April 5, 1917.

THE COLLIERY GUARDIAN

671

they had to thank Mr. Thompson, the representative
of the Administration, who proceeded to England to
supervise the construction of the plant. He believed
that the coaling industry was in its infancy in South
Africa. They had commenced coal fields in Natal
and in the Transvaal, and, although they were not
directly concerned with the Transvaal at the present
moment, they were, as a country, interested in the
essential development in the Transvaal as well as the
development in Natal. Not only was the coaling
industry proceeding at a very rapid rate, but they
found that the whole of the industries of South
Africa were developing rapidly at the present time.
Men who travelled about the country would know that
the whole of the South African industries were gain-
ing an impetus at the present time.

Capt. S. Carneirio, Director of the Portuguese
Railways, also spoke, and he said he thought it his
duty not to allow the occasion to pass without express-
ing his feelings in the new enterprise of Durban.
Durban was a rival of Lourenqo Marques, but not its
enemy, and the development and improvements of
the railway in this part of the Union of South Africa
were looked upon by Lourenqo Marques as a further
step in the development of South Africa, of which
Louren9o Marques was also a factor. He wished the
railways and harbours of South Africa and the new
Durban coaling plant every prosperity.

Sir William Hoy was accorded a unanimously warm
reception upon rising to respond to the toast. He
said that he merely wanted to add his testimony to
those of the previous speakers, and his appreciation
of the developments of Port Natal. He hoped
Durban people would take a lesson from what they had

Housed Position

:ootwatk

Bogie

Belt Drawing Motor
& Tension Gear

Telescoping^
Rope to Winch

Housed Position of

Telescopic Arm ____

Clear of

Quay line

Telescopic Shoot
(extended!

Highest Working
o.o Position_______

. 20 Gauge
'Corrugated
Sheeting

Tower Travelling
Motor

Lowest Position a!

(Extended)

I--------------

New Coaling Plant at Durban.



that day seen, and that with the new coaling plant
would discharge with greater expedition the coaling
of ships than they had before. Looking at the coaling
industry, he estimated that there was sufficient coal in
South Africa to last 1,000 years, which, he said,
would see him and others present through their
troubles. They had produced coal since 1888 to the
value of 37 million pounds. Natal was the first to
discover coal in 1838, and Cape Colony commenced
mining first in 1865, when the output was 16,500 tons.
Cape Colony reached her zenith in 1899, and in all
her glory turned out 208,655 tons, and was then
pushed out of the picture by Natal and the Trans-
vaal ; and to-day the Cape output was practically
nothing. Natal and the Free State commenced
mining in 1888, and the Transvaal in 1893. In 1889
Natal’s output was 28,700 tons; last year it was
3,366,202 tons, which was an increase of 33 per cent,
over the previous year, and of 80 per cent, over 1907.
In 1916 the output of the whole country rose to over
10,000,000 tons. In 1906 Natal bunkered 846,000 tons,
and in 1916 1,000,700 tons, being an increase of 25
per cent, over the 1915 bunkering. The earliest
bunkering was in 1904, and in 10 years it had increased
by 100 per cent. In 1916 the total South African
output was 14 per cent, better than in 1913, which was
the next best year’s output. In 1916 the tonnage of
bunkering and cargo was over 3,000,000 tons, or
500,000 tons more than in 1913, which was the next
best year. Sir William Hoy said that the develop-
ment of the coal industry meant an enormously
increasing traffic to the coast, and they were feeling
the benefit of it. Natal had reason to be proud of
the development, and they had a line which would
carry all the coal that was necessary. He found that
in 1907 the coal took 90 hours to travel from the mines
to the harbour, and to-day the load had increased
from 435 tons to between 650 and 700 tons, and was
carried down in 70 hours, so that every day they had

from 6,000 to 7,000 tons of coal arriving at the port.
They had had much trouble in getting the coaling
plant, and they must rejoice for more in having
accomplished this than in the praise that followed it.
He congratulated Messrs. Fraser and Chalmers
Limited for the way in which they had discharged the
contract.

The Mayor proposed the toast of “ Messrs. Fraser
and Chalmers Limited,” and alluded to the hospi-
tality accorded them that day. He was sure that the
plant would prove efficient in the handling of their
coal.

Mr. ,W. H. Haig responded, on behalf of the firm
of Messrs. Fraser and Chalmers Limited, acknow-
ledging the toast in most suitable terms. He had not
the slightest doubt that the progressive port of.
Durban would appreciate the new plant very much,
and he thanked Sir Thomas Hyslop and Sir William
Hoy for coming specially to Durban to open the plant,
and other officials of the Railways and Harbours for
the valuable assistance they had given during the
construction.

Sir T. K. Murray called attention to the services
of the late Mr. Harry Escombe in the development of
the port of Durban, and expressed the opinion that
an occasion such Rs that, when they were marking one
of the greatest developments anyone had seen in the
port necessitated that the name of their late bene-
factor should be recalled with honour.

The plapt is the only one of its kind yet installed in
South Africa, and, not only this, but it is the most
up-to-date machine for coal loading that has yet been



devised. It is certainly the largest belt conveyor
installation at present in operation for loading ships
with coal. The dumper connected with the new plant
has a lifting capacity of 75 tons on each load, and
this is so arranged that it can deliver coal either to
the incline belt or to the buckets for use in connection
with the old transporter appliances. The coal first
passes in trucks to the dumper, where the truck is
raised by means^of an elevator, and the contents tipped
into a concentrating pan. The load is then delivered
through a chute to the incline conveyor, which elevates
the coal to the height necessary for loading into any
steamer at any state of the tide. The coal is
delivered into a three-way chute, from whence it may
be discharged either on to the existing horizontal
tripper direct to the travelling tower, or to a further
horizontal tripper belt, which is to be the first portion
of the proposed programme of extension. The main
belt is 525 ft. long, and the incline belt 230 ft. long—
both 48 in. wide. The main belt travels at a speed of
450 ft. per minute, and the incline belt has a vari-
able speed, so as to feed the ship according to require-
ment. The horizontal belt is equipped with a travel-
ling tripper, which can be automatically traversed to
the position opposite the point at which the travelling
tower is required to deliver coal into the steamer’s
hatch. The tripper unloads the horizontal belt at this
point, and delivers the coal on to a telescopic cross
conveyor belt, which is mounted on the travelling
tower. This belt discharges its load directly into the
steamer’s hatch, through telescopic chute, which is
fitted with an “ elephant’s trunk,” a device invented
for the purpose of distributing the coal, and so
eliminating the necessity of hand trimming. The
whole plant is electrically driven, and controlled by
contactor control gear. On the dumper there is a
contrivance whereby, when the plant is once started,
it continues automatically until the whole of the con-
tents of the truck are discharged into the concentra-

tion bin. A distinct feature of the plant is the care
that has been taken in its construction so as to avoid
any undue breakage of the coal, and in this respect
the desired result has been attained by eliminating
the direct fall of coal, all chutes being so arranged
that the coal is lowered more or less gradually.

The plant has been designed for a capacity of 600
tons an hour, and this result is easily attained. The
new appliance is capable of handling considerably
greater quantities, but such acceleration of speed
depends upon external conditions being favourable—
such, for instance, as the necessary supply of trucks
in quick succession, their delivery and return, and the
necessary trimming in the vessels. These conditions
being favourable, it is estimated that 1,000 tons of
coal could be dealt with per hour. The total horse-
power on the new plant is about 1,000. There are
three 150 horse-power Westinghouse motors control-
ling the dumper, by means of the latest pattern con-
tactor control gear. There are other motors—seven
on the tower to operate the jib, and two 65 horse-
power motors controlling the big belt. All motors,
except the dumper motor, are controlled from a cabin
at the top of the travelling tower, so that all the belts
can be started and stopped by one man, who is in a
position where he can see at a glance what each
section of the plant is doing.

THE PRINCIPLES OF COAL WASHING.

Dr. Henry Louis, Professor of Metallurgy at
Armstrong College, Newcastle, addressed the members
of the Northern Section of the Coke Oven Managers’
Association at their meeting in Newcastle on Saturday
evening last on “ A General View of the Principles of
Coal Washing.” Mr. W. Diamond presided.

Prof. Louis said it appeared to him that there were
few subjects of more importance to the coke maker
than that of coal washing. He proposed to deal with
the scientific and technical sides of the subject only,
without going into the fully-as-important economic
side. The subject had been somewhat neglected in this
country. On the Continent—in France and, more
especially, in Germany—it had been very completely
and very thoroughly studied. When they remembered
that a great amount of German coal was naturally
dirty as it occurred in the seams and would not make a
good coke without previous treatment, and that, again,
Germany could not carry on the war as she was still
doing were she not able to get the supply of coke from
iron and steel manufacture and the by-products from
the manufacture of explosives, they would realise the
great importance to Germany of having made a
thorough and complete study of coal washings In this
country, the matter had not been so vital because we
had been blessed—or cursed—by Nature with a lot of
magnificent seams. We had had splendid thick seams
of very clean coal which gave us the best of coke
without the trouble of artificially improving the coal
before using it. Anyone who had been a user of coke
for a number of years must, however, have noticed that
coke was gradually becoming worse. People were now
buying as. foundry coke what they would not have
regarded as foundry coke 20 years ago. If he compared
present analyses of coke with the analyses of coke as it
used to be, he was struck by the larger percentage of
ash in the present-day coke. Nowadays, we were
working thinner seams of not so clean coal. A great
deal of our coal was got by machine cutting, and we
were cutting frequently into the thill and, necessarily,
the cuttings and chippings and dust got mixed with
the coal to some extent. It was, therefore, daily
becoming more important to consider the matter of
cleaning their small coal before attempting to coke it.
Coal always contained a certain amount of inorganic
matter or ash, which was intrinsically part of the coal.
The question as to whether one could wash a given coal
or not depended very largely—essentially, in fact—on
the way in which that inorganic matter was distributed
through the coal. He knew some Indian coal which
contained over 20 per cent, of ash, and one could not
wa^h it at all. That wars due to the fact that the
inorganic matter was so finely disseminated throughout
the co‘d. On the other hand, the inorganic matter was
often found in particles of definite size, sometimes
distributed through the coal in the form of defined
bands or streaks, sometimes of extraneous chippings.
All that inorganic matter the miner spoke of as “ dirt,”
and the speaker proposed to use that expression in the
same way that night.

If that dirt was in reasonably large-sized particles,
coal washing was possible.' Particles of similar size
could also be got rid of provided that the coal was
crushed sufficiently finely, but it might easily happen
that that course was not practicable. It was possible
that the particles of inorganic matter might be so
excessively fine that one would have to grind the whole
of one’s coal into impalpable dust and turn the whole
lot into slime, which would be an economic impossibiiity.
In addition to the dirt mentioned, there were brasses in
the coal, pyrites, which they might rank for the time
b ing as dirt also. In practice, only one method of
separating the dirt from the coal was lelied upon, and
that was the difference in their lespective specific
gravities. The specific gavity of coal ranged from
1*25 for soft bituminous coal up to 1'6 for anthracite.
For the ordinary run of bituminous coal it was about 1’3.
The specific gravity of “dirt” was about 2'5, and of
pyrites about 5'0. Obviously any method that would
separate the upper dirt from the coal would still more
readily separate the pyrites, from which fact was
derived a simple, ready way of determining how one
could separate the dirt and the coal in a given sample.
There was a very simple laboratory method, which he
was constantly using. If one took a solution of zinc