, 1870-07-28
THE GREAT OMAHA BRIDGE.
Description of the Vork-Thc rabe-
Ting III ode OF Sln&
Fncsx-Thc Bridge to be Completed
Within n X<nv,

From. the Omaha Herald. July g.
Ne yesterday visited the bridge site for tho
purpose OF taking notes Of the progress tl,at
IL being nade On this gigantic structure.
mcdlate supervision OF T. E. Sickies. Esq:,
Chief Engineer OF the Union Pacific lsailcoast,
assisted BY an abla corps Of experienced en-
gineera and mechanics
The supervision and inspection Of machin-
sry, ETC.. necessary to carry on tbs work il rn-
der the eye Of Fred. E. S.ckles, Esq, very
able and practical mechanical engineer. The
setting mp Of the engines and care Of the mo-
tive power is in the hands Of John Smith,
Esq, who has earned the reputation Of being
q fInt-c1ass macLinist and hard worker.
The woodwork necessary to pl&co the ma
cbinery in posision. consisting OF immense
dez1icks firmly sested On two ta1f barges, cut
in TWO and made strong for this purpose, IL
carried on under the efficient management Of
Mr.. Charles L. Haves, I practical ship carpen-
OF the beginning of the end Nc found two
Of these derrick barges on the west bank.
nearly in readiuess for final machinery. and
was told they will be towed to position in tho
middle Of the riyer+ firmly anchored, and tho
work OF. sinking columns on two mora pier
| sites begun in day or two.
The aletaelora il being oveshauled. and will
| be used By the company At towboat, CON-
mAnded By Captain Davidson.
| The tllsn:fe tubes are 10 feet long and 81;
feet il, diaretar, aa,t inches thick, and w,ish
! ISL W rtu1.:1s each fet system Of snatch
! b;-cke placcs one of them on 4 narrow gauge
! rlatfo:al car, made for the purpose. 10 pushed
10 the pier site on a temporary track hoisted
| to position, aud held by ueaua at \ combina-
ton Of blocks, tackle, dc-. attached to the
large derrick firmly bolted to the top of tht,
tube or column List sunk, the air lock replaced
on top, and the work OF sinking is resumed.
The pneumatic system OF sinking these col
nmns i, to most people, 2 very novel process,
interesting. to witness. and deserving close at
tention and study. Space will permit but \
brief DESCRIPTION.
4 small engine forces air down into the col
uuan, through an inner pipe, the only esclpc
1t is being sunk, the air thus excluding thu
water, which would otherwise GIL the column
and prevent the men from working this p.It
Of the process beng analogous to that expert
| enced IN operating 4 diving bell.
The sand and clay are excayated By the men.
and hoistel out by a separate hoisting engine
through the air lock, the weight OF the column
sinking itself gradually ~ the earth il recov-
cred, and being kept in place BY means Of
nicely adjusted puiIeys-
The column near lie cast bank now being
sunk, has been put down at the rate Of twelve
feet per day, aaa, At ono time it WIS sunk ten
feet IN an hour.
While the work Of sinking is being carried
on, tho men whote business it Is to reuoain on
the inside are obliged to work under = pressure
Of from ono to fo1ty pounds per square inch,
varying according to depth Of column, expert
encing no Inconvenience after becoming &ccus-
1 toned 10 it. It has demonstrated that strictly
temperate men arc able to wo,k under great
er atmospheric pressure than mon adafcte1 To
d1ink, and where atcidcuta have occirrtd III
other places they have been scel to this act.
A regular system Of tclegraphing j. carried
on between the wcEk1nen III tie column Aatl
the fofemen on the outriIe, for the purpose
Of giving orders and preventing aecidens.
4 table is furnished the engineer to guido
him regarding the number Of pounds Of air to
| te forced at certain depths, and tha greatest
care il taken that no more is foEred in thau
| tie wufkmen can bear
The work is progressing as fast rs brains,
muscle. and money can push it, and it ueces'
sary, ono year from to-day trains will be cross.
ing one of the finest structures on this CONT
nent+
The no.1us orerandi Of sinking the tubes o,
csisons is under the immediate management
Of George Miller. Esq who has had large e1-
pelience in this kind Of work He Was select.
ed by Mr.. s,ickl.s, having occupied eimilal
position nuder Mr. S. during the construction
q the Harlem bridge. and he mar we'll bt
proud Of tho record tbas. during at the t'fnt
| dent happened TO life or limb. aud under lli.
: | watchfnf re- and scientific management O.
, such heavy and cumtEous mtte1ial AZ il OF ne
| cessity brought into requisitlou. no a:ctdeht II
employees can happen or il anticipated.
, Tho east bank OF the river ut the bridge sit
presents novel spectacle, and the first 4ues
. fions are: "What are these huge thimble
for:" SLOW are thcF moved :" Z. How doyo,
fssten them together:" &c. Very brief 1ue=
, tions, but requiring column to properly an
nwer ether Of them.