A self-floating pontoon applied to the floating installation of a semi-submersible vessel

Abstract

The application relates to a self-floating pontoon applied to a semi-submersible ship floating installation operation, comprising a self-floating detachable pontoon and a limiting device layer, two self-floating detachable pontoons are installed on the two sides of the stern of a large semi-submersible ship, and the self-floating detachable pontoon and the two sides of the stern of the large semi-submersible ship are connected with the limiting device layer in the gap. The self-floating detachable pontoon of the application can cooperate with the large semi-submersible ship, so that the large semi-submersible ship has the floating installation function of a smaller module such as a converter station and the transportation function of normal large and medium-sized goods, various operation requirements are met, the operation capacity of the large semi-submersible ship is improved, and the large semi-submersible ship with a ship width of more than 55 meters meeting the stability requirement can be installed by floating at the stern, and the support spacing of the main side rod of the converter station is less than 50 meters.

Description

Technical Field

[0001] This invention relates to a detachable pontoon for a semi-submersible vessel, specifically a detachable pontoon with its own buoyancy. When dismantled, its draft can be adjusted to match that of the semi-submersible vessel. After the restraint measures are released, it can detach from the semi-submersible vessel and float to the sea surface, where it can be towed away by a tugboat. This invention belongs to the field of shipbuilding and marine engineering technology. Background Technology

[0002] Semi-submersible vessels are now generally equipped with movable pontoons on their cargo decks. When not in use for submersion operations, the pontoons can be slid on the deck or lifted by a crane vessel to change their position, thus providing a larger and more accessible cargo deck.

[0003] Currently, offshore wind power is developing towards deeper and wider seas, and the transmission and distribution distances are getting longer and longer. Flexible DC transmission technology is gradually becoming the trend, and booster stations are being transformed into converter stations. The weight of booster station modules is generally no more than 5,000 tons, which can be lifted using floating crane vessels; however, the weight of converter station modules can reach 14,000 to 24,000 tons, exceeding the coverage of floating crane vessels, and is generally installed using semi-submersible vessels for floating installation.

[0004] However, the net space between the main chord supports of the submerged foundation structure of the converter station is limited, generally not exceeding 50 meters. Considering a certain safety margin, the width of the semi-submersible vessel that can be inserted into the main chord supports cannot exceed 45 meters. Furthermore, the converter station modules are not only heavy but also have a high center of gravity, requiring semi-submersible vessels with stability requirements for long-distance transport, which would exceed 55 meters in width. Modifying the semi-submersible vessel using conventional methods would be a very large undertaking, and the resistance would be significant during long-distance navigation after modification, making restoration work also substantial. Summary of the Invention

[0005] To address the challenge of enabling semi-submersible vessels to simultaneously handle routine cargo and operations while conveniently performing float-over installation of booster station modules, and to facilitate rapid switching between these two operational modes, this invention proposes a self-contained buoyancy pontoon for use in semi-submersible vessel float-over installation operations.

[0006] To achieve the above objectives, the technical solution of the present invention is: a self-buoyant pontoon for use in the floating installation operation of a semi-submersible vessel, comprising a self-buoyant detachable pontoon and a limiting device layer, wherein two self-buoyant detachable pontoons are installed on both sides of the stern of a large semi-submersible vessel, and a limiting device layer is provided in the gap between the self-buoyant detachable pontoons and the two sides of the stern of the large semi-submersible vessel.

[0007] Furthermore, two self-buoyant detachable pontoons are symmetrically arranged on both sides of the stern of the large semi-submersible vessel with the midship as the center.

[0008] Furthermore, the self-buoyant detachable buoyancy tanks include: two ballast tanks located below the midships, and empty compartments located on both sides above the main deck of the hull, as well as other semi-submersible marine equipment.

[0009] Furthermore, the cross-section of the detachable buoyancy-supported pontoon is L-shaped, facing the midships; it extends a certain length from the stern plate towards the midships in the ship's length direction, the length of which is equal to the length of the main mast support of the target converter station; and it extends a certain distance from the side of the ship to a distance away from the propeller in the ship's width direction.

[0010] Furthermore, the self-buoyant detachable pontoons extend 30-50 meters from the stern plate to the midships in the longitudinal direction; the width of a single detachable pontoon in a semi-submersible vessel is 12.7 meters; and it runs through the entire vessel in the draft direction.

[0011] Furthermore, the two ballast tanks at the front and rear of the detachable buoyancy tank are used to complete ballasting with the assistance of the main hull, so that the "L"-shaped buoyancy tank can maintain good buoyancy in the water independently under ballast conditions and be smoothly towed by tugboats.

[0012] Furthermore, the detachable buoyancy-equipped pontoons have streamlined surfaces on both sides and bottom that fit the "convex" stern of a large semi-submersible vessel, while the front, rear, and midship sections are flat.

[0013] Furthermore, the front of the self-buoyant detachable pontoon is aligned with the midship plane and fits against the stern of the large semi-submersible vessel, with a certain limiting device layer forming the planar gap between the self-buoyant detachable pontoon and the large semi-submersible vessel.

[0014] Furthermore, the limiting device in the limiting device layer is rigidly connected to the detachable buoyancy pontoon and the hull, and controls the separation and connection of the detachable buoyancy pontoon and the hull.

[0015] Furthermore, the stern width after removing the detachable buoyancy-supporting pontoons should be greater than the range of two propellers, that is, greater than the stern wheelbase plus the length of one propeller diameter, greater than the width of the support truss on the semi-submersible deck, and greater than the spacing of the main mast supports of the converter station.

[0016] The beneficial effects of this invention are:

[0017] The self-buoyant detachable pontoon of this invention can be used with large semi-submersible vessels, enabling them to perform both the float-up installation of smaller modules such as converter stations and the normal transportation of medium and large cargo, meeting various operational needs and enhancing the operational capabilities of large semi-submersible vessels. This allows large semi-submersible vessels with a beam of 55 meters or more that meet stability requirements to perform float-up installation of converter stations at the stern with a main mast support spacing of less than 50 meters.

[0018] When the detachable pontoons are removed, the originally wide stern of the large semi-submersible vessel narrows within a certain range and becomes smaller than the spacing of the main hull supports such as those for the converter station. This allows the stern of the large semi-submersible vessel to enter between the main hull supports of the converter station to complete the floating installation of large modules. When the detachable pontoons are rigidly connected to the main hull, the pontoons can fit well with the shape of the stern and perform normal functions such as ballast and buoyancy, helping the large semi-submersible vessel to complete the transportation of medium and large cargo. Attached Figure Description

[0019] Figure 1 This is a top view of the semi-submersible vessel's detachable pontoon system;

[0020] Figure 2 This is a front view of the semi-submersible vessel's detachable pontoon system;

[0021] Figure 3 This is a side view of the semi-submersible vessel's detachable pontoon system;

[0022] Figure 4 This is a top view of the container ship separated from its cargo hold.

[0023] Figure 5 This is a front view of the container ship separated from its cargo hold.

[0024] Figure 6 This is a side view of the container ship separated from its cargo hold.

[0025] Figure 7 This is a top view of the floating installation after the container and ship are separated;

[0026] Figure 8 This is the main view of the floating installation after the container and ship are separated;

[0027] Figure 9 This is a side view of the floating installation after the container and ship have been separated;

[0028] In the diagram: 1 is a detachable buoyancy-supported pontoon, 2 is a large semi-submersible vessel, 3 is a limiting device layer, 4 is the main hull support of the converter station, 5 is the converter station module, 6 is the deck support truss of the large semi-submersible vessel, 11 is the ballast tank of the detachable pontoon, and 12 is the empty compartment of the detachable pontoon. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] like Figure 1 , Figure 2 and Figure 3 As shown in the figure, this embodiment of the invention proposes a self-buoyancy pontoon for use in the floating installation operation of a semi-submersible vessel. The self-buoyancy detachable pontoon 1 is located on both sides of the stern of the large semi-submersible vessel 2, with one pontoon on each side, and arranged symmetrically with the midship as the center.

[0031] The detachable buoyancy tank with self-contained buoyancy 1 mainly includes: a row of two ballast tanks 11 of the detachable buoyancy tanks arranged front and rear near the lower part of the midship, and a void tank 12 of the detachable buoyancy tank located on both sides and higher than the main deck of the large semi-submersible vessel 2. The floating state of the buoyancy tank is controlled by adjusting the two front and rear ballast tanks at the bottom of each detachable buoyancy tank.

[0032] The cross section of the detachable buoyancy tank is L-shaped facing the midship. The side of each detachable buoyancy tank close to the midship is a vertical tangent plane near the propeller of the semi-submersible vessel, and the two sides are streamline shapes matching the hull stern line. Both the front and rear of the detachable buoyancy tank are vertical planes, and the rear part is flush with the stern bulkhead of the semi-submersible vessel. In summary, the two detachable buoyancy tanks occupy most of the areas on both sides of the stern of the semi-submersible vessel.

[0033] Certain limiting devices are installed and arranged on the two planes of the two detachable buoyancy tanks that are close to the midship and the bow. The limiting device layer 3 is located between the flat contact surfaces of the main hull of the large semi-submersible vessel and the detachable buoyancy tanks. Rigid connection and separation between the buoyancy tanks and the main hull of the large semi-submersible vessel can be realized by various methods such as welding pullers and bolt fixing, and the acting force between the main hull and the detachable buoyancy tanks can be borne.

[0034] When the large semi-submersible vessel carries out normal cargo transportation operations, the detachable buoyancy tank with self-contained buoyancy 1 is connected and fixed on the main hull of the large semi-submersible vessel 2, and is normally used as functional modules such as ballast tanks and buoyancy tanks. When it is necessary to carry out floatover installation operations for substructures such as booster stations or converter stations where the support spacing of the main side rods is smaller than the beam of the large semi-submersible vessel, the detachable buoyancy tanks on both sides of the stern are removed from the main hull. Through reasonable ballasting of the internal ballast tanks of the buoyancy tanks to make their waterline consistent with that of the semi-submersible vessel, the limiting devices are released, the detachable buoyancy tanks float freely on the water surface, and are separated from the main hull by tugboats.

[0035] As shown in Figure 4 , Figure 5 and Figure 6 , the detachable buoyancy tank with self-contained buoyancy is separated from the large semi-submersible vessel. After the tank and the vessel are separated, the large semi-submersible vessel can still work normally alone. At this time, the stern of the vessel is in a "convex" shape, the stern beam is smaller than the midship beam, slightly larger than the sum of the stern wheelbase and one time the propeller diameter, and smaller than the width of the support frame required for the floatover installation.

[0036] After the large semi-submersible vessel removes the two detachable buoyancy tanks, the floatover installation of the converter station or booster station module can be carried out. After the converter station or booster station module is loaded on the vessel, it is transported to the installation site. The "convex"-shaped stern of the large semi-submersible vessel with the buoyancy tanks removed can smoothly enter between the supports of the main side rods, completing the floatover installation of the module.

[0037] During the floatover installation, as shown in Figure 7 , Figure 8 and Figure 9As shown, the stern space of the large semi-submersible vessel after removing the detachable pontoon is smaller than the space between the main hull supports 4 of the converter station. The longitudinal length of the pontoon is approximately equal to the length of the lower support of the converter station. The stern width is greater than the width of the support structure above the deck. The "convex" shaped stern can accommodate the deck support truss 6 of the large semi-submersible vessel supporting the converter station module 5.

[0038] Once the large semi-submersible vessel has completed the buoy installation, the detachable buoys on both sides of the stern can be reinstalled at the dock or anchorage with the assistance of tugboats for normal cargo transportation.

Claims

1. A self-contained buoyancy pontoon for use in semi-submersible vessel float-over installation operations, characterized in that: The system includes self-buoyant detachable pontoons and a restraining device layer. Two self-buoyant detachable pontoons are installed on both sides of the stern of the large semi-submersible vessel, and a restraining device layer is provided in the gap between the self-buoyant detachable pontoons and the two sides of the stern of the large semi-submersible vessel. The cross-section of the self-buoyant detachable pontoons is "L"-shaped facing the midships. In the length direction, it extends from the stern plate towards the midships for a certain length, equal to the length of the main mast support of the target converter station. In the beam direction, it extends from the side of the hull to a certain distance away from the propeller. The two ballast tanks in the self-buoyant detachable pontoons are used to complete ballasting with the assistance of the main hull, thus forming the "L" shape. The pontoon can maintain good buoyancy independently in the water under ballast conditions and be smoothly towed by tugboats; the self-buoyant detachable pontoon has streamlined surfaces on both sides and bottom that fit the "convex" stern of the large semi-submersible vessel, and its front, rear and midship sections are flat; the front and midship planes of the self-buoyant detachable pontoon fit snugly against the stern of the large semi-submersible vessel, and the planar gap between the self-buoyant detachable pontoon and the large semi-submersible vessel is a certain limiting device layer; the limiting devices in the limiting device layer are rigidly connected to the self-buoyant detachable pontoon and the hull, and control the separation and connection of the self-buoyant detachable pontoon and the hull.

2. The self-contained buoyancy pontoon for use in semi-submersible vessel float-over installation operations as described in claim 1, characterized in that: Two self-buoyant, detachable pontoons are symmetrically arranged on both sides of the stern of the large semi-submersible vessel, with the midship as the center.

3. The self-contained buoyancy pontoon for use in semi-submersible vessel float-over installation operations as described in claim 1, characterized in that: The self-buoyant detachable pontoons include: two ballast tanks located below the midships, and empty tanks located on both sides above the main deck of the hull, as well as other semi-submersible marine equipment.

4. The self-contained buoyancy pontoon for use in semi-submersible vessel float-over installation operations as described in claim 1, characterized in that: The self-buoyant detachable pontoons extend 30-50 meters from the stern plate to the midships in the longitudinal direction; the width of a single detachable pontoon in a semi-submersible vessel is 12.7 meters; and it runs through the entire vessel in the draft direction.

5. The self-contained buoyancy pontoon for use in semi-submersible vessel float-over installation operations as described in claim 1, characterized in that: After removing the detachable buoyancy-supporting pontoons, the stern width should be greater than the range of two propellers, that is, greater than the stern wheelbase plus the length of one propeller diameter, greater than the width of the support truss on the semi-submersible deck, and greater than the spacing of the main mast supports of the converter station.

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