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M/S Sewol salvage March 2017
The Korean ferry M/S Sewol was salvaged March 2017 at 45 m depth using two barges. She was 10 m shorter and 2 m less wide than M/S Estonia. Tunnels were dug below the wreck and steel wires were introduced there and then connected to the barges. The barges were ballasted/deballasted so the wreck was lifted and could be brought to shallow waters and inspected. Same method can maybe salvage the M/S Estonia 2021. M/S Sewol was, like M/S Estonia just built for coastal national trade and was not seaworthy at departure. But she was salvaged.
Some wild thoughts how to remove the MV 'Estonia' from the sea (written many years ago say 1996) If you can lift the Russian submarine 'Kursk' at >100 metres depth in the Arctic Ocean, it should be possible to lift the MV 'Estonia' that sank quickly 28 September 1994 in the Baltic. Why the vessel sank 1994 ... nobody knows! The official investigation was simply a cover-up of the Truth described here and here. The wreck is today lying at 80 m depth with about
120° list on the sea floor as shown below - figure 1.
Its weight is about
12.000 tons,
3.900 tons less,
if you allow for the buoyancy of structure and equipment.
The centre of gravity G is somewhere above the car deck and
a little aft of L/2.
This means that you cannot fill the watertight
hull compartments below the car deck no. 2
with air at 8 bar and expect the vessel to float
up, as the car deck itself has several openings,
where the air leaks out. Only if the vessel was
lying completely upside down - 180° list - you
could in principle fill the spaces below car deck
with air and expect the vessel to float up upside
down assuming the hull is intact as alleged
by the Commission. The underwater hull is expected to be
intact - some openings have been cut in the side of
deck 1 - and you could close the watertight doors,
to obtain several compartments with sides and
bottom tight, and then re-float the ship upside
down. But - the wreck must then be resting with the
bottom up, which is not the case. A feasible solution would be to open the forward
and aft ramps on the superstructure of the
wreck and pull out the 38 lorries and all small
cars and truck - about
1.000 tons and put
them on the sea bed. The heaviest objects are 50 tons and the others
are lighter, so you should be able to pull out all
objects by a tug. The cars and trucks are of course resting
against each other and the starboard (lower) side
and the deck 4 underside, but the writer sees no
major difficulties to pull out these objects from
the superstructure garage space without
damaging the starboard (lower) hull
side. Actually only the port (upper) side and the
starboard inside casing side need to be intact to
raise the wreck with below mentioned method. When the car deck is free from all objects, the
wreck weighs less than
11.000 tons and you
have a nice, free space on the car deck - and the
port side and the starboard side inside casing in
this space are intact. The idea would then be to pull in four
reinforced rubber pontoons in the car deck
space and fill them with air at 8 bar. These
very big pontoons are today available, and
sometimes used for transporting oil (at less
pressure), but special rubber pontoons must be
manufactured to raise the 'Estonia'. Each pontoon should be about 145 m long with
a diameter of 5.5 m (to fit into the car deck
space) and should provide, say 3 300 tons of
buoyancy each when inflated at 8 bar, as seen in
figure 2. If such big, strong 8 bar (!) rubber
pontoons exist is doubtful of course. Maybe smaller
ones can be used? The four pontoons provide >11 000 tons
lifting force and the Estonia should thus
float up to the surface more or less in the
inclined position as found on the bottom (as the
lifting force is in balance with the weight G).
Naturally - you need some extra floaters to balance
the wreck longitudinally (to be established by
detailed calculations). By varying the buoyancy
forces in the four pontoons you may later adjust
the list of the ship - actually tip it upside with
most of the deck house above water! Actually it
should be possible, after the Estonia has
reached sea level, to turn the wreck upright by
adjusting the buoyancy (amount of air) in the lift
pontoons. The floating wreck is then towed to
shallow waters and put on the bottom again. The
deck house - above water - can then be
emptied of dead bodies (most of the victims are
assumed to be in the deck house) - and later
the wreck can be raised to the surface using
conventional means. The situation when the Estonia is resting
on the bottom is shown right - figure 3. Thus all
bodies in the deck house can be removed from
the ship when the deck house is above water.
With the Estonia on the bottom as shown in
figure 3 it is then easy to lift her with
conventional pontoons, pump out the spaces below
the car deck and refloat her. It would be an
interesting salvage or removal and many
professional salvage/removal companies would
probably compete to get the contract. Thus the
wreck could be removed from the bottom at a very
competetive cost. It is of course also possible, and probably
much easier, to lift the'Estonia'
straight up from the bottom with floating
pontoons on the surface after having
installed lifting wires below the wreck. However,
this work would include digging (?) tunnels below
the wreck in the 10-20 m thick mud layer on the
seafloor to get the wires in place at 80 meters
depth. Or maybe the wires can be installed using
some other methods? A self propelled thing that can
bore through the mud with a rope behind, so that
wires can be pulled below the wreck using that
rope? Evidently lifting of the wreck will not cost
SEK 1 500 millions as suggested by the government
1994. SEK 50-100 millions is a more realistic
figure. Just ask the salvage/removal
companies. Contact anders.bjorkman@wanadoo.fr
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