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

No. 3.]

CHARCOAL IRON WORKERS.

165

you will get a deeper chill. If it is an inch and a half thick, you
will get a still deeper ole, if it is three or four inches thick, other
things being equal, you will get a still deeper chilling effect produced upon your wheel. My judgment has been for many years
that a very much heavier tread of wheel than formerly is required
for the service which is now exacted by railroad companies. You
are using a steel-tired wheel, the thickness of which is two and
a half inches, put upon a center of an inch and a half thick at
least, to bear the blows and hammering of a heavy load. Now
you put under your sixty-thousand-pound car a cast-iron chilled
wheel, with a tread an inch an three-eighths, or an inch and a half
thick, to stand the same blow. Your anvil is too weak for the
forging you are making upon it. You want a wheel of heavier
tread, and I am very glad to see that one of the railroad companies in New England has realized this sufficiently to stipulate that
the wheels that are made for them shall have a tread two inches
thick. The difficulty in making such a chilled wheel heretofore
has been the expansion of the chill from the wheel, and the contraction of the wheel from the chill. With the contracting chill,
however, if you have body enough of metal in the chilling surface, you can make any thickness of tread.
Mr. LOBDELL. Mr. Barr predicates the value of the sectional
chill, and so does Mr. Whitney, on the theory that the chill
expands inwardly and meets the wheel as it contracts. Now
to do that there must be an increase in the temperature
of the chill. Some experiments were tried in our foundry
which resulted as follows: The temperature of the chill before it
was poured was forty-eight degrees. In thirty seconds after that,
and after the wheel was poured entirely, it was but 52 degrees,
the temperature having been increased about four degrees. That
was long after the wheel was all formed and the chill all formedthirty seconds on the outside. You cannot expand the inside
until you expand the outside.
I have often had a wheel when half full to run out and leave a
chilled crust around of a quarter of an inch or more in thickness.
I have had a wheel to run out just as it was full, and it would
leave the entire flange all of a certain thickness. I have
had occasionally a chill roll, weighing from twelve to fourteen
thousand pounds, to break out at the bottom and leave a chilled