The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1879-04-12

lifting gear is brought over tho wreck.
This lifting gear consists Of couple 81
pontoons, connected together BY hollow
deck, aud fitted with screw engines, cen
triiugal pumps and winding gear, and
having controlling air chambers on tho top.
This forms wreck-lifting apparatus as
well as an ordinary dry dock structure.
The lifting gear having been brought
over the wreck, the booms are then parted,
and one is moored 10 each side Of The Iift.
ing gear The end Of the steel.wire ropes
from the toggles are then passed up sepa-
rately through distinct hawae pipes ID the
deck above. The end Of each rome is
made fast to winch-barrel, which Is ca
pable Of independent action, and is other.
wise so arranged as to insure uniformity
Of strain being brought on all the ropes.
The wire-rJpes are made fast at the top Of
the tide, and the winches are reyolved so
as to get fair strain on during the fall Of
the tide. At the same time water Is adj
mitted into the pontoons forming the bot
tom Of the dock until they arc sunk nearly
to the under side Of the deck. At dead
low tide the pontoons are pumped free Of
their contained water, and the Terticalli
obtained is equal to the rise Of the tide
plus any extra buoyancy which may exist
between the depth 10 which the dock was
originally submerged and its gfeatcr power
Of fotation than the weight Of the wreck.
The vertical lift having been accomplished,
the dock will steam in shore carrying the
wreck with Il until the latter grounds.
The pontoons viii again be filed with
water, and the wire ropes wound in as far
as possible Pumping out will then take
place, and another feet in shore would be-
made. These operations would be repeat
ed as often as necessary, and, after the
first, would he independent Of the state or
the tide. By this means the wreck would
thus be speedily brought into shallow
water, and made sufficiently watertight To
enable her to be aoated and received into
the floating dock which, in another char
acter, had assisted in rescuing her from
Immersion. In modified form Of the
gear for boring and making attachments,
the tube is only about 10 inches in diam
eter, and is used as fulcrum for carrying
the boring gear, the operations being
watched from above by the aid Of reiract-
Ing mirrors.
I We thus have an ingenious system Of
ship raising propounded, in which the risk
Of the outlay is confined to very small
proportion Of the plant--namely the tow
er, and its garland to the labor. Should
! the raising Of the week be rendered i'm.
possible by any unforeseen circumstance
the dock would still be perfectly capable
Of being used as dry dock. The total
cost Of such dock, capable Of liftisr
weights up to 10000 tons, Is stated to be
about 100000, The expenses Of making
a tower, taking it out, aud proving the pos
sibility or otherwise Of making an attach
ment, is estimated at $4,000 Seeing til,
number Of wrecks which are strewn aroune
our coast, it is, at least, question for con
sideration whether a trial could not b,
made with this apparatus, the principles q
which are based on considerable ezperi
enee Of Surprising. II would appear /,
be. more desirable, seeing that il the lift
ing plant failed to effect its object, !
! could at once be used as an ordinary Dir
dock.