Rock Island Argus. (Rock Island, Ill.) 1893-1920, 1900-01-16
FIGURES ON BRIDGE.
Crescent One of the Largest
Structures Across the Father
of Waters.
IT IS OPERATED BY ELECTRICITY

Especially Constructed for Big Engines
and Heavy Traffic 2,2OO Feet of River
Spanned-Longest Span Has Total
Weight of I.O39.o9I POunds-An Inter
esting Description.
There are three principal articles in
! the latest mum Der of the Engineering
News. the foremost journal of its kind
printed in this country. One of them
relates TO the Crescent bridge of this
city, the fourth bridge, in order. to
be erected between the Rock Island
and the Davenport shores of the
Mississippi. The article is of ex-
tended length. It fills more than
three pages of the large journal in
question, and detailed working draw
ings of n number of essentially inter-
esting features of the bridge fill, in
addition, a detached double sheet.
There are other working drawings
and illustrations scattered all through
the article. The information con-
| tanned in the article is from strictly
official sources and measurements,
and it is therefore reliable. These
are items of fact in relation to the
new bridge from the article:
The river proper at the site of the
bridge is about ?, 200 feet wide. The
slough at the west end of Davenport
is about 600 feet wide, and the island
between it and the river about half
that width. The draw span of the
bridge was located by The war de-
partment GOO feet from the Rock ISL
and shore. Tne total length of the
bridge proper is 2,3O7 feet. Begin
ming at the Rock Island or southern
end, there are three spans of 200 feet
each, laid on the curve that consti-
tuteS the Illinois half of the crescent.
Then comes the draw span, 442 feet,
covering three piers. After it comes
long span of 800 feet, then three of
500 feet each, which carries the struc-
turc to the shore Of the island. These
spans make the total length just
stated.
But the bridge proper is not nearly
all the bridge work there is in the
Crescent system. At the Rock Island
end there is 21S feet of skew girder
span structure, crossing the two coal
tracks of the Rock Island IL Peoria
road and Seventh street OF this city.
This is divided into NUM- Der of short
spans. running from 30 to 30 feet in
length.
Trestle Work.
At the Davenport end there is n So
foot approach girder, as the bridge
strikes the island. There is, after
this, $50 feet of trcstle, white oak pill
ing. well secured, crossing the island.
The slough is crossed by seven deck
plate girder spans of - feet each, or 5O4
feet in all. After this comes more
pile trestle, on the Davenport main
land, before solid Iowa soil at grade is
reached; go feet of it. The aggre-
gate is +, 155 feet of bridge construc-
ton, first and last.
A sheer boom 1000 feet long is
atloat along the the Illinois end of the
draw, for the protection Of navigation
interests.
The largest fixed span has total
weight of 1853, O9G pounds. The
three 3O0-foot fixed spans weigh,
in the aggregate, 2,277,314 pounds;
the three 200-foot spans weigh. in the
aggregate, 1,239, 6o5 pounds, and the
big draw span weighs HOO, 57I
pounds, inclusive of its operating
machinery, but exclusive of ties, rails,
or planking, or wiring. 5,906, Gel
pounds, or, roundly, 5000 tons.
Turned by Electric Motors.