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

N6. 3.1

CHARCOAL IRON WORKERS.

169

Mr. CHAMBERLAIN. Ten or fifteen years ago, all we could get
as an average mileage was thirty-five thousand miles. It seems to
me if we have an expansive and contracting chill by mechanical
force, or by the force of water acting as a mechanical power, the
wheel must be made a little more dense.' Now, the hotter you
can pour your metal, I think, the stronger will be your wheel and
the longer it will last, and by this squeezing process it must be
condensed. In the wheels manufactured by the old system, as I
said, thirty-five thousand miles was all that we could get as an
average. Individual wheels have run ninety thousand, and hundred thousand and one hundred and fifty thousand miles, but it
was a very rare thing that we got any big mileage.
Mr. WHITNEY. Wheels made in the old chills did, no doubt,
show some excellent mileage, but wheels made in new chills do
better. Take a wheel made in the ordinary chill, and a wheel
made in the contracting chill, take a part of the wheel which has
exactly the same depth of chill when made in the ordinary chill
as the one made in the contracting chill, made out of the same
iron, on the same day, and put the two pieces of wheel along side
of each other, and you may not detect any difference. We inspect our wheels with a very highly, finely tempered chisel, used
with skill and care.
A man that is accustomed to using that chisel may be blindfolded, and you may place before him half a dozen wheels made
in an ordinary chill and a half dozen made in a contracting chill,
and he will pick out every wheel made in the contracting chill by
the difference of the cut. The metal is so much more dense that
the chisel will tell it instantly.
Taking the specific gravity of those two specimens of chilled
iron, the one made in the contracting wheel will be from one to
three pounds heavier per cubic foot than the specimen made in
the ordinary chill.
Mr. CHAPIN For the past ten years I have been interested in a
foundry that has made in that time a quarter of a million of
wheels, with the old style chill. We have never been free from
out of round wheels, or free from blow holes, slag, wrinkles or
chill cracks. In the last year we have been using some contracting chills and are pouring our wheels in ten seconds. The molder
does not stop to cool his iron at all, but pours it into the mold