The daily morning journal and courier., 1907-05-28
4 HUGE TREADMrLL.
Constructed to Test the Speed and
 Power of Locomotives.

l built it was the custom to test her by l sending her out on the road. Rudyard | Kipling once wrote a story describing
 how great locomotive was tried out. This was true at that time. It was us-
 ual then to take the engine, hitch lot
 of heavy freight cars to her, and send her out over the line, on levels and tam gents, on curves and grades, until she showed exactly what was in her for
 those purposes. But nowadays the rail- road men want to know more, and they | want to know it before they intrust scheduled passenger or freight train to her mercies; so they put the engine on
 a treadmill. The first thing they do
 with her then is to allow her wheels to
 revolve to capacity for in that the
 maximum speed is figured. Then she is coupled to an arrangement with
 dial attachment, for the purpose of testing her pulling power. By back
 ward pull the engineer makes her draw
 the equivalent of everything from a l baggage car to a mile long freight | train.
 Now she Is to all intents and pur- poses racing over the meadows, the track clear and the way straight; now
 she is striking the grade on the other side of large town, and panting like a human being in distress. Stronger and stronger grows that backward pull until No. O0O0 finds herself slowing up. After q time she is required to start or
 try to start again, with every known
 condition against her, every brake, car, TIic e
 flo learn her starting power-a most im-
 portant thing in railroading.
 All the time the engine was pulling
 and hauling, racing and checking, her
 steam gauges and water gauges had
 been telling little stories of their own,
 and these stories were listened to with
 interest. They were telling about the
 pressure of the steam in the boiler,
 with the amount of water and coal
 used. They were saying whether the
 amount of fuel was producing the max
 imum of steam or whether there was a
 mistake somewhere. They were tell
 ing as plainly as words will whether
 the boiler was large enough for the
 grate or the grate too large for the
 boiler.
 Nowadays, with an engine on the
 treadmill, these skilled men can learn
 exactly what every part of the machine
 is doing, and woe to the part that fails
 in Its share. It means another trip to
 the construction department and the
 supplying of new parts.
 Speed and pull and pressure and ef-
 fectiveness of parts do not end the tests
 of No 0O0O. Another important and
 interesting thing is determined while
 she Is on the treadmill, and that is her
 best load. It is strange, but true, that
 engines for some reason are never ex-
 actly alike. They may be of the same
 type, parts made from the same pat . tern may go into them, and the same
 workmen may construct them on the l same plan; but, just the same, they ! differ. Old engineers will tell you of that, and therefore there must be a test for each engine. Once the test was to hitch on cars to an engine until she laid down and { cried" as they said--that is, until she couldn't pull another car over the line marked out. Nowadays they never do that, but by scientific arrangement of pulleys, levers and wheels strike the golden mean between too much weight and too little--the exact point where the machine can do It's best work in the shortest time under the most ad- verse conditions
 The principle is the same as in the case of a hodcarrler who overloads himself for climb up a ladder, and is therefore weared by single trip, while the man who loads light makes many trips with minimum of effort, and therefore accomplishes more. The modern railroad superintendent wants I to get 1he most bricks over his division every day.
 \ The proposition of putting locomo- q tive on Q treadmill and running 1t al 4 full speed just to find out what It can do is little startling. The demands 4 made upon locomotives to-day have 2 materially changed the conditions of ' former years. Longer runs are all fac. { tors which must be dealt with Moth ! ing short of the most accurate knowl- T edge obtalnable regarding every ele. H ment of design and its effect on the & operation of the machine as a whole H meets the needs of the man who builds Q locomotive
 4 There are certain qualities of a loco 8 motive which can only be determined 2 by actual trial in service; for instance
 the starting power. Other qualItie, 2 cannot be well determined when tht n machine is in service, because wher l. running at high speed conditions can I. not be kept uniform for lonl d enough period of time. If the tes |. were started on level, straight tracl if curve or hill would be reached be- 6. fore the running conditions had be- h come sufficiently established to meas - ure The difficulty of conducting S test at high speed can hardly be ap l. preciated. Some of the men making d the test are often required to ride in {
 small box secured to the outside O.
 the engine, near the cowcatcher
 where the noise, dust and jar ar,
 frightful.
 The testing machine itself is nothinG " but a huge treadmill. The locomo ' tive stands still when being tested To while it's driving wheels are spinning
 around as fast as if it were pulling { a train at full speed. The driving wheel!
 do not rest upon the tracks, but upor g large, heavy wheels which can revolv,
 and so allow the locomotive either for " ward or backward. The coupler of thu e locomotive, which under operatInl l. conditions would be attached to thu .- train, is secured to mighty scale
 especially arranged to weigh the put
 -.a