Ladysmith news-budget. [volume] (Ladysmith, Rusk County, Wis.) 1907-1927, 1907-06-06
State News of Interest
TO TEST RAILROAD BRIDGES.
Dean Turneaure of the State Universe
ty Perfects Testing Apparatus.

Dean Turneaure of the State Universe
ty Perfects Testing Apparatus.
Dean F. E. Turneaure of the college
of engineering of the University of
Wisconsin has perfected an instrument
designed to determine and register au-
Geographically the strain on various
parts of railroad bridges as rapidly
moving trains are passing over them.
The apparatus, which was designed by
Dean Turneaure and which was made
in the shop by the university mechani-
clan, was exhibited recently at a meet
ing of the American Railway Engi-
neering and Maintenance of Way as
ISOLATION AS a result of the eXamina
ton of the apparatus and of the sam
pie records obtained geographically
with it, it has been decided to make
ten or twelve of these instruments and
to begin as soon as possible an extern
sive series of observations. A num-
Der of railroads have offered to furnish
facilities in the way of special trains
and necessary assistance for the pros
ecutiOn of the work. The entire eX-
pense of the work is to be met by the
various railroad companies to whom
the results of the investigation will be
of great value. The work, which is in
charge of committee of which Dean
Turneaure is member, will be carried
on by a number of experts, including
several members of the faculty of the
university college of engineering. 1t
is expected that the field work will be
begun during the coming summer and
that a large amount of interesting and
valuable data will be secured.
The Importance of the work lies in
the fact that the strain on the various
parts of bridge when rapidly moving
trains are crossing can be accurately
measured and recorded automatically.
At present the strain to which a
bridge is subjected by high-speed
trains is necessarily largely matter
of estimate or pure guess work, since
engineers are practically without any
experimental data. Since the speed of
train determines from 25 to so per
cent of the total strain caused by the
train load. the Importance of more
exact determination is evident and is
we'll appreciated by bridge engineers.
| The greatest of uncertainty now ex-
| lists in regard to the exact amount of
strain from moving trains. The re-
suits of the use of the newly perfect
| ed testing apparatus will therefore be
of great value to the railroads and of
| interest to the general public.
1t is proposed to carry on expert
ments with ten or twelve of these in
struments attached to various parts OF
a bridge. By means of electrical con
nections simultaneous measurements
and records can be made as the train
crosses the bridge. Loaded trains will
be moved across the bride 10 be tested
at different rates of speed. Beginning
with low speed of from ten to fifteen
miles per hour, records will be taken
up to the maximum speed limit. BY
having a number of instruments re
cording the strain simultaneously g
/ thorough test of an ordinary bridge
can be made in the course of day OF
two with the use of the special trains.
The apparatus, which is known as
an autographs extensometer, is at
tached with a clamp to beam or pro
iecting corner of a bridge This re
cording device is jointed with light
rod to another clamp fastened some
three or four feet distant on the same
beam by means Of a. universal coup
ling. In the interior of the apparatus
is a rod running from the connecting
rod to the short end of lever, where
there is knife-edge bearing. The LONG
! end of the lever is very stiff, and Is
made of aluminium to be as light as
possible. At it's end is pencil to re
cord it's movement on moving strip
of paper. The instrument has been
tried on ten-foot I-beam stringers, I'M
der speeds of thirty or forty miles pei
hour with satisfactory results.-W.