The Topeka state journal. [volume] (Topeka, Kansas) 1892-1980, 1910-03-28
Deficiency Discovered in Steel
Passenger Equipment.
Said That Center Stills Are Not
as Strong as Needed.
FREIGHT CARS BETTER
Steel Passenger Coach Should
Withstand 100000 Id. Shock.
Other Items of General Interest
in Railroad World.

The importance of ample section of
center sills and cover plates for resist
ing bufing in steel passenger cars has
been demonstrated by the results of
collisions and wrecks. but, notwith-
standing this, there is a large amount
OF steel equipment building which is
nanifestly deficient in this particular
says the Railway Age Gazette. It
is unuc Ial in freight cars, which are
much shorter and should therefore
have greater stiffness for a given area
than the longer passenger car, for such
defects to be shown up In regular SER
vice, however severe, but in the last re-
port of the arbitration committee of the
Master Car Builders association there
is a case in which this question is dis
cussed
A 40 foot. $4,000 pound, steel under
frame car was offered to the owner in
interchange and refused on account of
two steel center stills and one side sill
being badly bent. The offering road
claimed that the defects were the result
of ordinary service. the parts yielding
nent set at four distinct places in the
longitudinal framing, the offsets
amounting to as much as 21a to 3
inches. These center sills consisted Of
two 10 inch. IS pound channels without
cover plates. and a comparison is made
to show their slight resistance as COM
pared with cars of similar capacity, but
of good design. Car A. with the light
inches, while car 3, of good design. has
a section of 29.4 square inches, a diff
ference OF AIS per cent in favor of car
3. The moment Of inertia, which in
columns Of the same length is a measure
of the stiffness, in car A is 6252, while
in car Z ii is 1883, a difference of 273
per cent in favor of car B. The section
modulus, which measures the compare
tive strength of sections is for car A,
s3.4. and for car B. 1868, a difference
of 1S4 per cent. The safe load for the
center siHs on car A is 1900 pounds,
while on car it is $4,000 pounds, a
difference of 2s6 per cent.
1t is thus shown that by the addition
of less than so per cent more weight in
the center sills and cover plates, which
is a small percentage of the total
weight OF. the car, their stiffness in re-
sisting buff1ng stresses and the
strength in carrying their portion of
the load are increased nearly 800 per
cent.
The arbitration committee ruled that
the damage was OF such an extent that
repairs were necessary and the Offering
road was responsible for them, thus
establishing the principle that the de-
sign and proportion of steel cars were
not proper subjects for discussion IN
disputes arising under the interchange
rules.
While this is a fair decision under the
present rules it suggests the desira-
bility of adopting some limits of cross
center stills of steel cars. both freight
and passenger. as there is a tendency
for some railways to buy cars which
are OF poor design and have light CEN
ter stills because they are cheaper than
others where these members are prop
erly designed.
In freight interchange some railways
which are careful to secure substantial
designs for their own cars, become Ii
able for the distortion of weaker cars
owned by other roads. and it would
seem that majority of the NJ. c. B.
votes ought to favor a simple rule
which would prevent the continuation
establish standards which would place
some minimum limits on the area of
bufhng members OF the underframe.
At the NJ G.. B. convention in 1908 a
committee report on steel passenger
cars discussed the question, as it was
standard sectional area for center sills
ard cover plates. 1t reported that it
had found a great difference in the
design and area of center silIs, one
type having an area of 1866 square
inches, another 1852 square inches, and
standard area It would be necessary
to take account of the length of the
car the application of the load and
the shape of the longitudinal sills: for
these reasons it did not make definite
recommendations for standard areas.
On account of the liability of the coll
lision of freight and passenger cars, the
latter should be at least as strong in
center sill construction as the strongest
freight cars ard a higher factor of safe
ty should be used. The committee rec
commended that steel passenger cars in
through service should be capable of
withstanding a shock of 10000 pounds