The Minneapolis journal. [volume] (Minneapolis, Minn.) 1888-1939, 1903-06-15
The LIFE OF A RAIL
It Depends Greatly on the Number
Of Curves in the Road and
Their Sharpness.
What Is Done When Defective
Rail Is Discovered in the
Line.
Parsons Weekly.


question which Is often asked. 1T is also
a matter which receives careful attention
at the hands of railway. engineers. For
1t affects very closely the safety of the
and the pockets of their share
holders. On most railways the rails are
carefully tested each year at certain
definite points, and the record compared
with that Of the previous year. These
results are tabulated and kept for the In
formation Of the engineer.
The testing is carried out either by
measurement or weighing. In the one
case special instrument registering to
LOO Of an inch Is used, and in the other
the rail Is taken out and weighed upon a
steelyard slung from tripod. The Sec
tion Of the rail and the traffic passing over
1T are the two dominant factors affecting
the life Of a rail. BY the term Section"
is meant the weight Of the rail per lineal
yard.
Attic there Is no recognized standard
minimum, it would be generally conceded
that rail Of less section than Is pounds
per yard is not safe for main line traffic
on busy railway. And so we find that
railway engineers are now using metals
of a much heavier section than those in
general use a decade or two ago.
On some railways rails so heavy as
100 pounds per yard have been laid down,
but these are not in general favor. Rails
weighing 85 pounds per yard are more
generally used than any other, and these
are found to be quite heavy enough for
ten or twelve men to move about with
that celebrity which is always necessary
when doing work which affects a running
road on our busy railways.
There are, however, many miles of 80
pound section rails still In use.
When some such rails laid down on a
certain railway in 1879 were tested last
year, none were found to have lost In
weight more than pounds per yard
Notwithstanding the fact that this SEQ
ton of line had over it a fairly heavy
mineral traffic.
On one Of our leading railways, in the
year 1882, some miles of s5-pound section
rails were laid down, and last years test
showed they had worn not quite 2 pounds
per yard.
If the traffic over this line should not
increase-and there are now 100 trains
passing up and down over it in the "a
hours-the rails will at least wear fol-
another fifty or sixty years before being
reduced to the 75-pound minimun-whicI
would bring them to the ripe old age Of
80 years!
Even then they would not be worn out
Put In refuge shunting siding they
would be good for another half century.
The life of a rail will vary with its
situation. On a. straight road between
stations the rails sustain very little fric.
ton from the wheels running over them
and in such places will last the longest.
The rails in curves will not wear Sc
long, as both the strain and friction are
greater. The "outside" rail Of cury,
has to be raised up higher than the 'in
side" rail, and this super elevation," a.
it is termed, will vary from one inch t,
SIX inches, In accordance with the sharp
ness OF the curve and the speed required
of the trains passing over it.
The tendency of an engine is, Of course
to run In straight line, and the QUITE
were, to lead the engine round.
Consequently the inner edge of the higl
rail gets an abnormal amount Of friction
While the lower rail receives a create
proportion of weight
It Is, however, between the platforms O
a station that the rail suffers most, b,
the constant brake action of stopping
trains. This can be readily understood
when one considers the enormous frtc
ton produced by a train sliding into
station at the rate Of ten or fifteen mile
an hour, with all its wheels braked, I,
such q position an S5-pound section raj
will be worn out, for main line purposes
IN about twenty years.
There is always small percentage o
faulty rails sent out by the manufac
turers, the fault being such that canno
be discovered until after the rail ha,
been in wear for zEme time.
In rolling, small blob or blister ma,
be formed under the skim of the rail
or a rail may be turned out a. little to-
soft" in its temper.
After being run upon for two or thre
years-som etimes a much longer perio,
than this will elapse before the faul
shows-a bad place will appear in tn
rail. The skin will crack and become in
denied, or a small piece of metal ma,
come off. This makes the rail unfit 70
main line traffic, and it has to be re
placed.
In order to obtain rails of the same age
so that a good and even juncture NAV b
made with the rail at either end ,
length OF new rails is generally laid dow
somewhere on the same section of rail
way, and the faulty rails replaced wit
those taken up.