Honolulu star-bulletin. [volume] (Honolulu [Oahu, Hawaii]) 1912-2010, 1915-01-30
Drydock Plans Result Of Careful Study
Greatest Engineers in Country Employed

such sections. placed about 5 feet
apart
Obj The base of each section Is
formed by a system of structural steel
trusses extending across the dock,
with steel bracing lengthwise OF the
dock, together with the embedding
concrete of the dock floor, which will
be Is feet thick and fat on the bot.
tom. The steel work Of each section
weighs approximately $50 tons and is
shown in figure 3.
(c) The bases will be built upon
floating dock, designed for this speci
fic purpose, to be provided by the con-
tractors as a tool fer use during the
construction of the dry dock The
steelwork of the base, erected on the
floating dock, is shown in figure 4.
The concrete at the sides and ends
of the base viii be carried up to the
full height CT the base, forming
heavy inclosing wall. and to about half
height, or feet, IN the middle por5
ton The average thickness OF the
concrete OF the base, completed to this
extent, will be about 10 feet and its
gross weight will be about 1860 tons;
but, due to its partial submergence.
the net weight carried by the floating
dock at this stage will be less than
5000 tons This condition is shown
in figure 5.
Id The floating dock. carrying a
base completed to the extent describ-
ed in the preceding paragraph, will
then be sunk to an extent sufficient to
receive the ballast tank and cofferdam
structure, illustrated in figure 6 (top
viewl and figure Z (bottom view).
This is strongly braced steel struc.
tire, consisting of ballast tank go
by 10S feet in plan, with integral end
ccfferdams forming working spaces
for building the side walls. The total
width over the plating of the end
cofferdams is 152 feet, and the total
height of the structure is IS feet. To
the bottom of the tank are secured
steel pedestals feet high, designed to
rest on the top cords of the transverse
trusses of the dock bases, thereby pro-
viding a working chamber for COM
pleting the dock floor. The end cof-
ferdams have no bottom and extend
downward to about feet lower than
the bottom of the tank, the two sides
of the tank being also extended down
ward in the form of fixed aprons, so
that the bottom outside line of the
entire. structure Is in the same hori-
zontal plane with the bottom of the
pedestals. The pedestals and the ped
estal braces can be seen in figure q.
The entire structure will weigh APP
proximately 1,750;000 pounds and will
cost about $4,000.
(e) The floating dock now being
submerged to a depth of % to 80 feet
over the deck, the tank and cofferdam
structure is fioated into place exactly
over the previously prepared base.
The floating dock is then pumped up,
the structure being guided into place
by means of tapered steel guides mt
ted ON the outside of the aprons and
the cofferdams. In the joint between
the base and the structure resting
upon it there is lead gasket previ.
ously placed. The pumping is contin-
ued and water also removed from the
interior of the upper structure until
the joint is above water and exposed
to view, when It is made secure by
means of hoIding-down bolts. This
condition is shown in figure 8. The
holding-down bolts can be seen in this
view. extending from the upper edge
of the structure to angle brackets on
the steel plate which forms the upper
edge of the base.
co The floating dock is then sunk,
water being excluded from the int.
rior of the cofferdams. until the tank
and cofferdams carrying thet base
float free. This occurs when the
draft of the base is about % feet.
This condition is shown in figure 8.