New-York tribune., 1903-07-25

cents pound. Nobody knows exactly what these
chaln cables will cost until a bid has been made
toi tleIn' AT the recently constructed Budapest
prldge. which is much smaller and where all con-
oluoh3 are favoring much cheaper prices than are
prevailing at the Manhattan Bridge the chain
cables have cost sa4 a pound 1t is therefore
very improbable that they will cost less for tho
Mammalian Bridge but, even if they could be
erected at 612 cents a pound the total excess of
cost would still be &14S5OO
On the other hand 1t must be borne in mind that
the strength Of the eye-bars was assumed TO be
the same as that Of small test pieces while every
pody Knows that the strength Of large bars is at
least - per cent less. This taken into account n
will require much heavier chains than stated above
All other items will also increase in weight and
cost so that even at 612 cents a pound for the
chain the total excess of will not materially
differ from my first given figure.
In other words The Manhattan Bridge as de-
signed by Mr. Lindenthal without being safer or
carrying larger loads will about So more
than the Williamsburg Bridge has cost"
lhese are appalling figures, but true! They are
Puohshed repeatedly in various scientific papers
and In the daily press but they have never been
cohtradicted or disputed either by Mr. LindenthaI
or by the five experts. Why not? Tbev are cor
rect and every alderman and intelligent citizen
can with the above explanations verify them for
hlmsef If Mr.. Lindenthal and his secretary claim
that the figures not correct let them roirt ont
where they are wrong
Now, viii show how Mr. Iindenthal intends
10 cut doWn thlS enormous cost. He proposes to do
II py cutting down the capacity the safety Of the
prldge- On his own statement, the weight of the
eye-oar chain, designed for the Manhattan
Bridge weighs only $500 pounds a IneaI foot
This means that the ultimate strength of the chain
Is 1O9SO tons, and its elastic limit So 900 tons while
the average tension will be $50 tons; therefore:
l999so = 2a.54O 341 factor Of safety for breaking
5000 = 29540 - 19s factor safety for elastic
Average. 2.67. in place 60. as it ought to be
Therefore, by his own figures. Mr. Lindenthal will
give to the city bridge hardly more than half as
strong as the Williamsburg Bridge and with n
factor Of safety much smaller than that Of the old
Brooklyn Bridge, Basing the calculation how
ever on the correct strength Of eye-bars which IS
p per cent smaller than that stated by Mr.. Lin
oentha the true average factor of safety sinks to
-OS WnlCn every engineer would consider unsafe
Lhese ,. are the clear Facts which every alderman
should bear in mind before he IS trusting the
sioner.
The Tribune of July II publishes also a letter
Commissioner. which purpOrts to be an argune Mt
IN favor Of eye-bars- Every attentive reader will
see that all the statements made by Mr.. Marriott
are without proofs. As fact, nearly all of his
statements are incorrect and based either on ignor
ance or on wllful misrepresentation. as 7 shall
point out in the following:
He says that eye-bsrs are superior TO wire ca bes
because they easier be replaced if injured. No
worse argument than this be found, To re-
place a pin or any bar in the chain which is not
the outside bar is next to impossible.
An eye-bar chain gives rigidity to the
bridge. he claims. Another bad argument. A solid
wire cable Is 19 inches thick, has an in
a chain, hinged every 40 feet, has absolutely
no stiffness Let anybody try steel wire say
one-eighth Of inch thick, watch chain. and
compare it with the chain he is wearing He will