82

THE COLLIERY GUARDIAN

January 11, 1918.

LIFT FOR WINDING MEN?

By C. E. Arnold.

In making a comparison between the common method
of hoisting men i$ mine shafts, and elevator practice
in high buildings, the former shows to great dis-
advantage both as regards safety measures and smooth-
ness of operation. It is surprising that, in view of the
inducements offered, the step of applying the building
equipment direct to the mine shaft has not been taken
before, as in many respects the conditions of service are
similar, and the objects to be attained are identical.
Even without doing this, it is certain that safety to
life and limb in the usual method of hoisting men
underground can be greatly enhanced by the applica-
tion to the mine hoist of some of the features of the
building elevator.

The Inspiration Consolidated Copper Company have
installed in their shaft an Otis elevator, the cage of
which runs in a vertical concrete-lined shaft compart-
ment, 5 ft. Ilin, by 5 ft. 6 in. (1-8 m. by 1*68 m.) in
section, and 585 ft. (178 m.) deep, while the counter-
weight runs in the pipe and ladder compartment of a
twin shaft 102 ft. (31m.) distant. The section of the
division of this compartment occupied by the counter-
weight measures 2 ft. 4} in. by 3 ft. 10| in. (0-72 m.
by 1-18 in.), and the counterweight is made in the form
of a small cage, which suffices to carry two men for
the purpose of making inspections or repairs in the
pipe and ladder way.

The hoist is designed to carry a load of 7,5001b.
(3,401’94 kilogs.), exclusive of the cage, which weighs
7,5001b., at a maximum speed of 800 ft. (243 m.) per
minute. It is installed in the main hoist and com-
pressor building, about 220 ft. away from the elevator
shaft, and is driven by a 160 horse-power direct-
current motor, which is served by a 190 horse-power
motor generator set. A small direct-current gener-
ator mounted at the end of the motor generator set
furnishes the current for the controller magnets, brake,
and fields of the hoist motor and generator. The drum,
which is 72 in. (1-83 m.) in diameter, is driven through
the medium of a single reduction herring-bone gear. A
Francke flexible coupling connects the motor and
pinion shafts, and at the periphery of this coupling
the hoist brake is applied.

The cage and counterweight cables are 1| in.
(28-575 mm.) diameter. The cage guides are steel,
and of T section, 6 in. by 5 in. by 1 in. (15’2 cm. by
12*7 cm. by 2-5 cm.), with the guiding surfaces planed
smooth. These are screwed to steel plates, which are
anchored to the concrete lining of the shaft by means
of expansion bolts. The counterweight guides are of
3J in. by 5| in. pine (8-9 cm. by 14 cm.).

The cage is double-decked, and the sides facing the
guides are of solid sheet steel, while the four front
and back openings are protected by collapsible steel
gates, each extending from the floor to the top of the
opening. The two halves of the bonnet are hinged
parallel to the centre line of the guides. The upper
deck, on which the operator stands, is provided with
a telephone, annunciator, incandescent lamp, emer-
gency switch, and operating switch. The latter switch
is self-centring, i.e., should the operator remove his
hand from the switch when the cage is running, the
switch will instantly come to the neutral position.
There is a second operating switch in the engine house,
which can be used after disconnecting the cage oper-
ating switch by means of a throw-over switch, which
is also located in the engine house. In operating the
cage from the engine house, the engineer knows the
cage’s position by means of an ordinary vertical indi-
cator, and he can communicate with a person on the
cage by telephoning, even though the cage be in
motion. However, the occasions when there is neces-
sity for operating the cage from the engine house
are quite rare.

For signalling the cage operator, there is an cc Up ”
and “Down” pair of push buttons on each landing,
and these connect with the annunciator facing the
operator. Eafch landing is likewise provided with a
telephone, w’hich connects with the cage and engine
house telephones. The elevator operator controls the
movement of the counterweight, so that all signalling
between the operator and persons riding the counter-
weight has to be performed by telephone.

The cage ordinarily carries 36 men besides the
operator, 16 on the upper deck and 20 on the lower;
16 only are carried on the upper deck in order to leave
plenty of elbow room for the operator. The landings
are two-decked, so that both decks of the cage may be
loaded or unloaded simultaneously.

The installation is equipped with numerous safety
devices designed to stop the current supply to the
motor, and bring the cage to a standstill should the
occasion require it. These safety devices are as
follow: —

'Brake.—The engine band brake is so arranged that
when the current supply to the hoist motor is inter-
rupted, the brake is automatically applied. It is
actuated by means of a weight, and the pressure of a
heavy helical spring, both of which are controlled by
an electro-magnet. So long as the current is supplied
to the hoist motor, the electro-magnet keeps the brake
released.

Gate Switches.—Each of the four cage gates is pro-
vided with a switch connected in series with the con-
troller, and it is only when the gates are properly
closed that current can be supplied to the hoist motor.

Limit Switch, Emergency Switch, and Slack Cable
Switches.—There is a switch so placed in the head-
frame that in the case of overwinding the current
supply is interrupted. A hand-operated emergency
switch is located on the cage beside the controller. At
the bottom side of the opening through which the

* From a paper presented to the American Institute of
Mining Engineers.

hoisting cable passes from the hoist house to the head-
frame, there is a switch that is opened by means of
the weight of the sagging cable, should it become
slack. Also, there is a slack cable switch at the point
of attachment of the hoisting cable to the cage.

Buffers. — There are two long stroke oil cataract
buffers located at the bottom of the hoisting compart-
ment, so designed that, should the cage pass its lower
terminal at normal full speed, it will be gradually
brought to a stop without shock to the passengers.

Stop-Motion Controller. — By means of a screw-
operated controller, attached to an extension of the
drum shaft, the engine is automatically retarded and
stopped at each of the limits of cage travel.

Wedge-Clamp Safety Device. — By means of this
device, which is attached to the under-side of the
lower cage deck, each guide is gripped by a pair of
clamps, and the cage brought to a standstill upon
having attained a speed of 1,120 ft. per minute. A
governor, which is situated in the head-frame, is con-
nected with the cage by means of an endless | in. hoist-
ing cable extending the depth of the hoisting compart-
ment. When the cage speed exceeds 850 ft. (259 m.)
per minute, the governor, by means of switches, auto-
matically reduces the speed of the hoist motor. When
the cage speed reaches 960 ft. (292 m.) per minute, the
governor cuts off the current supply to the motor.
Should this procedure fail to stop the cage, and the
speed reach 1,120 ft. (341 m.) per minute, the governor
will grip the | in. cable, and hold it fast. This cable,
by means of a short attached cable, then causes the
drum of the safety device on the descending cage to
revolve, thus causing the clamps to grip the guides. In
order to re-open the clamps, the drum is reversed by
the use of a socket wrench applied through a small
trap door in the lower deck of the cage.

The time required for making the complete cycle of
one round trip between the surface landing and the
fourth-level station—a distance of 347 ft. (105 m.)—is
2 minutes 59 seconds, being divided as shown : —

Seconds.

Lowering  \............................... 45

Discharging and loading 36 men at fourth
level  ,.............................. 45

Hoisting ................................. 44

Discharging and loading 36 men at surface ... 45

Total ................. 179

The distances between the surface landing and the
six stations served by the elevator are :—Surface land-
ing to shaft collar, 21 ft. ; third level, 235 ft.; fourth
level, 347 ft.; sixth level, 471 ft.; skip loading station,
531 ft.; pump station, 584 ft. In addition to wind-
ing the 1,000 men employed underground at the
Inspiration mine, the elevator is run intermittently,
carrying bosses, engineers, mechanics, etc.; for the
transferring of minor supplies, such as carbide, oil, and
tools; and for hoisting mine samples. The power
required for this work amounts to approximately
430 kw.-hours per day.

POWER FROM COAL.

The following scheme has been suggested to save the
losses recently referred to by Mr. Dow in an article
on the production of electricity by steam power, viz.,
the losses necessary to give the requisite draught, and
the big losses of heat thrown overboard (in the con-
densing water)—they seem to be inherent in steam.
These two major losses constitute about 80 per cent,
of the heat value of the fuel.

The proposed remedy is as follows: —Conceive a
cycle embracing:

(1)	A gas producer of the Mond or similar type,
utilising large quantities of steam.

(2)	A special steam boiler, with great furnace capa-
city compared with its heat-absorbing surface, whose
fuel is gas from the producer burning in a closed fur-
nace under a pressure of, say, 150 lb. per square inch.

(3)	A gas turbine for the main power production,
utilising as motive fluid the high-pressure exit gases
from the steam boiler.

By means of this arrangement two great ends are
accomplished: —

(1)	Reversing the usual method for power produc-
tion through the use in the turbine of the exit gases
—the products of combustion—and not the steam;
whilst, through the use of the latter in the producer,
its latent heat is largely conserved.

(2)	Avoiding the usual loss in the sensible heat of the
exit gases in the ordinary methods of steam raising.

Thus the two difficulties stated above are solved,
and the important by-products of the Mond producer
—ammonia and tar—are realised.

The chief problem, however, in the scheme is the
economical compression of both gas and air—to, say,
150 lb.—prior to combustion in the special closed fur-
nace of the steam boiler. But as single-stage rotary
compressors, with an efficiency of over 60 per cent.,
have been designed, probably the difficulty here is not
insurmountable. It is doubtful whether the Diesel
engine, with its multistage air compressor and its
water-cooled cylinder, can compress its air at an effici-
ency of 60 per cent.

With regard to the temperature of the exit gases
from the boilers, which are to be conducted direct to
the power turbine, this should be in the neighbourhood
of 1,500 degs. Fahr. In arriving at this figure, it is
estimated that two tons of steam will be required by
the producer for every ton of coal gasified, in order to
develop the greatest possible amount of ammonia prac-
ticable. And the raising of 2 lb. of steam from every
pound of coal gasified should reduce the temperature
of the gases from the combustion in the boiler to about
1,500 degs. Fahr., or a temperature within the working
limits of a properly designed turbine. If one is afraid
of this temperature, the turbine casing and the shaft
may be water-cooled, and the rotor made of nichrome
or some of the alloy steels containing chromium or
tungsten, which hold their strength even at low red
heat.—Metallurgical and Chemical Engineering.

Notes from the Coal Fields.

[Local Correspondence.]

South Wales and Monmouthshire.

Breach of Agreement with Colliery Proprietors—The
Transfer of Men from Mines on Short Time—Miners'
Parliamentary Candidates—Inquiry into Stoppages.

A strong protest has been made by Mr. Finlay A. Gibson
(secretary of the Coal Owners’ Association) against the
interference with the return of coal wagons despatched from
South Wales to other parts of the country under the agree-
ment with the Controller. Ever since the transport
reorganisation scheme came into operation in September,
the colliery proprietors in South Wales and Monmouthshire
have, in compliance with request, sent large quantities of
coal to the south-western counties, diverting as many as
possible of their export trade wagons into this extended
inland service. Because of the necessity of the wagon being
returned promptly when empty, arrangements were made
with the Coal Controller that the wagons should not be
used by the railway companies for return loads, and they
were informed by the Controller that the Railway Executive
agreed to this. Special labels were attached by the District
Coal and Coke Supplies Committee of South Wales, and
instructions were given that the trucks were not to be
loaded for return journeys. In spite of this arrangement,
however, wagons have been loaded on the return journey
contrary to the understanding arrived at, and Mr. Gibson
states that the Great Western Railway “ has gone so far
as to adopt the extreme course of instructing their servants
to remove the labels from the wagons.” Mr. Gibson com-
ments upon this act of the railway company in disregard-
ing an arrangement to which the Railway Executive has
been a party. He points out that even the Executive itself
has objected to the use of a label, notwithstanding that
these merely carried out an arrangement which it had
entered into. The Great Western Railway Company is
stated to dispute the existence of any agreement concerning
the return of the colliery wagons unloaded, and Mr. Gibson
points out that “ the colliery owners agreed to the condi-
tional diversion of their wagons in order to assist the Con-
troller in successfully carrying out his inland transport
scheme. That object is defeated when wagons are detained
on the way back, and collieries compelled to stop work
through lack of empties, thus substantially reducing the
supply of coal so urgently required.” He adds that the
coal owners “ deplore and protest against the operation of
a system of dual authority which permits one branch of
the public service to act without regard to the decisions of
another, in their opinion, to the prejudice of the transport
facilities of the country ”; and “it is because they believe
that only by public exposure can these evils be remedied
that they consider it necessary to draw attention to this
particular illustration.”

The West Wales colliery tribunal has had before it the
question of boys who entered the mines 12 months before
they were 18 years of age. Col. Pearson, in the chair,
stated that it was a wrong impression that these boys could
claim exemption, for, according to the latest instruction,
it was entirely at the discretion of the tribunal to decide
whether a boy had entered mining in order to evade mili-
tary service. This was clearly the fact in some cases, for
the lads had come from steel works, farms, etc.

At Glamorgan Quarter Sessions, a collier was prosecuted
for obtaining £1 by false pretences from the Powell Duffryn
Coal Company, it being alleged that whilst in receipt of
compensation he went hop-picking in Herefordshire. But
he was found not guilty, his defence being that his wife
and family were the pickers, and that he only accompanied
them to Herefordshire.

A coal dealer of Swansea, who was summoned for selling
coal at 2d. per cwt. above the fixed price, pleaded that the
fixed price was too low, and that he could not carry on
business on the terms stated. The maximum was £2 per
ton, and the coal cost him £1 14s. at the siding, with 6s.
for hauling. It was contended, on his behalf, that the local
authority had no power to take legal proceedings unless
they first of all obtained the consent of the Coal Controller.
The magistrates, however, imposed penalties of 40s. for sell-
ing the coal in bags without having labels attached, and £5
in each of two cases for selling above the fixed price.

The Coal Controller’s Commission of Enquiry into short
time work in South Wales collieries is carrying out its
work. Mr. F. A. Gibson (the coal owners’ secretary), on
behalf of the employers, and Mr. T. Richards, M.P. (secre-
tary of the Federation), on behalf of the workmen, are
arranging to collect evidence of the stoppages, and this
will be done in such a way as to assist in providing work
elsewhere for men who are compulsorily idle.

The South Wales miners’ executive meeting in Cardiff
on Friday of last week congratulated their general secre-
tary (Mr. T. Richards, M.P.) upon having been honoured
by membership of the Privy Council, and reference was
made to the fact that he had two sons on active service.
Congratulations were also tendered to Maj. Watts Morgan,
formerly miners’ agent in the Rhondda, who has gained the
D.S.O. He also has twessons on active service.

The executive then considered the question of Federation
candidates for Parliamentary seats, the Miners’ Federation
of Great Britain having allotted 10 candidates to South
Wales; and it was decided that, in addition to seven pre-
viously named, the Labour candidates should contest Bed-
wellty, East Rhondda, and Aberavon. The Pontypridd
district made an application to be included, but as the 10
seats had been already allotted, it was resolved that the
question of Pontypridd Division should be considered by
those sections of the miners who were directly interested.

Further discussion has taken place on the subject of con-
structing super-power electrical stations which shall supply
the collieries, iron works, etc., in South Wales; and among
the criticisms evoked is that of Mr. F. L. Jacob, general
manager of the Tylorstown and Ferndale Collieries, where
electric installation has long been in operation most suc-
cessfully. Mr. Jacob points out that any such scheme as
that which is now described for central power production
ought to be controlled by the authorities; otherwise the
owners of the super-power stations would secure a mono-
poly, and be able to charge any price they chose. Further,
it would be necessary to standardise the current in order
to overcome the difficulty of periodicity. Some inducement
would have to be offered to concerns such as their own if
they were to be called upon to scrap existing plant. It
was important to extend the area of use, otherwise the
“ load ” on the super-power station, although very great
during the time coal was being raised, would be extremely
reduced at other parts of the day. What they should aim
at should be to obtain a uniform “ load.”

Swansea traders, reviewing the business of the past year,
consider that, in the very difficult circumstances, it has
been fairly well maintained. Complete returns have not
yet been made up, but it is estimated that the total ship-
ments of coal, coke, and patent fuel will not be far short