Evening journal., 1913-05-31
OPEN BIDS
MONDAY FOR
RIVER DREDCE

Bids will be opened at II o'clock
on Monday at the United States en-
gineer's Office, Sixth and King streets,
for the construction of the steel sea-
going suction dredge. The dredge,
together with the plant necessary to
operate It, will cost in round num-
bers about s25O.OOO. the money having
already been appropriated by the
Government
The dredge is intended to operate
in Wilmington harbor. The width OF
channel Is 200 feet at bottom in the
main part OF the harbor, and the yes
sci must be able to turn in this width
OF channel The harbor is TO be
dredged TO q feet depth at mean low
water and maintained at that depth by
dredging.
The material is very soft silt, and
occasionally sand and gravel The
silt predominates. The dredge must
be designed TO handle this material
with the least possible admixture OF
water. in order that the material may
be retained in the hoppers. Dilution
Of the material when discharging
ashore is permissible and at times
desirable.
Numerous pipes and cables cross
the channel below the depth of dredg-
ing. necessitating accurate control of
the suction head and a type Of head
that can work economically with a
broad shallow cut.
The dredge Will be sea-going, twin
screw, self propelled, hopper type,
with one or two suction drags and
heads suitable for dredging in water
varying in depth from just sufficient to
permit the dredge TO run to 35 feet.
The suction drag head shall be of a
type possessing the following feat
ures:
Considerable breadth of head to
avoid dredging burrows and leaving
ridges, and TO permit economical work
when making a shallow cut; means OF
forcing the material through the sue
ton drag, such as water jets, pres
sure caused by the motion of the yes
sci. a combination of these or other
means already proved satisfactory
lateral rigidity to drag, to prevent
head from avoiding high places on the
river bed.
There shall be provided one ol
more hoppers having a total capacity
Of 400 cubic yards. Hoppers shall be
open on top, and shall be divided into
separate compartments provided witt
longitudinal overfows on each side
with discharges outboard below deck
Means shall be provided for dis
charging of dredged material by pump.
ing from bins, suitable provision be-
ing made for discharging ashore
through a pipe line from either side
of the vessel. Hoppers shall be with
out bottom doors. A chute shall bC
provided, with suitable valves, fol
wasting overheard the discharge from
the dredge pump. in order that dredg
ed material. when too greatly diluted
with water 10 settle in the hoppers
may be allowed to escape overheard
The dredge shall be designed for 9
speed OF 9 statute miles per hour II
light working condition. and Z statute
miles per hour fully equipped anC
| loaded.
The length OF the hull between per
pendiculars shall not exceed 146 feet
and the draft fully equipped will
water and fuel and hoppers contain
ing 200 cubic yards OF sand, shall no
exceed 10 feet. Auxiliary overflow
for this purpose shall be provided will
means for closing them water-tight.
The vessel will travel along as J
scoops up the mud and deposits !
I'm the vessels bins. later to be dis
charged ashore. In this way naviga
ton will not be interfered with anC
the channel will remain unobstructe'
which is impossible with stationar!
dredges.