The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1922-05-25

~ service at the White RAISE or
n supply shaft of the Bunker
Hill mine, the old air operated
hoist is nearing the end of its period
of usefulness in this location, and is
soon to be replaced by a larger and
more modern machine. Ever since
sinking the last level of the shaft the
old hoist of S5 horse power rated ca
pacity, while it still lowers material
quite well, has been taxed to the very
limit when it has been called upon to
hoist from the lower levels an espec-
tally heavy piece of equipment which
needed to be brought above ground for
repairs. In fact in order to accom-
plish this at all it has been necessary
to heavily counterweight the skip in
the other shaft compartment. There
fore it was perfectly obvious that
larger hoist would improve the present
situation, and would be absolutely nee
essary before going any deeper.
Only the most superficial review of
the hosting machinery field was nee
essary in reaching the conclusion that
an electric hoist was by far the best
type AS the reader will readily agree,
it is more logical and more economi-
cal to convert electric energy directly
into hosting power in one machine
than to first change it into air pressure
by means of a compressor. then convey
it through long pipe lines, and finally
change the compressed air into hoist
ing power through an air engine. The
latter course might very we'll be char
acterized as "going around Robin
Hoods barn" to produce the desired
result Since the shaft has a rather
flat incline (42 degrees to the hori
zontal or 4S degrees to the verticaD
and hence a long distance between
each level, large rope capacity was
necessary. To amply provide for any
possible future development, a maxi
mum distance of 5000 feet on the in
cline equivalent to 1000 feet vertical
heighth) was decided upon. Then the
duty required called for special con-
sideration since it consists principally
in the lowering of supplies and equip
ment, and incidentally the worlmen,
as well as a small amount of hosting.
What the Hoist Handles.
To enumerate some of the things
handled. there are. first. the drilling
machines, drill Steel air pipe air hose,
blasting powder, caps and fuse, picks,
hammers, shovels and occasionally a
mechanical mucking machine and
parts for same Then comes the mine
timbers, which make up the greatest
bulk of material lowered Another
group consists of track ties, spikes,
rails, switches, ore cars and electric
locomotives. Then there are electric
motors, starters, pumps, piping, valves,
and all the auxiliary equipment for the
wate- pumping stations. Venitlating |
fans and blowers with their motors, |
starters and accessories comprise still
another group of supplies. Electric |
wire fittings and everything necessary |
for the power lighting, telephone and
signal systems of the mine should be |
mentioned. Also might be included the
small timber and auxiliary hoists along
with the necessary wire rope, sheaves, |
idlers. etc. Other items, too numerous
to mention here, aggregate a further
group of materials of appreciable size. !
Hosting duty at the White raise
consists principally in bringing up
workmen at the close of shifts, also
dulled drill steel and such machinery |
or parts as need to be overhauled. The
heaviest load hoisted occurs when an
electric storage battery locomotive
must be brought up to the surface for
repairs Hosting of ore, or more pop !
ularly termed muck" is done at the
main shaft, located at some distance
from the supply shaft.
New Hoist a Home Product.
After considering all conditions. the
following hoist specifications were de-
cided upon: Rated capacity, $50 horse
power; rope pull, 5000 pounds (sus-
tanning a load of 5000 pounds on the
inclined, and rope speed 800 to $50 feet
per minute. The electrical equipment |
Of General Electric company's make, is
to consist first of a $50 horse power
continuous rated, slip ring, three phase |
go cycle induction motor to operate on
a 22OO volt current, at a speed of 45O
revolutions per minute. Motor opera !
ton is controlled by a master switch
which acts through magnetic contact |
ors in both the primary and secondary
circuits. the speed acceleration being
full automatic A special and unique
electric bral1ing system which is also
being provided is described below in
connection with the mechanical hoist
brakes.
Upon considering the phenomenal
success with which the Occur d'Alene'
sinele drum electric hoists had met, |