Method of lifting sunken floating object by restoring its own buoyancy

Abstract

FIELD: lifting sunken floating objects to surface.SUBSTANCE: invention relates to methods for lifting sunken floating objects lying on the slope of the bottom of a water area at a shallow depth with a roll. To lift a sunken floating object lying on the slope of the water bottom at a shallow depth with a roll, the sunken object's own buoyancy is restored. Hollow metal piles are driven into the bottom of the water area next to the object being lifted, onto which the pile caps are welded, and slings are secured to the body of the object, which are passed through the lower cap and secured to the upper cap of each pile with a small amount of slack. The elevated side of the raised floating object is secured by changing the pattern of forces acting during lifting, where the raised sunken object is emerged as water is pumped out of the internal volumes of the hull of the raised object without increasing its initial roll.EFFECT: reducing the duration and labour intensity of ship-lifting operations by eliminating the need to create a righting moment and ensuring the stability of the object being lifted with the help of additional devices that create external buoyancy forces or mechanical efforts, in the form of ship-lifting pontoons or large-capacity floating cranes.1 cl, 3 dwg

Description

[0001] The invention relates to methods for raising sunken floating objects lying on the slope of the bottom of a water area at a shallow depth with a list (trim).

[0002] The simplest method for raising sunken floating objects lying in shallow water is known by pumping out (squeezing) water from their internal volumes [1]. A disadvantage of this method is the significant difficulties of its application at a list of more than 5 degrees [2] due to the lack of stability of the object being lifted due to the presence of an overflowing free surface of water in the compartments, which leads to its capsizing, especially if the center of gravity of the object being lifted is shifted towards the recessed side, and the object itself is on the slope of the bottom of the water area with a trim (Fig. 1). With the start of pumping out (squeezing) water, a lifting force Q appears, located to the left of the force of gravity (Fig. 1a). As the internal volume dries out, the lifting force Q increases, and its point of application shifts towards the recessed end and the center of application of the force of gravity P (Fig. 16). When the moment of lifting force Q exceeds the moment of gravity P, the shallower side of the sunken object floats up (Fig.1c). A heeling moment is applied, and the trim continues to increase as the internal volume is drained until the point of application of the lifting force Q is to the right of the point of application of the gravity force P (Fig. 1d). The resulting trim will significantly exceed the permissible safe value. This may result in the object being lifted capsizing or shifting to a deeper depth, as well as the collapse and failure of the drainage equipment.

[0003] The heeling moment is counteracted by a snap on the recessed side of the buoyancy (ship-lifting pontoons) or by mechanical forces (floating cranes or deadrise vessels), creating a righting moment from external forces [1]. This significantly complicates the method of recovery by restoring the vessel's own buoyancy due to the complexity of the snap on the righting technical means and requires a high lifting capacity of the additional technical means used. At the same time, the effectiveness of the method of lifting sunken floating objects by pumping (squeezing) water from their internal volumes decreases, and the method itself turns into a more expensive and complex combined method of lifting, requiring a wide range of technical means, including high lifting capacity.

[0004] The objective of the invention is to expand the scope of application of the method for raising a sunken floating object by restoring its own buoyancy by raising objects with a center of gravity displaced in width, lying on the slope of the bottom of a water area with a list (difference) of more than 5 degrees, without the use of additional means of ensuring stability in the form of creating straightening moments of external buoyancy forces or mechanical forces applied at the recessed end.

[0005] The problem is solved by fixing the elevated side (extremity) of a sunken floating object being raised, lying on the slope of the water body bottom with a list (trim), in order to prevent its surfacing when the point of application of lifting forces shifts towards the deeper side (extremity). A possible fixation option (Fig. 2) involves driving hollow metal piles 4 into the bottom of the water body 1 next to the object being raised 7, the upper ends of which are located above the water surface 2. Eyes 5 are welded to the piles and to the hull of the object, if possible in its above-water portion 6, wherein the eyes are paired and located above the water level and directly above the ground. Slings 3 are secured to the object, passed through the lower eye and fixed in the upper eye with a small slack, which is eliminated when they begin to remove water 8 from the body of the object being lifted.

[0006] The diagram of the acting forces after the elevated side (end) is fixed changes (Fig. 3). At the points of fixation, a net force ΔP appears, directed against the lifting force Q (Fig. 3a). As the internal volume of the lifted object dries out, the point of application of the lifting force shifts towards the point of application of the resultant force P+ΔP, which, as the net force ΔP increases, shifts towards the elevated side (end) (Fig. 3b). The position of the lifted object remains unchanged until the lifting force Q is to the right of the point of application of the resultant force P+ΔP (Fig. 3c), after which the recessed side (end) of the lifted object will float up (Fig. 3d).

[0007] The new distinctive features of the method are the fixation of the elevated side (end) of the object being lifted and thereby changing the pattern of forces acting during lifting, when the surfacing of the lifted sunken object by restoring its own buoyancy by pumping out (squeezing out) water occurs with the free, submerged end after, as the water is pumped out (squeezed out), the point of application of the lifting forces is beyond the point of application of the resultant force of gravity and the fixation forces directed in the same direction without a preliminary change (increase) in the list (trim) of the object being lifted.

[0008] These distinctive features ensure the lifting of a sunken object lying with a list (trim) of more than 5 degrees by restoring its own buoyancy by pumping out (squeezing out) water without increasing its original list (trim), without requiring the use of additional technical means of ship lifting in the form of ship-lifting pontoons or large-capacity floating cranes.

[0009] The economic effect of introducing a method for lifting a sunken floating object by restoring its own buoyancy with the fixation of the elevated side (end) consists in reducing the duration and labor intensity of ship-lifting operations by eliminating the need to create a righting moment and ensuring the stability of the object being lifted with the help of additional technical means that create external buoyancy forces or mechanical efforts, in the form of ship-lifting pontoons or large-capacity floating cranes.

[0010] Literature

[0011] 1. Handbook of calculations for ship salvage. - M: Military Publishing House, 2005. - 480 p.

[0012] 2. Technological maps for performing typical operations during the recovery of sunken objects from shallow depths. Practical guide. / Ed. Kramorenko A.V. - M: Krasnaya Zvezda, 2014. - 496 p.

Claims

A method for raising a sunken floating object lying on the slope of the bottom of a water area at a shallow depth with a list, characterized by the restoration of the sunken object's own buoyancy, characterized in that hollow metal piles are immersed in the bottom of the water area next to the object being lifted, to which the pile eyes are secured by welding, and slings are secured to the hull of the object, which are passed through the lower eye and fixed in the upper eye of each pile with a small slack, while the fixation of the raised side of the floating object being lifted is carried out by changing the pattern of forces acting during lifting, where the floating of the sunken object being lifted is carried out as water is pumped out of the internal volumes of the hull of the object being lifted without increasing its initial list.

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