Cast-Iron Car Wheels. [Volume: 8, Issue: 3, 1889, pp. 153-170]

No. 3,]

CHARCOAL IRON WORKERS.

163

tigations have convinced us that the cast wheel, properly made,
has everything in its favor for any class of service-freight, passenger car or locomotive.
For safety, we have a record of 300,000 wheels made and put
in every kind of service during the Fast five years, out of which
frot one case of breakage has occurred. As to economy of use
and ultimate cost, that depends principally on the service obtained. It is a fact well known that cast wheels do not go into
service under proper mechanical conditions. The work of boring
the wheels for fitting on axles is often carelessly done; the boring tools are frequently in bad shape. and the most careful workman could not do proper work with them. The consequence is
tlat wheels go into service more or less out of round and out of
balance.
When we consider that under 60,000 lb. cars each wheel must
sustain under the most favorable forms of construction, including
the weight of the car, a load of five tons; that it must revolve 275
times per minute in running at a speed of thirty miles per hour;
that it must, under these conditions, withstand all kinds of brake
service-it is not difficult to conclude that proper mechanical conditions must accompany this service if a good result is to be expected.
Mr. W. T. HILDRUP, Jr. From experiments conducted in our
foundry, we have found that some mixtures of iron are more apt
to produce chill cracks than others. We attribute this largely to
the presence of sulphur, either in the iron or fuel, and try to keep
our fuel as free as possible from this element. The chill cracks,
all of which are scrapped, is about four per cent, of our make,
representing a loss in labor, fuel, etc.. of say about eight cents per
good wheel. To make a good wheel the greatest care and watchfulness is necessary, not only in the mixture of the irons, but in
the manipulation of the cupola; the best of wheels are those
poured from the hottest iron. The difficulty with slag we have
overcome, first by the introduction of a slag tap in our cupola,
and by carefully skimming the iron in the wheel ladle before it
is poured. We have found that as high as four-tenths of one per
cent. of phosphorus in the mixture materially improves the smoothness and hardness of the wheel, and that with this percentage of
phosphorus a percentage of manganese as high as eight-tenths of