The New York herald., 1922-07-29
Made Safe by Distribution
Of Load and Should Last
Forty Years, He Says.
EXPERT VIEWS DIFFER
Outside Engineers Say Defect
Should Not Make Rebuild
ing Necessary.

The discovery that two of the giant
main cables supporting the old Brook
lyn Bridge had slipped in their sad
dies atop Of the bridge tower on the
Manhattan side caused. the Depart
ment of Plant and Structures to move
formally yesterday for the reconstruc-
ton of the old structure and also fo.
the building OF an additional bridge
across the East River.
Commissioner Grover A. Whalen de-
clared that there was not tho slight
est cause for alarm. With the Danish
ing of motor traffic effective on June
IL last and with proper maintenance.
he said. the bridge not only is perfect
ly safe but probably will continue to
serve another forty years.
Commissioner Whalen said that his
order of June Is banishing motor tras-
fic was the result of the discovery by
inspectors and engineers who con-
tinually maintain surveillance of the
bridge. They found that the. north
ernmost Of the four supporting main
cables. at the point where it passes
over the saddle on the Manhattan
tower. had slipped from its true posi-
ton longitudinally toward the center
of the river, distance of about 1N
inches. 1t is known as Cable A.
Caused by Uneven stress.
-ot t.. s1t> -
mated Cable B. was found to'siave slipped
in the saddle only half an inch. while
Cables c and D. toward the southerly side
of the tower showed no perceptible
divergence. The engineers deduced that
the slipping had been caused probably
by some uneven stress. due perhaps to
the passing Of a heavy truck at the
same moment with heavily loaded cleo
trio trains. The saddles rest upon rollers
and are supposed to show a certain
amount of motion as the stresses vary.
but the slipping of two cables in their
saddles is not normal occurrence.
Commissioney whalen said yesterday
that railroad officials are cooperating
by keeping trains from crossing the
bridge at closer intervals than i20 feet
Mr.. Whalen, commenting upon reports
In some afternoon papers. emphatically
denied that there had been any stretch
ing of the cables. There Is no intention
of closing the bridge to traffic. which,
the Commissioner said. would he the
first step II there were the slightest
danger in keeping II open to the public.
He feels, however. that the time has
come to have the bridge replaced. He
wrote Mayor Hylan yesterday that the
four main cables cannot be reinforced
or replaced unless the bridge Is rebuilt"
In his letter he says:
whalen writes tn Mayor.
ION May "a. 1923. the Brooklyn
Bridge will have arrived at the age of
10 years. During these twoscore years
of useful Afe the Brooklyn Bridge has
carried burden for which 1t was never
designed. At the time Of the opening
OF the Brooklyn Bridge eight and ten
ton motor trucks were never dreamed Of.
However. the evolution from the horse
drawn vehicle to the motor driven
vehicle has been SO rapid that the de-
signers of the Brooklyn Bridge could
not possibly have anticipated 1t, and
therefore made no provisions for the In
creased load which this bridge was COM
pelled to bear up to June Is, 1922.
with this new method of transporta-
tion came tremendous increase in the
load unit. There was also added to this
increased weight of trolley cars, in
creased weight of elevated cars. and in
creased weight OF subway cars. All
these elements Of weight factor have
been daily calling upon the main cables
of the Brooklyn Bridge for increased
carrying capacity.
THE four cables that support the
Brooklyn Bridge are made of galvanized
steel wires and in each cable there are
5,296 wires. For almost forty years
these cables have been called upon to
carry not only the dead load of the
bridge itself. but also the live load, such
as vehicles of all types. elevated and
trolley cars passengers, &c.
1T is not my purpose In this COM
munication to in any way call the atten-
tion of the public to the condition Of the
Brooklyn Bridge. except, In this respect.
that the engineers of this department
report the Brooklyn Bridge In absolutely
safe condition. However, the age of the
bridge Is such that II is deemed advis-
able that the load which the bridge Is
compelled to- carry be properly spaced
at all times.
Must Distribute Load.
'It Is most essential that the active
load factor on this bridge be properly
distributed. This. OF course. will seri-
ously affect the efficiency OF the Brook
lyn Bridge. This means that the Brook
lyn Bridge can no longer be considered
In connection with any additional inter-
borough motor vehicle traffic that the
constant increase in population will pro-
duce.
THE Manhattan Bridge In few years
will not be adequate to accommodate the
motor vehicle II this character OF traffic
continues to increase at the same rate