The barge was semi sunk, with her bow touching the sea bottom and her stern being afloat, whilst her port side was moored at the pier.
Initial planning process
1) Detailed underwater survey of the barge took place from our divers, in order to record the exact condition of the plates, longitudinal and transverse frames, girders, manholes, etc., as well as checking for existing damages or wears, so that the estimation of the strength of the side tanks in case of pumping in compressed air to be possible.
2) Where deck openings were found due to wear, as well as cracks in the bottom and the side of the hull, due to collisions at the sea bed and elsewhere, new plates were welded covering them, in order the water tightness of the hull to be restored. Thus pumping in compressed air became possible, and consequently the sea water inside the barge to be driven out.
3) In the machine shop of “MEGADIVE LTD” we manufactured eight (8) blind manhole flanges, on which manometers and ball valves were adapted, in order to control the quantity of pressurized air.
4) Eight (8) holes of diameter four (4) inches each were opened in the keel plating of the barge, using hydraulic drill. The reason for that was the sea water removal from the side tanks, when the deck of the barge will be pressurized with air.
5) The above eight (8) blind flanges were bolted on the manholes and patches were welded on every opening or crack on the deck. The cracks on the bottom of the hull could not be closed, due to lack of approach.
6) Consequently the side tanks of the barge were pressurized with air, which resulted to the rise of the hull from the sea bed at the depth of ten (10) meters to five (5) meters. Even so the semi sunk barge could not be afloat as wanted, fact which led us to reconsider the whole process.
Change of planning process
7) The initial planning process which was based on pressurizing air in the side tanks, was changed to pumping out sea water from the side tanks.
For doing so, the blind flanges of the manholes were opened and submersible pumps were put inside the side tanks. The blind flanges of the manholes were bolt again, on which a special pipe (air vent pipe) had been adapted, which remained higher than the sea level.
8) Pumping out sea water from the side tanks started, whilst fresh air entered through the air vent pipe, replacing the sea water in the sea tanks, providing constantly additional buoyancy to the barge. Thus after 3 ½ hours pumping out the sea water from the side tanks, which enabled the 70% of the whole water volume to be removed, the deck level was a bit higher than the sea level.
9) Following that, the manholes were opened and the pumping out of the sea water was continued till the rest 30% of the water in the side tanks to be removed, and the vessel to be in a steady floating condition.
10) Due to the fact that the keel of the barge was now possible to be inspected, our divers welded temporary patches to the cracks at the bottom of the barge, as well as at the whole surface of the hull, so that absolute water tightness to be achieved and the function of the pumps to stop.
11) Finally after thorough inspection of the hull, permanent welding of the patches took place and our equipment was removed from the vessel, which was given in safety to the ship owners.