566

THE COLLIERY GUARDIAN.

March 13, 1914.

Difficulties with Sand.

The pumps were designed specially to deal with the
very sandy character of the water, and the whole of the
internal wearing parts were made of, or armoured by,
hard phosphor-bronze.

The sand carried by the water through the pumps at
a high velocity occasioned considerable wear and tear to
the internal parts, and frequent renewals were necessary.
As the various clearance spaces increased, so the efficiency
of the pumps diminished, and when one of the two pumps
showed signs of being under its work, arrangements were

by 16 in. stroke, driving, by means of worm gearing, a
heavy cast iron drum 5 ft. diameter on the barrel, 8 ft.
diameter over the flanges by 5 ft. wide. Each winch
was capable of handling 40 tons (single purchase).

Owing to the short lead of the ropes and to the heavy
weight to be handled (the final load on each winch being
50 tons), it became necessary to make a traversing
arrangement in order to prevent the ropes “ copying ”
on the drum. This traversing gear is shown in fig. 6.
It consists of a massive cast iron nut carrying two
rollers, the nut being moved to and fro by a strong

These pumps, also supplied by Messrs. Sulzer- Brothers,
are of a special mining pattern. Each pump is of the
horizontal stationary six-stage type, rated for a normal
delivery of 1,000 gallons of water per minute against a
manometric head of 1,300 ft. The guaranteed efficiency
is 73 per cent., a figure which would have been higher
but for the fact that the internal packing rings and
packing bushes had to be made of bronze, and in order
to avoid any possible heating up between the bronze
impellers and these bushes, a suitable clearance had to be
provided. The end thrust produced in the pump is taken

Cable ' brum '

% Ca b le brum

at once made to change the internal wearing parts.
This method of removing the whole of the internal parts
of the pump is preferable to that of renewing on the
spot only such parts as have become defective. On no
occasion after adopting this method was any trouble
experienced upon starting up. The old wearing parts
sent to the workshop were taken apart and carefully
examined, those unfit for use being discarded, while
those which admitted of it were repaired and reassembled
for further use. The gate valves controlling the pump
deliveries were also found to be seriously affected by the
sandy character of the water, and on several occasions
it was found necessary to raise the delivery columns in
order to allow of the gate valve being changed. This
raising of the delivery column was, of course, no small
task, and with a view to avoiding the loss of time occa-
sioned, the writer has suggested to the pump-makers an
arrangement wherein the gate valve is not placed
vertically in the line of the delivery column, but is
off-set from it in such a way that the gate valve can
be removed without necessitating the raising of the
column.

Suspension.

The pump, motor, pipes, clamps and cables were
suspended on a 2-in. diameter flexible steel wire rope of
6/37 construction having a steel-wire core. The rope

up by a patented balancing device, which works entirely
automatically, and wffiich is not influenced adversely
within a]wide range of delivery head. The stuffing box
on the suction side is sealed by pressure water from the
first stage, thus preventing air entering the pump. The
stuffing box on the delivery side is sealed by the water
leaving the balancing disc.

®^A most important feature is that all internal parts
which are liable to excessive wear, such as packing rings
and packing bushes, are easily replaceable, at compara-
tively small cost. These rings and bushes as well as the
complete balancing device are made of hard bronze, the
latter being armoured by hardened steel rings. The writer
is now using a steel balancing device which promises well
as regards wear. It may be mentioned that the water
in its passage through the pump does not actually come
in contact with the casing, so that the wear of this
expensive part is avoided.

Pump Motors.

Each pump is mounted on a common bedplate, and
is coupled direct by means of an elastic coupling to a
three-phase motor of the ventilated enclosed type,
capable of developing at 3,000 volts, 50 cycles, a
continuous output of 680-b.h.p. at a synchronous speed
of 1,500 revolutions per minute. The rotor has slip-

Oinking

Fig. 3.—Sectional Elevation
on A B (Fig. 2).

Pump Room
Inset

Fig. 4.—Sectional Elevation on 0 D (Fig. 2).

Guide Clamp -

Pilot Cable

I a

th I	i 4$

Fig 5.—Guide Clamp and Cable-suspending
Clamp for Sinking Pumps.

passed from the drum of the winch engine over a head-
gear pulley, round the suspension pulley on the pump,
and was brought back to the headgear where the end
was secured by a strong capping. This consisted of a
steel forging 21 in. deep by 15 in. diameter, having a
central conical hole tapering from 5 in. to 21 in. diameter,
the end of the rope being opened out and fixed in the
capping by white-metal. A separate steam winch was
provided for each pump. These winches consist of a
pair of slide-valve engines having cylinders 11 in. bore

screw operated by hand wheels, the rope passing
between the rollers.

In order to facilitate the pipe-changing, two steam
winches were fixed at bank, and these lowered the
delivery pipes to the 600-ft. level, where they were added
to the pipe columns as required. The upper end of. the
delivery column terminated in a flexible hosepipe having
internal and external armouring, the hose pipe being
36 ft. long and consequently heavy to handle. In order
to counterbalance the weight and to facilitate the taking
in of the hosepipe when a further length of steel piping
was about to be put on, it was secured to a wire rope
which passed round a series of pulleys, the inbye end
of the rope being weighted, as shown in fig. 3. This
arrangement also acted as a safeguard in preventing the
hosepipe accidentally falling down the shaft.

Rules0

With a view to initiating the switchboard and sinking
pump attendants in their duties, and in order to obtain
uniformity in the carrying out of the various operations,
two sets of rules were drawn up—one for the switch-
board attendant at the 600-ft. level, the other for the use
of the sinking-pump attendant. The successful carrying
out of the pumping operations at Tilmanstone is largely
due to the care exercised in drawing up these rules and
to the admirable manner in which they were carried out
by those connected with the working of the plant.

Operations with the electric sinking pumps were
confined to No. 2 shaft, and when the water had been
lowered sufficiently, the steam pumps at the 1,140-ft.
inset were recovered and were set to work. The bore-
holes communicating with the sandbed were opened
with a view to reducing the pressure on the sandbed.

Pumps at 1,140-ft Inset.

Meanwhile a new pump inset was made from No. 3
pit at the same level as the steam-pump room, viz.,
1,140 ft., and three electric pumps, together with suit-
able][switchgear, were installed, as shown in fig. 7.

A
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