The Cairo bulletin. (Cairo, Ill.) 1???-1928, 1911-11-12
Wa. Built By, Day Labor At co,'
OF More Than Half
~" 3N ~ " '.'-t4
Million

Spokane, Wash. Nov. 70 Nation
al, state and municipal officials, en-
ginecrs OF prominence In America
and Europe and visitors from many
cities and towns in the Northwest
will join residents of Spokane in
the dedicatory exercises and public
celebrations incident to the formal
opening of the Montrose-steel bridge,
y November % to 80. The structure,
which Is of concrete, partly reinforc-
ed, with a center arch of 2S1 feet,
the largest of its kind In the world,
was built by day labor at a cost of
$500, 900. Business property, valued
at more than 100000. was re
claimed by the city at the south a.
butment, which iswithin four blocks
OF the banking center.
The structure was designed by
] C.. Ralston. NJ. Anne. SO c. e., for
Iferly head of the city engineering
department, and built under the SUI
i pervision of Morton MacCartney, city
engineer. 1t replaces a street bridge
+ of 1900 feet, consisting of can't
! lever main span, approached by truss
Rpans and trestIe which proved
too light for street car and other
I heavy traffic after II years use.
The new bridge crosses the Spo-
kane river at the lower end of the
falls where the drop in series OF
cataracts is 1876 feet within length
of 1900 feet. The river has food
flow ar 10000 second feet and 1000
second feet low water flow The
downtown streets on both sides OF
the river are more than 10 feet
above high water at the crest of the
falls, but within four blocks 1t drops
into a gorge $40 feet in depth ano
$500 feet in width at IT'S top The
structure is 791 feet i'm length with
a so foot roadway, the difference be-
tween It and the old bridge being
made up by an earth fill. requiring
more than 100000 cubic yards OF
material, furnished from the deck OF
the old span and downtown excava-
tions
Has Double Car Tracks
The new structure carries double
track electric car line and highway
and has two 9-foot cantilevered side
walks 1t consists of a, middle seq
\ mental span of 2Sl fleet, two 49,
afoot .samicircular spans, lOo-foot
semicircular span, a. retaining wall
1913 feet in length With maximum
height, Of. SO feet. 8The main arches
are not reinforced but others are
either, of concrete reinforced with
rods and wire mesh or OF structural
steel encased In concrete.
The main arch has an intrados on
on u 141.23-foot radius and 1f5-foo,
rise 1t is of twiif-rib construction
each being 6.75, feet In depth and 1f
feet in width at the crown and 49,
4 feet deep and 20 feet wide at the
4 spring. with 36lfootspaeing be-
3 tween center ribs. The arches are
Y surmounted with solid spandre
walls, spanned by semicirculal
\ arches of 20 feet 5ts inches up te
the four middle PANELS, which are
sub-divided by smaller walls.
The spandrel walls are spannet
transversely all the way across the
structure by fioor-beams made up Of
concrete encased I-beams, 21-inche.
built-up beams across the two centel
spandrels for the street railway sup
port and 12-inch 1beams for the
roadway. The food-beams are longi
tudinally connected by similarly con
structed stringers. making regular
rectangular noor-supporting system
upon witch the reinforced concret,
!. fioorsSlab rests
The south abutment, which forms