The San Francisco call., 1897-02-14
II SUBMARINE SUMMERSEULT
New Idea for Raising Sunken Vessels.
! Their Positions Are Reversed and
the Hold Pumped Full Of Air

IHT1N ingenious invention for raising
t&AE sunken wrecks, which has just
1%ASbeen invented by Felix Gaillard, a
Frenchman of Bordeaux, is beginning to
attract considerable attention in the
marine world as we'll as among wreckers
and divers
The device is so very simple and at The
same time constructed upon principles
which have 80 long been thoroughly
familiar TO every schoolboy that the only
wonder is why it was not applied long
ago.
From his experience as a practical
diver, Mons. Gaillard early in his career
knew and appreciated the numerous
difficulties encountered in raising wrecks
by the slow and Iaborious method OF slnx-
ing caissons, binding them 10 the null
and slowly raising it 10 the surface where
the water could be pumped out OF the null
and the work of pair done.
Often, when this difficult task was nearly
completed and the wreck was almost at
the surface, a slight leak in one OF the
caissons would allow the hull to SINK oack
to the bottom ana the work would have TO
be done all over again.
= At such times Gailiard wished most de-
voutlv that some other means OF wreck
raising could be devised, but as no one
appeared TO be able TO produce the much
Ionged-for invention he set about devising
cne himself.
: As boy he had been familiar with the
principle by which when an inverted cups
Is forced beneath the surface of the water
d. the air pressure within the vessel keeps it
dry and prevents the water from filling it.
This was the first idea of the French in
ventor, and 1t is the fundamental princi-
pie of the perfected Gaillard system of
wreck-raising.
Simple as is the method as applied by
the inventor, it took long months to make
the theory practicable. Both time and
money were required. and while he had
almost too much of the former. there was
a lamentable scarcity of funds until
number of financially solid wrecking
companies became interested il the mat
ter and furnished Gaillard with the ne ces-
sary capital with which to carry on his
work.
The result of this work is simply num-
Der of waterproof bags made in the shape
OF huge cylinders or pipes long tubes
which connect these bags with a powerful
air pump and some stout pieces of canvas
and chains.
That is the entire invention, complete
and ready for service, yet it represents
: long hours of thought as well as days and
weeks OF work which were necessary be-
fore the persistent inventor could 20 to
those who had furnished him the money
with which TO carry on the work and say
with. certainty: ~ have com pleted and
perfected my plans and machine for rais-
ing wrecks"
The air pumps used in this wreckiug ma
chine are much more powerful than the
ordinary kind, and are carried in the stern
of stanch ocean-going tugs, capable OF
withstanding any kind OF weather, and
which are furnished with engines OF the
most powerful construction.
The engines IN these tugs are so ar
ranged that whenever it is desired thev
can be connected with the air pumps and
used TO force air through them, while the
tug remains stationary.
The air is forced first through draught-
pipes into huge bellows-like arrange
ment made OF steel, wood, canvas and
leather, and re-enforced at every possible
point with a double thickness OF each ma
terial. 1t is circular in form and held in
position between two horizontal steel
plates which are connected by powerful
screws.
When the air is forced into the drum it
naturally expands and forces the two
steel plates, between which it is held,
apart. After it has been completely filled
with air the huge screws which connect
the rims OF the plates are turned by the
engines, and by screwing the two steel
plates together a powerful pressure is
brought to bear and the air within the
drum is forced out through the pipes
which lead TO the cylinder-like bags and
the large main pipe which forces the
water from the sunken hull. Automatic
valves prevent the air being forced back
through the pump.
When a wreck is to be raised by this
method the cargo, if there is any, Is first
removed and tug supplied with air
pumps, bags and the rest of the equip
ment is sent to the place where the ship
went down and anchored little to one