Delaware gazette and state journal. (Wilmington, Del.) 1883-1902, 1890-06-19
kirk w0OD PAAn sBA-WALh.

The Interesting ana SOPet Operh-
lions GOicg On Along the River
Front Of the New Park.
An extremely interesting, and, 30 far as
Wilmingtonians arc concerned, novel
operation is being carried on just now
along the water front Of the new Kirk
wood Park. Contractor Alvin Il. Morri-
son has commenced building the sea wall
at that location by the method, so often
read Of, but never witnessed here before,
of cofer-dsmming. At first sight the
general impression OF things suggests the
appearance Of mammoth barrtcnde
being constructed almost in the middle
OF the river. Tbs big aredge, No. ., and
q powerful centrifugal pump are at work.
Superintendent McNeliy with large
gang OF men are pushing operations just
| now. Through the EuperintendenSs
courtesy party Of visitors including tie
reporter were shown the operations.
Tho coffer-dem OF the present stage OF
| operations ia most Interesting study in
engIneeling--at least it was SO to the
noVices who Investigated it yesterday.
! Ii is literally an immense water-tight box,
some 100 feet long, Is feet ACROSS and
from the top is about 20 feet or so to
lowest standing bottom. All the sides
are double with about &c inches or 40 OF
| spooe between which has been filled with
clay.
This with the addition of clamping the
outside base with numerous tons OF clay
has given compartment impe.meable to
water. That beiEg established success
fully thu next joh and an extremely inter
esting one to witness, WAS o empty the box
OF its contents Of water, sand and mud,
SO as to bs ready for the concrete wall to
be built within.
A powerful centrifugal pump was set to
work. This is wonderful piece oil
mechanism. As soon as it began work
water and mud was belched out OF its
capaoious mouth quickly emptying the
big compartment or Golfer dam. The
wonder of this pump is that it fetche.
cut sand, mud, stones and sticks quicker
than water. 1t works as il the more diff
cult the work the more easily it accom-
plishes it. Apparently all that it cannot
do IL to suck the big rocks from the bot
tom of the Brsndywine. When the IN
terror OF the coff sr-dam had been pumped
dry several feet below the water line out
, side, the workmen descended with
} shoyels and spades and proaesded tx
throw up all loose material 80 an to nhort
o firm Foundation for the concrete build
ing. This is what the workmen arr
doing Just now. As soon as the bot
tom Is ready the concrete matte
: made up of granite broken to egg sig
. and mixed up with sand snd Rosendal,
8 cemsnt will be thrown into the box AMI
filed up to its rim. lutsrsticss of q few
feet will be left all around for the tina
purposea of the operation. The concret
/ dries and becomes hard almost as sooi
! as the workmen bsvs finished throwing
p It 10. When that han been completed
I certain wedgas or slots to which or
fastened the ropes which anchor the sid
! bcardings and keep them rigid in thei
: places are loosened, the clay between th
! boards falls away, and that without i
/ thrown in when the water gains entranc
= and the boarding floats of by its ow
9 buoyancy. Thus the hard concrete wall
t as steady end stiff ss its bases of Brandy
!. wine granite, is revealed, showing wa
stronger tnsn any masonry possible
4 being erected under the circumstance
5 and substantial! and firm enough to stan,
Y for osnturies-
:. -