New-York tribune., 1908-11-06
BRIDGE CANNOT BE FIN
ISHED AS PLANNED.
Boiler & Hodge and Professor Burr
Agree Dead Load Is ErcessiUe-
Must Cut Traffic Facilities.


employed by the Bridge Commissioner TO make
an investigation, concur in the statement that
the structure would be dangerously overstrained
If completed and equipped for traffic in accord
ance with the terms of the contraction erection.
This joint admission of both investigators estab-
fishes the truth of the charge made in The Trib-
une five months ago that the structure was
being dangerously overloaded.
The only way in which the bridge can be
made safe for public use without reconstruc-
ton, according to the report Of Messrs Boiler
& Hodge, is by a change in the plans for COM
pletion to remove part of the weight of the
structure itself and by great reduction in the
traffic facilities provided for IN the contract
specifications. This reduction in traffic facili-
ties comprises the abandonment of all four ele
waited railway tracks which the bridge was TO
carry under the terms of the contract. the
fining Of all traffic to the four trolley tracks
with the traffic spaced at least one fun car
length apart, and considerable reduction in
the live load allowances called for in the con-
tract for the roadway. the four trolley tracks
and the foot passenger walks.
The report of Professor Burr admits that for
the present the Of all four elevated railway
tracks should be deferred and states that mas
much as there are no elevated railway connec-
tions at the Queens end of the bridge and no
immediate prospect of such connections the
bridge will not be required to carry any elevated
railway traffic for some indefinite period after
its completion
MUST REDUCE DEAD LOAD.
Professor Burr recommends. however, a
further reduction in dead load. OF weight of the
structure itself. beyond that advised by Messrs-
Boiler & Hodge IN the belief that. with con-
siderable increase in the unit stresses beyond
those deemed prudent by the other investigators
and corresponding reduction in the factor of
safety regarded as necessary in their report the
traffic facilities can be later increased by two
elevated tracks when such facilities are re-
qutred.
The report of Messrs. Boiler & Hodge rec
orInends that the bridge be opened for public
use with reduced traffic facilities as soon as it
can be got ready. The traffic Facilities which
the report states the structure can be made to
carry safely are:
The 35-foot wide roadway for vehcuIar traf-
ic with a maximum live load 90 per cent less
than the maximum live load specified in the
contract specifications.
Two 11-foot wide passenger walks with a
maximum live load 25 per cent less than the
maximum live load specified in the contract
specifications
-Four trolley tracks with maximum live load
so per cent less than the maximum live load
specified in the contract specifcati tions. secured
by proposed regulation of trolley traffic which
tween each car of at least one fun car length
or eighty feet from centre to centre
This schedule Of traffic facilities which the
report states the bridge can be made to carry
safely excludes all provisions for running ele-
waited cars over the structure upon any one Of
the four lines of track designed for that traffic
The report emphaticaIly and specifically
states that before the bridge be safely
equipped with even the restricted traffic facili-
ties enumerated the dead weight must be re-
duced by 1000 pounds per lineal foot OF the
bridge II is proposed to secure this reduction
in the weight of the structure itself by:
The removal of the steel stringers in place
upon the bridge upon which It was proposed to
Law the tracks for the inside pair Of elevated
lines upon the upper floor or deck.
The permanent retention of the two passen-
ger walks upon the upper floor, where they are
at present located, laid upon the stringers for
the second pair of elevated tracks. In the
contract it was specified that these passenger
walks should be laid upon two overhapging
balconies attached to the outside Of the trusses
Of the bridge Many months ago, when the
officials Of the bridge department found that
+ra bridge was largely exceeding the estimated
,,-eieh+ il was decided TO alter this plan and
for the present lay the two passenger walks
,,r,on the stringers for the second pair OF ele-
,-a+a7 railway tracks with the idea that later,
,-ba, the second pair of elevated tracks were
needed. the passenger walks could be moved
ont Upon the balconies where they were in
tended to 20 under the terms o. the contract
specifications The recommendation in the re-
mort is that the entire provision FOR one pair OF
elevated tracks be removed altogether and that
-ba nrovision and location planned for the sec
o,d nair be permanently used for passenger
walks.
two oh
p, sac,,re reduction in dead load. by the weight
of tho s+r3ngers for the two inside elevated
+r.o,s and the portion Of the ironwOrk not al
ready i place for the overhanging balconies
,,non which 1t was intended ultimately to lay
the two ,7assenger walks, the report makes some
startling reductions in the live load specified in
tho contract which show that great effort has
baan made by the experts TO allow the bridge
every pound of live load It can safely carry.
LIVE LOAD CUT 30 p CENT.
The contract specifies that the roadway for
,-sbic,,lar traffic shall be capable Of safely car
wing q maximum live load OF one hundred
ro,,,ds square foot. This allow ance for max
t,,-, live load IS cut down by the report 10
ef+v hounds 4 square foot, which allowance is /
declare, 70 he within fair margin of safety.
The contract calls for a maximum live load
allowance OF So enty-hve pounds square foot
for the two passenger walks. This requirement
,s also cut down in the report To fifty pounds
square foot
The contract stipulates maximum live load
,uousnce for the four trolley tracks of 1,GOo
mounds a linea foot of bridge for each track.
The report states that the heaviest trolley cars
,,ead IN the city-those that run in Broadway
weigh only 1.460 pounds each. and the maxi
mum live load for trolley tracks Is cut down TO
! $50 pounds a lineaI foot of bridge for each