March 24, 1916.

THE COLLIERY GUARDIAN.

557

whereas if funds were allocated to the extension of
electrical enterprise on the lines indicated, an increasing
income, amounting finally to a handsome return, would
accrue to the State. There should be no difficulty, there-
fore, in the way of financial assistance being forth-
coming, for, granted a fair return on the money it
expended, the credit of the State was unlimited. The
enormous income, amounting to many millions per
annum, derivable from the increased quantity of coal
available for export was an obvious factor in the case.

Matters could be accelerated by legislation, for even
if something ware done as he had suggested, it would
also, be necessary to have more active co-operation
between municipalities and companies operating in
adjacent territories; the old idea that electric power
must be all sold by a municipality or all sold by a
company was disappearing, and the time appeared ripe
for a scheme entailing some closer co-operation between
municipalities and companies. But some lead would

i i

%

Fig. 2.—General View of Engine House, showing Driver’s Platform and Control Gear.

shall we be able to ensure that State recognition of
■science, without which all the committees under the sun
will be but ploughing the sands.” He (the speaker)
thought the nation did now realise the effectiveness of
the weapon possessed by Germany. If this great war
had not brought this home to us, nothing else would.

ELECTRIC WINDING PLANT IN
SCOTLAND.

Electric winding plant is being installed in Scottish
collieries and shale pits, and a recent adaptation is to
be seen working at the Breich pit of the Pumpherston
Company, not far from Edinburgh, where an up-to-date
form of Siemens-Ilgner system has been installed.
One of the principal features of this plant is the
inclusion of a very effective system of remote

is that in the event of the main supply failing at any
time, sufficient stored energy is available to complete
one or more winds.

The winder itself is of the ordinary parallel-drum type,
with direct coupled winding motor, and winds from a
maximum depih of 65 fms. The duration of .one wind
from bank to bank is 20 seconds, the period of accelera-
tion being eight seconds, full speed run six seconds, and
retardation .six seconds. The average interval between
winds for changing .trucks is 20 seconds, and under these
conditions the winder is capable of raising material at
the rate of 112 tons per hour from the dep.h specified.

The power supply is taken from a three-phase high-
tension line, conveying energy from the, company’s
Deans Works power station at a pressure of 3,300 volts,
50 cycles. This, supply, after passing through iron-
clad switch panels fitted with tho necessary protecting
devices, etc., is carried to the alternating-current end
of a motor generator set (figs. I. and 2), consisting of
a high-tension three-phase .motor, a variable-voltage
direct-current generator, a constant-voltage direct-
current exciter generator, and a cast steel flywheel,
which is capable, with a suitable reduction in
speed, of giving off the surplus energy required above
the average when the winder is working to the specified
conditions.

The normal speed of this motor-generator-flywheel set
is 750 revolutions per. minute (synchronous). The
three-phase motor is of the ordinary slip ring type, and
the necessary speed reduction, to enable tho flywheel to
give up its energy, is accomplished by means of an auto-
matic slip resistance inserted in the rotor circuit. The
variable-voltage direct-current generator is separately
excited from the constant-voltage exciter, and is so
arranged as to give an armature voltage varying between
zero and plus or minus the maximum.

The winding motor (fig. 3) is also separately excited,
and has its armature permanently connected (electric-
ally) to that of the variable-voltage generator. The
speed and direction of rotation of the winding motor arc
controlled by regulating and reversing the- excitation,
that is, the pressure, of the variable-voltage generator.

The most important feature of this control is that
the speed and direction of rotation of the winding motor
are determined solely by the regulator, that is, by the
position of the driver’s control lever. This holds true,
irrespective of the load in the cage, or of the direction
of the torque, whether positive or negative, that is,
whether loads are being raised or lowered.

Moving the operating lever towards the “ off ” posi-
tion induces a strong electrical braking effect, the motor
acting as a generator, and returning energy through the'
converter generator to the line. Energy is also returned
to the line when loads are lowered. The low speed
required for inspection purposes can be readily obtained
by moving the operating lever only slightly from the
“ off ” position. The controller, being only called upon

have to be given by the Government, and further legisla-
tion would be necessary. The slow progress up to date
was a proof that the business could not be entirely dealt
with by municipalities, though they could do a great
deal.

In considering these points>t should not bo forgotten
that the United Kingdom, on account of the density of
its population compared with other countries, and the
comparatively small distance between industrial centres,
was far more suitable to a general use of electricity
for power purposes than any other country, including
Germany, and far more suitable than the United States
of America.

It was due to the want of realisation of’the two points
mentioned above that this country, instead of being
ahead of both the United States and Germany in such
a development, was behind, except . in one or two
instances.

After dealing with our resources of iron ore, limestone,
and non-ferrous metals, and improvements in the
methods in the dressing and metallurgical treatment of
ores, the speaker passed on to

The Organisation and Development of Scientific and
Industrial Research.

The action of the late President of the Board of. Educa-
tion, in securing the appointment of the Advisory
Council to the Committee of the Privy Council to ascer-
tain the best methods of securing the organisation and
development of industrial and scientific research,
marked a welcome development, and might lead to great
strides being taken in our industrial methods. But it
was not sufficient to organise industry and inaugurate
research if we had not the material in the shape of
highly-trained persons to undertake research work,
organise, and captain industry. Great improvements in
our educational system had been carried out during the
last 20 years. One had only to point to the rise of the
provincial universities, with their great applied science
departments, to instance this, but we were still behind
some of our Continental neighbours; the modern side of
our public schools was not what it should be, and the
cost of our higher education generally was excessive.

Sir James Dewar, in his presidential address to the
British Association in 1902, had said that the really
appalling thing was that the German population had
reached a point of general training and specialised
equipment which it would take us two generations of
hard and intelligently directed educational -work to
attain. It was that Germany possessed a national
weapon of precision which must give her an enormous
initial advantage in any and every contest depending
upon disciplined and methodical intellect. But, as the
editor of a well-known technical periodical in a recent
article,* in alluding to these words, pertinently asked :
“ Does the nation realise this? For not until it does,

* “ The Organisation of Industry,” Colliery Guardian,
January 21, 1916.

v*

F t

Fig. 3.—Winding Motor and Drum.

control, which, in the event of anything unfore-
seen taking place, will automatically bring the cages to
rest, and apply the brake in such a way as to preclude
the possibility of injury to the plant.

The principle on which the winder is designed com-
bines the Ward-Leonard system of control with a
flywheel equaliser between the winding motor and the
supply mains. The absolute control and the degree of
safety which the Ward-Leonard system renders possible
constitute one of the chief claims of superiority of this
over any other system of winding. The object of the
flywheel is to reduce the peak loads on the source, of
supply during the, acceleration periods, and so keep
down the .size, and improve the efficiency, of the
generating units in the power station.

As showing the advantage of the flywheel equaliser in
this instance, it may be stated that, whereas the peak
load on the winding motor at the end of the acceleration
period is about 400 horse-power, the maximum power
demand on the generating plant never exceeds about
200 horse-power. A further advantage of the flywheel

to deal with the energy in the exciting circuit of the
variable-voltage, generator (about 2 to 3 per cent, of the
energy consumed by the winding motor), is small and
simple; and is therefore readily operated by the control
lever without the use of auxiliary gear. The fact that
any given position of the operating lever corresponds to
only one speed and direction of rotation, makes it
possible to provide safety appliances of absolute reli-
ability.

The depth indicator (seen in fig. 2), which is of the
pillar type, operates, through its driving spindle, two
tapered tappets (one for each cage), which are arranged
to operate over the full travel of the indicator. These
tappets act through a system of links, in such a manner
as to limit the maximum throw of the control lever.
When starting a wind, the control lever is gradually
released by the tappets, which, in turn, come into opera-
tion again towards the end of the wind, and force the
control lever back into the “ off ” position, in case this
should not be done in time by tho driver. In this way
the cages are automatically brought to rest at the pit