A multi-layer mobile platform roll-on / roll-off ship based on the conversion of a container ship

Abstract

The present invention discloses a multi-layer mobile platform roll-on / roll-off ship based on the modification of a container ship, which includes two parts: hull modification and vehicle transportation method. Among them, in terms of structural modification, the present invention does not modify the internal structure of the container ship in large quantities, does not set up a driving walkway, and basically all vehicles are loaded in the cabin to maximize the capacity of the cabin. Since the modification amount of this ship is not large, it can continue to load containers in the future to achieve dual-purpose of containers and roll-on / roll-off. In conjunction with the vehicle transportation method provided by the present invention, the cargo transportation device greatly increases the number of vehicles carried by the ship, and compared with container ships of the same size, the number of vehicles loaded can be increased by 30%. Time is saved by about 50%. In addition, the height of the mobile platform of the present invention is not limited and can be set according to the size and weight of the same type of cargo, thereby reducing the height of the center of gravity of the ship and increasing the safety of the ship during shipping.

Description

Technical Field

[0001] The present invention relates to a ship transformation technology, and more specifically, to a process for converting a container ship into a roll-on / roll-off ship. Background Art

[0002] At present, the container ship orders have surged. When the popularity decreases, the future container shipping market may be seriously oversupplied. Container ships and ro-ro ships have certain similarities. Container ships can be transformed to transport cars or other goods. The conversion of container ships into ro-ro ships will save a lot of new ship construction costs, shorten the construction period, and provide more possibilities for the future container and ro-ro ship markets.

[0003] Container ships are characterized by thin lines and high speed. Their main advantage over roll-on / roll-off ships is that they shorten transportation time. Container ships mainly use onboard cranes to transport standard-sized cargo into the ship's hold, which has fixed loading and low efficiency. Summary of the invention

[0004] The present invention solves the problem of excess container ship capacity by transforming container ships, improves the cargo capacity and efficiency of ro-ro cargo ships, shortens the construction period of new ships, enhances the competitiveness of the ro-ro ship market, and even realizes the dual use of container ships and ro-ro ships. The height of the mobile platform of the present invention is not limited and can be set according to the size and weight of the same type of cargo, reduces the center of gravity height of the ship, and increases the safety of the ship during shipping.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a multi-layer mobile platform ro-ro ship based on the modification of a container ship, including two parts: hull modification and vehicle carrying mode;

[0006] The hull transformation of the first part includes: an engine room is set at the rear of the hull, and a diesel engine and a power generation device for generating electricity and providing power are set in the engine room; a cargo hold area composed of a number of cargo holds is set below the deck, and the cargo hold area is converted from the cargo hold of a container ship, and a pair of side ballast tanks and bottom ballast tanks for providing buoyancy are set on the side of the cargo hold area; two fuel tanks are set in the middle of each of the cargo holds, and the fuel tanks are of the same size and symmetrically distributed; mooring reinforcement structures are set at the bow and stern of the hull for ship port positioning and loading and unloading; an inspection passage is set on the ballast tank, and ventilation and lighting devices are set in the cargo hold area; a double-layer watertight door for cargo entry is set in the inspection passage; a multi-layer movable deck is set in the cargo hold, and the movable deck is fixed and moved by the slide of the container ship.

[0007] The lower side of the watertight door is an inspection passage, and watertight bulkheads are arranged on the front and rear sides, and the watertight bulkheads on the front or rear sides are arranged with the help of transverse bulkheads. The ro-ro ship removes the original ship deck, hatch cover and lashing bridge, extends the side outer plate and inner shell plate upward, and sets the cabin top plate at a height not exceeding the front mast. Several horizontal girder structures are arranged between the inner shell and the outer shell for support, and the horizontal girder can be used as an inspection passage. This structure is an empty cabin, and all components are welded.

[0008] The transverse bulkheads of the ro-ro ship are double transverse bulkheads below the deck of the original ship. The space between the two transverse bulkheads is the fuel tank. The fuel tank is arranged in two adjacent cargo holds, and its height is the area below the deck. The front bulkhead of the fuel tank also extends upward, with a large opening on the top, and is a non-watertight structure. Horizontal support structures and vertical support structures are arranged on the rear bulkhead of the fuel tank for placing cables, pipelines and lamps, or as a maintenance passage for the cargo hold area.

[0009] A multi-layer movable platform is arranged in the cargo hold of the ro-ro ship, and the multi-layer movable platform moves up and down through the original container ship slideway. The slideway is realized by adding a positioning and limiting structure to the container ship slideway; for details, reference may be made to the structural implementation of patents US13262247, CN214463043U, and CN111039241B.

[0010] The mobile platform is a truss structure, with a reinforcing structure that supports each other vertically and horizontally arranged at the bottom, and buckles for tying goods are arranged above the mobile platform for tying goods; a conveyor belt or ball bearings are arranged on the mobile platform to realize automatic loading of goods.

[0011] In addition, the vehicle transportation method of the second part includes the following steps

[0012] S1: First, fill the double bottom and side ballast tanks with water, lift the first platform to the highest platform to the top, then move the lowest first platform down to the bottom of the inner hull watertight door, then open the watertight door on the inner hull, and use the watertight door as a step to put it on the first platform.

[0013] S2: Open the watertight door on the side and place the step outward at the port. If the step is not long enough, use the boarding platform built at the port.

[0014] S3: The vehicle enters the cabin through the side watertight door and the inner shell watertight door, drives directly to the first-level platform, stops the vehicle and ties it to the first-level platform

[0015] S4: Pull up the inner hull watertight door and move the first platform down to the lowest level in the cabin. Here, in order to ensure the stability of the entire ship, the platform for loading vehicles is moved to the lowest level to lower the center of gravity of the entire ship to prevent capsizing.

[0016] S5: Move the second platform from the top to the bottom of the inner shell watertight door, and then use the watertight door as a step to put on the second platform. After it is full, move it down to the highest position of the cargo on the first platform and reserve 10% of the height space.

[0017] S6: Repeat S3 to S5 until the space below is close to the height of the platforms above. In other words, repeat S3 to S5, move the platforms above one by one downwards, and proceed to S7 when the height of the stop position of one platform from the lowest end of the inner shell watertight door is close to the height of all the platforms above.

[0018] S7: Move all the upper platforms downward until the highest platform is flush with the inner shell channel;

[0019] S8: Open the inner shell door, and the vehicle enters the cabin through the side watertight door and the inner shell watertight door, and drives directly to the top platform, stops the vehicle and ties it to the top platform.

[0020] S9: Pull up the inner hull watertight door and move the highest platform upwards to the uppermost level in the cabin;

[0021] S10: Move the second high-level platform from the lower end to the lowest end of the inner shell watertight door, then put on the board, and after it is full, move it downward to 10% of the space from the highest point of the cargo on the second high-level platform.

[0022] Here, the second height platform is moved upward until the height between the cargo on the second height platform and the bottom of the first height platform is 10% of the cargo height, which means that 10% of the cargo height is reserved between the platform and the cargo as a safety space during ship transportation to avoid crushing the cargo when the ship is deformed.

[0023] S11: Repeat S8 to S10 until all the cargo is loaded onto the platform and the cargo hold is full;

[0024] S12: At this time, adjust the platform height so that the platforms are evenly placed.

[0025] In the vehicle transport method, during the loading process, the overall weight center of gravity of the ship is calculated according to the cargo loading situation, the stability and shear bending moment of the ship are checked, and then the weight center, buoyancy and shear bending moment of the whole ship are adjusted; the specific calculation process is:

[0026] According to the type of vehicle to be loaded, the vehicle height is confirmed to be Hc1, Hc2...Hcn, and according to the vehicle height, the height limit of the mobile platform at each level is confirmed to be Hm=max(Hc1, Hc2...Hcn)+Hx, where Hx is the height limit parameter of the platform deformation calculated for different platform structures to prevent the platform deformation from squeezing the vehicle between platforms;

[0027] According to the required loading vehicles, the vehicle weight is confirmed as Mc1, Mc2...Mcn, and the vehicle loading position is estimated according to the platform height limit. The vehicle's center of gravity position along the ship length direction from the ship's stern perpendicular is Lc1, Lc2...Lcn, and the vehicle's center of gravity position along the ship's width direction is Tc1, Tc2...Tcn, where the port side is positive and the starboard side is negative; the vehicle's center of gravity position along the vertical distance from the ship's baseline is Vc1, Vc2...Vcn, and the total loading weight can be obtained as Mcs=∑Mc1+Mc2...+Mcn, the total loading weight The center of gravity along the length of the ship corresponding to the weight is Lcs = [∑(Mc1*Lc1)+(Mc2*Lc2)…+(Mcn*Lcn)] / Mcs, the center of gravity along the width of the ship corresponding to the total loading weight is Tcs = [∑(Mc1*Tc1)+(Mc2*Tc2)…+(Mcn*Tcn)] / Mcs, and the center of gravity along the vertical direction corresponding to the total loading weight is Vcs = [∑(Mc1*Vc1)+(Mc2*Vc2)…+(Mcn*Vcn)] / Mcs;

[0028] Then the total weight of the ship is obtained, Ms = Mv + Mo + Mb + Mcs, where Ms is the total weight of the ship, Mv is the empty ship weight, Mo is the total weight of the ship's fuel, lubricating oil, spare parts, etc., and Mb is the weight of the ship's ballast water. The center of gravity corresponding to the total weight of the ship is KGs = [∑(Mv*Lv)+(Mo*Lo)+(Mb*Lb)+(Mcs*Lcs)] / Ms, where Ls is the center of gravity corresponding to the total weight of the ship, Lv is the center of gravity corresponding to the empty ship weight, Lo is the center of gravity corresponding to the total weight of the ship's fuel, lubricating oil, spare parts, etc., and Lb is the center of gravity corresponding to the weight of the ship's ballast water; According to the balance of gravity and buoyancy, gravity moment and buoyancy moment balance, the ship's draft, metacentric height and buoyancy distribution are inverted through the interpolation of the ship's hydrostatic table;

[0029] Confirm whether the ship's floating state meets the rules and regulations or the shipowner's requirements through the calculation results of the ship's draft. If not, adjust the vehicle distribution method first, that is, adjust Mcs and Lcs, and then adjust the floating state of the entire ship. If the floating state requirements cannot be met by adjusting the vehicle distribution method, it is necessary to adjust the floating state of the entire ship by adjusting the ballast water to meet the rules and regulations or the shipowner's requirements. After meeting the requirements, perform stability related checks;

[0030] The ship's stability height GM = KMs-KGs, where KMs is the ship's metacentric height. The ship's stability height is calculated by weight and buoyancy, and then the ship's initial stability and large inclination stability are checked. If not satisfied, it is preferred to adjust the platform height, and then adjust the center of gravity height of the entire ship, and re-check the stability. If it is still not satisfied, adjust the buoyancy of the entire ship by adjusting the vehicle distribution, and re-check the stability. If it is still not satisfied, it is necessary to adjust the weight and buoyancy of the entire ship by adjusting the ballast water to meet the stability requirements. After meeting the requirements, a strength assessment is performed.

[0031] The total longitudinal bending moment and shear force of the ship can be calculated through the weight distribution and buoyancy distribution of the ship. If they are not satisfied, it is preferred to adjust the platform height, and then adjust the center of gravity height of the entire ship, and re-check the strength. If it is still not satisfied, adjust the buoyancy of the entire ship by adjusting the vehicle distribution, and re-check the strength. If it is still not satisfied, it is necessary to adjust the weight and buoyancy of the entire ship by adjusting the ballast water to meet the strength requirements.

[0032] In a preferred embodiment, a conveyor belt or ball bearings are installed on the mobile platform for transporting goods.

[0033] In a preferred embodiment, in the vehicle transport mode, the total amount of cargo loaded increases, the hull draft deepens, and the ship's heel and pitch states change. When the inclination of the gangway at the side gate exceeds 30°, the ballast water is discharged from the ballast tank to lower the hull draft to ensure the normal passage of vehicles or cargo.

[0034] Preferably, the cargo hold main frame of the cargo hold area is composed of the bottom, inner hull, watertight transverse bulkhead, semi-watertight transverse bulkhead and cabin top plate.

[0035] In a preferred manner, every two cargo holds are interconnected and share a double-layer watertight door; the watertight door is a double-layer structure, wherein the outer watertight door is arranged on the outer plate of the side, and rollers and compression rods are arranged at the bottom; the inner watertight door is arranged on the inner shell, and rollers and compression rods are also arranged at the bottom, and tilted into the cargo hold to serve as a pedal for vehicles to enter the mobile platform.

[0036] In the preferred embodiment, rubber strips are provided on the watertight doors on the inner hull and the side outer plate to achieve watertightness; the watertight doors must be opened above the full load waterline; and the watertight doors are set in the inspection passage of the original ship's empty compartment.

[0037] In a preferred embodiment, a ship's crane is provided at the rear of the ship's hull.

[0038] Preferably, the additional cables will be laid throughout the ship through the bottom conduits and the maintenance passages on the side.

[0039] Preferably, the cargo hold is obtained by removing a non-watertight truss structure in a cargo hold of a container ship.

[0040] The invention can shorten the loading time after modification, has less modification content, and is reasonably priced, which helps to solve the problem of overcapacity in the container ship shipping industry. The beneficial effects are:

[0041] 1. The present invention provides a method for converting a container ship into a ro-ro ship, which has the characteristics of short construction time and low price for the converted ship, and more hull structures can be used.

[0042] 2. The present invention provides two sets of cargo transportation devices, one of which is for transporting cars to designated locations after the cars drive onto the platform, where they are tied up and then transported to designated locations by moving the platform up and down; the other set is for automatically arranging cars and limiting loading of cars after the cars are transported to the platform through sliding devices on the platform, thereby realizing an efficient car transportation method.

[0043] 3. The present invention loads cargo by arranging watertight doors above the waterline on the side of the ship, so that cargo can be loaded in the container cabin and on the deck at the same time, greatly shortening the time for loading cargo.

[0044] 4. The present invention can realize automatic transportation of goods by arranging devices such as balls or conveyor belts on the mobile platform, thereby reducing the use of cranes on the ship.

[0045] 5. The height of the mobile platform described in the present invention is not restricted and can be set according to the size and weight of the same type of cargo, thereby lowering the center of gravity height of the ship and increasing the safety of the ship during navigation.

[0046] 6. The present invention does not require extensive modification of the internal structure of the container ship, does not require the installation of a driveway, and the cabin is basically fully loaded with vehicles, thereby maximizing the cabin capacity. Since the modification of the ship is not large, it can continue to load containers in the future, thus achieving dual-use of containers and roll-on / roll-off.

[0047] 7. The mobile platform and cargo transport device of the present invention greatly increase the number of vehicles carried by ships, and compared with container ships of the same size, the number of vehicles loaded can be increased by 30%, saving about 50% of time. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a schematic diagram of the structure of the ro-ro ship after transformation.

[0049] Figure 2 This is a schematic diagram of the watertight door structure.

[0050] Figure 3 It is a schematic diagram of the watertight transverse bulkhead structure of a ro-ro ship.

[0051] Figure 4 It is a schematic diagram of the non-watertight transverse bulkhead structure of a ro-ro ship.

[0052] Figure 5 It is a schematic diagram of the interior structure of the mobile platform cabin.

[0053] Figure 6 It is a schematic diagram of the structure of the mobile platform.

[0054] Figure 7 It is a structural diagram of the ball platform solution.

[0055] Figure 8 It is a schematic diagram of the conveyor belt platform structure.

[0056] Fig. 9 It is a schematic diagram of the structure after the car is fully loaded and tied to the platform.

[0057] Fig.10 It is a flowchart for loading computer usage. DETAILED DESCRIPTION

[0058] The present invention provides a multi-layer mobile deck roll-on / roll-off cargo ship based on the modification of a container ship, such as Figure 1 As shown, a multi-layer mobile platform roll-on / roll-off cargo ship modified from a container ship is provided with a cabin 1 at the stern of the roll-on / roll-off cargo ship, and a diesel engine and a power generation device for power generation and power supply are provided in the cabin. Several cargo hold areas 2 are provided below the deck, and the cargo hold areas 2 are modified from the cargo holds of container ships. A pair of side ballast tanks 3 and bottom ballast tanks 8 for providing buoyancy are provided on the side of the cargo hold area; two fuel tanks 4 are provided in the middle of each cargo hold, and the fuel tanks are of the same size and symmetrically distributed. The roll-on / roll-off cargo ship is provided with a mooring reinforcement structure at the bow and stern, which can be used for port positioning and loading and unloading of ships. An inspection channel 5 is provided on the ballast tank, and a ventilation device and a lighting device are provided in the cargo hold area; on the side of each two cargo holds, above the full load waterline 16, a double-layer watertight door 6 is provided in the inspection channel 5 for cargo entry; each two cargo holds are interconnected and share a double-layer watertight door; a multi-layer movable deck 7 is provided in the cargo hold, and the movable deck is fixed and moved by the slide of the container ship.

[0059] The multi-layer mobile deck ro-ro cargo ship based on the container ship modification mainly uses diesel generators for navigation power, and the power transmission of the whole ship mainly comes from generators. Compared with the modified container ship, the diesel generators can remain unchanged. Although the modified ship needs electricity to lift the mobile platform, the number of generators can remain unchanged because the cabin no longer needs to load refrigerated containers. The newly added cables of this ship will be laid throughout the ship through the bottom pipe 15 and the side maintenance channel 5.

[0060] The main frame of the cargo hold of the ro-ro cargo ship is composed of a bilge 9, an inner hull 10, a watertight transverse bulkhead 11, a semi-watertight transverse bulkhead 12 and a cabin top plate 13. The cargo hold is obtained by removing the non-watertight truss structure in the cargo hold of a container ship.

[0061] The watertight door 6 of the ro-ro ship is arranged on the side outer plate 14 and the inner shell 10. In order to ensure the strength of the hull structure, as few watertight doors as possible are opened, so two cargo holds share one watertight door, or the watertight door can also be opened in the middle of the hull so that all cargo holds are connected on the side. The more watertight doors there are, the higher the loading efficiency. The watertight door 6 is a double-layer structure, in which the outer watertight door 17 is arranged on the side outer plate 14, and rollers and compression rods are arranged at the bottom, which can be directly placed on the shore as a pedal for transporting cars. In addition, the inner watertight door 18 is arranged on the inner shell 10, and rollers and compression rods are also arranged at the bottom, which are tilted into the cargo hold 2 and can be used as a pedal for vehicles to enter the mobile platform 7. Rubber strips are arranged on the watertight doors on the inner shell and the side outer plate to ensure their watertightness.

[0062] In order to meet the requirements of ship anti-water ingress and damage, the watertight door must be opened at a position 16 above the full load waterline. In order to change the original ship structure as little as possible, the watertight door is set in the inspection channel of the original ship's empty compartment.

[0063] The lower side of the watertight door is the passage 5 of the container ship to be converted. Watertight bulkheads 19 are arranged on the front and rear sides. In order to minimize the modification, the watertight bulkheads 19 on the front or rear side can be supported by the transverse bulkheads 12. The watertight structure formed in this way ensures that vehicles can still pass through without destroying the function of the ballast tank. Figure 1 As shown; the schematic diagram of the watertight door structure is as follows Figure 2 shown.

[0064] The roll-on / roll-off ship removes the original ship deck, hatch cover and lashing bridge, extends the side outer plate 15 and the inner shell plate 10 upward, and sets a cabin top plate 13 at a height not exceeding the front mast. A plurality of horizontal girders 20 structures are set between the inner shell 10 and the outer shell 15 for support. The horizontal girders can be used as maintenance channels. This structure is an empty cabin and all components are welded.

[0065] In order to prevent the bow of the hull and meet the structural strength requirements, the transverse bulkhead of the ro-ro ship is set as a double transverse bulkhead below the original ship deck 21. The space between the two transverse bulkheads is the fuel tank 4. The fuel tank is arranged in two adjacent cargo holds, and its height is the area below the deck. Since the structural strength requirements above the deck are relatively small, the deck is a single transverse bulkhead support structure, which is obtained by extending the uppermost tank top plate 13 from the rear bulkhead of the fuel tank upward. A watertight door is set on the transverse bulkhead to facilitate the passage of vehicles. The front bulkhead 12 of the fuel tank also extends upward, with a large opening 24 on the top, which is a non-watertight structure. A horizontal support structure 22 and a vertical support structure 23 are set on the rear bulkhead 11 of the fuel tank, which can be used to place cables, pipelines and lamps, and can also be used as a maintenance channel in the cargo hold area.

[0066] The watertight transverse bulkhead of the ro-ro ship is as follows: Figure 3As shown, non-watertight transverse bulkheads are Figure 4 shown.

[0067] A multi-layer movable platform 7 is arranged in the cargo hold of the ro-ro ship. The multi-layer movable platform moves up and down through the original container ship slideway, which is realized by adding a clamping and limiting structure on the container ship slideway. The movable platform is a truss structure, and a reinforcing structure that supports each other vertically and horizontally is arranged at the bottom. Buckles for tying goods are arranged above the platform, and goods can be tied. In order to improve the loading efficiency of goods, a conveyor belt or ball bearing can be arranged on the movable platform to realize automatic loading of goods. The layout of the movable platform cabin is as follows: Figure 4 As shown, the mobile platform structure is as follows Figure 5 As shown, the ball platform solution is as follows Figure 6 As shown, the conveyor belt platform solution is as follows Figure 7 As shown, the car is fully loaded and tied to the platform. Figure 8 shown.

[0068] The loading order of the ro-ro cargo is to move all platforms to the top layer first, and set one of the platforms in a position parallel to the lowest point of the watertight door. The platform is loaded with the heaviest cargo first, and the platform is transported to the bottom layer; then the upper platform is moved down to parallel to the watertight door, and after the cargo is filled, it is moved to 10% of the distance from the bottom cargo; and so on. Then all the platforms above are moved downward, the top platform is flush with the watertight door, the top platform is filled, and then moved upward to 500mm from the deck, and then the second highest platform is moved upward to parallel to the watertight door, and the cargo is filled and continued to be lifted upward, and the above steps are repeated until only one platform is left, and it is moved to a position close to the watertight door, and then the cargo is filled, and then it is moved up and down according to the position of the upper and lower cargo. The schematic diagram of the mobile platform cabin is shown in the figure.

[0069] Here is an example of how the platform can be used:

[0070] S1: First, fill the double bottom and side ballast tanks with water, lift platforms 7-1 to 7-6 to the uppermost side, then move the lowest platform 7-1 downward to the lowermost end of the inner shell watertight door, then open the watertight door on the inner shell, and place the pedal on platform 7-1.

[0071] S2: Open the watertight door on the side and place the pedal outward at the port. If it is not long enough, a boarding platform can be built at the port.

[0072] S3: The vehicle enters the cabin through the side watertight door and the inner shell watertight door, drives directly to the platform, stops the vehicle and ties it to the platform

[0073] S4: Pull up the inner hull watertight door and move platform 1 downward to the lowest level in the cabin.

[0074] S5: Move platform 7-2 from the upper end to the lower end of the inner shell watertight door, then put the plate on it, and move it downward to 10% of the space from the highest point of the cargo on platform 1 after it is filled.

[0075] S6: Repeat S3 to S5 until the space below is close to the height of the platform above.

[0076] S7: Move all the upper platforms downward until the top platform 7-6 is flush with the inner shell channel.

[0077] S8: Open the inner shell door, and the vehicle enters the cabin through the side watertight door and the inner shell watertight door, and drives directly to the platform, stops the vehicle and ties it to the platform.

[0078] S9: Pull up the inner hull watertight door and move platform 7-6 upwards to the uppermost level in the cabin.

[0079] S10: Move platform 7-5 from the lower end to the lowest end of the inner shell watertight door, then put the plate on it, and move it downward to 10% of the space from the highest point of the cargo on platform 5 after it is filled.

[0080] S11: Repeat S8 to S10 until all the cargo is loaded onto the platform and the cargo hold is filled.

[0081] S12: At this time, adjust the platform height so that the platforms are evenly placed.

[0082] Since two compartments share one watertight door, vehicles can be loaded in both compartments at the same time. If multiple watertight doors are opened, vehicles can be loaded and unloaded in all compartments at the same time.

[0083] Provides 2 methods of automatic placement of vehicles and goods. When the trolley reaches the platform, a conveyor belt or ball bearing can be installed on the platform. Just drive the vehicle to the side of the conveyor belt close to the watertight door, and the conveyor belt and ball bearing can directly arrange the goods and transport them to the platform. This way, loading efficiency is higher. Fig. 9 The car is shown fully loaded and tied to a platform.

[0084] The ro-ro ship needs to use a loading instrument or a loading computer to fit and calculate or estimate the ship's floating state, stability, and shear bending moment during the cargo loading process. There is no need to update the hardware of the loading instrument or the loading computer. Only by upgrading the software and adding a new module suitable for ro-ro operations, the use requirements can be met. The weight center of gravity of the entire ship can be adjusted through the ballast tanks at the bottom and the side, thereby adjusting the purpose of the ship's floating state. With the increase in the total amount of loaded cargo, the hull draft deepens, and the ship's heel and longitudinal inclination state change. When the inclination of the ramp at the ship's side gate exceeds 30°, the ballast water is discharged through the ballast tank to reduce the hull draft to ensure the normal passage of vehicles or cargo. When the cargo loading position is relatively concentrated, the hull draft will be different at the front and rear or the left and right drafts will be different. At this time, the hull floating state and shear bending moment are adjusted by the ballast water volume in the ballast tank to ensure the normal passage of cargo and the safety of the ship structure. According to the different types of cargo loading, the overall weight and center of gravity of the ship are recalculated, and then the stability, shear force and bending moment of the ship are calculated and checked. The weight center, buoyancy and shear force and bending moment of the whole ship are adjusted by moving each layer of platform and dispatching cargo. Fig.10 .

[0085] The vehicle height is confirmed as Hc1, Hc2...Hcn according to the required loading vehicle type, and the platform height limit is confirmed as Hm=max(Hc1, Hc2...Hcn)+Hx according to the vehicle height, wherein Hx is the height limit parameter of the platform deformation calculated for different platform structures to prevent the platform deformation from squeezing the vehicles between platforms.

[0086] According to the required loading vehicles, the vehicle weight is confirmed as Mc1, Mc2...Mcn, and the vehicle loading position is estimated according to the platform height limit. The vehicle's center of gravity position along the ship length direction from the ship's stern perpendicular is Lc1, Lc2...Lcn, the vehicle's center of gravity position along the ship width direction is Tc1, Tc2...Tcn (port is positive, starboard is negative), and the vehicle's center of gravity position vertically from the ship's baseline is Vc1, Vc2...Vcn, and the total loading weight can be obtained as Mcs=∑Mc1+Mc2...+Mcn. The total loading weight is The center of gravity along the direction of ship length corresponding to the weight is Lcs = [∑(Mc1*Lc1)+(Mc2*Lc2)…+(Mcn*Lcn)] / Mcs, the center of gravity along the direction of ship width corresponding to the total loaded weight is Tcs = [∑(Mc1*Tc1)+(Mc2*Tc2)…+(Mcn*Tcn)] / Mcs, and the center of gravity along the vertical direction corresponding to the total loaded weight is Vcs = [∑(Mc1*Vc1)+(Mc2*Vc2)…+(Mcn*Vcn)] / Mcs.

[0087] The total loading weight and center of gravity obtained above can be used to obtain the total weight of the ship, Ms = Mv + Mo + Mb + Mcs, where Ms is the total weight of the ship, Mv is the empty ship weight, Mo is the total weight of the ship's fuel, lubricating oil, spare parts, etc., and Mb is the weight of the ship's ballast water. The center of gravity corresponding to the total weight of the ship is KGs = [∑(Mv*Lv)+(Mo*Lo)+(Mb*Lb)+(Mcs*Lcs)] / Ms, where Ls is the center of gravity corresponding to the total weight of the ship, Lv is the center of gravity corresponding to the empty ship weight, Lo is the center of gravity corresponding to the total weight of the ship's fuel, lubricating oil, spare parts, etc., and Lb is the center of gravity corresponding to the weight of the ship's ballast water. According to the balance of gravity and buoyancy, gravity moment and buoyancy moment balance, the calculation results of the ship's draft, metacentric height, buoyancy distribution, etc. are inverted through the interpolation of the ship's hydrostatic table.

[0088] The calculation results of the ship's draft are used to confirm whether the ship's buoyancy meets the regulations or shipowner's requirements. If not, it is preferred to adjust the vehicle distribution method, that is, adjust Mcs and Lcs, and then adjust the buoyancy of the entire ship. If the buoyancy-related requirements cannot be met by adjusting the vehicle distribution method, it is necessary to adjust the buoyancy of the entire ship by adjusting the ballast water to meet the regulations or shipowner's requirements. After meeting the requirements, stability-related verification is performed.

[0089] The ship's stability height GM = KMs-KGs, where KMs is the ship's metacentric height. The ship's stability height can be confirmed by the above method, which affects the ship's stability. The greater the stability height, the greater the ship's restoring force and the better the stability, but the shorter the rolling period, resulting in poor ship comfort. Therefore, the ship's stability height is calculated through the above weight and buoyancy, and then the ship's initial stability and large inclination stability are checked (for specific calculation methods, see IS CODE 2008 or Sheng Zhenbang, Liu Yingzhong. Ship Principles (Part 1) [M]. Shanghai: Shanghai Jiaotong University Press, 2004.). If it is not satisfied, it is preferred to adjust the platform height and then adjust the center of gravity height of the entire ship, and re-check the stability. If it is still not satisfied, adjust the buoyancy of the entire ship by adjusting the vehicle distribution, and re-check the stability. If it is still not satisfied, it is necessary to adjust the weight and buoyancy of the entire ship by adjusting the ballast water to meet the stability requirements. After meeting the requirements, perform strength assessment.

[0090] The total longitudinal bending moment and shear force of the ship can be calculated through the weight distribution and buoyancy distribution of the ship. If they are not satisfied, it is preferred to adjust the platform height, and then adjust the center of gravity height of the entire ship, and re-check the strength. If it is still not satisfied, adjust the buoyancy of the entire ship by adjusting the vehicle distribution, and re-check the strength. If it is still not satisfied, it is necessary to adjust the weight and buoyancy of the entire ship by adjusting the ballast water to meet the strength requirements.

[0091] The engine room area and the rear car cannot pass through, so a ship crane is set at the rear to lift the cargo on the ship into the rear cargo hold. You can also use containers to load cargo to maximize the use of the entire ship's cargo.

[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 multi-layer mobile platform ro-ro ship based on the modification of container ship, It is characterized in that It includes two parts: hull modification and vehicle transportation method; The hull modification of the first part includes: an engine room (1) is arranged at the stern of the hull, and a diesel engine and a power generation device for generating electricity and providing power are arranged in the engine room (1); a cargo hold area (2) composed of a plurality of cargo holds is arranged below the deck, and the cargo hold area (2) is converted from the cargo hold of a container ship, and a pair of side ballast tanks (3) and a bottom ballast tank (8) for providing buoyancy are arranged on the side of the cargo hold area; two fuel tanks (4) are arranged in the middle of each cargo hold, and the fuel tanks are of the same size and symmetrically distributed; a mooring reinforcement structure is arranged at the bow and stern of the hull for ship port positioning and loading and unloading; an inspection channel (5) is arranged on the side ballast tank (3), and a ventilation device and a lighting device are arranged in the cargo hold area (2); a double-layer watertight door (6) for cargo entry is arranged in the inspection channel (5); a multi-layer mobile platform (7) is arranged in the cargo hold, and the mobile platform is fixed and moved by the slide of the container ship; The double-layer watertight door (6) is provided with a watertight bulkhead (19) on both the front and rear sides, and the watertight bulkhead (19) on the front or rear side is provided by means of a transverse bulkhead (12); The ro-ro ship removes the original ship deck, hatch cover and lashing bridge, extends the side outer plate and inner shell plate (10) upward, and sets a cabin top plate (13) at a height not exceeding the front mast. A plurality of horizontal girder structures (20) are set between the inner shell plate (10) and the side outer plate for support. The horizontal girder can be used as a maintenance channel. This structure is an empty cabin, and all components are welded. The transverse bulkhead of the ro-ro ship is a double transverse bulkhead below the original ship deck (21), the space between the two transverse bulkheads is the fuel tank (4), and the fuel tank is arranged in two adjacent cargo holds, and its height is the area below the deck; the front bulkhead of the fuel tank also extends upward, and has a large opening (24) on the top, which is a non-watertight structure; the rear bulkhead (11) of the fuel tank is provided with a horizontal support structure (22) and a vertical support structure (23), which are used to place cables, pipelines and lamps, or as a maintenance channel for the cargo hold area; A multi-layered mobile platform (7) is arranged in the cargo hold of the ro-ro ship, and the multi-layered mobile platform moves up and down through the original container ship slideway, and the slideway is realized by adding a clamping and limiting structure on the container ship slideway; the mobile platform (7) is a truss structure, and a reinforcing structure that supports each other vertically and horizontally is arranged below, and a buckle for tying goods is arranged above the mobile platform (7) for tying goods; A conveyor belt or a ball bearing is arranged on the mobile platform (7); In addition, the vehicle transportation method of the second part includes the following steps: S1: First, fill the double bottom and the side ballast tanks with water, lift the first platform (7-1) to the highest platform to the top, then move the lowest first platform downward to the bottom of the inner shell watertight door, then open the inner shell watertight door, and use the inner shell watertight door as a step to put on the first platform (7-1); S2: Open the outer watertight door and place the step outward at the port. If the step is not long enough, use the embarkation platform built at the port. S3: The vehicle enters the cabin through the outer watertight door and the inner shell watertight door, drives directly to the first-level platform, stops the vehicle and ties it to the first-level platform; S4: Pull up the inner hull watertight door and move the first platform (7-1) downward to the lowest level in the cabin; S5: Move the second platform (7-2) from the upper end to the lower end of the inner shell watertight door, and then use the inner shell watertight door as a step to put it on the second platform (7-2). After it is full, move it downward to the highest position of the cargo on the first platform (7-1) and reserve 10% of the height space; S6: Repeat S3 to S5 until the space below is close to the height of the platform above; S7: Move all the upper platforms downward until the highest platform is flush with the inner shell channel; S8: Open the inner shell door, and the vehicle enters the cabin through the outer watertight door and the inner shell watertight door, and drives directly to the top platform, stops the vehicle and ties it to the top platform; S9: Pull up the inner hull watertight door and move the highest platform upwards to the uppermost level in the cabin; S10: Move the second high-level platform from the lower end to the lowest end of the inner hull watertight door, then put the board on it, and after it is full, move it upward to a position 10% of the space from the highest point of the cargo on the second high-level platform; S11: Repeat S8 to S10 until all the cargo is loaded onto the platform and the cargo hold is full; S12: At this time, adjust the platform height so that the platforms are evenly placed; In the vehicle transport method, during the loading process, the overall weight center of gravity of the ship is calculated according to the cargo loading situation, the stability and shear bending moment of the ship are checked, and then the weight center, buoyancy and shear bending moment of the whole ship are adjusted; the specific calculation process is: According to the type of vehicle to be loaded, the vehicle height is confirmed to be Hc1, Hc2...Hcn, and according to the vehicle height, the height limit of the mobile platform at each level is confirmed to be Hm=max(Hc1, Hc2...Hcn)+Hx, where Hx is the height limit parameter of the platform deformation calculated for different platform structures, so as to prevent the platform deformation from squeezing the vehicle between platforms; According to the required loading vehicles, the vehicle weight is confirmed as Mc1, Mc2...Mcn, and the vehicle loading position is estimated according to the platform height limit. The vehicle's center of gravity position along the ship length direction from the ship's stern perpendicular is Lc1, Lc2...Lcn, and the vehicle's center of gravity position along the ship's width direction is Tc1, Tc2...Tcn, where the port side is positive and the starboard side is negative; the vehicle's center of gravity position vertically from the ship's baseline is Vc1, Vc2...Vcn, and the total loading weight can be obtained as Mcs=∑Mc1+Mc2...+Mcn, the total loading weight The center of gravity along the length of the ship corresponding to the weight is Lcs = [∑(Mc1*Lc1)+(Mc2*Lc2)…+(Mcn*Lcn)] / Mcs, the center of gravity along the width of the ship corresponding to the total loading weight is Tcs = [∑(Mc1*Tc1)+(Mc2*Tc2)…+(Mcn*Tcn)] / Mcs, and the center of gravity along the vertical direction corresponding to the total loading weight is Vcs = [∑(Mc1*Vc1)+(Mc2*Vc2)…+(Mcn*Vcn)] / Mcs; Then the total weight of the ship is obtained, Ms = Mv + Mo + Mb + Mcs, where Ms is the total weight of the ship and Mv is the empty ship weight. Mo is the total weight of the ship's fuel, lubricating oil, spare parts, etc., and Mb is the weight of the ship's ballast water; the center of gravity corresponding to the total weight of the ship is KGs = [∑(Mv*Lv)+(Mo*Lo)+(Mb*Lb)+(Mcs*Lcs)] / Ms, where Ls is the center of gravity corresponding to the total weight of the ship, Lv is the center of gravity corresponding to the light ship weight, Lo is the center of gravity corresponding to the total weight of the ship's fuel, lubricating oil, spare parts, etc., and Lb is the center of gravity corresponding to the weight of the ship's ballast water; According to the balance of gravity and buoyancy, and the balance of gravity moment and buoyancy moment, the ship's draft, metacentric height, and buoyancy distribution are inverted through the interpolation of the ship's hydrostatic table; Confirm whether the ship's floating state meets the rules and regulations or the shipowner's requirements through the calculation results of the ship's draft. If not, adjust the vehicle distribution method first, that is, adjust Mcs and Lcs, and then adjust the floating state of the entire ship. If the floating state requirements cannot be met by adjusting the vehicle distribution method, it is necessary to adjust the floating state of the entire ship by adjusting the ballast water to meet the rules and regulations or the shipowner's requirements. After meeting the requirements, perform stability related checks; Ship stability height GM = KMs-KGs, where KMs is the ship metacentric height. The ship stability height is calculated by weight and buoyancy, and then the initial stability and large inclination stability of the ship are checked. If not satisfied, the platform height is adjusted first, and then the center of gravity height of the entire ship is adjusted, and the stability is rechecked. If still not satisfied, the buoyancy of the entire ship is adjusted by adjusting the vehicle distribution, and the stability is rechecked. If still not satisfied, the weight and buoyancy of the entire ship need to be adjusted by adjusting the ballast water to meet the stability requirements. After meeting the requirements, strength assessment is carried out; The total longitudinal bending moment and shear force of the ship can be calculated through the weight distribution and buoyancy distribution of the ship. If they are not satisfied, it is preferred to adjust the platform height, and then adjust the center of gravity height of the entire ship, and re-check the strength. If it is still not satisfied, adjust the buoyancy of the entire ship by adjusting the vehicle distribution, and re-check the strength. If it is still not satisfied, it is necessary to adjust the weight and buoyancy of the entire ship by adjusting the ballast water to meet the strength requirements.

2. According to claim 1, the multi-layer mobile platform roll-on / roll-off ship converted from a container ship, It is characterized in that In the vehicle transport mode, as the total amount of cargo loaded increases, the hull draft deepens, and the ship's heel and pitch states change. When the inclination of the gangway at the side gate exceeds 30°, the ballast water is discharged from the ballast tank to lower the hull draft to ensure the normal passage of vehicles or cargo.

3. According to claim 1, the multi-layer mobile platform roll-on / roll-off ship converted from a container ship, It is characterized in that The cargo hold main frame of the cargo hold area (2) is composed of a tank bottom (9), an inner shell plate (10), a fuel tank rear bulkhead (11), a fuel tank front bulkhead and a tank top plate (13).

4. According to claim 1, the multi-layer mobile platform roll-on / roll-off ship converted from a container ship, It is characterized in that Every two cargo holds are interconnected and share a double-layer watertight door; The double-layer watertight door (6) is a double-layer structure, wherein the outer watertight door (17) is arranged on the side outer plate (14), and rollers and compression rods are arranged at the bottom; the inner watertight door (18) is arranged on the inner shell plate (10), and rollers and compression rods are also arranged at the bottom, and tilted into the cargo hold area (2) to serve as a step for vehicles to enter the mobile platform (7).

5. According to claim 4, the multi-layer mobile platform roll-on / roll-off ship converted from a container ship, It is characterized in that The watertight doors on the inner shell and the side outer plate are provided with rubber strips to achieve watertightness; the watertight doors must be opened above the full load waterline (16); the watertight doors are set in the inspection channel of the original ship's empty compartment.

6. According to claim 1, the multi-layer mobile platform roll-on / roll-off ship converted from a container ship, It is characterized in that A ship's crane is arranged at the rear of the hull.

7. According to claim 1, the multi-layer mobile platform roll-on / roll-off ship converted from a container ship, It is characterized in that The additional cables will be laid throughout the ship through the bottom conduit (15) and the maintenance passage (5) on the side.

8. According to claim 1, the multi-layer mobile platform roll-on / roll-off ship converted from a container ship, It is characterized in that The cargo hold is obtained by removing a non-watertight truss structure inside a cargo hold of a container ship.

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