cylinder.

the date of the Westfield engine. Both the pumps
have proved themselves very reliable, and will con-
tinue working until the Barnsley Seam Collieries are
abandoned; possibly in a year or two. In order to
safeguard the neighbouring dip-side collieries it will
still be necessary to carry on the pumping, although

probably the companies con-
cerned will instal more
modern plant.

The Westfield Engine.

This is dated 1823, and has
therefore been working 95
years. The engine house is
set back 7 ft. from the shaft.
A man-power “gin-wheel”
is used for lowering men in
the shaft, and is now operated
by a small steam winch.

The shaft, 9 ft. in diameter,
is 75 yards deep, and is lined
with stonework for the first
20 yards; the rest is “ tubbed ”
with planking nailed on to
wood rings let into the sides
of the shaft.

The water for injection is
pumped from the near end
of an adjacent pond into a
tank on the top floor of the
engine house by a 9| in. ram
pump worked by the “ plug
tree.” The returned hot
water from the cylinder enters
the pond at the far end, for
cooling.

The boilers originally used
were of the beehive or haycock
pattern, but were replaced
by the Cornish type in 1839.
In 1884 three 30 ft. by 7 ft.
Lancashire boilers were put
in. Two of these are in use
at one time. The usual work-
ing pressure is between 1| and
2| lb. to the square inch, but
the engine will work with | lb.
pressure. The boilers are

automatically fed by a float arrangement from small
tanks placed about 10 ft. above each boiler, so as to
give the necessary head to overcome the pressure.

The feed water is pumped into these tanks from the
“hot well” by a 4| in. ram pump worked by the
“plug tree.” The pump and feed arrangements were
put in probably at the same time as the Cornish boilers.

The beam is 25 ft. long and 5 ft. 6 in. high at the
centre. It is in two sections, with a space of 8 in.
between, and must weigh at least 8 tons. The spring
beams are long timbers, with the undersides cut away
in the form of a wedge. The maximum movement is
about 5 in. During ordinary working the tupping
pieces come down to within 4 in. or 5 in. of the spring
beams. The plug tree is a vertical rod attached
to the beam midway between the centre bearing and
the piston end, and consequently moves up and down

* From a paper read before the Midland Institute of
Mining, Civil and Mechanical Engineers.

with only one-half the vertical movement of the piston.
This shaft works the valves and also the injection
and boiler feed ram pumps.

The action of the engine is well known. When
steam is admitted to the cylinder, the piston rises,
due to the unbalanced weight of pump rods in the
shaft, and to a smaller extent the pressure of steam.
At or near the end of the stroke the steam is cut off
and water injected. The steam is condensed, and a
partial vacuum formed. The weight of the atmosphere
then forces the piston down, performing the power
stroke.

Fig. 1 shows the position of the plug tree and
valve gear at the commencement of the outdoor stroke
(the up stroke of the piston). The injection valve
is closed and the steam valve opened. The rods BB
are weighted. The steam valve box is marked E. The
plug tree R, on rising with the piston, causes
tappet F to catch and lift steam lever A, and by
means of rod K and a small beam on the first floor,
the rod V is lowered and the steam valve closed.
This takes place between two-thirds and four-fifths of
the stroke. In this engine, during the last third of
the stroke, the piston is steadied by a gradually in-
creasing vacuum, and is finally brought to rest by
the injection. During the time the steam valve is
closing, the tappet L rises and allows the lever H
to lift, giving a half-turn movement to the rod M,
thus opening the injection valve. The piston and
plug tree now descend, and the tappet L closes the
injection valve early in the down stroke. The tappet
F leaves the steam lever at about one-third of the
down stroke. The 10 in. mushroom steam valve lifts
to open, and consequently has during the power stroke
the atmospheric pressure keeping it closed. Towards
the end of the power stroke Ithe atmospheric pressure
on the valve is reduced, and the weights on rod B,
etc., overcome this pressure and open the valve. It
will thus be seen that the steam valve is partly auto-
matic in action. Extra cheese weights to open the
steam valve sooner can be hung on rod K. Both
the tappets L and F are adjustable.

The sink or exhaust valve is entirely automatic.
It opens, owing to the weight of water and the
pressure of steam on it, as soon as the vacuum in
the cylinder is destroyed by the opening of the steam
valve. It is closed by a weighted lever. The valve
works under water to prevent air entering the
cylinder.

The injection valve is both opened and closed
mechanically ■ it consists of two circular brass plates
having two openings in each. The bottom plate is
fixed in the lower part of the box, and forms a recess
for the top plate. The weights on rod M (fig. 1) are
to keep the plates tight on to one another. The half-
turn movement of the rod M causes the holes in the

two plates to coincide at the proper time for injection.

The amount of water injected per stroke can be
varied by means of an adjustable carrot-shaped valve
in cylinder bottom shown controlled by a screw P
(fig. 2). The shape of the valve causes the injection
water to spray. The necessary pressure for injection

T7.

DELIVERY TO
I NJ ECTIO N
TANK ON
TOP FLOOR

SPUN YARN
PACKING

INLET FROM
INJECTION TANK
ON TOP FLOOR

POS IT I 0 N
OF STEAM
^JNLET

Fig. 2.—Diagrammatic Sketch of Westfield Engine.

is obtained by reason of the supply tank being on
the top floor about 22 ft. above the valve.

The engine is stopped by fastening up the steam
lever A (fig. 1), thus keeping the steam valve closed.
The engine will stop at the end of the “indoor”
stroke, but usually, after several hours, the piston
slowly creeps to the top. To start the engine, the
steam valve is opened and the cylinder blown through
to clear out any air and water. The injection valve
is then opened. The steam lever is worked by hand
for a few strokes. Very little injection water is
required for the first few minutes, owing to the
cylinder being cold.

The shape of the cylinder bottom is shown in fig. 2.
The sloping bottom is to more easily rid the cylinder
of injection and condensation water.

The piston is packed with hemp tightly rammed in
the packing space. A ring of thick hard rope is
nlaced at the top and bottom. About a foot of water