The Cairo bulletin. [volume] (Cairo, Ill.) 1872-1878, 1878-01-22
NOTICE TO CONTRACTORS.
OFFICE OF CITY CLERK,
Cairo, Ill.,, Jan. Q, 1873.

Cairo, Ill.,, Jan. y, 1873.
Sealed proposals will be received at this
Office, directed to the city council of CAIRO,
Illinois, until o'clock Tuesday evening,
February 10th. A. ID. 1878, for the construc-
ton OF q one span iron bridge, together
with The approaches or abutments and
foundation, across Cache river, about one
and 0ne-iali miles from Mound City rail-
road depot, and four miles north Of the city
Of Cairo, In the counties Of Alexander and
Pulaski, state OF Illinois, according TO the
plans and specifications prepared by John
=. Hely, Esq, q. h., now on Tile and sub
ject TO examination In this office, the speci.
ticatiOns OF which are rs follows, viz:
Said bridge and trestle work 10 be made
up OF eighteen Qs) openings OF eighteen uS)
feet from centre TO centre OF posts, and one
span OF one hundred 900 feet across the
river bed.
The one hundred (l00) feet span to be OF
iron, and 80 proportioned that's load OF ten
(l0) tons distributed over twenty (10) lineal
feet at the centre OF the span, shall not
strain the iron over twelve thousand
~, Vc0) pounds per square inch tensile, or
over seven thousand five hundred & bnO)
pounds per square inch thearing strain
the strain In compression to be in at,
least In the proportion to the ratio OF
length to diameter, by Gordon's formula.
The span OF said bridge TO be one hun
dred Q0O) feet in the clear and the roadway
twelve Q2) feet wide.
The floor to BIO OF white oak plank two
and one.half CA inches thick and not over
twelve u2) inches wide.
The floor beams to BIO OF white oak and In
proportion to the balance OF the one hun.
dfeu QG0) feet span structure, and also 10
be provided with suitable axle guard.
The above to rest upon iron columns pro.
portioned 10 the structure to be supported,
the columns al each end OF the bent or iron
span TO be placed on mud sill l2Xl2, twen-
~ COY feet long mOrtced and tenoned to
sufficient number OF white oak piles, firm.
ly driven into the river bank.
1REsTLE WORK.
The bents to be formed offour posts 1OXln
inches square, the two inner parts to stand
perpendicular and the two outer parts to
be framed and stand at batter Of one in
eight. The cap and sill OF the bsnts to be
l2Xl2 inch square TIMBER the caps to be
twenty (2O) feet long, and the stills 10 pro-
ject on each end two feet past the outer
edge Of the outside posts. The posts to be
mOrticed and tenOned into the caps and stills,
and each tenor to be pinned with two
tbree-quarter ~ inch square iron pirs, and
each bent to be braced by two diagonal
braces OF l2N.l inch plank, well lifted and
spiked on caps, posts and stills.
The bents to rest or stand upon four mud
stills l2X12 inches and eight 10y feet long set
In the ground and placed on the alignment
Of the work.
The carriage way Of the ,trcstlework to
be sixteen tl6) feet wide, the floor plank
10 be three CD inches and not over twelve
III? inches wide, and to be well spiked on
to the strtDgers and floor beams.
The loor beams to he made up as follows:
TWO ~ stringers Of SXl2 inches set on the
caps aud sixteen (l6) feet apart from Out.
| side TO outside. The space between said
stringers to be equally divided for seven
| (D beams Of aka inches each, and each set
OF floor beams or spans to have three (a) sets
o. herfingbone bridging OF 2X4 inch scsnt-
ling.
The stringers and floor beams to rest at
least six 80 inches on The caps.
Inc etringors to connect by half JOINTS
| anu to be fastened to the caps by one inch
round spikes or bolts eighteen (ls) inches
long.
A railiog or ballssters four az feet high
to be constructed on each side Of above dis.
cribed trestlew0rk. The posts to be Axe
Inch clees and brsced on the caps and fasten.
cd on TO the striDgers by two (2) one.half
inch bolts. The parts TO be six Coy feet
apart; the hand rail AKA inches, and an
axle guard Of aka inches, al well fastened
on TO the posts.
Or burr oak Of best qua lily, and
the WORK u0ne In thorough and work
mAnliIe manner, and under the supervision
OF such person % the committee on streets,
l the rffv eon0nfi NJ thA NJ ne N.t -