Omaha daily bee. (Omaha [Neb.]) 187?-1922, 1914-08-09
DAM HUDSON TO BUILD PIER
Great Engineering Feat Under Way
at New York Now.
COST is HALF MILLION DOLLARS
BtRRest Thing OF Its Kind Ever Tn
dertaken, but ~ d MOvinE
steadily 20 successfuI
Completion.

steadily 10 successfuI
Completion.
In the work Of iucrcRsiug the dock
facilities OF Manhattan Island the dock
department OF New York city Is solving
several problems almost as difficult AS
those faced by the builders OF the Panama
canal The greatest feat OF all In connec-
ton with the construction of deep water
piers az West Forty-slNth street lie tho
damming Of the Hudson river at that
point, Dredging operations were ut first
instituted, and after these had Deen car.
ried on to the rock bottom, It became
necessary to construct Golfer dam TO
hold back the waters OF the river so that
the rock might be blasted and removed
This dam had to be something more ca
pahle OF resistance than anything of the
kind that had gone before, because II
literally had TO dam tho waters OF the
Hudson. Tho most modern and ingenious
devices that engineering skill has devised
are being employed In the construction Of
this dam.
when the water lying between the dam,
when completed, and the upland has been
pumped out. this dam will be holding
the prodigious weight OF the volume of
water OF tho main body OF the Hudson
This dam Ia unusual in the size and the
demands on g. No duplicate OF the di-
mansions OF the situation has ever been
created by engineering processes.
AZ to the details OF the work of con-
struotion OF piers for the accommodation
Of the largest passenger steamships be-
tween Forty-fourth and Forty-eighth
streets, on the North river. Dock Conn
missioner Smith says;
1.-THE plan In course OF execution will
provide one entire pier in the line of
West Forty sixth street and a half pier
in the line of Forty-fourth street, which
can readily be converted into one entire
pier by going back into the land south Of
Forty-fourth street, These structures will
be 1000 feet In length and 1870 feet in
width, with slips between them OF t60
feet in width. These slips viii be dredged
and eNcavated TO q depth Of forty-four
feet below mean low water, allowing
ample accommodations for the longest
and deepest steamships now entering the
port or likely TO arrive here for number
of years to come. The pier and a half
will furnish three berths. which will be
| sufficient for some time to take care OF
all the largest passenger steamships.
The construction of these piers has in
volved unique engineering problems OF
very great interest. The site selected is
/ located over a shelving rock ledge twenty
4 feet below mean low water at the inshore
end and from forty-four 20 fifty feet
below mean low water at a point approx
mately 40 feet from the present shore
! line. In order to remove this subaqueous
rock It is necessary TO uncover II by
holding back the waters OF the Hudson
! river by means of a temporary dam and
by blasting Il out In the dry. This method
Is not only considerably cheaper than it's
removal by blasting under water but
makes It possible TO complete the work
| in much more satisfactory manner. II
| is essential for the safety OF the ships
which are to use these piers that the rock
be removed to n uniform depth, and that
no jagged points be left TO work possible
injury to their hulls, This uniformity
could only be secured by working upon
the rock uncovered by water. II IL posi-.
BILE also, through dry excavation. TO leave
a solid pillar OF rock to support the pier
structure and TO provide for smooth, uni
form pier walls at the sides OF the piers.
las a preliminary to the construction
OF the temporary dam a contract wa,
let for the dredging away Of all soft
material covering the rock The first
contract for this dredging has been salts.
factorily completed. A recent modlfica.
ton OF the plan 20 include the oonstruc.
ton OF half pier on the line of Forty.
fourth street has necessitated the ex,
tention of the dredging to include the
entire area between Forty-slxth and
lCForty-fourth streets. This supplementary,
dredging contract has been let and Ii
proceeding satisfactorily. Meanwhile q
contract has been lot for the construc
ton Of the temporary dam and the rocl
excavation. This work was estimated
by our engineers to cost Sls7 500. Eloyer
contractors bid upon this work, thel
estimates ranging from sis7.si2.sO to Sos.
1852. The contract was awarded 4
IIolbrook. Cabot & Rollins, the low bid
der. In view Of the novelty OF the worl
and its magnitude, / consider that tn,
engineers of this department are entitled
to great credit for the accuracy OF thel
estimate as shown by the bidding. Worl
has been proceeding rapidly under thi
contract II calls for the construction
Of a cofferdam built with interlocklni
steel piles. These piles are 70 feet an,
over in length and are driven to bed rocl
in two parallel rows, forming a success
sion OF pockets approximately 10 feet Il
width and "a feet in length. These pocket
) are filled with material dredged iron
the bottom Of the river. When the dar
Is finished II will be Approximately 50
feet in length and will hold back "A heal
OF water estimated at 90 feet. The pres
sure OF this enormous mass OF water
20 great that II will be necessary to SUE
tain the steel piles by a bank OF ripra
on the inshore side. approximately 20 Zee
IN width at tho base and reaching to a
elevation of about feet above mean 10,
water. On the outshore side the dRr
} will be supported by a similar embank
ment OF clay. When the dam is CON
pleted the water between IL and the shor,
. amounting 10 approximately 5O.0O0O
gallons, will be pumped out. II is "a
pected that this operation will take thrs
or four days 10 accomplish. II viii leav
a dry area 500 feet IN length by approx
mately 300 feet In width. Then this arel
> which is estimated At H5OO cubic yard
. OF solid rock. will have to be- blasted OF