New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1907-05-26
A HUGE TREADMILL.
Constructed to Test the Speed and
PozCer of Locomotives.

In the old days when an engine built it was
the custom to test her by sending her out on the
road. Rudyard Kipling once wrote story de-
scribing how q great locomotive was tried out.
This was true at that time. It usual then to
take the engine, hitch a lot OF heavy freight cars
her. and send her out over the line. on levels
and tangents. curves and grades. until she
showed exactly what in her for those pur-
poses. But nowadays the railroad men want 10
know more, and they want to know 1t before
they intrust a scheduled passenger or freight
train her merces; they put the engine on
q treadnill The first thing they do with her theh
is TO allow her wheels to revolve TO capacity TOT
in that the maximum speed is figured Then she
is coupled TO an arrangement with a dial attach
ment for the purpose Of testing her pulling power
By a backward pull the engineer makes her draw
the equivalent of everything from a baggage car
to n mile long freight train.
Now she is to all tntents and purposes racing
over the meadows. the track clear and the way
straight: she Is striking the grade on the other
side of large town, and painting like human
being In distress Stronger and stronger grows
that backward pull until No COCO finds herself
slowing up. After a time she is required TO start
Or try TO start again. with every known condi-
ton against her. every brake, bar lock and lever
set wrong This Is TO learn her starting power
a most important thing in railroading.
All the time the engine was pulling and hauling
racing and checking. her steam gauges and water
gauges had telling little stories Of their own.
and these stories We're listened 10 with interest
They were telling about the pressure OF the steam
in the boiler with the amount of water and coal
used. They saying whether the amount OF
fuel producing the maximum of steam or
whether there was a mistake somewhere. They
were telling as plainly words will. whether the
boiler was large enough Tor the crate the CRATE
large for the boiler.
Nowadays, with an engine the treadmill. these
skilled men can learn exactly what every part Of
the machine Is doing, and to tho part that
fails in it's share. II means another trip TO the
construction department and the supplying CT new
speed and pull and pressure and effectiveness r,
Important and interesting thing is determined
while she Is on e bt and that faf' engines
for some reason never exactly alike Ihey
s sae De eat Ht me m Se GO into them and tho
workmen may construct them on the same plSm ii
tell you of that. and therefore there must be
once the test Was to hitch cars to an engine
until she laid down and cried as they said-that
marked out. Nowadays they never do that but by
scientific arrangement OF pulieys levers ala
wheels strike the golden mean between 700 ihu !I
weight and too little-the exact point where the
under the most adverse conditions.
The principle is the in the case OF hod-
der and is therefore wearied by single trip,
while the man who loads light makes many uips
plishes The modern railroad superintendent
wants to get the bricks his division every
The proposition Of putting a locomotive on a
treadmill and running it at full speed just to find
out what it do Is little startling. The de-
mands made upon locomotives to-day have mate
rally changed the CONDITIONS OF former years;
Longer cars. heavier trains. higher speed and
with. Nothing short Of the most accurate knowl-
edge obtainable regarding every element OF design
and its effect the operation OF the machine as q
whole meets the needs of the man who builds
There are certain qualities of locomotive which
only be determined by actual trial in service;
cannot car be- Well detsrned When the machine is in
service because when running at high speed con-
period OF time If the test were started on a level
straight track curve or nh YOU'D ns reaG ,,
GENTLY established to measure; The difficulty OF
some of the men making d the test are
often required to ride in a small box secured TO
where the noise. dust and jar are frightful.
e1nf e se stands s She being
tested while its driving wheels spinning around
The driving wheels do not rest upon the tracks but
upon large hesyy wheels which can reyoiyg ,h ana
moving the locomotive either forward or backward.
ating conditions would be attached to the train. is
secured to mighty scale especially arranged 10
would seem easy for great locomotive with Its
around almost any speed but It is possible under
these conditions to make II do as much work as II
is as easy to make the locomotive work in the test
ing plant as it is to make horse or dog work on a
With the apparatus arranged 1t is possible to
ling In miles an hour tho pull exerted to haul the
train the pressure Of steam in the boiler, the coal
sary to make the test record complete Many OF
the measurements are automatically recorded as
the test that when II is finished its
history is complete and ready for examination.
One OF the interesting things the test plant
determines is the best load for each different type
OF locomotive 1t used TO be the custom to make
freight train as large engine could handle
the theory that in this il did the greatest
amount of work. This method has been superseded.
for it has been proved that could actually
do more If it were not so heavily loaded.
the locomotive to is CAPACITY of Ise eH-
ness, considering the grades. curves and weather
AS q result there fewer hrpakdoWns fewer de-
lays due TO trains being stalled and better salts
faction all around.-Harper's Weekly