The Cairo bulletin. [volume] (Cairo, Ill.) 1872-1878, 1878-01-11
NOTICE. TO CONTRACTORS.
OFFICE OF CITY CLERK, I
i.lru IA. Ian z 1879

J
Stalled proposals will be received at this
Office, directed 10 the city eounclio of Caro-,
Limos, until 3 O'Clock TUESDAY evening,
February lOth. A. u. 1878, ioy The construc-
tion OF 4 one span iron bridge, together
with The approscnes or abutment7 anu
foundation, across Cache river, ABOUT one
and one al miles from Mound cary rsi-
rosd uepOl, and four miles north o. tue city
OF Cairo, III the counties Of Aiexsnder and
Pula. hi, state OF Limos, accorclng 20 me
plans and speclii 'ations prepared ny John
i. Hely, Esq, Y, b., now on Tie aud -uO-
jecEto examination IN this Office, toe speci-
ucatiOus Of which are ~ follows, VIZ:
Said bridge 4nd trestie work o he made
up OF eighteen u.s. openings OF eight en- 49,
feet from centre 10 ceuire oi 20 l., snd. one
span OF one hun 1red lly0J feet across the
river bed.
Tue one hundred 600 feet span tn be Of
IRON, and 50 prOpOrtloued that u load OF ten
40 tons dist lbuted over twenty (g0) linea
teet at the centre OF the span, shall not
strain the iron over Twelve thousand
~ 900 pounds per square inch tensile, OF
over seven thousand I'VE hundred Il jN0J
pOunos per square lnch sheariDg strain
the strain IN compression 10 be IN AZ,
least in the proportion 70 the ratio OF
length TO diameter, by Gord0n's formula
the span OF said bridge TO be one hun
deed (lUg) feet In the clearand the roadway
twelve ny feet wide.
The floor 10 be OF white oak plank two
and obe-hali (2lj inches thick ana not over
twelve (l2) inches vide
The floor beams to be OF white oak and in
proportion TO the balance OF the one hun.
die = 400 feet span structure, and also TO
be provided vita u suitable axle guard,
The above 10 rest upon iron columns pro.
p1rtioned 10 the structure to be supported,
the columns at each end Of the bent or iron
span to be placed on a mud iii i2Xl2, tween.
~ (20J feet long morticed aud teuoned n n
sufficient number Of waite OAK pies. firm.
ly driven into the river bank.
1REsTLE WORK.
The bents TO be formed oiiOur posts 10Xi'
inches square, the TWO inner parts 10 stand
perpendicular and the Two outer parts to
DO framed and stand at a batter OF one in
eight. The cap and Fill OF the bents to be
l2Nl2 inca square timber, tie caps TO be
twenty (2Jl feet long, and the stills to pro-
jet on each end two feet pasi the outer
euge OF the outside posts. The posts to be
morliced gndtenone into the caps and stills,
| and each tenor 10 be pinned with two
spiVS-pu1t 'V' w hCh Hrulic llVu HlLr, hDn
each bent TO be breced by two diagonal
braces OF l2H21 inch plank, well little and
| spiked on caps, posts and slls.
The bents 10 rect or stand upon four mud
siis l2Al2 Inches and eight Isl feet long se,
In the ground and placed on Inc alignment
| Of the work.
The carriage way Of the :tres,lework to
DesiHteen (lp feet wide, the door plank
10 DC tbiee ljl inches and not over twelve
y. ihches vide, and TO be well spiked on
10 the slrlDgefs and floor beams.
| The floor beams 70 be made M A. follow,
TWO ~ strlDgers Of ski inches set ON the
caps aud sixteen (lG) ieet apart from out
side TO outside. The space between said
stripBer' to be equslly divided Tor sever