The Marietta journal and courier. (Marietta, Ga.) 1909-1918, 1910-11-18
STOPPING A TRAIN
Many Things Combine to Make 1t
an Uncertain Operation.
THE NUMBER OF CARS COUNT

the RaIs-Freight Trains More I'm
certain Than Passenger Trains.
'In what distance can a train be
brought to a stop? Well. that de-
pends," said the grizzled engineer,
with hand like a ham and an eye
that could see red. white and green a
mile away down a slvery track. That
depends, son, and the more 1 think of
it the more | realize how it depends
on circumstances.
I'm the first place, it 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 it were a 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 If it has a half dozen
freight cars hooked on to it. 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 it stop quicker
if you had a dozen cars on instead OF
six? Well, sonny. for the simple rea-
son that the weight Of the train, or,
rather, the momentum, oyercomeS the
braking strength of your air, and so
you're carried along. If you had less
than six cars it would be just the
other way-you wouldn't have enough
brak1ng power to overcome what
weight you have got. Yes. sir, with
every freight train and with every
passenger train there is a certain
number of cars necessary to make the
train most effective when it comes to
stopping quickly. This is a very prac-
teal question too. An engineer will
say TO himself. Well I've got more i
cars on today; I'll have to put on
brakes sooner in order to stop Just
right at the station
81 once heard an engineer say that
an engine with a baggage car and two
passenger coaches travelling at the rate
of thrty-tive miles an hour would re
qulre 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
particular train and particular condi-
lions in mind. and most likely partic-
ular times in mind The fact is you
can't tell within what distance train
can be stopped
e" ny, 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 1t? No. son. they don't, be-
cause it can't be done
1.-The stopping of a train depends on
conditions, just as l 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
QVtpnf thof ho 10
station. Everybody has seen that done
And then the engineer says things I'M
der his breath and backs up his train
10 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 it
doesn't matter as much An applica-
ton Of ten pounds Of air may produce
no braking at all, due to the wear of
the system. and. on the other hand. ff-
teen pounds might put on more brake
than the engineer wanted He NAV
throw on 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 cant always tell what the
brakes are going to do.
"V"r wouldn't suppose that the tenn
perflure of the rails would make any
difference about brakes. would you?
ats fact. A rule OF thumb is that a
tran will brake twice as quickly in
VI, i",er as in the summer. The
VIII is stick to tue rails more when
the, are cold. The scientific folk tell
you hat the cohesion is greater. And.
anU 1er thing. the oil on the rail when
u !, warm is more slippery. All the
st"e rods. pipes. etc. on warm day
arr expanded. and SO they have TO
mo' through greater distances to be
CO.. effective. When they are con
ira ~ hy the cold the brakes grip the
wi is that much quicker and tighter
W thn ma onannn4 nf ;w sbo4 49,.