RoRo cargo ship converted from gas fuel container ship

Abstract

The present invention discloses a roll-on / roll-off cargo ship modified from a gas-fueled container ship, wherein a power device and a power generation device are provided at the stern of the roll-on / roll-off cargo ship. The main body is provided with a cargo hold area, and the cargo hold area is modified to provide a passage that runs through the entire ship for the movement of loading and unloading vehicles, and is composed of a main passage at the bottom of the cargo hold, a passage at the bottom of the bow, a main passage on the upper part of the cargo hold, and a bow cross-cabin lifting passage. A large gate is provided at the side of the bow as an entrance and exit for loading and unloading vehicles. The present invention has high economic efficiency, so that the modified roll-on / roll-off ship no longer needs a dedicated collection terminal for loading and unloading, and the roll-on / roll-off transfer of goods in the cargo hold area is efficiently realized. Only a hole is opened at the bow, which maximizes the integrity of the longitudinal components of the hull and avoids damage to the overall longitudinal strength.

Description

Technical Field

[0001] The present invention relates to the field of ship modification, and more particularly to a roll-on / roll-off cargo ship modified from a gas fuel container ship. Background Art

[0002] In recent years, the capacity of the container ship market has continued to increase, and the container shipping market may be seriously oversupplied in the future. Shipowners have sufficient potential to convert container ships to enter other markets. On the other hand, the large-scale trend of the ro-ro cargo ship market has emerged. Ro-ro cargo ships load and unload goods through automobile activities, do not require lifting equipment, and have high loading and unloading efficiency. In addition to loading containers, they can also carry special goods, various large goods, mixed multiple materials and even special function ro-ro transportation. Large-scale transportation can significantly reduce unit transportation costs. In addition, with the increasingly stringent carbon emissions, the conversion of existing gas-fueled container ships into gas-fueled ro-ro ships can be sufficiently competitive in the ro-ro shipping market. The main scale characteristics of container ships are similar to those of ro-ro cargo ships, and the cargo capacity is larger than that of conventional ro-ro cargo ships. Therefore, by converting gas-fueled container ships into ro-ro cargo ships, on the one hand, the excess capacity of container ships can be effectively solved and the fleet structure can be optimized; on the other hand, the large-scale converted ro-ro cargo ships provided can be sufficiently competitive in the ro-ro cargo ship transportation market.

[0003] There are many technical difficulties in converting a gas-fueled container ship into a roll-on / roll-off cargo ship: 1. Container ships are loaded and unloaded through dock lifting equipment, and there are no openings or passages for loading and unloading vehicles to get on and off the ship. 2. The cargo holds of container ships are independent of each other, and loading and unloading vehicles cannot be transported between the holds. 3. Containers are of uniform size and suitable for stacking, while the cargo loaded on roll-on / roll-off cargo ships is more flexible and needs to be classified and placed according to different sizes. 4. Cargo above the main deck of container ships is stacked in the open air without shelter, while roll-on / roll-off cargo generally requires wind and rain shelter, and provides separate ventilation, lighting and fire protection requirements. 5. Modification of the loading and unloading passage will cause damage to the overall longitudinal strength of the hull. 6. The location of the gas fuel tank affects the transshipment of roll-on / roll-off cargo. Summary of the invention

[0004] The present invention provides a roll-on / roll-off cargo ship modified from a gas-fueled container ship, which has less modification content and lower modification difficulty, meets the use requirements under the premise of ensuring safety, is not only economical and practical, but also flexible and changeable, and helps to solve the problem of overcapacity in the container ship shipping industry.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a roll-on / roll-off cargo ship modified from a gas-fueled container ship, wherein a power unit and a power generation unit are provided at the stern, a bow superstructure and a stern superstructure are provided above the main deck, a gas fuel tank is provided below the bow superstructure, and the roll-on / roll-off cargo ship comprises an upper loading area above the main deck and a lower loading area below the main deck.

[0006] The upper loading area includes a bow upper loading area located in front of the bow superstructure and a stern upper loading area located behind the bow superstructure.

[0007] The bow upper loading area is composed of the original longitudinal bulkheads and the original transverse bulkheads of the forward cargo hold area of ​​the gas fuel container ship before the modification extending vertically upward to the height below the blind spot line of sight to form the bow transverse and longitudinal bulkheads and the bow horizontal weathertight top plate located on the top.

[0008] The stern upper loading area is composed of the original longitudinal bulkheads and the original transverse bulkheads of the rear cargo hold area of ​​the gas fuel container ship before the modification extending vertically upward to the height of the highest box top of the original container ship to be modified to form the stern transverse and longitudinal bulkheads and the stern horizontal weathertight top plate located on the top.

[0009] Multiple layers of fixed decks are arranged inside the upper cargo area of ​​the bow and the upper cargo area of ​​the stern.

[0010] A first opening is provided at a middle position below the bow superstructure, the bottom surface of the first opening is located on the main deck, and the first opening can be used for the passage of loading and unloading vehicles.

[0011] A passage platform for loading and unloading vehicles to pass through is built on one side of the stern superstructure.

[0012] The lower loading area includes a bow lower loading area located in front of the gas fuel tank and a stern lower loading area located behind the gas fuel tank.

[0013] The bow lower loading area and the stern lower loading area each include a plurality of independent cargo holds, and the independent cargo holds adjacent to each other along the length direction of the roll-on / roll-off cargo ship are separated by transverse bulkheads, and a first bulkhead opening is provided under each transverse bulkhead to connect the independent cargo holds on both sides thereof, and a gangway platform connecting the inner decks of two adjacent independent cargo holds is provided at the bottom of each of the first bulkhead openings; a multi-layer movable deck is provided inside the independent cargo hold.

[0014] The roll-on / roll-off cargo ship is provided with a passageway running through the upper loading area and the lower loading area for the movement of loading and unloading vehicles, and the passageway includes a main passageway located at the bottom of the stern lower loading area, a bow bottom passageway located at the bottom of the bow lower loading area, a bow cross-cabin lifting passageway, and an upper cargo hold passageway.

[0015] The bow cross-cabin lifting passage consists of a bow cross-cabin lifting platform that can be lifted vertically and a main deck passage located on the main deck that can enter the bottom of the bow upper loading area and the bottom of the stern upper loading area.

[0016] The cargo hold upper passage includes a bow upper fixed deck passage, a stern upper fixed deck passage, and the passage platform located on one side of the stern superstructure.

[0017] A bow lifting platform is arranged in front of the bow upper loading area and the bow lower loading area. The bow lifting platform can carry loading and unloading vehicles to move up to each of the bow upper fixed deck passages, and can also carry loading and unloading vehicles down to the bow bottom passage.

[0018] A midship lifting platform is also provided in front of the stern upper loading area and the stern lower loading area. The midship lifting platform can carry loading and unloading vehicles to move up to each of the stern upper fixed deck passages, and can also carry loading and unloading vehicles down to the main passage.

[0019] A gate is provided on the bow side of the roll-on / roll-off cargo ship as an entrance and exit for loading and unloading vehicles. The gate is a double-layer structure, with a watertight door structure on the inner side of the hull and a non-watertight door structure on the outer side of the hull. The non-watertight door structure is a curved surface that is smoothly connected to the hull shell of the roll-on / roll-off cargo ship; a retractable and rotatable movable springboard is provided between the watertight door structure and the non-watertight door structure, and an anti-slip strip is provided on the movable springboard; an inclined platform is provided between the watertight door structure and the non-watertight door structure, and the angle between the inclined platform and the horizontal plane does not exceed 4°, and an anti-slip strip is provided on the inclined platform.

[0020] The method for loading cargo by berthing a ro-ro cargo ship comprises the following steps:

[0021] S1. First, open the non-watertight door structure of the gate on the bow side, then rotate the movable springboard outward and lower it to connect it to the dock; after the water outside the watertight door structure is drained through the inclined platform, open the watertight door structure again.

[0022] S2. During loading, all the movable decks are stacked at the bottom of the independent cargo hold, and the loading and unloading vehicles reach the designated cargo hold through the main channel or the bow bottom channel. When the movable decks of this layer are full, the movable decks of this layer are moved up by manipulating the hydraulic support columns under the movable decks of this layer until all the movable decks are full.

[0023] S3. When the cargo needs to be unloaded to the bow upper loading area, the loading and unloading vehicle is lifted to the height of the target cargo stacking layer through the bow cross-cabin lifting platform, and moves forward to the target point along the bow upper fixed deck passage; when the cargo needs to be unloaded to the stern upper loading area, the loading and unloading vehicle moves to the midship lifting platform through the main deck passage, and then rises to the height of the target cargo stacking layer with the midship lifting platform, and then passes through the stern upper fixed deck passage of this layer, and the passage platform located on one side of the stern superstructure to reach the target point.

[0024] S4. After the cargo is fully loaded, first close the watertight door structure of the gate, then retract the movable gangway, and finally close the non-watertight door structure on the outside of the hull. At this point, the ro-ro cargo ship is fully loaded.

[0025] The above-mentioned roll-on / roll-off cargo ship converted from a gas-fueled container ship, in a preferred manner, is provided with one or more temperature-adjustable low-temperature cabins in the stern cargo hold area of ​​the roll-on / roll-off cargo ship, and a rolling door is provided at the opening of the first bulkhead below the transverse bulkhead of the low-temperature cabin, and the rolling door has a heat insulation function; a plate is added upwardly in the vertical direction to the transverse bulkhead on the bow side of the low-temperature cabin, and the plate extends upward to the horizontal wind and rainproof top plate of the stern and downward to the transverse bulkhead of the bottom of the ship, and is connected to the longitudinal bulkheads on both sides by welding to form a complete new transverse bulkhead; an insulation layer is added to the new transverse bulkhead to form a temperature separation between the low-temperature cabin and other cargo holds; the low-temperature cabin is provided with a temperature sensing and temperature control system, and the temperature of the low-temperature cabin is adjusted and detected by the temperature control system.

[0026] Goods with special temperature requirements should be loaded and unloaded centrally, and the roller shutter door of the low-temperature compartment should be closed after loading and unloading.

[0027] The above-mentioned roll-on / roll-off cargo ship converted from a gas-fueled container ship, in a preferred embodiment, further comprises a ballast system, and the ballast system remains unchanged relative to the gas-fueled container ship before conversion.

[0028] In step S4, when the ro-ro cargo ship docks to load cargo, the draught of the hull deepens with the increase in the total amount of cargo loaded. When the inclination of the movable gangway at the gate exceeds 4°, ballast water should be discharged through the ballast tank of the ballast system to reduce the draught of the hull; when the cargo loading positions are relatively concentrated, it will cause different draughts at the bow and stern or different draughts at the left and right sides of the hull. At this time, the buoyancy of the hull is adjusted by the ballast water amount in the ballast tank of the ballast system, so that the angle between the movable gangway at the gate and the horizontal plane is always maintained within 4°.

[0029] In the above-mentioned roll-on / roll-off cargo ship converted from a gas-fueled container ship, in a preferred manner, the multiple layers of the fixed deck, the movable deck, the bow transverse and longitudinal bulkheads, and the stern transverse and longitudinal compartments are provided with lashing devices for fixing cargo; in the step S3, after the cargo reaches the designated compartment, the cargo is lashed by the lashing devices.

[0030] In the above-mentioned roll-on / roll-off cargo ship converted from a gas-fueled container ship, in a preferred embodiment, both the upper loading area and the lower loading area are provided with inspection passages, ventilation devices, lighting devices, and fire-fighting devices.

[0031] In the above-mentioned roll-on / roll-off cargo ship converted from a gas-fueled container ship, in a preferred embodiment, a grille is provided between the inspection passage and the fixed deck and the movable deck.

[0032] The present invention adopts the method of converting container ships into ro-ro ships to greatly reduce the cost of the ship hull, and at the same time helps consume the excess container ship inventory. Container ships generally have a large load capacity, so the ro-ro cargo ship converted from them has a larger cargo capacity than conventional ro-ro cargo ships, which reduces the unit transportation cost and makes the converted ro-ro cargo ship more competitive in the market. There are movable decks and fixed decks in the cargo hold. The movable deck can meet the use of cargoes of different sizes and fully and flexibly arrange the cargoes. And unlike conventional ro-ro cargo ships, the structural characteristics of container ships are fully utilized.

[0033] The weight support point of the movable deck in the present invention is located at the bottom of the cargo hold, which can fully meet the requirements of structural strength without additional structural reinforcement. The fixed deck is arranged above the main deck, which not only carries cargo but also strengthens the overall longitudinal strength of the hull. The reasonable combination of the movable deck below the main deck and the fixed deck above the main deck ensures the safety of the hull to the greatest extent while saving the modification cost. The cargo hold area is equipped with a low-temperature cargo hold, which not only makes full use of the cold box equipment and system in the container cabin, but also can meet the transportation of goods with special temperature requirements.

[0034] By setting up multiple lifting platforms, cargo transfer channels within the cargo hold area of ​​the entire ship are realized, overcoming the problem of disconnection between cargo holds due to the inability to open holes in the gas fuel tank. Container ships are affected by the height of the containers on the main deck, and the height of the cabins where crew members usually live is very high. Therefore, after being converted into a roll-on / roll-off cargo ship, the increase in the height of the cargo hold will not affect the crew's line of sight, and there is no need to increase the height of the cabin, which brings convenience to the conversion and saves conversion costs. The main dimensional characteristics and stability characteristics of container ships are similar to those of roll-on / roll-off cargo holds, so there is no major modification to the main strength components of the hull, the cargo hold and the ballast tank type and capacity, which provides the possibility and convenience for conversion. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0036] Figure 2 It is a longitudinal cross-sectional schematic diagram of the bow superstructure and the gas fuel tank of the present invention.

[0037] Figure 3 It is a longitudinal cross-sectional schematic diagram of the stern upper loading area and the stern lower loading area of ​​the present invention.

[0038] Figure 4 The diagram is a schematic diagram of the structure of the gate of the roll-on / roll-off cargo ship of the present invention viewed from the top to the bottom.

[0039] Figure 5 It is a schematic diagram of the longitudinal cross-sectional structure of the gate of a ro-ro cargo ship according to the present invention.

[0040] In the figure, 1, main deck, 2, independent cargo compartment, 3, first opening, 4a, bow horizontal weathertight top plate, 4b, stern horizontal weathertight top plate, 5, blind spot sight, 6a, fixed deck, 6b, movable deck, 7, first bulkhead opening, 8, gate, 9, gangway platform, 10a, main passage, 10b, bow bottom passage, 10c, bow cross-cabin lifting passage, 11, inspection passage, 12, hydraulic support column, 13, grille, 14, gas fuel tank, 15, plate, 16, watertight door Structure, 17. Non-watertight door structure, 18. Movable ramp, 19. Inclined platform, 20. Ballast tank, 21a. Bow cross-tank lifting platform, 21b. Bow lifting platform, 21c. Midship lifting platform, 22a. Main deck passage, 22b. Bow upper fixed deck passage, 22c. Stern upper fixed deck passage, 30. Bow superstructure, 31. Bow upper loading area, 32. Stern upper loading area, 33. Bow lower loading area, 34. Stern lower loading area, 40. Stern superstructure. DETAILED DESCRIPTION

[0041] like Figure 1 As shown, the present invention is a roll-on / roll-off cargo ship converted from a gas-fueled container ship, wherein a power unit and a power generation unit are provided at the stern, a bow superstructure 30 and a stern superstructure 40 are provided above the main deck, a gas fuel tank 14 is provided below the bow superstructure 30, and the roll-on / roll-off cargo ship comprises an upper loading area above the main deck 1, and a lower loading area below the main deck 1.

[0042] The upper cargo area includes a bow upper cargo area 31 located in front of the bow superstructure 30 and a stern upper cargo area 32 located behind the bow superstructure 30 .

[0043] The bow upper loading area 31 is composed of the original longitudinal bulkheads and the original transverse bulkheads of the forward cargo hold area of ​​the gas fuel container ship before modification extending vertically upward to the height below the blind spot line of sight 5 to form the bow transverse and longitudinal bulkheads and the bow horizontal weathertight top plate 4a located on the top.

[0044] The stern upper loading area 32 is composed of the original longitudinal bulkheads and the original transverse bulkheads of the rear cargo hold area of ​​the gas fuel container ship before conversion, which extend vertically upward to the height of the highest box top of the original container ship to be converted to form the stern transverse and longitudinal bulkheads and the stern horizontal weathertight top plate 4b located on the top.

[0045] Multiple layers of fixed decks 6a are provided inside the bow upper loading area 31 and the stern upper loading area 32.

[0046] like Figure 2 As shown, a first opening 3 is opened at a middle position below the bow superstructure 30, and the bottom surface of the first opening 3 is located on the main deck 1. The first opening 3 can be used for loading and unloading vehicles to pass through.

[0047] A passage platform for the passage of loading and unloading vehicles is built on one side of the stern superstructure 40.

[0048] The lower loading area includes a bow lower loading area 33 located in front of the gas fuel tank 14 and a stern lower loading area 34 located behind the gas fuel tank 14 .

[0049] like Figure 3 As shown, the bow lower loading area 33 and the stern lower loading area 34 each include a plurality of independent independent cargo holds 2. The independent cargo holds 2 adjacent to each other in the length direction of the ro-ro cargo ship are separated by transverse bulkheads. A first bulkhead opening 7 is provided under each transverse bulkhead to connect the independent cargo holds 2 on both sides thereof. A gangway platform 9 connecting the inner decks of two adjacent independent cargo holds 2 is provided at the bottom of each first bulkhead opening 7. A multi-layer movable deck 6b is provided inside the independent cargo hold 2.

[0050] A passage for loading and unloading vehicles is arranged in the roll-on / roll-off cargo ship, which passes through the upper loading area and the lower loading area. The passage includes a main passage 10a at the bottom of the independent cargo hold 2 in the stern lower loading area 34, a bow bottom passage 10b at the bottom of the independent cargo hold 2 in the bow lower loading area 33, a bow cross-cabin lifting passage 10c, and an upper passage in the cargo hold.

[0051] The bow cross-cabin lifting passage 10c is composed of a bow cross-cabin lifting platform 21a that can be lifted vertically and a main deck passage 22a located on the main deck 1 and accessible to the bottom of the bow upper loading area 31 and the bottom of the stern upper loading area 32.

[0052] The upper passage of the cargo hold includes a bow upper fixed deck passage 22b, a stern upper fixed deck passage 22c, and a passage platform located on one side of the stern superstructure 40.

[0053] A bow lifting platform 21b is arranged in front of the bow upper loading area 31 and the bow lower loading area 33. The bow lifting platform 21b can carry loading and unloading vehicles to move up to each bow upper fixed deck channel 22b, and can also carry loading and unloading vehicles down to the bow bottom channel 10b.

[0054] A midship lifting platform 21c is also provided in front of the stern upper loading area 32 and the stern lower loading area 34. The midship lifting platform 21c can carry loading and unloading vehicles up to each stern upper fixed deck passage 22c, and can also carry loading and unloading vehicles down to the main passage 10a.

[0055] like Figure 4 , Figure 5 As shown, a gate 8 is provided on the bow side of the ro-ro cargo ship as an entrance and exit for loading and unloading vehicles. The gate 8 is a double-layer structure, with a watertight door structure 16 on the inner side of the hull and a non-watertight door structure 17 on the outer side of the hull. The non-watertight door structure 17 is a curved surface, which is smoothly connected to the hull shell of the ro-ro cargo ship; a retractable and rotatable movable gangplank 18 is provided between the watertight door structure 16 and the non-watertight door structure 17, and an anti-slip strip is provided on the movable gangplank 18; an inclined platform 19 is provided between the watertight door structure 16 and the non-watertight door structure 17, and the angle between the inclined platform 19 and the horizontal plane does not exceed 4°, and an anti-slip strip is provided on the inclined platform 19.

[0056] The method for loading cargo by a ro-ro cargo ship at the shore includes the following steps:

[0057] S1. First, open the non-watertight door structure 17 of the gate 8 on the bow side, then rotate the movable gangway 18 outward and lower it to connect with the dock; after the water outside the watertight door structure 16 is drained through the inclined platform 19, open the watertight door structure 16.

[0058] S2. During loading, all movable decks 6b are stacked at the bottom of the independent cargo hold 2, and the loading and unloading vehicles reach the designated cargo hold through the main channel 10a or the bow bottom channel 10b. When the movable deck 6b of this layer is full, the movable deck 6b of this layer is moved up by manipulating the hydraulic support columns 12 under this layer of movable deck 6b until all movable decks 6b are full.

[0059] S3. When the cargo needs to be unloaded to the bow upper loading area 31, the loading and unloading vehicle is lifted to the height of the target cargo stacking layer through the bow cross-cabin lifting platform 21a, and moves forward to the target point along the bow upper fixed deck passage 22b; when the cargo needs to be unloaded to the stern upper loading area 32, the loading and unloading vehicle moves to the midship lifting platform 21c through the main deck passage 22a, and then rises to the height of the target cargo stacking layer along the midship lifting platform 21c, and then passes through the stern upper fixed deck passage 22c of this layer, and the passage platform located on one side of the stern superstructure 40 to reach the target point.

[0060] S4. After the cargo is fully loaded, the watertight door structure 16 of the gate 8 is first closed, then the movable gangway 18 is retracted, and finally the non-watertight door structure 17 on the outer side of the hull is closed. At this point, the ro-ro cargo ship is loaded.

[0061] In another embodiment of the present invention, Figure 1 As shown, one or more temperature-adjustable low-temperature cabins 2a are arranged in the cargo hold area at the stern of the ro-ro cargo ship, and a rolling door is arranged at the first bulkhead opening 7 below the transverse bulkhead of the low-temperature cabin 2a, and the rolling door has a heat insulation function; a plate 15 is added upwardly along the vertical direction to the transverse bulkhead on the bow side of the low-temperature cabin 2a, and the plate 15 extends upward to the horizontal weathertight top plate 4b at the stern and downward to the transverse bulkhead at the bottom of the ship, and is connected to the longitudinal bulkheads on both sides by welding to form a complete new transverse bulkhead; an insulation layer is added to the new transverse bulkhead to separate the temperature of the low-temperature cabin 2a from other cargo holds; the low-temperature cabin is provided with a temperature sensing and temperature control system, and the temperature of the low-temperature cabin is adjusted and detected by the temperature control system.

[0062] Goods with special temperature requirements should be loaded and unloaded in a centralized manner, and the roller shutter door of the low-temperature compartment 2a should be closed after loading and unloading.

[0063] The ro-ro cargo ship also includes a ballast system, which remains unchanged compared to the gas-fueled container ship before conversion.

[0064] In the above step S4, when the ro-ro cargo ship docks to load cargo, the draft of the hull deepens with the increase of the total amount of cargo loaded. When the inclination of the movable gangway 18 at the gate 8 exceeds 4°, ballast water should be discharged through the ballast tank 20 of the ballast system to reduce the hull draft; when the cargo loading positions are relatively concentrated, it will cause different drafts at the bow and stern or different drafts at the left and right sides of the hull. At this time, the buoyancy of the hull is adjusted by the ballast water amount in the ballast tank 20 of the ballast system, so that the angle between the movable gangway 18 at the gate 8 and the horizontal plane is always maintained within 4°.

[0065] The multi-layer fixed deck 6a, the multi-layer movable deck 6b, the bow transverse and longitudinal bulkheads and the stern transverse and longitudinal compartments are provided with lashing devices for securing the cargo; in the above-mentioned step S3, after the cargo reaches the designated compartment, the cargo is lashed by the lashing device.

[0066] The upper loading area and the lower loading area are both provided with an inspection passage 11, a ventilation device, a lighting device, and a fire-fighting device. A grille 13 is provided between the inspection passage 11 and the fixed deck 6a and the movable deck 6b.

[0067] The technical solution adopted by the present invention is: a roll-on / roll-off cargo ship converted from a gas-fueled container ship is provided with a power device and a power generation device at the stern of the roll-on / roll-off cargo ship; the main body is provided with a cargo hold area, which is divided into a plurality of relatively independent but mutually interconnected independent cargo loading chambers 2 below the main deck, and a transverse bulkhead is provided between adjacent independent cargo loading chambers 2, and a first bulkhead opening 7 is provided below each transverse bulkhead, and a gangway platform 9 is provided at the first bulkhead opening 7 to connect the inner decks of adjacent cargo holds for the passage of loading and unloading vehicles between the cargo holds; a multi-layered movable deck 6b is provided in the cargo hold below the main deck of the cargo hold area, according to The specific number of layers and the specific number of the movable decks 6b are determined according to loading needs; a large integral loading cabin which runs through the bow and stern is arranged above the main deck 1 in the cargo hold area, and the cabin is provided with multi-layer fixed decks 6a. The specific number of layers and the specific number of the fixed decks 6a are determined according to loading needs, a first opening 3 is opened in the middle of the main deck 1 of the bow superstructure 30 for the passage of loading and unloading vehicles, and a passage platform is built on one side of the stern superstructure 40 for the passage of loading and unloading vehicles; the multi-layer fixed decks 6a, the multi-layer movable decks 6b and the side walls of the cargo hold are provided with lashing devices for fixing the cargo. The passage for loading and unloading vehicles in the cargo hold area that runs through the entire ship is composed of a main passage 10a at the bottom of the cargo hold, a passage 10b at the bottom of the bow, a main passage on the upper part of the cargo hold, and a bow cross-cabin lifting passage 10c; the cargo hold area is equipped with inspection passages, ventilation devices, lighting devices, fire-fighting devices and temperature control devices; both sides of the cargo hold are provided with cabin structures that provide buoyancy and adjust the draft for the roll-on / roll-off cargo ship, namely ballast tanks 20; a large gate 8 is provided on the bow side as the entrance and exit for loading and unloading vehicles.

[0068] The roll-on / roll-off cargo ship converted from a gas-fueled container ship is equipped with a power and power generation device at the stern for navigation and power transmission throughout the ship, and the original engine room layout of the container ship to be converted can be maintained.

[0069] The present invention is a roll-on / roll-off cargo ship converted from a gas-fueled container ship, and its main part is provided with a cargo hold area for loading cargo, and the cargo hold area is composed of a large integral cargo hold above the main deck 1 that runs through the bow and stern, and a plurality of relatively independent but mutually interconnected independent cargo holds 2 below the main deck. According to the characteristics of the cargo hold of the gas-fueled container ship, the cargo hold area is divided into a front cargo hold area and a rear cargo hold area from the midship by the gas fuel tank 14. The main deck of the container ship to be converted is removed, and the original longitudinal bulkhead and transverse bulkhead are vertically extended upward to a height below the blind spot line of sight 5 in the front cargo hold area, and a bow horizontal weatherproof top plate 4a is provided. In the rear cargo hold area, the original longitudinal bulkhead and transverse bulkhead are vertically extended upward to the height of the highest box top of the original container ship to be converted, and a stern horizontal weatherproof top plate 4b is provided.

[0070] A large integral cargo hold that runs through the bow and stern above the main deck of the cargo hold area is provided with a multi-layer fixed deck 6a; each independent cargo hold 2 below the main deck 1 of the cargo hold area is provided with a multi-layer liftable movable deck 6b; a plurality of lashing devices are provided on the deck and on the walls around the deck for fixing the cargo.

[0071] A first bulkhead opening 7 is provided on the transverse bulkhead between each cargo hold below the main deck of the cargo hold area. The opening height is the maximum distance between two movable decks. A gangway platform 9 is arranged at the bottom of the opening to connect adjacent decks.

[0072] The bow superstructure 30 of the cargo hold area is provided with a first opening 3 on the main deck 1, and the opening height is the distance between the main deck and the fixed deck above it.

[0073] The passage in the cargo hold area that runs through the entire ship for the movement of loading and unloading vehicles consists of the main passage at the bottom of the cargo hold, the bottom passage at the bow, the bow cross-cabin lifting passage, and the upper passage at the cargo hold. The main passage 10a at the bottom of the cargo hold is composed of the inner bottom of the cargo hold of the container ship to be modified and the gangway platform 9 at the opening of each transverse bulkhead; since the inner bottom of the bow of the container ship is raised forward in a stepped manner with the converged lines, it is necessary to add a connecting passage at the bottom of the first cargo hold at the bow, and the connecting passage is connected to the bottom passages of other cabins at the bow to form the bow bottom passage 10b. Anti-slip strips need to be added to the upper surface of the connecting passage, and the angle between the connecting passage part and the horizontal is determined according to the loading requirements to avoid cargo collapse, squeezing or threatening the driving safety of loading and unloading vehicles; the bow cross-cabin lifting passage 10c is composed of a bow cross-cabin lifting platform 21a that can be lifted vertically and a passage on the main deck that can enter the cargo cabin on the main deck; a passage connecting the fixed decks of the front and rear cabins is provided on one side of the stern superstructure 40, which together with the fixed decks on the main deck and above constitutes the upper passage of the cargo hold for loading and unloading vehicles to pass in the cargo cabin above the main deck.

[0074] In order to meet the transportation needs of special goods, the cargo hold area can be provided with one (or more) temperature-adjustable low-temperature cabins 2a, which are converted from the cargo hold of the container ship to be converted. A rolling door is provided at the opening of the transverse bulkhead on the bow side of the low-temperature cabin 2a, and the rolling door has a heat insulation function. A plate 15 is added to the transverse bulkhead on the bow side of the low-temperature cabin 2a in the vertical direction. The plate 15 extends upward to the top plate of the cargo hold area and downward to the transverse bulkhead. Both sides are connected to the longitudinal bulkheads and are connected by welding to form a completed new transverse bulkhead. The modified new transverse bulkhead is equipped with an insulation layer to separate the temperature of the low-temperature cabin from other cargo holds. The low-temperature cabin is provided with a temperature sensing and temperature control system, which is converted from the cold box cooling system of the container ship to be converted. The cold box cooling equipment of the container ship is disassembled and centrally arranged in the low-temperature cabin 2a. The temperature of the low-temperature cabin is adjusted and detected by the temperature control system to meet the different temperature requirements of different goods.

[0075] The cargo hold area for roll-on / roll-off cargo is provided with an inspection passage 11 for personnel inspection on both sides of the movable (or fixed) deck. A grille 13 is provided between the inspection passage 11 and the movable deck 6b to prevent cargo from scattering and blocking the passage or endangering the safety of the crew. The inspection passage 11 allows personnel to check the cargo or the lashing status at any time, and alarm devices are provided at specified distances. At the same time, the passage meets ventilation and escape requirements.

[0076] The cargo hold area is equipped with ventilation equipment and fire-fighting equipment, and fixed or mobile lighting equipment.

[0077] The ballast tanks and ballast system of the container ship to be converted remain unchanged, providing buoyancy and adjusting draft for the converted ro-ro cargo ship.

[0078] The roll-on / roll-off cargo ship converted from a gas-fueled container ship has a large gate 8 on the bow side as an entrance and exit for loading and unloading vehicles. The gate 8 is a double-layer structure, with a watertight door structure 16 on the inner side of the hull and a non-watertight door structure 17 on the outer side of the hull. The non-watertight door structure 17 is a curved surface that smoothly connects with the hull shell to ensure the hydrodynamic performance of the hull and save fuel consumption. A retractable and rotatable movable springboard 18 is provided between the watertight door structure 16 and the non-watertight door structure 17, and an anti-slip strip is provided on the springboard; an inclined platform 19 is provided between the watertight door structure 16 and the non-watertight door structure 17, and the angle between the inclined platform 19 and the horizontal plane does not exceed 4°, and an anti-slip strip is provided on the inclined platform 19.

[0079] The following is a further explanation of the method of use of this patent in conjunction with the accompanying drawings.

[0080] like Figure 1~Figure 5 As shown, when the ro-ro ship docks at the wharf, the draft and the hull state are adjusted through the ballast tanks 20 in the cargo hold area, so that the hull floats flat and the inclined platform 19 under the bow gate 8 is close in height.

[0081] First, the non-watertight door structure 17 of the bow side gate is opened, and then the movable springboard 18 is rotated outward and lowered to be connected to the dock. After the water outside the watertight door structure 16 is drained through the inclined platform 19, the watertight door structure 16 is opened again.

[0082] The loading and unloading vehicles are lifted to the main deck 1 through the bow cross-cabin lifting platform 21a. When the cargo needs to be unloaded to the bow lower loading area 33 below the main deck 1, the loading and unloading vehicles move to the bow lifting platform 21b through the main deck and descend with the platform to the bow bottom passage 10b; when the cargo needs to be unloaded to the rear cabin below the main deck, the loading and unloading vehicles move to the midship lifting platform 21c through the main deck passage 22a and descend with the platform to the main passage 10a at the bow bottom.

[0083] During loading, all the movable decks 6b are stacked at the bottom of the independent cargo hold 2, and the loading and unloading vehicles reach the designated cargo hold through the main channel 10a at the bottom of the cargo hold or the channel 10b at the bottom of the bow. After unloading, the cargo is tied and fixed by the tying devices on the movable deck 6b and the bulkhead. When this layer of movable deck 6b is full, the movable deck 6b of this layer is moved up by operating the hydraulic support column 12 under the movable deck 6b of this layer until all the movable decks 6b are full. Cargo with special temperature requirements should be centrally loaded and unloaded in the low-temperature cabin 2a, and the rolling door of the low-temperature cabin 2a should be closed after loading and unloading.

[0084] When the cargo needs to be unloaded to the cabin position above the main deck before the bow superstructure 30, the loading and unloading vehicle is lifted to the height of the target cargo stacking layer through the bow cross-cabin lifting platform 21a, and moves forward to the target point along the bow upper fixed deck passage 22b; when the cargo needs to be unloaded to the cabin position above the main deck after the stern superstructure 40, the loading and unloading vehicle moves to the midship lifting platform 21c at the middle of the ship through the main deck passage 22a, and then rises to the height of the target cargo stacking layer with the platform, and then reaches the target point through the stern upper fixed deck passage 22c on this fixed deck, and the passage on the side of the stern superstructure 40.

[0085] When a ro-ro cargo ship docks to load cargo, the draft of the ship deepens as the total amount of cargo loaded increases. When the inclination of the movable ramp 18 at the gate 8 at the bow exceeds 4°, ballast water should be discharged through the ballast tank 20 to reduce the draft of the ship. When the cargo loading position is relatively concentrated, it will cause different drafts at the bow and stern of the ship or different drafts at the left and right sides. At this time, the buoyancy of the ship is adjusted by the ballast water in the ballast tank 20, so that the angle between the movable ramp 18 at the gate 8 at the bow and the horizontal plane is always kept within 4°. After the cargo is fully loaded, the watertight door structure 16 of the gate 8 is first closed, then the movable ramp 18 is retracted, and finally the non-watertight door structure 17 on the outside of the hull is closed. At this point, the ro-ro cargo ship is loaded.

[0086] In order to solve the many problems raised in the background technology, the present invention provides an overall solution for converting a gas-fueled container ship into a roll-on / roll-off cargo ship. The modification content is relatively small and the modification difficulty is relatively low. It meets the use requirements while ensuring safety. It is not only economical and practical, but also flexible and changeable, which helps to solve the problem of overcapacity in the container ship shipping industry.

[0087] The ro-ro cargo ship converted from a gas-fueled container ship is equipped with a power unit and a power generation unit at the stern of the ro-ro cargo ship. The main part is equipped with a cargo hold area, which is modified to provide a passage for loading and unloading vehicles throughout the ship, consisting of the main passage at the bottom of the cargo hold, the bottom passage at the bow, the main passage on the upper part of the cargo hold, and the bow cross-cabin lifting passage. A large gate is set at the side of the bow as an entrance and exit for loading and unloading vehicles. It is highly economical, so that the converted ro-ro ship no longer needs a dedicated container terminal for loading and unloading, and the ro-ro transfer of goods in the cargo hold area can be realized efficiently. Only holes are opened at the bow, which maximizes the integrity of the longitudinal components of the hull and avoids damage to the overall longitudinal strength.

[0088] The present invention provides a cargo hold modification method, which converts the main deck of the container ship to be modified into a flat fixed main deck that can be loaded with cargo, extends the original longitudinal bulkhead and transverse bulkhead vertically upward to a height below the line of sight, and provides a weathertight top plate. The cargo hold is arranged with ventilation and escape passages, and is equipped with lighting, ventilation, fire-fighting and other equipment.

[0089] The cargo hold of the present invention is provided with multiple layers of movable decks and fixed decks, the main deck in the cargo hold and the upper part of the main deck are provided with multiple layers of fixed decks, and the lower part of the main deck in the cargo hold is provided with multiple layers of movable decks, and the specific number and quantity of the multiple layers of decks are determined according to the location of the decks and the loading requirements. A more efficient and multiple compatible ro-ro arrangement method is proposed, which is conducive to improving the utilization efficiency and economy of ro-ro ships.

[0090] The present invention proposes to provide one (or more) temperature-adjustable low-temperature cabins, which are converted from the cargo hold at the rearmost part of the cargo hold area of ​​the container ship to be converted. A rolling door is provided at the opening of the transverse bulkhead on the bow side of the low-temperature cabin, and the rolling door has a heat insulation function. A plate is added to the transverse bulkhead on the bow side of the low-temperature cabin in the vertical direction, and the plate is connected to the top plate of the cargo hold area upward and to the transverse bulkhead downward, and to the longitudinal bulkheads on both sides, and they are all connected by welding to form a complete new transverse bulkhead. The converted transverse bulkhead is equipped with an insulation layer to form a temperature separation between the low-temperature cabin and other cargo holds. The low-temperature cabin is provided with a temperature sensing and temperature control system, which is converted from the cold box cooling system of the container ship to be converted. The cold box cooling equipment of the container ship is disassembled and centrally arranged in the low-temperature cabin. The temperature of the low-temperature cabin is adjusted and detected by the temperature control system to meet the different temperature requirements of different goods, thereby broadening the transportation capacity of the ro-ro ship.

[0091] The present invention proposes a cross-tank transfer method, which facilitates a fast and low-cost modification method for the gas fuel storage tank in the cargo hold area, and also provides a reference for the modification of conventional fuel-powered container ships.

[0092] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A roll-on / roll-off cargo ship converted from a gas-fueled container ship, wherein a power unit and a power generation unit are provided at the stern, a bow superstructure (30) and a stern superstructure (40) are provided above the main deck (1), a gas fuel tank (14) is provided below the bow superstructure (30), and the ship is characterized in that: The ro-ro cargo ship comprises an upper loading area above the main deck (1) and a lower loading area below the main deck (1); The upper loading area comprises a bow upper loading area (31) located in front of the bow superstructure (30) and a stern upper loading area (32) located behind the bow superstructure (30); The bow upper loading area (31) is composed of the original longitudinal bulkhead and the original transverse bulkhead of the forward cargo hold area of ​​the gas fuel container ship before modification, which are vertically extended upward to a height below the blind spot sight line (5) to form the bow transverse and longitudinal bulkhead and the bow horizontal weathertight top plate (4a) located on the top; The stern upper loading area (32) is composed of the original longitudinal bulkheads and the original transverse bulkheads of the rear cargo hold area of ​​the gas fuel container ship before conversion, which are vertically extended upward to the height of the highest box top of the original container ship to be converted to form the stern transverse and longitudinal bulkheads and the stern horizontal weathertight top plate (4b) located on the top; The bow upper loading area (31) and the stern upper loading area (32) are both provided with multi-layer fixed decks (6a); A first opening (3) is provided at a middle position below the bow superstructure (30), the bottom surface of the first opening (3) is located on the main deck (1), and the first opening (3) is capable of allowing loading and unloading vehicles to pass through; A passage platform for loading and unloading vehicles to pass is built on one side of the stern superstructure (40); The lower loading area comprises a bow lower loading area (33) located in front of the gas fuel tank (14) and a stern lower loading area (34) located behind the gas fuel tank (14); The bow lower loading area (33) and the stern lower loading area (34) each include a plurality of mutually independent independent cargo holds (2), the independent cargo holds (2) adjacent to each other along the length direction of the ro-ro cargo ship are separated by transverse bulkheads, a first bulkhead opening (7) is provided below each transverse bulkhead to connect the independent cargo holds (2) on both sides thereof, a gangway platform (9) is provided at the bottom of each first bulkhead opening (7) to connect the inner decks of two adjacent independent cargo holds (2); a multi-layered movable deck (6b) is provided inside the independent cargo hold (2); The ro-ro cargo ship is provided with a passageway for loading and unloading vehicles that runs through the upper loading area and the lower loading area, the passageway comprising a main passageway (10a) located at the bottom of the stern lower loading area (34), a bow bottom passageway (10b) located at the bottom of the bow lower loading area (33), a bow cross-cabin lifting passageway (10c), and a cargo hold upper passageway; The bow cross-cabin lifting passage (10c) is composed of a bow cross-cabin lifting platform (21a) that can be lifted vertically and a main deck passage (22a) located on the main deck (1) and capable of entering the bottom of the bow upper loading area (31) and the bottom of the stern upper loading area (32); The cargo hold upper passage comprises a bow upper fixed deck passage (22b), a stern upper fixed deck passage (22c), and the passage platform located on one side of the stern superstructure (40); A bow lifting platform (21b) is arranged in front of the bow upper loading area (31) and the bow lower loading area (33), and the bow lifting platform (21b) can carry loading and unloading vehicles to move up to each of the bow upper fixed deck passages (22b), and can also carry loading and unloading vehicles to move down to the bow bottom passage (10b); A midship lifting platform (21c) is also provided in front of the stern upper loading area (32) and the stern lower loading area (34). The midship lifting platform (21c) can carry loading and unloading vehicles to move up to each of the stern upper fixed deck passages (22c), and can also carry loading and unloading vehicles to move down to the main passage (10a); A gate (8) is provided on the bow side of the ro-ro cargo ship as an entrance and exit for loading and unloading vehicles. The gate (8) is a double-layer structure, with a watertight door structure (16) on the inner side of the hull and a non-watertight door structure (17) on the outer side of the hull. The non-watertight door structure (17) is a curved surface and smoothly connects with the hull shell of the ro-ro cargo ship. A retractable and rotatable movable springboard (18) is provided between the watertight door structure (16) and the non-watertight door structure (17). An anti-slip strip is provided on the movable springboard (18). An inclined platform (19) is provided between the watertight door structure (16) and the non-watertight door structure (17). The angle between the inclined platform (19) and the horizontal plane does not exceed 4°. An anti-slip strip is provided on the inclined platform (19). The method for loading cargo by berthing a ro-ro cargo ship comprises the following steps: S1. First, open the non-watertight door structure (17) of the gate (8) on the bow side, then rotate the movable springboard (18) outward and lower it to connect it to the dock; after the water outside the watertight door structure (16) is drained through the inclined platform (19), open the watertight door structure (16); S2. During loading, all the movable decks (6b) are stacked at the bottom of the independent cargo compartment (2), and the loading and unloading vehicles reach the designated cargo hold through the main channel (10a) or the bow bottom channel (10b). When the movable deck (6b) of this layer is full, the movable deck (6b) of this layer is moved upward by manipulating the hydraulic support column (12) under the movable deck (6b) of this layer until all the movable decks (6b) are full. S3. When the cargo needs to be unloaded to the bow upper loading area (31), the loading and unloading vehicle is lifted to the height of the cargo stacking target layer through the bow cross-cabin lifting platform (21a), and moves forward to the target point along the bow upper fixed deck passage (22b); when the cargo needs to be unloaded to the stern upper loading area (32), the loading and unloading vehicle moves to the midship lifting platform (21c) through the main deck passage (22a), and then rises to the height of the cargo stacking target layer along the midship lifting platform (21c), and then passes through the stern upper fixed deck passage (22c) of this layer, and the passage platform located on one side of the stern superstructure (40) to reach the target point; S4. After the cargo is fully loaded, first close the watertight door structure (16) of the gate (8), then retract the movable gangway (18), and finally close the non-watertight door structure (17) on the outside of the hull. At this point, the ro-ro cargo ship is fully loaded.

2. The roll-on / roll-off cargo ship converted from a gas-fueled container ship according to claim 1, characterized in that: The stern cargo hold area of ​​the ro-ro cargo ship is provided with one or more temperature-adjustable low-temperature cabins (2a), and a rolling door is provided at the first bulkhead opening (7) below the transverse bulkhead of the low-temperature cabin (2a), and the rolling door has a heat insulation function; the transverse bulkhead on the bow side of the low-temperature cabin (2a) is vertically provided with a plate (15) upwardly, and the plate (15) extends upwardly to the horizontal weathertight top plate (4b) at the stern and downwardly to the transverse bulkhead at the bottom of the ship, and is connected to the longitudinal bulkheads on both sides by welding to form a complete new transverse bulkhead; the new transverse bulkhead is provided with an insulation layer to separate the temperature of the low-temperature cabin (2a) from other cargo holds; the low-temperature cabin is provided with a temperature sensing and temperature control system, and the temperature of the low-temperature cabin is adjusted and detected by the temperature control system; Goods with special temperature requirements should be loaded and unloaded in a centralized manner, and the rolling door of the low-temperature compartment (2a) should be closed after loading and unloading.

3. The roll-on / roll-off cargo ship converted from a gas-fueled container ship according to claim 1, characterized in that: The ro-ro cargo ship further comprises a ballast system, which remains unchanged relative to the gas-fueled container ship before conversion; In step S4, when the ro-ro cargo ship docks to load cargo, the draft of the ship deepens as the total amount of cargo loaded increases. When the inclination of the movable gangway (18) at the gate (8) exceeds 4°, ballast water should be discharged through the ballast tank (20) of the ballast system to reduce the draft of the ship. When the cargo loading positions are relatively concentrated, the draft of the ship will be different at the bow and stern or the left and right. At this time, the buoyancy of the ship is adjusted by the ballast water volume of the ballast tank (20) of the ballast system, so that the angle between the movable gangway (18) at the gate (8) and the horizontal plane is always maintained within 4°.

4. The roll-on / roll-off cargo ship converted from a gas-fueled container ship according to claim 1, characterized in that: The multi-layered fixed deck (6a), the movable deck (6b), the bow transverse and longitudinal bulkheads and the stern transverse and longitudinal compartments are provided with lashing devices for securing cargo; in the step S3, after the cargo reaches the designated compartment, the cargo is lashed by the lashing devices.

5. The roll-on / roll-off cargo ship converted from a gas-fueled container ship according to claim 1, characterized in that: The upper loading area and the lower loading area are both provided with an inspection passage (11), a ventilation device, a lighting device, and a fire-fighting device.

6. The roll-on / roll-off cargo ship converted from a gas-fueled container ship according to claim 5, characterized in that: A grille (13) is provided between the inspection passage (11) and the fixed deck (6a) and the movable deck (6b).

Images