The Cairo bulletin. [volume] (Cairo, Ill.) 1872-1878, 1878-01-24
NOTICE 70 CONTRACTORS.
OFFICE OF CITY CLERK,
Esirn Ills Ian g. fe-9

\
Sealed proposals. will be received at this
office, directed to the city council of Cairo,
Illinois, until O'clock Tuesday evening,
February 9TH, A. ID. 1873, for the Construc-
ton OF one span iron bridge, together
with the approaches or abutmepts and
foundation, across Cache river, about one
and one. ,ali miles from Mound City rail-
road depot, and four miles north OF the city
OF cairo, 10 the counties of Alexander and
Pulaski, state OF Illinois, according 10 the
plans and specifications prepared by John
r. Hely, Esq, &. f., now on file and sub
feet to examination IN this Office, the speci.
fcations of which are a. follows. viz:
Said bridge and trestle work 10 be made
up of eighteen (1s) openings ot eighteen Isl
feet from centre to centre Of p0sIs, and one
span OF one hundred 400 feet across the
river bed.
The one hundred 400 feet span To be Of
iron, and 40 proportional that load OF ten
(l0) tons dist ibuted over twenty (20) lineai
teet at the centre OF the span, shall not
strain the iron over twelve thousand
| ~, UO0) pounds per square inch tensile, or
over seven thousand five hundred q 500
pounds per square inch bhearing strain
the strain In compression TO be IN NJ,
least in tho proportion to the ratio OF
length to diameter, by Gordon's formula.
The span OF said bridge 10 be one hun
dred l0O) feet in the clear and the roadway
twelve (l2) feet wide.
The floor TO be OF white oak plank two
and one-halt ca inches thick and not over
twelve ll2) inches wide.
The floor beams to be OF white oak and In
proportion to the balance Of the one hun.
dIeu (lC0) feet span structure, and also to
be provided with suitable axle guard.
The above to rest upon iron columns pro.
portloned 10 the structure to be supported,
the columns at each end Of the bent or iron
span TO be placed on mud sill !2Xl2, TWEEN.
~ (20) feet long morticed and tenoned TO q
sufficient number Of white oak piles, firm.
" driven into the river bank.
TREsTLE WORK.
The bents to be formed offour posts l0X II
inches square, the two inner parts to stand
perpendicular and the two outer parts To
eight. The cap and sill OF the bents TO be
| twenty (2O) feet long, and the sills to pro-
edge Of the outside posts. The posts to be
morticed and tenoned into the cape and stills
| and each tenon to be pinned with two
| tbree.qusrter ca inch square iron pirs, and
each bent to DO braced by two diagona
braces OF l2X21 inch plank, well lifted ant
spiked on caps, posts and stills.
| The bents to rest or stand pom four mut
stills l2Xl2 inches and eight (s) feet long se
| In the ground and placed on the ahgnmen,
Of the work.
The carriage way OF the strestlework Ia
be sixteen 49, feet wide, the floor plank
70 DO three (3j inches and not over twelve
| az inches wide, and to be well spiked OF
10 the stripgers and floor beams.
The floor beams to be made IN as follows
two (?) stringers of sXl2 inches set on IN,
CAPS and sixteen (lG) feet apart from ont
side to outside. The space between sais
stringers 20 be equsily divided iOr seve,
| "a beams OF 3Xls inches esoh and each ne y,
Of floor beams or spans TO have three tSS All
OF clearinghouse bridging Of .X4 inch scsnt
| ipg.
The striurers and floor he,ms IN roo, q
least liz 10y inches on The CAPS. :" ''''
The stringsrs 70 connect nv half ;o,nt
and 20 DO fastened TO the cans hy one incj