The daily Gate City and constitution-Democrat. (Keokuk, Iowa) 1916-1922, 1916-07-24

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Made at Niagara Falls, N. Y.
is turned. The room on the second
floor contains the controllers, switch
board, clutch levers and mechanical
indicators for the end lifts and will
be used for operating the bridge
with electrical power. The first
floor contains the gas tank, the water
tank, hot water heating plant and
the gas engine. No interlocking plant
Is provided. w.
Because the channel Of the river
is bare rock is was considered u1-
safe to transmit the electrical power
by means of marine cable. The
current is carried by wire to pole
mounted over the top of the tower
and which carries the cross arm
which supports telephone and tele-
graph wires carried across the bridge.
This pole consists of two pipes, an
S-inch extra heavy pipe on the out
side which is held in position by the
cross arm and the wires, and 2k-
Inch pipe on the inside which turns
with the bridge. A drum at the top
of the pole contains collector rings
for transferring the current to the
swing span.
FaIsework and Erection.
Owing to the fact that the river
has rock bottom, piles could not
be driven and the falsework consist
ed of frame bents of six posts each,
arranged in pairs to form towers, the
longitudinal and transverse bracings
being carried as low as the water
level permitted. For falsework string
ers, temporary use was made OF floor
beams from the old spans and string
ers from the new spans, the string
ers for the 2541s foot spans. being
used in the erection Of the eight
shorter spans.
Because the new highway deck
could not be placed In service until
all the new spans were erected, 1t
was necessary to maintain the high
Fway on the lower deck until the new
bridge was entirely completed. The
plans for the erection were there
fore perfected with this in mind.
The old trusses were dismantled,
leaving the old floor system in place,
the oxy-acetylene torch being used
extensively in removing the old ma
teriaI. Because of the loose-pointed
nature of the old trusses it was
necessary to guy them thoroughly as
soon as they were placed on false
work and any members were remoy-
ed. After the old trusses were out
Of the way, the old floor was replaced
by the new floor, panel by panel, and
the old floor beams and stringers
were taken out, depending upon the
continuity OF the old track rails to
carry the highway deck until the
panel of the new floor system was
put in place. Owing to a difference
in length in the old and new panels,
the old stringers were cut off each
time and blocked as required to fit
I'D against the last new floor beam
set.
The erection was started in July,
1915, beginning with enough false
work to carry the two spans at the
east end of the bridge the falsework
was used over and over as the work
progressed, about rs per cent of ad-
ditional falsework material being
provided later. The short spans
were completed by January Z, 1916
The erection of the draw span was
started on November %, 1915, and
completed about March 1, 1915.
Owing to a delay in the delivery OF
the drum the trusses were erected
except for the towers before the drum
arrived. The bottom chords were
lacked u inch above the final posi-
ton and the threads, rollers and the
drum in four sections were slipped
under the trusses. The four tower
posts were not erected until after
the drum was in place to provide
room. for swinging out the boom OF
the derrick car while the drum sec
lions were being erected. After the
drum and its radial braces were
completely assembled, the drum was
rotated on the rollers until the holes
in the top flanges of the drum regis
tered with those in the bottom chord
of the trusses, thus permitting the
connection of the drum to the trusses.
The erection of the westerly 25412
foot span followed that of the draw
snan but when the falsework for the
easterly 2541s foot span was to be
nlaced high water made 1t necessary
to stop the work on January 20. the
stage of the river continued hlgh
and work could not be resumed until
May 81.
The new bridge was designed by
Ralph Modjeski, consulting engineer,
Chicago, who was represented at the
bridge by G. G. Hinckey, residene
engineer. The Strobel Steele Con
strllction company, chicago, had the
onntract for the entire new bridge
inclnding alterations to the sub
structure.
A Fatal Sunday.
NEW YORK. July 24.-Speedlng