A watertight ramp door device for lightering operations between roll-on / roll-off ships

Abstract

The present invention discloses a watertight gangway door device for lightering operations between ro-ro ships. The watertight gangway door device comprises a gangway door body, the gangway door body is rotatably connected to the loading hold, the gangway door body is smaller than the door frame of the loading hold, a jacking oil cylinder is provided at the top of the loading hold, and a plurality of watertight bolts are provided inside the periphery of the door frame of the loading hold. When the watertight bolts are jacked out, the gangway door body can be sealed with the door frame when it is closed. A movable wing plate is provided on the platform of the loading hold, a starting winch is provided inside the loading hold, the starting winch is connected to the top of the gangway door body through a steel wire rope, and the starting winch and the jacking oil cylinder can control the gangway door body to open bilaterally inwards or outwards. The present invention realizes the lightering operation between two ro-ro ships at sea, and still can satisfy the normal outward opening of the gangway door, and can satisfy both the lightering operation at the dock and the lightering operation at sea at the same time. The watertightness of the gangway door when it is closed is ensured by setting the hinge long shaft and the watertight bolts.

Description

Technical Field

[0001] The invention relates to a watertight gangway door device used for barge operations between roll-on / roll-off ships, belonging to the technical field of large roll-on / roll-off ship transport channel equipment. Background Art

[0002] Ro-ro ships are vessels that can transport vehicles. If a malfunction occurs while at sea and the vessel is unable to continue transporting vehicles, it can cause significant economic losses for a ship carrying a large number of vehicles. Therefore, a "cargo transfer" is necessary. Conventional vehicle transfers between two ships at sea typically occur between a ro-ro ship and a barge or a semi-submersible vessel. Transfers between two ro-ro ships present certain challenges. Barges and semi-submersible vessels are open-air platforms, similar to docks, facilitating vehicle transfers. Ro-ro ships, on the other hand, are constructed as a watertight hull, with gangways serving as access points. Common stern doors or portholes on ro-ro ships, which serve as gangways, open outward, not inward. Most gangway doors are designed only for dockside vehicle transfers when deployed, ensuring a watertight seal when closed. An outward opening configuration is sufficient for conventional vehicle transfers. Furthermore, the door area can be larger than the door frame, making it easier to achieve a watertight seal with the use of various restraining, supporting, stopping, and watertight devices.

[0003] However, when a ro-ro ship opens its gangway door at sea to transfer between two ships, it faces two problems. First, the gangway door is unsupported by the dock on one side, relying entirely on the ship's support equipment to bear the weight of the gangway door and the load of vehicles. Second, the gangway door itself is of a certain length, and when deployed, it increases the operating distance between the two ships, increasing the risk of transfer operations at sea. Ro-ro ships do not have gangway doors that can open in both directions. If a gangway door can open in both directions, it means that the door itself is smaller than the door frame, making it more difficult to achieve watertightness. In addition, the multiple activation devices connected on the inside of a conventional gangway door hinder inward opening, making it impossible. Summary of the Invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a watertight gangway door device for transshipment operations between roll-on / roll-off ships, to realize transshipment operations between two roll-on / roll-off ships at sea, to improve the stability and safety of the transshipment operations between the two ships at sea, and to ensure the watertightness of the gangway door device when it is closed.

[0005] Technical solution: The watertight gangway door device for lightering operations between ro-ro ships of the present invention includes a gangway door body, which is rotatably connected to the loading compartment of the ro-ro ship. The gangway door body is smaller than the door frame of the loading compartment. A pushing oil cylinder is provided at the top of the loading compartment. A plurality of watertight bolts are provided inside the periphery of the door frame of the loading compartment. When the watertight bolts are pushed out, the gangway door body can be sealed with the door frame when it is closed. A movable wing plate is provided on the platform of the loading compartment. A starting winch is provided inside the loading compartment. The starting winch is connected to the top of the gangway door body through a steel wire rope. The starting winch and the pushing oil cylinder can control the gangway door body to open inward or outward on both sides.

[0006] Further, the gangway door body is rotatably connected to the loading compartment through a hinge long shaft, and the gangway door body opens inward or outward on both sides with the hinge long shaft as the rotation axis.

[0007] Further, the gangway door body includes a double-layer plate structure, and a horizontal and vertical strengthening structure is provided inside the double-layer plate structure.

[0008] Further, a hinge hollow cylinder is provided at the bottom of the gangway door body, and the hinge long shaft passes through the inside of the hinge hollow cylinder.

[0009] Further, a trapezoidal groove is provided around the gangway door body, and when the watertight bolt is pushed out, the front end is embedded in the groove to achieve the sealing function.

[0010] Further, the watertight bolt includes a hydraulic bolt, and a rubber watertight strip matching the groove is fixedly provided at the front end of the hydraulic bolt. The watertight bolt is used to imprison and support the closed state of the gangway and ensure watertightness.

[0011] Further, the hinge long shaft includes a hinge long shaft body, and cylinders are provided at both ends of the hinge long shaft body. The cylinders are fixed on the loading compartment. When the gangway door body is closed, the cylinders are closely attached to both ends of the hinge hollow cylinder. The hinge long shaft is used to fix and support the gangway door body.

[0012] Further, the movable wing plate includes a ramp plate and a steel wire rope. A horizontal and vertical support structure is provided at the bottom of the ramp plate. The higher side of the ramp plate is of the same height as the thickness of the gangway door body and is used to join the gangway door body. The lower side of the ramp plate transitions to the platform of the loading compartment.

[0013] Furthermore, winches are provided on both sides outside the length where the gangway door body is spliced with the ramp plate after being opened inward. The front end of the winch is provided with a front pulley block, and rear pulleys are fixedly provided on the inner sides of the door frames on both sides of the platform in the loading cabin. Eye plates are provided on both sides of the ramp plate. The winch extends two steel wire ropes. Among them, the upper steel wire rope is connected to the eye plate through the front pulley block, and the lower steel wire rope is connected to the eye plate through the front pulley and the rear pulley, facilitating the forward and backward movement of the movable wing plate. The steel wire ropes drive the ramp plate to move forward and backward through the winch, the front pulley block, the eye plate and the rear pulley. The forward and backward movement of the movable wing plate assists in the operation of hoisting vehicles by the gangway door body with a certain thickness, eliminating the inconvenience of passage caused by the thickness difference.

[0014] Furthermore, spring rollers are provided at the bottom of the ramp plate. The stiffness of the spring can support the ramp plate to facilitate the movement of the ramp plate. When the vehicle load is increased, it is just pressed to the maximum contraction state, and the vehicle load is borne by the ramp plate.

[0015] Furthermore, the jacking oil cylinder includes a hydraulic oil cylinder, a hinge eye plate and a backing plate. The hydraulic oil cylinder is connected to the top of the loading cabin through the hinge eye plate and the backing plate. When the jacking oil cylinder extends, it pushes the gangway door body to open outward. Since the starting device of the gangway door body only has a starting winch and the steel wire rope cannot provide power when opening outward, the jacking oil cylinder tilts the gangway door body, and then the gangway door body is opened by its own gravity.

[0016] Furthermore, the starting winch is used for winding and unwinding the gangway door body, and includes a large winch, a top pulley and a steel wire rope. The top pulley is fixed on the top of the loading cabin. The steel wire rope passes through the top pulley and is connected to the upper part of the gangway door body. Due to the arrangement of the top pulley, the longitudinal and vertical positions of the starting winch are not restricted, and the horizontal position only needs to keep the steel wire rope parallel during operation. The steel wire rope is used to connect the large winch and the gangway door body. Furthermore, an eye plate is provided on each side of the top of the gangway door body. An inner small pulley group is provided inside the eye plate, and an outer small pulley is provided outside the eye plate. The inner small pulley group and the outer small pulley facilitate guiding the direction of the steel wire rope.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following remarkable advantages:

[0018] Due to the adoption of the above-mentioned gangway door equipment and its opening method, the present invention realizes the lightering operation between two ro-ro ships at sea, and the gangway door equipment can still meet the normal outward opening of the gangway door. Thus, the same gangway door equipment is used for the lightering operation at the terminal and the lightering operation at sea. And due to the existence of the hinge long shaft and the watertight plug pin, the watertightness when the gangway door is closed is ensured. Description of the Drawings

[0019] Figure 1Schematic diagram of the closed state of the watertight ramp door device for lightering operations between ro-ro ships according to the present invention;

[0020] Figure 2 Schematic diagram of the outward opening state of the watertight ramp door device for lightering operations between ro-ro ships according to the present invention;

[0021] Figure 3 Schematic diagram of the inward opening state of the watertight ramp door device for lightering operations between ro-ro ships according to the present invention;

[0022] Figure 4 is Figure 2 the top view of;

[0023] Figure 5 Partial schematic diagram of the outer plate structure where the watertight ramp door device for lightering operations between ro-ro ships according to the present invention is located;

[0024] Figure 6 Schematic diagram of the structure of the ramp door body;

[0025] Figure 7 Schematic diagram of the structure of the watertight bolt;

[0026] Figure 8 Partial schematic diagram of the structure of the watertight bolt;

[0027] Figure 9 Schematic diagram of the structure of the movable wing plate;

[0028] Figure 10 Schematic diagram of the structure of the push cylinder;

[0029] Figure 11 Schematic diagram of the structure of the starting winch;

[0030] Figure 12 Schematic diagram of the structure of the hinge long shaft;

[0031] Figure 13 Partial top schematic diagram of the closed state of the watertight ramp door device for lightering operations between ro-ro ships according to the present invention;

[0032] Figure 14 Partial bottom schematic diagram of the closed state of the watertight ramp door device for lightering operations between ro-ro ships according to the present invention;

[0033] Figure 15 Installation method and partial side schematic diagram of the watertight ramp door device for lightering operations between ro-ro ships according to the present invention.

[0034] Figure 16 Schematic diagram of the spring roller structure of the movable wing plate. Detailed implementation manners

[0035] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings.

[0036] Embodiment 1

[0037] As Figure 1 、 Figure 2 Figure 3 and Figure 4 shown, a watertight ramp door device for lightering operations between ro-ro ships according to the present ro-ro invention includes a ramp door body 1, a watertight bolt 2, a movable wing plate 3, a push cylinder 4, a starting winch 5, and a hinge long shaft 6. Among them, the ramp door body 1 is connected to the bottom of the door frame of the loading hold 7 of the ro-ro ship through the hinge long shaft 6 and can be turned outwards or inwards to open or close. The starting winch 5 is arranged in the loading hold 7 and is used to retract and extend the ramp door body 1. The push cylinder 4 is arranged at the top of the loading hold 7 and is used to assist in opening the ramp door body 1. The movable wing plate 3 is arranged on the platform of the loading hold 7 and is used to join with the opened ramp door body 1 around the door frame of the loading hold 7. A plurality of watertight bolts 2 are arranged around the door frame for imprisoning and supporting the closed ramp door body 1 and ensuring watertightness. The size of the ramp door body 1 is smaller than the size of the door frame of the loading hold 7, so as to ensure that it can be opened bilaterally outwards and inwards, and no longer cooperate with the locking hooks and bolts of conventional watertight doors and other equipment to ensure watertightness during sea voyages. The watertightness will be ensured by the method described in this solution.

[0038] As Figure 1 、 Figure 5 、 Figure 6 and Figure 15 shown, the ramp door body 1 includes a double-layer plate structure 11 that can support vehicle passage. A hinge hollow cylinder 12 is provided at the bottom of the double-layer plate structure 11, and the hinge long shaft 6 passes through the hinge hollow cylinder 12 of the ramp to achieve the imprisonment, support of the ramp door body 1, and facilitate the rotation of the ramp door body 1 around the hinge long shaft 6, so as to achieve the opening and closing of the ramp door body 1. Trapezoidal grooves 16 are provided around the ramp door body 1 to facilitate the insertion of the watertight bolt 2 during closing to ensure watertightness. Among them, the trapezoidal groove 16 at the bottom of the ramp door body 1 is provided at the bottom of the hinge hollow cylinder 12. One eye plate 15 is provided on each side of the top of the ramp door body 1 to facilitate connection with the starting winch 5. An inner small pulley group 13 is provided inside the eye plate 15, and an outer small pulley 14 is provided outside the eye plate 15. The inner small pulley group 13 and the outer small pulley 14 facilitate guiding the wire rope of the starting winch 5.

[0039] As Figure 7 、 Figure 8 、 Figures 13 - 15As shown, the watertight bolt 2 is arranged inside the periphery of the loading compartment 7 when the gangway door body 1 is closed, covering substantially the entire perimeter of the gangway door body 1. The watertight bolt 2 is divided into a steel hydraulic bolt 21 and a rubber watertight strip 22. When the hydraulic bolt 21 is retracted, it is inside the door frame. A rubber watertight strip 22 is fixed to the front end of the hydraulic bolt 21, and the hydraulic bolt 21 is activated to ensure the ejection and retraction of the watertight bolt 2. When the hydraulic bolt 21 is fully extended, it needs to cross the edge line of the gangway door body 1 to play a supporting role. The front end of the rubber watertight strip 22 is set as a trapezoid corresponding to the groove 16. When the hydraulic bolt 21 is fully ejected, the rubber watertight strip 22 is in a tight state with the groove 16 of the gangway door body 1. Using rubber is convenient to achieve a watertight state and can also prevent steel-to-steel contact.

[0040] As Figure 9 and Figure 16As shown in the figure, the movable wing plate 3 is arranged on the platform inside the loading cabin 7 and is used for splicing with the inward-opening of the gangway door body 1 with a certain thickness. The movable wing plate 3 is composed of a ramp plate 31, a winch 32, a steel wire rope 33, a rear pulley 34, side eye plates 35, spring rollers 36 and a front pulley set 37. The ramp plate 31 is the main structure for supporting the vehicle load. It relies on the winch 32 to control the forward and backward movement of the ramp plate 31 through the steel wire rope 33 around the rear pulley 34 and the front pulley set 37. The bottom of the ramp plate 31 is provided with a transverse and longitudinal support structure. The higher side of the ramp plate 31 is at the same height as the thickness of the gangway door body 1 for splicing with the gangway door body 1. The lower side of the ramp plate 31 transitions to the platform of the loading cabin 7 to eliminate the thickness difference with the platform of the loading cabin 7. Winches 32 are provided on both sides of the platform of the loading cabin 7, and the position of the winch 32 should be outside the length during the splicing operation with the ramp plate 31 after the gangway door body 1 is opened inward. The front pulley set 37 is provided at the front end of the winch 32, and the pulley set 37 is also arranged on the platform of the loading cabin 7 following the position of the winch 32. Rear pulleys 34 are fixedly arranged on the inner sides of the door frames on both sides of the platform of the loading cabin 7. Eye plates 35 are welded on both sides of the ramp plate 31. The winches 32, rear pulleys 34 and front pulley sets 37 are all arranged on both sides of the lane of the platform of the loading cabin 7, and the transverse position is wider than that of the gangway door body 1. There are two groups of winches 32 on each side. The first group directly connects the steel wire rope 33 to the eye plate 35 through the high-position pulley of the front pulley set 37, and the second group connects the steel wire rope 33 to the rear pulley 34 through the low-position pulley of the front pulley set 37 and then connects it to the eye plate 35 after passing around the rear pulley 34. Thus, the forward and backward movement of the ramp plate 31 is driven by the winding and unwinding of different steel wire ropes 33 of the winches 32 on both sides. The spring rollers 36 are fixed at the bottom of the ramp plate 31. Since the ramp plate 31 is made of steel structure, the direct forward and backward movement on the platform of the loading cabin will result in relatively large frictional force. Therefore, the installation of spring rollers 36 at the bottom facilitates the movement of the ramp plate 31. The stiffness of the springs of the spring rollers 36 can just support the ramp plate 31 to be separated from the platform of the loading cabin, but when bearing the vehicle load, the springs will be compressed and the ramp plate 31 will fall to the platform of the loading cabin. In this way, the ramp plate 31 itself can resist the vehicle load without damaging the spring rollers 36.

[0041] As Figure 10 As shown in the figure, the jacking oil cylinder 4 is arranged at the top of the loading cabin 7. The jacking oil cylinder 4 is composed of a hydraulic oil cylinder 41, a hinge eye plate 42 and a backing plate 43. The hydraulic oil cylinder 41 is connected to the top of the loading cabin 7 through the hinge eye plate 42 and the backing plate 43. Since the outer plate of the ship may be vertical without an inclination angle, the gangway door main body 1 may also be in a vertical state when it is closed. Its starting device has only one starting winch 5, and there is no assisting device when it is opened outward. Therefore, the hydraulic oil cylinder 41 is used to push out the gangway door main body 1. After reaching an inclination, the opening is completed by relying on the self-weight of the gangway door main body 1. The hinge eye plate 42 and the backing plate 43 are only used for connecting the hydraulic oil cylinder to the loading cabin 7.

[0042] like Figure 2 and Figure 11 As shown, the starting winch 5 is positioned within the loading bay 7. Its longitudinal and vertical positions are not restricted, as long as installation is convenient. The starting winch 5's lateral position aligns with the eye plate 15 on the ramp door body 1. The starting winch 5 is the sole actuating device for retracting and extending the ramp door body 1. It comprises a large winch 51, a wire rope 53, and a top pulley 52. The top pulley 52, located at the top of the loading bay 7, guides the wire rope 53, the rear end of which is connected to the eye plate 15 on the ramp door body 1.

[0043] like Figure 4 、 Figure 5 、 Figure 12 、 Figure 15 As shown, the hinge shaft 6 is located at the bottom of the door frame of the loading bay 7 and is used to penetrate the hollow hinge cylinder 12 of the gangway door body 1. The hinge shaft 6 is mainly composed of the hinge shaft 61 and the cylinders 62 on either side. The cylinders 62 are welded to the loading bay 7 and are hollowed out at the top and bottom to form two ears. They fit tightly with the ends of the hollow hinge cylinder 12 of the gangway door body 1 when closed. The hollowed-out areas at the top and bottom facilitate the insertion of the watertight latch 2, thus ensuring complete watertightness.

[0044] When using:

[0045] like Figure 1 As shown, when a ro-ro ship is sailing at sea, the gangway door body 1 is closed. The hydraulic latches 21 of the surrounding watertight latches 2 extend, pushing the rubber watertight strips 22 into the trapezoidal grooves 16 of the gangway door body 1, thereby achieving watertightness on all sides. At this time, the hydraulic latches 21 also partially penetrate into the grooves 16, thereby restraining and supporting the gangway door body 1 in its closure. This meets the two requirements of the ro-ro ship's watertight door at sea: watertightness and tightness.

[0046] like Figure 2 and Figure 4 As shown, when a ro-ro vessel is maneuvering vehicles at a dock, the watertight latch 2 is first retracted, leaving the ramp door body 1 unsupported and in a vertically stationary position. If it tilts to one side due to external forces, it can be restrained outward by the starting winch 5 and stopped inward by the thrust cylinder 4. When the ramp door body 1 opens outward, the thrust cylinder 4 pushes the ramp door body 1 outward, tilting it. Once it reaches a certain angle, the ramp door body 1 can be deployed outwards and placed on the dock using gravity and the starting winch 5. Due to the relatively thick ramp door body 1 of the present invention, the dock will require auxiliary wings or other tooling. The interior of the ship will be supported by the movable wing 3, which then allows the winch 32 of the movable wing 3 to pull it into alignment with the deployed ramp door body 1, eliminating the inconvenience caused by the thickness difference and hindering vehicle passage.

[0047] like Figure 3As shown in the figure, when a roll-on / roll-off ship transfers vehicles between two ships at sea, first, the watertight bolts 2 are retracted, and the pushing cylinders 4 are fully retracted, which does not prevent the inward opening of the ramp door body 1. When the ramp door body 1 opens inward, the steel wire rope 53 of the winch 5 is in a tension state, and no other assisting equipment is required to pull the ramp door body 1 inward to cooperate with gravity to complete the inward opening. The steel wire rope 53 can rely on the inner pulley block 13 and the outer pulley 14 to guide the steel wire rope 53 to avoid friction between the steel wire rope 53 and the ramp door body 1, and can be completely laid flat on the platform of the loading compartment 7. The movable wing plate 3 still cooperates with the operation. The roll-on / roll-off ship that needs to transfer vehicles can place the ramp on the ramp door body 1 of this ship, and the two ships can carry out vehicle transfer operations between the ships, and the problem of no support on one side of the ramp door body 1 is avoided.

Claims

1. A watertight ramp door device for lightering operations between roll-on / roll-off ships, comprising a ramp door body (1), characterized in that, The gangway door body (1) is rotatably connected to the loading compartment (7) of the ro-ro ship. The gangway door body (1) is smaller than the door frame of the loading compartment (7). A jacking oil cylinder (4) is provided at the top inside the loading compartment (7). A plurality of watertight bolts (2) are provided inside the periphery of the door frame of the loading compartment (7). When the watertight bolts (2) are jacked out, the gangway door body (1) can be sealed with the door frame when it is closed. A movable wing plate (3) is provided on the platform of the loading compartment (7). A starting winch (5) is provided inside the loading compartment (7). The starting winch (5) is connected to the top of the gangway door body (1) through a steel wire rope. The starting winch (5) and the jacking oil cylinder (4) can control the gangway door body (1) to open bilaterally inward or outward.

2. The watertight ramp door device for lightering operations between roll-on / roll-off ships according to claim 1, wherein The gangway door body (1) is rotatably connected to the loading compartment (7) through a hinge long shaft (6). The gangway door body (1) opens bilaterally inward or outward with the hinge long shaft (6) as the rotation axis.

3. The watertight ramp door device for lightering operations between ro-ro ships according to claim 2, characterized in that, The gangway door body (1) includes a double-layer plate structure (11). A transverse and longitudinal strengthening structure is provided inside the double-layer plate structure (11). A hinge hollow cylinder (12) is provided at the bottom of the double-layer plate structure (11). The hinge long shaft (6) passes through the inside of the hinge hollow cylinder (12). Trapezoidal grooves (16) are provided around the gangway door body (1). When the watertight bolts (2) are jacked out, the front ends are embedded in the grooves (16) to achieve the sealing function.

4. The watertight ramp door device for lightering operations between ro-ro ships according to claim 3, characterized in that, The watertight bolt (2) includes a hydraulic bolt (21). A rubber watertight strip (22) matching the groove (16) is fixedly provided at the front end of the hydraulic bolt (21).

5. The watertight ramp door device for lightering operations between roll-on / roll-off ships according to claim 3, characterized in that, The hinge long shaft (6) includes a hinge long shaft body (61). Cylinders (62) are provided at both ends of the hinge long shaft body (61). The cylinders (62) are fixed on the loading compartment (7). When the gangway door body (1) is closed, the cylinders (62) are in close contact with both ends of the hinge hollow cylinder (12).

6. The watertight ramp door device for lightering operations between ro-ro ships according to claim 1, wherein, The wing plate (3) includes a ramp plate (31) and a steel wire rope (33). A transverse and longitudinal support structure is provided at the bottom of the ramp plate (31). The higher side of the ramp plate (31) is of the same height as the thickness of the gangway door body (1) and is used to join the gangway door body. The lower side of the ramp plate (31) transitions to the platform of the loading compartment (7). Winches (32) are provided on both sides outside the length of the joint with the ramp plate (31) after the gangway door body (1) opens inward. A front pulley block (37) is provided at the front end of the winch (32). Rear pulleys (34) are fixedly provided on the inner sides of the door frames on both sides of the platform of the loading compartment (7). Eye plates (35) are provided on both sides of the ramp plate (31). The winch (32) extends two steel wire ropes. Among them, the upper steel wire rope is connected to the eye plate (35) through the front pulley block (37), and the lower steel wire rope is connected to the eye plate (35) through the front pulley (37) and the rear pulley (34), facilitating the forward and backward movement of the wing plate (3).

7. The watertight ramp door device for lightering operations between ro-ro ships according to claim 6, characterized in that, Spring rollers (36) are provided at the bottom of the ramp plate (31).

8. The watertight ramp door device for lightering operations between ro-ro ships according to claim 1, characterized in that, The jacking cylinder (4) includes a hydraulic cylinder (41), a hinge eye plate (42) and a backing plate (43). The hydraulic cylinder (41) is connected to the top of the loading cabin (7) through the hinge eye plate (42) and the backing plate (43). When the jacking cylinder (4) extends, it pushes the gangway door body (1) to open outwards.

9. The watertight ramp door device for lightering operations between ro-ro ships according to any one of claims 1-8, characterized in that, The starting winch (5) includes a large winch (51), a top pulley (52) and a steel wire rope (53). The top pulley (52) is fixed to the top of the loading cabin (7). The steel wire rope (53) passes through the top pulley (52) and is connected to the upper part of the gangway door body (1).

10. The watertight ramp door device for lightering operations between ro-ro ships according to claim 9, characterized in that, On both sides of the top of the gangway door body (1), there is an eye plate (15) respectively. Inside the eye plate (15), there is an inner small pulley group (13). Outside the eye plate (15), there is an outer small pulley (14). The inner small pulley group (13) and the outer small pulley (14) facilitate guiding the direction of the steel wire rope (53).

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