The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1900-07-29
TESTS OF TRAIN LOADS.
Resistance Discussed Before North
west Railway Club.


''Some Notes on Train Resistance" was
the topic of an interesting, though some
what technical, paper read by T. L.. Dan
iel, of the state university, at a recent
meeting of the Northwest Railway club.
He said:
The Lake Shore G. Michigan Southern
railroad, in 1873 figured that $7S5 900 a.
year could be saved by reducing train re-
sistance 25 per cent, but in spite Of the
incentive to effort in this direction train
resistances are the same today they We're
then
1t seems as though a reduction Of Is
per cent were easily within the range
of probability. inasmuch as Wellington
has shown that reduction of IS per
cent. in axle friction could be made by
substituting oil bath fabrication In place
OF the common pad fabrication now In
use, and when it is considered that axle
friction constitutes by far the largest
part OF train resistance and that there
Is further chance for It's reduction by
changing bearing metals, proportion of
journals and quaffty of lubricant, 1t is
seen that there is opportunity for con-
siderable improvement. to say nothing of
the saving that might be made in the
1mperfectly understood rolling friction.
tonnage ratings could be made much
more accurately with better knowledge
OF the factors composing train resistance
Tor knowledge of the factors as well
as the sum total is essential as can be
seen from the following: The proceedings
" It y
1SOO. cite an instance where a rise in
temperature lowered the resistance "a per
cent. and the G.. 3. & Q. railroad tests
snow that arstrong~ side wind increases
lne resistance 60 per cent. The above
number of the proceedings of the West
ern Railway. club also records an in
stance where a train of empty cars
pulled harder than train of loaded
cars by q per cent per ton, and these fac
tors l. e., empty cars, temperature and
VINO VINO nave received so little attention
tnat they nave never been ineorpora fed
IN the common formulas for train 70
slStance. Obviously, a better under
STANDING or these would result In a much
more satisfactory tonnage rating.
:, 1raln resistance is generally expressed
IN pounds OF draw-bar4 pull per ton of
weight hauled on straight and level
track; It amounts to about six pounds al
ten mics per hour and sixteen pounds
at sixty miles per hour; it is seen to in.
crease with the speed, which is in ac-
cordance with the well known exoeri-
| mental laws of friction. In colder and
windy weather the few isolated observa.
tons that have been made indicate tha,
the resistance would be larger. and
many other changes besides that Of We
Iocity might be imposed affecting the
result, but unfortunately experiments
have been restricted almost entirely In
velocity variation
The condition OF bearings. condition
and size of wheels. condition of rails
ana roadbed also affect the result. to-
az cars. velocity. grades. acceleration
air friction and curva ture of track
Inc resistance due to curvature de-
pends on It's compensation. elevation OF
outer rail: kiHd of coupIers. whether
rigid or flexible head. length of wheel
base. and probably upon the kind Of
trucks used
The increased resistance due to curva-