Virginia citizen. (Irvington, Va.) 1891-1921, 1910-11-18
STOPPING A TRAIN
Many Things Combine to Make 1t
an Uncertain Operation.
THE NUMBER OF CARS COUNT

Likewise the Momentum and the Brak-
ing Power and the Temperature of
the Rails-Frsisht Trains More I'm
certain Than Passenger Trains.
"iD what distance can train be
brought to stop? Well. that de-
pends." said the grIzzled engineer,
with hand like a ham and an eye
that could see red. white aud green a
mile away down silvery track. THAT
depends. son. and the more ! think Of
st the more I realize how II depends
on circumstances.
''In the first place, II depends on the
number Of cars you have on your
train. The fewer cars you have the
quicker you can stop. eh? Well. that's
where you're dead wrong" The ensI-
neer rested his gnarled est across his
knee as IL II were fifteen pound
monkey wrench. Yes. sir" he re-
peated. III you've got that idea you're
wrong, just like folks are likely to be
on railroad matters which they don't
know anything about. Now. the fact
Is that certain type of engine can be
stopped quicker II II has a half dozen
freight cars hooked oB to IL. That's
SO because there are brakes on each of
the cars. and they all grind iuto the
wheels when you sling on the emer-
gency. Why wouldn't IL stop quicker
If you had dozen cars on instead of
six: Well. sonny. for the simple rea-
son that the weight of the train. or.
rather. the momentum. overcomes the
braking strength OF your air. and so
you're carried along. IL you had less
than six cars II would be Just the
other way-you wouldn't have enough
braking power to overcome what
weight you have got. Yes. sir. with
every freight train aud with every
passenger train there Is certain
number Of cars necessary to make tho
train most effective when 1t comes TO
stopping quickly. This is a very prac-
teal question too. An engineer will
say TO himself. We'll. I've got more
cars on today: I'll have to put on
brakes sooner in onier to stop just
right Mt the station.
II once beard an engineer say that
an engine with baggage car and two
passenger coaches travelling at the ratio
OF thirty-ive miles M hour would re-
quire about 600 feet 10 stop and trav-
cling at twenty-five miles an hour
would require 400 feet TO halt Now.
he was just guessing. or else he had a
particular train and particular condi-
tons In mind. and most likely partic-
ular times I'm mind. The fact Is you
can't tell within what distance a train
can be stopped.
why. take the same type of engine
and the same type of coaches and run
them over the same track and apply
the brakes in precisely the same man.
ner and the two trains will not stop
In the same distance Of track. Indeed.
take the same train over the very
same track at different times, run her
at exactly the same speed and apply
the brakes In the very same manner
and you can't stop in the same dis
lance. Engineers would like TO stop at
each station at precisely the same spot
that they did the day before. Do they
ever do II? No. son. they don't. be-
cause II can't be done.
1.-The stopping of train depends on
conditions, Just as 1 said before. En-
gineers who have travelled over a par
ticular road for years can't do It Some
times the conditions vary to such an
extent that the train is run past the
station. Everybody has seen that done.
And then the engineer says things IN
der his breath and backs up his train
to let the passengers on aud to take
on baggage Sonny. engineers never
know within yards where their trains
will stop. s.
Freight trains are more uncertain
than passengers. This is so because It
doesn't matter as much. An applica-
tion or ten pounds OF air may produce
no braking at all, due TO the wear OF
the system. and. on the other hand. If
teen pounds might put on more brake
than the engineer wanted. He may
throw on a small quantity OF air. and
without expecting 81 the emergency
brakes get Into action as a result.
When the brakes are already on the
engineer may release them a little and
by so doing release them entirely, GO
that the train leaps forward. So. you
see. you can't always tell what the
brakes are going to do.
"You wouldn't suppose that the tenn
perature Of the rails would make apy
difference about brakes. would your
It's fact. A rule Of thumb il that a
train Will brake twice as quickly I'm
the winter as in the summer. The
wheels stick to the rails more when
they are cold. The scientific folk tell
you that the cohesion Is greater And, |
another thing. the oil on the rail when |
1t Is warm Is more slippery. ALI the |
steel RODS. pipes. etc., on a warm day |
are expanded. and SO they have to |
move through greater distances to be-
come effective. When they are con-
traeted by the cold the brakes grip the |
wheels that much quicker and tighter |
with the same amount OF air that you |
applied on a warm day.
You see. sonny. every road in the |
country keeps tabs on the temperature
three or four times a day all along
its lines. Temperature Is quite an
important thing In railroading. All
this goes to show that there is quite a
lot OF science In running trains And
never saw man yet who had been
IN the service so long that ne couldn't
learn heap OF things. The fellows
who think about their business are
always iearning."-New York Tribune.