The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1917-11-29
(By II. NJ. Sigafoos, of wilkesbarre,
Pa, paper read before the New
York Safety Council)

| Wy IL W. oiSdiooSs VI NAhS5pabic
Pa. paper read before the New
| York Safety Council)
In the United States wire rope was
first manufactured in the early 40's
and has been improved upon year By
year until the present time, when Il
represents the very highest develop
ment of this means of hosting and
haulage. In the last fifty years there
has been a gradual change from the
use Of one kind Of rope material to
another, and this was brought about
| by the demand for an increased pro-
duction by speed and efficiency. In
preceding paragraphs / have shown
that iron was practically the only
material used for wire rope. and this
continued to be the case until the
Introduction of crucible cast Steel
which opened the second period in the
manufacture of wire rope. The third
period came with the introduction OF
higher carbon steel known by the
trade as plough and special high
strength steel. In none of these
periods has the material in the pro-
duction of wire rope Of the preceding
period been forgotten, for certain OPP
erations still demand iron cables and
there are other operations in which 1t
10 ~ ha IN rhctit fat 10
plough steel or the special high
strength steel for cast steel.
Materials Used in Manufacture of
Ropes.
The material entering into the man
ufacture of wire ropes is perhaps of
greatest Importance in the wire rope
industry, for upon its quality depends
largely the final result of the finished
product. Through careful selection,
constant experimentation and analysis,
with minute researches into the ply
steal and chemical properties of the
raw materials, the industry is guided
toward the production of depend
able wire rope with durability and
ductility as two Of it's fundamental
qualities.
Until recent years in the manufac-
ture of wire rope it was generally con-
ceded that the foreign steels were by
far the best, due principally to the
use of Swedish ores Foreign steel
material as imported by the Ameri-
can manufacturer for wire rope pur-
poses is made to meet rigid specifi-
cations. This insures as nearly as
possible a uniform quality. Such steel
is carefully tested and analysed to
verify the percentages of manganese,
silicon and carbon as we'll as of sui
phur and phosphorus, which must be
extremely low. Acid, open hearth
steels are generally admitted to be
OF better quality than basic open
hearth and it has been suggested that
this is due to the higher oxygen con-
tent in the basic steel.
Much has been claimed for the quail
tiles of chemically treated steels, such
as vanadium, chromium, etc, and in
many instances the manufacturers of
steel products have proved the claims
made for them. So far as their adop-
ton to wire rope is concerned, how
ever, they are still in the experiment
tai stages, and no data are available
at this time. Without doubt such
elements may eventually be used in
connection with domestic ores and
produce finished article for the
wire rope industry as it has for other
purposes.
Wires made from materials intend
ed for the manufacture of wire rope
for ordinary purposes are divided into
three classes, as previously stated
namely, iron with a breaking strain of
approximately $4,000 pounds per
square inch, cast steel, often erron-
eously called crucible cast, which has
a breaking strain of 10000 to 100000
pounds per square inch, and plough
steel with breaking strain of 100000
to 1000 pounds per square inch.
Wire of higher tensile strength is
often drawn. but this is rarely used
for any other purpose than for stand
ing rigging on racing yachts, where
maximum strength with the lightest
possible weight is essential Such
wires are sometimes drawn to $50, 900
pounds per square inch. Small sizes
of even higher tensile strength are
drawn for wire rope or strands for
aeroplane guys.
Life, Stresses and Speeds.
There has been much discussion on
the question; When has a wire rope
reached the end of its usefulness, and
when should it be removed? Up to
the present, it seems, the question re-
mains unanswered-at least, satisfac-
torily. In an exhaustive investiga-
ton conducted by the bureau of STAN
dards on this subject the recommen-
dalton was made that rope should
be removed after a certain number Of
broken wires appear in each of the
strands. These tables have undoubt-
eddy been compiled from stated loads.
speeds, head sheave and drum diam
eters from shafts of various depths,
the tensional and load stresses being
taken into consideration. II Is no doubt
81 a.