British salvage experts have performed extraordinary feats; the
American Navy has produced divers excelling even our own; but it has
been left to the Italians to accomplish the seemingly impossible. As a
sheer feat of salvage, the raising of the _Leonardo da Vinci_ remains
unsurpassed.
The night of August 2, 1916, will long be remembered in Taranto, for
just before midnight the whole town was awakened by a tremendous
explosion. The people leapt from their beds and rushed towards
the harbour, to find searchlights sweeping the bay and the finest
battleship in the Italian Navy belching forth flames and smoke. The
_Leonardo da Vinci_ was doomed. In a moment 250 officers and men
were wiped out of existence, and although the survivors fought most
valiantly to quell the fire that enveloped the ship their efforts were
vain.
Suddenly the decks of the battleship canted beneath them, shooting them
like flies into the bay, and she swung right over and sank upside-down
in 36 feet of water. The searchlights from the surrounding battleships
lit up the darkness. Round and round they flashed, seeking the enemy
who had dealt this mortal blow; but there was no sign of a periscope,
nothing but the heads of the Italian sailors fighting for their lives
in the sea.
A time bomb, secretly introduced into one of the magazines, had robbed
the Allies of one of their most powerful battleships. This loss of a
first-class ship of 24,000 tons, equipped with an armament of thirteen
12-inch guns, was a grave one to the Italian Navy, and the question of
salving her at once arose. Famous foreign experts came on the scene,
gazed on the visible portion of the keel of the ship which had cost
£4,000,000, and shook their heads dubiously.
“Impossible!” they said. “The only thing to do is to blow her to
pieces.”
The eyes of the Italians flashed. Somehow, at some time, they
determined to salve the battleship. It might be impossible during the
war, owing to the difficulty of getting material for the operations,
but in their own minds the honour of Italy would never be satisfied
until the ship which lay at the bottom of Taranto bay once more floated
on the seas.
The sinking of the _Leonardo da Vinci_ was, indeed, a great blow to
the pride of the Italian Navy, and there was a general desire on the
part of the nation to wipe out the stain and turn defeat into a triumph
by refloating the ship. The more difficult the task, the greater the
triumph; the more impossible it seemed to foreign experts, the more
determined were the Italians to achieve it.
Throwing themselves heart and soul into the matter, the officers of the
Italian Naval Engineering Corps studied the problem most carefully and
formulated several schemes, among them a plan to build around the ship
a floating dock which, when completely pumped out, would automatically
lift the wreck. Shortage of steel and other materials at that time
made this plan impracticable. Then General Ferrati, the chief of the
Italian naval constructors, evolved a plan to raise the ship by means
of compressed air and carry her upside-down to the dry dock at Taranto,
where she could be prepared for righting.
It must never be forgotten that the battleship was upside-down, and
that not only had she to be raised, but she also had to be righted.
Rivet by rivet and plate by plate she had in the course of years been
built up by hundreds of men into one of the strongest structures known.
All the rivets and plates had been welded into a compact mass of 24,000
tons which now lay at the bottom of the sea. Afloat, she obeyed the
hand and brain of man, would go wherever he desired; at his behest she
turned to right or left, sped furiously through the sea or stopped.
Now she was immovable as the mountains; to smash her to pieces would
have been a gigantic task, costing months of time, tons of much-wanted
explosives, and well over £100,000 in money. The queer thing is that
Ferrati proposed to harness air to lift the sunken monster, just as
though she were an airship instead of a battleship. In such ways do
master-minds work.
So brilliantly conceived were Ferrati’s plans that orders were at once
given to put them into execution. Divers went down to make a survey
of the wreck, which was so rent by the explosion that a vast hole had
been blown right through her from keel to top deck. A further survey
indicated that the huge ship was literally digging her own grave. The
weight of the upside-down battleship was all resting on the funnels and
gun turrets, and these, owing to the enormous pressure from above, were
piercing a way slowly but surely through the mud. Day by day the ship
sank lower and lower, until the whole of her upper deck was completely
buried and the greater part of her hull at the stern had disappeared.
In six months the funnels cut down through a bed of mud over 30 feet
thick before they encountered a bed of clay, which arrested the sinking
of the ship.
[Illustration: THE ITALIANS BRINGING THE LEONARDO DA VINCI UPSIDE DOWN
INTO DOCK AT TARANTO ON SEPTEMBER 17, 1919, AFTER FIGHTING FOR OVER TWO
YEARS TO RAISE HER FROM THE SEABED]
No wonder the experts gave up hope. It really seemed that nothing but
a miracle could bring the great vessel to the surface again. There
she was, upside-down, buried deep in the clinging mud, an enormous,
unwieldly mass that the biggest cranes ever invented were powerless
to lift. It is a comparatively easy task to raise a weight of 10 tons
from the seabed, but it is quite a different proposition to lift a
mountain of metal weighing upwards of 20,000 tons.
[Illustration: THE UPSIDE-DOWN BATTLESHIP SAFELY DOCKED ON SEPTEMBER,
18, 1919, WITH THE GIANT PONTOONS WHICH HELPED TO RAISE HER STILL
LASHED TO HER SIDES]
In no wise discouraged by the difficulties of the problem, General
Ferrati and his associate, Major Gianelli, ordered large-sized models
of the ship to be built. These were accurately constructed down to the
smallest detail, with miniature engines, propellers and guns; and every
compartment was loaded to represent the things on board the battleship
when she foundered.
A stranger might have laughed at the childishness of the Italian
officers who were apparently playing with toy battleships. But things
are not always what they seem. Actually these same officers were
puzzling out the most abstruse problems, carrying out remarkable
experiments which enabled them to determine how the ship should behave
in certain circumstances. As a result were evolved some intricate
calculations upon which depended the whole operation of raising the
ship.
The small part of the keel still showing above the surface was used as
a platform on which to build huts for the salvage workers. Other huts
were erected, in due course, on platforms built up from the submerged
keel. The assembling of the plant for the work was completed by the
spring of 1917, when the people of Taranto began to observe the
figures of divers about the wreck.
Those divers had no enviable time. They quickly discovered that
the explosion had liberated a quantity of thick oil which clung to
everything within the ship, and as they went down it obscured the
glass of their helmets and rendered the men practically blind. As if
the oil were not sufficient handicap, there were thick clouds of rust
which fogged the water and added to the discomfort of the divers. Yet
the oil, despite its drawbacks, proved something of a blessing, for it
adhered to hundreds of shells and protected them so efficiently from
the action of the sea that the Italians were able to use them after
salving them!
The recovery of the ammunition was the first step to lightening the
ship. Day after day shells were hoisted out of the wreck and loaded
into lighters. It was dangerous work, but it became rather monotonous
to those engaged in it. Monotony, as is well known, is apt to lead to
carelessness, and carelessness in handling shells may lead to terrible
results. It is a fine tribute to the carefulness of the men engaged on
the work to know that they salved nearly a thousand 12-inch shells,
three thousand 4·7-inch shells, some torpedoes, thousands of explosive
charges and hundreds of tons of other ammunition without a single
mishap.
Meanwhile, a cable was laid from the power station at Taranto right out
to the wreck, a distance of a mile and a half; and with the power thus
furnished the divers began drilling holes to take the rivets that were
to hold the patches over the great rents in the hull. Slow and arduous
work it was, and not without danger, for it cost one man his life. The
patches were lowered into place, a layer of rubber was fitted betwixt
the hull and the edges of the patches to make them watertight, then the
patches were successfully bolted home.
More cables were carried out from the power station to work the
air compressors, and, as soon as the divers had made a number of
compartments watertight, the salvors began to pump air into the sunken
vessel. The air which was pumped in naturally rose. It tried to get
away to the surface, but the keel of the battleship, which had been
most carefully repaired and made airtight, prevented it from escaping.
The air was thus caught, as it were, in a trap. There was no way out
for it. It was not strong enough to break through the bottom of the
ship, but it was strong enough to press down the water within. As the
volume of air increased, the belt which it formed grew in depth until
it had forced the water down for a distance of 26 feet below the level
of the sea outside, and men were able to enter the bottom of the vessel
through an air-lock, work in security in this belt of compressed air,
and lighten the vessel by taking out her stores and coals.
By the beginning of November, 1917, the salvors occasionally felt the
battleship stir slightly beneath their feet. Despite the fact that she
was buried deeply in the mud, her bow was showing the slightest of
inclinations to rise. The engineer in charge noted this with delight.
Barely perceptible as was the movement, it was more than sufficient to
encourage him to persevere.
Once more the thick oil cropped up to hamper operations and increase
the many difficulties. As the water was forced down inside the vessel
by the compressed air, the oil was deposited on everything. In most
cases this did not matter much, but it was of far-reaching importance
when it came to searching for leaks in the hull. The oil so obscured
these places that it was extremely difficult to locate them, yet
everything depended on their being discovered, for had they been left
unstopped they might have let out the air and made it impossible to
refloat the ship, or, alternatively, let in the water at a critical
time and led to her sinking in such a position that she could never be
floated again. Fortunately, the Italian salvage men were able to detect
all the leaks and stop them effectively, as the sequel amply proved.
[Illustration: AFTER FLOATING FOR TWO DAYS IN DOCK, THE BATTLESHIP
WAS COAXED INTO POSITION UNTIL SHE SETTLED WITHOUT ACCIDENT ON THE
WONDERFUL TIMBER FRAMEWORK SHOWN HERE. IT WAS A FINE FEAT TO ACCOMPLISH]
Critics of the operations pointed out that, should the salvors succeed
in floating the battleship upside-down, there was not sufficient depth
of water to allow her to be taken across that mile and a half of sea
to dry dock. Even if they managed to get her to dry dock, all their
work would be wasted, for the battleship floating upside-down would
draw at least 50 feet of water, and the dry dock at Taranto was only 40
feet deep.
[Illustration: A REMARKABLE PHOTOGRAPH TAKEN FROM AN AIRSHIP OF THE
UPSIDE-DOWN BATTLESHIP IN DRY DOCK]
These difficulties were fully considered and plans made for overcoming
them. As it was an impossibility to increase the depth of the dry dock,
the only way to solve this problem was to decrease the depth of water
that the battleship would draw. The engineer accordingly proposed to
detach the funnels, gun-turrets and other top hamper from the deck of
the vessel.
So firmly embedded were these things in the mud, that the feat of
cutting them off appeared to be more than mortal man could accomplish.
It was, too, pointed out that if divers tried to clear the mud away
from round the funnels, to enable them to work at their task, the sea
would quickly fill up the cavities again. Yet another aspect of the
problem was that the mud pressing upwards against the deck of the
battleship was preventing her from sinking deeper, and if the mud were
removed the whole weight of the _Leonardo da Vinci_ would once more
rest on her funnels and turrets and drive them deeper still into the
clay.
But the engineer, with a stroke of genius, made no attempt to clear
away the mud at all. Instead, he tackled the job from inside the ship.
Certain compartments were pumped out and used as air-locks, and in one
turret the salvors succeeded, by the use of compressed air, in lowering
the water to a level of 56 feet below the surface of the sea.
The men who performed the mighty task of detaching the turrets from the
ship actually worked 20 feet below the level of the mud. All around
them outside was 20 feet of thick black ooze, and above that the
illimitable ocean; yet the air we breathe, properly compressed, held
back the deadly waters and enabled the men to work in safety. No wonder
the experts say we are only just beginning to discover the remarkable
power of compressed air as an aid to salving ships!
Throughout 1918, some 150 men laboured about the ship to free her from
her top hamper and masts. Despite all difficulties, the gun-turrets,
funnels and other deck projections were detached from the ship and
specially prepared so that when the vessel was raised they, too, could
be brought to the surface. The open spaces in the deck left by funnels
and turrets were covered in and made quite watertight, scores of tons
of cork being packed into the _Leonardo da Vinci_ to give her buoyancy.
Early in 1919 one or two tests showed that they could raise the monster
when the time was ripe. But Major Gianelli, the engineer in charge,
was taking no chances. To make quite sure of lifting her, he caused
eight large pontoons to be fixed to her, each capable of sustaining a
load of 350 tons, so in all he obtained from them the power to lift
2800 tons. These pontoons, or camels as they are sometimes called in
salvage circles, are strong metal cylinders something like big boilers
or tanks. They are of the utmost importance in salvage operations and
figure in most wreck-raising work. All were filled with water and sunk
into position exactly where their lifting power was most wanted. The
divers lashed them with strong steel cables securely to the sides of
the battleship, and by the month of June the work on the mammoth craft
was all but complete.
Remained the problem of making it possible to tow her to dry dock.
Notwithstanding that all projections had been cut away from her deck,
she drew so great a depth of water that it was obvious she would foul
the bottom before going any distance. To obviate this danger, the
Italians set dredgers to work to cut a channel all the way from the
wreck to the gates of the dry dock. The making of this channel, which
was a mile and a half long, entailed the removal of thousands of tons
of mud, but the salvors regarded this task as trivial compared with the
work they had accomplished on the overturned ship.
Then the dock itself required to be specially prepared, for like all
dry docks it was planned to take a vessel upright and not upside-down.
The chocks down the centre of the dock, which normally support the keel
of a docked vessel, were quite useless so far as the _Leonardo da
Vinci_ was concerned. So a forest of timber began to spring up in the
dry dock. Mighty baulks of wood, 15 inches and more square, were built
up from the bottom of the dock. These followed the outline of the ship
so that the deck could be brought exactly over them and allowed to sink
into place upon them. Other gigantic piles of timber were constructed
to support particular parts of the deck.
By September 17, 1919, all these preparations were completed. The
air compressors forced the water out of the pontoons and out of the
hull. Certain compartments of the ship were filled with water in order
to balance her evenly--and then the keel, with the great pontoons
straining upwards, slowly arose out of the sea. For a time a stern
battle went on between the mud which was gripping her and seeking
to hold her down and the air which was striving to lift her to the
surface. Then the air won. The battleship slipped from the grip of the
mud, leaving her guns and turrets still embedded, and floated on the
surface once more.
[Illustration: A UNIQUE PHOTOGRAPH OF THE LEONARDO DA VINCI AS SHE LAY
IN THE BAY OF TARANTO WITH ALL THE SALVAGE CRAFT AROUND HER JUST BEFORE
SHE WAS TURNED OVER]
A rapid survey was made to see that she was fit for her journey, then
the tugs took up their task and began to tow her slowly along the
channel between the lines of buoys marking the passage. A stranger
spectacle than the towing of this upside-down battleship was never
before seen on the seas. The tugs managed to keep the capsized
leviathan right in the centre of the channel, and by nightfall the
vessel was at the entrance to the dry dock, and was skilfully
manœuvred inside on the following day.
[Illustration: TOWING THE UPSIDE-DOWN BATTLESHIP OUT OF DOCK ON JANUARY
22, 1921 IN ORDER TO RIGHT HER]
For two days she floated, held up by the compressed air within her
hull, and during this time certain adjustments were made in the mighty
timber frame that was to support her. The water was now drawn off from
the dock and the _Leonardo da Vinci_ settled down comfortably on her
timber framework.
Her settling down placed a huge strain on the timbers, some having
to bear the very great pressure of 225 tons to the square inch. The
calculations, however, were so cleverly made, and the vast weight was
so evenly distributed, that the framework supported her in perfect
security. In itself this was a remarkable achievement. The slightest
miscalculation, or one weak timber, might have brought about the
collapse of the whole structure, and the battleship would have fallen,
an absolute wreck, on the bed of the dry dock.
For months men swarmed about the upturned battleship, doing the final
repairs that were necessary before she could be righted. The conclusive
test of the Italians was nigh. Could they succeed in turning the great
mass of metal the right way up again? No power known to man would
suffice to right the vessel on land. Before the task could be attempted
it was essential to place her once more in her element, the sea. On
land she was immovable, on the sea she floated and could be more or
less controlled by man, but whether man could perform the miracle of
turning her right way up again, nobody knew.
The bottom of a ship, of course, has to be strongly built to withstand
the pressures to which it is subjected. The deck, not having to stand
the strain that the bottom is called upon to bear, need not be built
so strongly. In this case the deck and the bottom had changed places,
and it was therefore of the utmost importance that the deck should be
strengthened to withstand the increased pressures that would arise in
righting the ship.
Out in the bay the dredgers scooped a deep basin to enable her to turn
over without fouling the seabed, and towards the end of January, 1921,
the _Leonardo da Vinci_ was towed to the place where it was proposed to
right her. Four hundred tons of solid ballast had been loaded into her,
and the engineers made preparations for pumping 7500 tons of water into
certain compartments on her starboard side. Being above the centre of
gravity, this weight would make her so top-heavy that she was bound to
overbalance and thus turn right side up again.
[Illustration: UPRIGHT ONCE MORE AFTER BEING UPSIDE DOWN FOR FOUR
YEARS. SHE RAISED A HUGE WAVE AS SHE SWUNG OVER, AS MAY BE SEEN FROM
THIS PHOTOGRAPH WHICH WAS TAKEN FROM AN AIRSHIP]
There in the bay lay the still stricken leviathan. The valves were
opened to allow the sea to enter her compartments, and the salvage men
scrambled from the upturned keel and pulled away from her in their
boats. The water began to flow in, and by the time some 800 tons
had entered she began to turn ever so slowly. Soon, as the weight of
water increased, she swung over with a rush, raising a big wave as the
deck swept clear of the water. For a moment it looked as though she
would swing right over and finish upside-down again. But the engineers
had worked out their calculations to such a nicety that the battleship
finally came to rest with a slight list, just as they had foreseen.
[Illustration: THE LEONARDO DA VINCI READY TO GO INTO DRY DOCK AGAIN TO
BE REFITTED. A BRILLIANT SALVAGE FEAT IS RECORDED IN THESE REMARKABLE
PHOTOGRAPHS WHICH ARE REPRODUCED BY COURTESY OF THE ITALIAN NAVAL
ATTACHE]
Across her deck, in big letters, was seen the motto of the famous
_Leonardo da Vinci_: “Every wrong rights itself,” painted while the
vessel was still upside-down in dry dock. It was a happy thought, and a
pandemonium of cheering broke out as the legend came into view to tell
of the most remarkable salvage feat ever accomplished.
The salving of the ship and her final righting took four and a half
years. It was a Herculean task, and from first to last cost the Italian
Government £135,000. Unhappily, General Ferrati, who conceived the
brilliant plan, did not live to see it completed. He was succeeded as
director of operations by General Faruffini, who in turn was succeeded
by General Carpi, but during the whole time Major Gianelli was in
charge of the work and to him is due the credit for carrying out from
beginning to end, and bringing to a triumphant conclusion, the most
wonderful salvage feat ever performed by man.