Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1909-03-25
TESTING sTRUCT-
URAL MATERIALS.
Largest Machine in the World for
this Purpose to he Erected In
Islttsburg, Pa.

PttSburR, "a.
Tho largest machine in the world for
testing the strength OF structural ma
terials used in great buildings and en-
gineering works IL about to be erected
by the United States government at the
geological survey testing station. Pitts
burg. Pa. II will weigh more than ao0
tons and will tower in the air TO an ex-
treme height OF about eighty feet above
the foundations. II will exert a maxi
mum pressure OF ten million pounds.
which is equivalent to placing load OF
5000 tons upon tho beam or column to
be tested
This great machine will! be housed in a
structure 100 feet in height and OF un-
usual strength to which the testing ap-
paratus will be secured by great rod. in
order TO brace II against any sudden
pressure while the columns are under
going the strain upon them. Elevators
will run to the top Of the machine so
that the experts may examine the col
umns being tested from any point Of
View to dctcc, the first signs Of weaken
ing.
When the Quebec bridge collapsed with
great loss of life. general comment was
\
lack of knowledge concerning the
strength Of great columns used in such
structure and plea was made that a
testing machine Of sufficient strength
be erected so that the engineers may
have accurate data as to the amount Of
load such bridge should carry. with
the construction Of this machine It will
be possible to test steel columns one
49,
used in any bridge This will be de-
cided gain 20 the engineering world
which has been anxiously awaiting the
construction of such machine.
However. this il not the primary pur-
pose ~ this powerful testing apparatus
MIR. Joseph A. Holmes, expert in charge
Of the techroloRic branch United States
geological survey, under whose general
direction the Investigations are to be
conducted. said to-day: This machine
was acquired for the purpose OF testing
the strength Of large blocks OF stone
columns OF concrete and brick used in
the building and construction work OF
the government. The federal government
is the IL rrest builder In the world. and IL
is essential. n the money Il to be ex-
pended wisely. that there be complete
knowledge Of the strength Of the ma
tcrials used. The building and engineer
ing construction work Will require dur
ing the present and the next few years
more than s-oOo0Ct0 per unnum. II en-.
braces the most important and far.
reaching engineering work undertaken
by any government at any time and q
program OF public buildings costing from
81, OO0 0n to sI5 600 yearly.
THE testing IN this machine Of the
stone. concrete ana brick columns Will
determine the relative safety. adaptable
ity and durability OF these materials
and how the quantity Of each materia
used may be safely diminished thus re-.
ducing the cost OF the construction work
I'm tho past It has been necessary tc
determine the strength Of large column,
on the assumption Of the values obtain
ed from testing smaller columns, In the
case OF stone. the small pieces tested
were without the usual quarricd effects
and seams which are 10 be found ir
large pieces Of stone. and such tests a
have been made show that the strength
of the stone decreases as the size OF th'
stone increases. In the erection OF large
buildings the strength OF these column'
Becomes very important matter and
Is absolutely necessary that there be &C
curate data MS to the strength which
may be expected from these material
when used In larger masses,
In the rapid development OF thi
country the enormous locomotives o
constantly increasing size and the heav
Ter tonnage have demanded a constan
increase In the size Of bridges. will
builtup structural members OF sue
size that we have been unable to keel
pace with experimental data to serv
as guide for such structures. As n re-
suit. to-day We have practically NJ
knowledge OF the strength OF thes
structures from actual tests and mus
base our information on the tests o
very much smaller members. Bridge
such as that which collapsed at Quebec