New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1877-01-11
RIDGES NEEDING INSPECTION.

Commitments to the Lake Shore Railroad
seem just now out of place. At any other
time people might have heard its praises
sounded with patience. At present the open
ing sentences of Col. CarringtOn's letter,
which we printed yesterday, will fall on I'M
willing ears If it be true that there is 'no
"railroad in America built or conducted
"under more skillful care" it follows that
there is as great or greater probability OF
being flung into an abyss and there beng
burned to death in travelling on any other
railroad in the country. Ii the fatai
bridge was well built of good design, OF sound
material. carefully tested and afterward in
spccted mt intervals why did it break 7 The
fact of the disaster is prima facie evidence
that the bridge was defective. That evidence
can only be set aside by showing that the
train or part of it was off the track or course
if that was the case it can be said with some
show of justice that the bridge broke down
because it was subjected to strain which 1t
was not built to meet and that no trestle or
truss bridge can be built to endure such
strain. But as yet there is only meager testl-
mony Indicating that the train was off the
track. Such testimony cannot be supplemented
by the inner consciousness of the friends-of
the road or their firm conviction that the work
on the road is generally we'll done.
The question is as to the condition of this
particular bridge just before it broke. On this
point Col. CarrngtOn's letter offered capital
suggestion He has found that in all that class
of iron structures there is likelihood that the
vertical rods will slowly but certainly slip out
of the nuts with which they are screwed, being
pulled down gradually by the weight. His
statement that the screw is simply an inclined
plane will be recognized as familiar truth by
all students of mechanics. But the release OF
one or two rods would not be sufficient to
cause the failure of the bridge. Col. Car
ringtOn also suggested that the rods arc
liable to become weakened by change OF
their interior stiucture-by partial crystallza-
ton. His observations on this point are
noteworthy; the instances he gives are strlk-
ing. 1t is not quite clear whether this process
of crystalzation takes place in the best of
iron. That is point on which very exact in
formation is greatly needed. If the expert
ments had been continued which were begun
by the United States Commission that was APP
pointed to test iron and steel, there would now
be something definite known on that point,
and also respecting the erect OF low tehlpcra-
lures on iron. Unfortunately the failure OF the
appropriation checked those experiments Mt
their most promising stage.
As we have before said, proof will have to
be brought concerning the quality of the iron
used in the Ashtabula bridge. Portions OF it
should now be subjected to careful test. The
whole history of that iron must be ascertained
Till the question rs to its quality is squareiy
answered, other speculations rs to the cause OF
breakage are somewhat premature. But as to
all the causes which Col. Darlington lucidly
presented excepting only the possibility that
the train was off the track, they point con-
clusiyely to this inference: that Il thorough,
freouent examination of the bridge at regular
intervals would have revealed its weakness
and led TO its repair 1t follows that there is
no safety in iron bridges unless they are sub
iected to examination at regular and not very
distant intervals, and that the quality of the
iron as we'll rs the condition of its fastenings
must then be tested. Col. Darlington deserves
thanks for pointing cut this absolute necessity.
Now we're such periodical examinations made
on that railroad than which no other In Amer
lea is conducted with more skillfui care "