The watchman and southron. [volume] (Sumter, S.C.) 1881-1930, 1911-04-15
STOPPING A TRAIN FIRST SUBMARINE,
Many Things Combine to Make It
an Uncertain Operation.
THE NUMBER OF CARS COUNT
Likewise the Momentum and the Brak.
ing Power and the Temperature of
the RaiIs-Freisht Trains More Un.
certain Than PASSENGER Trains.

"e NaHs-freight Trains More On-
certain Than Passenger Trains.
In what distance can train be
brought to stop? Well. that de-
pends." said the grizzled engineer.
with a hand like ham and an eve
that could see red, white and green
mile away down silvery track. THAT
depends. son. and the more think of
1t the more I realize how It depends
on circumstances.
I'm the first place, 1t 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 engi-
neer rested his gnarled fist across his
Knee as If Ii were fifteen pound
monkey wrench. Yes. sir" he re-
peated, IF 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 1t has half dozen
freight cars hooked on to Ii. That's
so because there are brakes on each of
the cars. and they all grind into the
wheels when you sling on the emer-
gency. Why wouldn't 1t stop quicker
II 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 II 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 and with every
passenger train there Is certain
number Of cars necessary to make the
train most effective when 1t comes to
stopping quickly. This is a very prac-
tical question too. An engineer will
say To himself. Well. I've got more
cars on today; I'll have to put on
brakes sooner In Oroer to stop Just
right at the station
IL once heard an engineer say that
an engine with baggage car and two
passenger coaches travelling at the rate
OF thirty-five miles an hour would re-
quire about 600 feet to 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-
tions in mind. and most likely partic-
uiar tunes In mind The fact is you
can't tell within whit distance 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
tance. Engineers would like to stop at
each station at precisely the same spot
that they did the day before. Do they
ever do 1t? No, son. they don't. be.
cause II can't be done.
"The stopping Of train depends on
conditions, just as l said before. En-
gineers who have Travelled over q par
ticular road for years can't do II. Some
times the conditions vary to such an
extent that the train Is run past the
station. Everybody has seen that done
nd fhan tho uinaar yo thtpuo ~,
der his breath and backs up his train
to let the passengers on and to take
on baggage. Sonny. engineers never
know within yards where their trains
will stop.
Freight trains are more uncertain
than passengers. This Is so because 1t
doesn't matter as much. An applica.
tion Of 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 OH a small quantity Of air, and
without expecting 1t the emergency
brakes get into action as result
When the brakes are already on the
engineer may release them little and
by so doing release them entirely. so
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 any
difference about brakes, would YOU?
It's a fact. \ rule Of thumb is that a
train will brake twice as quickly In
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 il greater. And.
another thing. the oil on the rail when
II Is warm Is more slippery. All the
steel rods. pipes. etc, on n warm day
are eNnnnlnl- and so lhnY hnNn 10