Activate Javascript or update your browser for the full Digital Library experience.
Previous Page
–
Next Page
OCR
The Pennsylvania Steel Company
The Pennsylvania Steel (‘ompany submitted eleven tenders, ten being on
the Board's design and one on an eyebar suspension bridge designed by Mr.
Gustav Lindenthal, of New York. On each of the designs ll, Ill. V, VI, two
tenders were submitted which (littered only in the manner of Hoating in of the
suspended span, the method or erection of the cantilever and anchor arms being
the same in all cases.
mu
are-r
mt
AK IE1 [K
V Ill "I WI ,9
" "vtt‘rtwlt‘vrl-t'A‘lA'i7"‘
‘ ’t-ti-llllllllltttea
-DENNSVLVANIA SYEEL. cowuyws scuzws rut: ERECHDN or ammo: Dtsvmt
Fig. 2
They proposed to start erection on the north shore, where a heavy timber
elevator could be erectttl to deliver the bridge material from the upper to the
lower level (see Fig. 2). On the lower level a yard was to be arranged, served
by a 100-ton gantry and laid out for the storing and handling of material required
for this side. The material lor the south half of the bridge was also to be brought
()6
to the north side and carried by the nortlt gantry crane. as sled by a special
derrick car, to a barge slip, whence the steel would be transferred across the river
on barges. On the south shore, it would be received by a gantry equipment simi-
lar to that installed on the north shore. All machinery
An electric winch was to handle the >L‘0“'s, and a motor to operate
to be operated by
electric power.
the material trucks on the tracks from the gantry yard to the slip.
The first step in the erection of the bridge would be the rnisim: of a steel tower
-16’ ()”><S(l’ 0” and 248’ 6" high behind the main pier. This tower was to be
equipped with lour booms of ‘)0 tons capacity. one operating from each of the
four corners of the tower. The booms were to be fed either directly from the
gantry yard or by a special track leading from the main yard. The derricks
on the tower were to erect the falsework between the pier and AI.1tl, at which
point a temporary steel bent was to be placed on a concrete pier and designed
to act both as a support and an anchorage. The permanent bridge steel, including
the shoe, bottom chords, laterals, etc., up to the level of the bridge lloor, could
then be put in place. When the erection had progressed to this point, the upper
part of the tower was to be disconnected from the lower part at the lloor level, and
skidded along the bridge tloor on special stringers until it was in position directly
over the main pier. The lower part of the tower was then to be taken down and
re-erected on top of the section already in place. On the top of this reconstructed
tower, the booms were to be again erected. the hoisting engines remaining on a
platform at the lloor level.
The tower in thi' ' cond position would erect the pertn.'u1et1t members of the
truss that could be handled within the swing of the booms. Tln-se booms would
then erect the top chord traveller for the erection of the trusses, one for the
anchor arm and one for the cantilever arm. Material was to be supplied to these
travellers by a derrick situated on the bride,e tloor, which connnanded the gantry
yard below.
St: >1-:xn1;o 5l’.tN (‘.xx"1‘1I,tcv15Rtr,I>. After the main altchorages were plac -d
in position, the traveller on the cantilever arm would continue ahead on the sus>
pended span until the whole bridge was completed.
Hlon l-‘I.o.t'rIV<'. liklr "I‘I()X. The suspended span was to be erected on high
steel falsework at. Victoria (iove, about one-hall mile below the bridge site. The
span was to be erected on two falsework towers connected together at the top
by trusses. “'hen the span was fully assembled, these trusses would be lowered
from their top position and connected to the bottom ol the towers, thus acting as
struts between the pontoons and holding them in their proper relative positions.
Two pontoons were proposed, each 252’ 0" X75’ 0” and I3’ 0" deep.
l.ow l-‘t.o.vt‘IN<; lCRIr,t'TIoN. In accordance with this scheme, the suspended
span w s to be erected in the same manner as for high tloating. except that the
span would be erected on low timber falsework. When the span had been con-
pletely assembled the falsework would be removed, allowing the span to rest on
four concrete piers, in which position it would be hnally riveted up. Six scows
three at each end, were proposed for this scheme, each 257' 0" long 38’ 0" wide’
and 10’ 6" deep. ' '