20

THE COLLIERY GUARDIAN

July 2, 1915.

CURRENT SCIENCE

Marine Bands in the Belgian Coal Fields.

M. Stainier has recently discovered marine bands in
the Belgian coal measures, which facilitate correlation
between the seams in the Mons basin with those of
Charleroi and Liege. In pit No. 23 of the Fl&iu district
the Buisson seam is divided into two parts, the lower
or Grand-Buisson, and the upper or Petit-Buisson.
These are separated by shale with a rich flora. The
Petit-Buisson has a softer shaly roof, but here and there
sandy and micaceous with hard bands. Where the
latter become very hard and sandy, they form a good
roof to the seam, and it is here that a rich marine fauna
has been found. Immediately above the coal is a layer
with Lingula mytiloides, pyritised, above which is a
harder band with a large Lingula, accompanied by
Ctenodonta and Orthoceras. A section of the measures
exposed in the shaft shows several metres of strata, and
at a height of 3-4 m. above the coal seam is a particu-
larly fossiliferous bed with abundant remains of
Chonetes, as well as Discina, Productus, and some
Gasteropods. It is interesting to note that a very
similar assemblage of fossils has been found in the 606 m.
level of the Maurage Pit, in the Centre basin, and in
each case the fossiliferous band is overlaid by a barren
bed of felspathic grit, with conspicuous nodules of
siderite.

Considering the distance between Maurage and Fffinu,
this shows a remarkable persistence in the marine band,
which may now be expected to be recognised at other
places in the neighbourhood. The identity of the Petit-
Buisson seam with the 606 m. level at Maurage is thus
proved, and an excellent horizon has been established
for the correlation of all the gas coal seams of the
Borinage. Already the identity of these seams with
those of Jemappes and Ghlin has been recognised, and
interesting correlations are thus made possible through-
out the separate basins of the Belgian coal fields.

Coal Prospecting in India.

In the general report of the Geological Survey of India
for the year 1914, Mr. C. S. Middlemiss, officiating
director, devotes some space to an account of the
so-called Wetwin coal of Burma. This coal is a kind of
carbonaceous shale, of dull black colour, crumbling
quickly in air, and high in ash and moisture content.
Analysis showed results of which the following is an
example :—

Per cent.

Fixed carbon............ 33*56

Volatile matter......... 37*84

Moisture ............... 17*44

Ash...................... 11*6

The preponderance of volatile matter over fixed carbon
seems to relegate this sample to the class of lignites. As
a boiler fuel it has not been successful, and it possesses
the same defects as those exhibited by the Shan States
coal.

An interesting question is raised with reference to the
possible existence of coal beneath the Deccan Trap of
Western India. Recently Mr. F. L. G. Simpson,
manager of the Mohpani Colliery, suggested that
Kalyan, Bhusaval, and Khandwa were localities suit-
able for test borings, as the traps were believed to be
thinner here than elsewhere, and there was a chance of
reaching the subjacent rock within a depth of 250 ft.
The problem has been investigated by Mr. C. S. Fox
upon geo-tectonic considerations, and there seems to be
a possibility that another line of Gondwana coal basins
exists beneath the traps. This seems to agree with
Medlicott’s opinion that the Satpura basins had an outlet
to the west. Mr. Fox thinks that two borings of
1,000 ft. each should be put down, one at Bhusawal or
Dhulia, and the other at Kalyan, and he does not think
a “timid” boring of 250ft. would either get through
the traps or furnish any useful information. Mr.
Middlemiss is in hopes that the board will sanction
these experimental borings, which he thinks must
sooner or later be made in Western India, in the
interests both of coal and water.

A Large Electric Hoist in Ontario.

An electric hoist of unusual size, with many
interesting automatic safety devices, which has recently
been installed by the Hamilton Mountain Park Com-
pany Limited, is described in the Canadian Mining
Journal. Although the incline on which it is used to
raise and lower cars is called a railway, this apparatus
is really a development of a mining hoist on a very large
scale, and with special reference to the demands upon it.
The difference in elevation between the general level of
the city and the Country at the top of the mountain is
about 325 ft.

A special double fixed drum double-geared electric
incline hoist, built by the Lidgerwood Manufacturing
Company, of New York, operates two cars in balance
on an incline 800 ft. long, with a grade of 40-27 per
cent. Each car weighs 30,0001b., and runs on tracks
having a gauge of 12 ft. l|in., the centre to centre of
tracks being 20 ft. 3 in. The average load on the cars
will be about 20,0001b., with a maximum load of
30,0001b. The hoist arrangement is suitable for either
hoisting the maximum load with empty car descending,
or for lowering the maximum load with the empty car
ascending.

The time required for making a single trip is 1|
minutes, and the rest period between trips three
minutes. Attached to each car are two ropes of If in.
diameter, each rope weighing 4-15 lb. per ft. One of
these ropes is used for hauling the car, and the other
for the purpose of safety. The average rope speed
during the run is 585 ft. per minute.

The hoist is located in a house 106 ft. from the knuckle
between the incline and the level of the summit. There
are four head sheaves and four deflecting sheaves. The

AND TECHNOLOGY.

head sheaves are arranged vertically so as to carry the
hoist ropes and safety ropes in a direct line from the
cars, the deflecting sheaves are placed horizontally at
such an angle that the rope will be led in a direct line
to either the top or bottom of the hoist drums, as the
case may be. Floating sheaves are also furnished to
guide the ropes, and are placed in the rope tunnels
between the head sheaves and the hoist drums. In
case of an accident to the left hand side of the hoist,
the safety rope on the left hand car would take care of
it properly, being wound on the right hand drum; the
same thing would apply if the other drum of the hoist
should become disabled, that is, the main ropes and
the safety ropes from each car lead to opposite drums.
Further advantage is gained by the fact that each drum
is equipped with an independent double-acting brake,
and in case either of the main ropes should break, the
safety rope will hold the cars. Furthermore, the safety
rope, if called upon to take the load, will be controlled
by all the automatic brake features in exactly the same
manner as when the load is being handled by the main
ropes. In actual operation, the length of the safety
ropes will be slightly more than that of the main hoist
ropes, thereby relieving the safety ropes of any hoist
stresses other than those required to keep the ropes
themselves in motion.

The operator’s cabin is fitted with one electric control
and two hand brake levers. The levers will not be used
ordinarily, as the hoist is equipped with solenoid brakes
operating on the motor shaft. The hand brakes, there-
fore, need only be used for the locking of the cars at the
top and bottom positions, or for cases of emergency.
In starting a run, the operator releases the drum post
brakes by the hand lever, puts his foot on the small foot
pedal located at bottom of master controller, and moves
the handle of the controller to either the right or the
left, as the case may be. The cars will start, and will
automatically accelerate to the normal rope speed. At
a pre-determined point on the incline the controller
handle will be automatically turned to such a position
that the speed will be cut down to one-tenth of the
normal, and finally be turned to the off position, thus
setting the solenoid brakes, and bringing the cars to
rest. Should the operator become disabled during a
run, he will of necessity remove his foot from the foot
pedal, thereby cutting off the current, bringing the cars
to rest. In order for the cars to move, the operator’s
foot must be on this pedal. In case the cars should
stop short of their landing positions, due to the auto-
matic overwinding mechanism, there are available two
or three points on the controller, so that the operator
can bring them to their proper positions. Should the
cars fail to stop, due to the fault of controller, an
attached overwinding device will shut off the current,
and set the solenoid brakes. Should the speed of the
cars exceed the normal by a pre-determined amount,
an overspeeding device will trip a weight of 5701b.,
which will set the drum post brakes. This overspeed-
ing device, or governor, is of the fly-ball type, and it
will be caused to operate by an excessive speed, whether
due to motor or a breakage of the hoist parts. The
emergency weight may also be tripped manually from
the cabin.

The drum shaft is steel forging made in two pieces,
12 in. diameter. Including the two sections, it is 32 ft.
long, and weighs 13,3001b. The intermediate shaft
has been machined from a single steel forging, and is
7 in. diameter its entire length. It is 20 ft. long, and
weighs about 3,0001b. There are two cast iron drums
96 in. diameter, 70 in. face, and coil 800 ft. of ljin.
rope, plus three holding coils at each end on one layer.
The intermediate gears are of cast steel, with herring-
bone teeth, cut. The intermediate pinions are of
forged steel.

Power is supplied in the form of three-phase 25-cycle
alternating current, and for transforming this to direct
current a Canadian General Electric motor generator
set has been installed of sufficient capacity to supply
the average demand of the hoist, plus some surplus for
charging the battery described below. The direct
current end of this machine is rated at 165 amperes
continuously at 550 volts, the latter being the floating
voltage of the battery. This generator is driven by a
2,200-volt. induction motor. The generator end is
designed with a special drooping characteristic by means
of a reversed series field for the purpose of throwing
load fluctuations on the battery. A small percentage of
the load fluctuations falling on the machine will lower
its voltage to such an extent that the battery must dis-
charge and furnish the balance of the momentary
demand. The regulation is, therefore, inherent in the
design of the machine, and is entirely automatic.

The hoist is driven through two gear reductions, the
total ratio of which is 29-84 to 1 by a 180-horse power
500-volt 475-585 revolutions per minute direct-current
motor, which is especially designed to stand such voltage
variations as come from a storage battery when it is
frequently charging and discharging. The motor is
controlled by a magnetic contactor panel, so that it is
convenient to control the motor remotely from the
operator’s station. This system of control admits of
the various protective devices already described to
ensure against the cage operating at greater than a pre-
determined speed. To ensure a greater degree of
continuity of service, a reserve 180-horse power motor
and solenoid brake are provided. The machinery of the
hoist is so constructed that in a very few moments’
time one motor can be disconnected from the hoist and
the other clutched in ready for service. The master
controller is situated in the operator’s cabin at the top
of the incline.

The power plant has been supplemented by a storage
battery built by the Electric Storage Battery Company,
of Philadelphia. One of the objects of installing this

was to reduce the maximum peaks due to the fluctuating
load of the hoist, and thus reduce the power bills.
Another object was to furnish current for operating the
hoist if alternating current supply is interrupted.

The demand of the hoist motor when lifting a load
of 7| tons was estimated at 470 amperes for 10 seconds,
followed by a demand varying from 410 down to 230
amperes for a period of 80 seconds, the voltage being
approximately 550 volts. Under the conditions of
maximum schedule, it was estimated that the load
period of 90 seconds, mentioned above, would be
followed by a three-minute rest, thus providing for ft
trip of the hoist every 4J minutes. For handling a
10-ton load, the maximum 10-second demand was esti-
mated at 530 amperes, followed by 80 seconds of load
varying from 470 down to 310 amperes. The hoist is
designed to handle a 15-ton load occasionally, but this
will not occur when the battery is handling the entire
load with the power supply cut off. It is believed that
hoisting a 7|-ton load every 4J minutes will represent
the average conditions during the hours of maximum
traffic. The average load is 112 ampdres on this basis.

Under normal conditions, with the motor generator
supplying the average load, the battery does not become
exhausted, but receives back sufficient charge during
the period of rest between trips to make up for the
discharge while the hoist is in operation. The battery,
therefore, while relieving the motor generator and power
line of the severe load fluctuations, is maintained at all
times practically full, and ready to supply the entire
demand in case of interruption to the power supply.

THE GERMAN AND AUSTRIAN COAL
AND IRON TRADES.

We give below further extracts from German
periodicals that have reached us, showing the course of
the coal and iron trades in Germany and Austria :—

The Iron Market in Upper Silesia.

The war has completely dominated the situation in
this market, and labour is increasingly scarce and dear.
A partial remedy was sought by engaging workmen from
the invested districts of Poland, but these proved
unreliable, and were too fond of changing from one
employment to another. The cost of production con-
tinues to advance, owing to the difficulty in procuring
the various raw materials, the sources and possibilities
having changed considerably, for the worse, in com-
parison with heretofore. Prices have therefore gone
up all along the line. Most of the home consumption is
in war material, whilst for export, the only unrestricted
trade is in ordinary rolling mill products for the north,
everything else being under prohibition, so that the
considerable orders in hand from Roumania and Bulgaria
have had to remain unfulfilled. Traffic on the Oder has
been greatly restricted, and the same applies to business
with East Prussia. The trade in rolled iron is satis-
factory, for though merchants have not been buying,
there has been a large demand from small makers for
material for bolts, rivets, horse shoes, etc. Prices rule
about 137-50 mk. for ingot iron bars and universal iron,
147-50 mk. for hoop iron, and 155 mk. for welding bars,
basis price ex Upper Silesia. Since only high-grade
material is wanted for military purposes, the orders in
rolled iron were not for direct supply to the army.
Large orders have been placed for railway wagon
material and ferro-concrete bars; and the works pro-
ducing high-grade steel have been very busy on war
material. The lack of activity in the building trade has
lessened the demand for universal and heavy bars, and
the orders for girders have been unsatisfactory. On the
other hand, there is plenty of business in railway super-
structural material, rails and pit rails (for the con-
quered territory). The demand for heavy plate for
shipbuilding and armour plate is active; and large
orders are in hand from Roumania for oil tank plate.
The home demand for high-grade fine plate is so active
that the works find difficulty in meeting it, and the
export trade has been abandoned altogether. Delivery
cannot be promised for a long time ahead, and prices
have been repeatedly advanced. On the other hand,
the usual large trade in fine plate for electrical purposes
has fallen off a good deal. In wrought iron pipes there
is little doing, but though enquiries for ordinary com-
mercial pipes are few, prices have gone up in harmony
with the general tendency. However, this trade is
hardly missed, the works being fully occupied with war
orders. The iron and steel foundries are also very busy
on army work, and it is therefore very difficult to place
orders for other castings, even at high prices. Orders
for ingots and blooms have been very plentiful, and the
supply of scrap for steel making is abundant, owing to
the cessation of exports to Italy and Sweden, and the
large parcels consigned from the invaded districts both
in the east and west. Hence scrap prices are easier.

German Pig Iron Market.

The Pig Iron Association reports a continuance of the
home demand for high-grade pig, the foundries and
open hearth steel makers being very busy. Haematite
pig and grades high in manganese are in special request,
and orders are coming in satisfactorily from abroad for
phosphoritic grades. The May deliveries were equiva-
lent to 59-37 per cent, of the participation, as compared
with 60-77 per cent, in April. Sales for the third
quarter of the year have commenced, prices being raised
in view of the considerable increase in the cost of raw
materials—haematite, Bessemer and steel iron, by
15 mk.; spiegeleisen, Siegen addition iron, foundry pig
I. and III., by 7-50 mk. per ton—so that, for Rhenish
Westphalia, haematite pig now sells at 115 mk. (100 mk.),
ex Oberhausen; spiegeleisen at 98-50 mk. (91 mk.), ex
Siegen; bar iron at 96-102 mk. (81-87 mk.), ex Siegen;
foundry pig I. at 94mk. (86-50mk.), and III. at
89 mk. (81-50 mk.), ex Siegen-Wetzlar-Haiger; with the
usual differences for other districts.