Hatch coaming structure incorporating overall longitudinal strength

Abstract

The present application relates to a kind of hatch coaming structure in total longitudinal strength, hatch coaming structure on deck presents a continuous pipeline structure;The coaming of the pipeline structure includes: first longitudinal hatch coaming in the first longitudinal hatch coaming of one in each side of the ship in the hatch, the second longitudinal hatch coaming of one in each side of the side of the ship, the hatch coaming top of the first longitudinal hatch coaming and the second longitudinal hatch coaming, the curvature plate that hatch coaming top plate is smoothly connected, the plane plate that curvature plate is connected;The first longitudinal hatch coaming, second longitudinal hatch coaming are provided with weight-reducing hole.The present application does not increase the highest point position of longitudinal continuous component, additionally increases the hatch coaming top plate, and one in each side of the side of the longitudinal continuous component to jointly participate in total longitudinal strength, it is more simple on construction relative to existing scheme, and the total longitudinal strength and local strength of structure have been further improved, also realize the ideal weight-reducing effect.

Description

TECHNICAL FIELD

[0001] The present application relates to a hatch coaming structure, in particular to a hatch coaming structure taking into account the longitudinal strength, and belongs to the technical field of ship design. BACKGROUND

[0002] When a ship sails on the sea, it not only bears the gravity, buoyancy and inertial force acting on the whole ship body, but also bears the wave load from the waves, which makes the ship body bend longitudinally. The ability of the ship body to resist longitudinal bending is called the longitudinal strength of the ship body, when the ship body is regarded as a hollow beam with a variable cross section. The ship body components participating in resisting longitudinal bending, i.e. participating in the longitudinal strength, are called longitudinal strength components, such as the outer plate, inner bottom plate, deck, longitudinal bulkhead, and longitudinal girder, longitudinal bone and other longitudinal continuous components. The longitudinal strength is of great importance to ensuring the safety of ship navigation. Insufficient longitudinal strength will cause deformation and damage of the structure, and in severe cases, the ship body will be broken.

[0003] The cargo area of a cargo ship is generally divided into several independent cargo holds, each cargo hold has a large opening, i.e. a hatch, and in order to ensure the weather tightness of the cargo hold, the four sides of the hatch need to be enclosed by a pair of transverse hatch coamings and a pair of longitudinal hatch coamings, and the top is covered by a hatch cover. Due to the particularity of the cargo ship itself, the distance between each cargo hold hatch is often quite far, and the longitudinal hatch coaming is generally discontinuous along the ship length direction, so the longitudinal hatch coaming of the traditional cargo ship hatch coaming does not participate in the longitudinal strength. The neutral axis of the cross section of the cargo ship is relatively close to the bottom plate and far from the main deck, so the top edge hatch coaming, the top end of the outer plate, and especially the main deck, bear the maximum longitudinal bending stress. The size of the plate and the bone material above the plate in these areas is generally larger, and the weight is also larger. In order to effectively reduce the longitudinal bending stress of these three areas, and further achieve weight reduction of the ship, components participating in the longitudinal strength need to be added near the main deck position, and changing the longitudinal hatch coaming from discontinuous to continuous can achieve good weight reduction effect.

[0004] In the design of the traditional discontinuous longitudinal hatch coaming, the hatch coaming only plays the role of ensuring the weather tightness of the cargo hold, supporting various blocks, thrust blocks and other devices under the hatch cover. Since the longitudinal hatch coaming is discontinuous along the ship length direction, it cannot bring any benefits to the longitudinal strength, and this part of weight is wasted invisibly, as shown in Figure 2

[0005] Therefore, in order to solve this problem, the prior art proposes a new improved scheme, Figure 3 is the design scheme of the traditional cargo ship in the transverse view, and the design of the existing improved continuous longitudinal hatch coaming in the transverse view is completely consistent with this scheme, and the only difference is that the design in the longitudinal view is different, as shown in Figure 1 ​The improved scheme uses a section of flat steel to transition between the longitudinal hatch coaming of the two cargo holds. According to the definition of the relevant specifications for ship structure design, the effective longitudinal strength component can be obtained by drawing two tangents with the ship length direction at 15°, as shown in Figure 1 The shadow part is the component participating in the total longitudinal strength, but since the scheme only has one longitudinal hatch coaming on each side participating in the total longitudinal strength, the weight reduction effect is not ideal, and the benefits to the total longitudinal strength are discounted, as follows:

[0006] The existing improved longitudinal hatch coaming design scheme has one longitudinal hatch coaming on each side participating in the total longitudinal strength. At this time, the hatch coaming not only serves to ensure the weather tightness of the cabin and support various pads, thrust blocks and other devices under the hatch cover, but also brings some benefits to the total longitudinal strength, which can reduce the overall stress level. However, setting continuous longitudinal hatch coaming on the main deck, according to the content of the relevant specifications for ship structure design, the influence of these newly added longitudinal continuous components on the calculation of the deck section modulus at the main deck should be considered. For the ship beam cross section, the farther the component is from the neutral axis, the greater the total longitudinal bending stress. These added longitudinal components on the main deck increase the distance between the structure at the farthest point of the ship beam and the neutral axis, and for the ship beam, whether the total longitudinal strength is met should depend on the structure at the worst point. Therefore, in general, the benefits of this scheme to the total longitudinal strength are discounted. SUMMARY

[0007] The purpose of the present application is to provide a hatch coaming structure that takes into account the total longitudinal strength, which is further improved on the basis of the continuous design scheme of the existing improved longitudinal hatch coaming: without increasing the highest point of the longitudinal continuous component, an additional hatch coaming top plate and one longitudinal continuous component on each side are added to participate in the total longitudinal strength. The construction is relatively simple compared to the existing scheme, and the total longitudinal strength and local strength of the structure are further improved, achieving a more ideal weight reduction effect.

[0008] The present application adopts the following technical solutions:

[0009] A hatch coaming structure that takes into account the total longitudinal strength, the hatch coaming structure on the deck is a continuous pipeline structure; the coaming of the pipeline structure includes: one first longitudinal hatch coaming 2 on each side of the ship in the port and starboard at the hatch, one second longitudinal hatch coaming 3 on each side of the ship in the port and starboard on the side, a hatch coaming top plate 1 on the top of the first longitudinal hatch coaming 2 and the second longitudinal hatch coaming 3, a curvature plate 14 connected smoothly with the hatch coaming top plate 1, and a flat plate 13 connected with the curvature plate 14; the first longitudinal hatch coaming 2 and the second longitudinal hatch coaming 3 are provided with weight reduction holes.

[0010] Preferably, the planar plate 13 is also provided with lightening holes.

[0011] Preferably, the pipe structure further comprises a lower longitudinal plate 9 of the second longitudinal coaming 3 by the side.

[0012] Preferably, the pipe structure further comprises a transverse plate 4, which is provided with a first passage hole 5 for lightening, rainwater flowing and personnel passing.

[0013] Further, the first passage hole 5 is provided with a second passage hole 6 below the main deck 7 for lightening, ballast water flowing and personnel passing.

[0014] Further, the second passage hole 6 is provided on the transverse plate 4. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a longitudinal schematic view of a continuous design scheme of the longitudinal coaming of the prior art improved type.

[0016] Figure 2 is a longitudinal schematic view of a design scheme of the traditional discontinuous type of longitudinal coaming.

[0017] Figure 3 is a transverse schematic view of a design scheme of the traditional and prior art improved type of coaming.

[0018] Figure 4 is a transverse schematic view of the coaming structure of the present application taking into account the overall longitudinal strength.

[0019] Figure 5 is a transverse partial schematic view of the traditional and prior art improved type of coaming. Wherein (a) is a partial enlarged view of Figure 3 (b) is a VIEW A view in (a).

[0020] Figure 6 is a partial schematic view of the coaming structure of the present application taking into account the overall longitudinal strength. Wherein (a) is a partial enlarged view of Figure 4 (b) is an A-A sectional view in (a), (c) is a B-B sectional view in (a).

[0021] Figure 7 is a three-dimensional view (starboard view) of the coaming structure of the present application taking into account the overall longitudinal strength.

[0022] Figure 8 is a three-dimensional view (port side view) of the coaming structure of the present application taking into account the overall longitudinal strength.

[0023] In the figure, 1. hatch coaming top plate, 2. first longitudinal coaming plate, 3. second longitudinal coaming plate, 4. transverse plate, 5. first passing hole, 6. second passing hole, 7. main deck, 8. hatch area, 9. longitudinal plate, 10. first longitudinal rib, 11. second longitudinal rib, 12. transverse rib, 13. flat plate, 14. curvature plate, 15. top edge hatch inclined plate. DETAILED DESCRIPTION

[0024] The application is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0025] Explanation: The "transverse direction" mentioned below is the direction of the ship's transverse section, and the "longitudinal direction" is the direction of the ship's longitudinal section (i.e. the direction of the side).

[0026] In the existing improved design, referring to Figure 1 , 3 , 5, in order to involve more components in the total longitudinal strength, although there is a design scheme that changes the discontinuous longitudinal coaming plate to a continuous one, but since only one longitudinal coaming plate on each side of the ship is involved in the total longitudinal strength, the weight reduction effect is not ideal. The present application additionally increases the hatch coaming top plate, one longitudinal coaming plate on each side of the ship, and the longitudinal continuous plate below it to participate in the total longitudinal strength based on the existing improved design, achieving a relatively ideal weight reduction effect, and since the pipeline type design is adopted, it also has a good optimization effect on bearing the local load of the hatch cover, and the welding of the elbow plate below the coaming to the main deck and the welding of the panel of the elbow plate below the coaming to the main deck can also use general fillet welds instead of the penetration welds in the existing design.

[0027] EMBODIMENT

[0028] This embodiment is to solve the defects mentioned above and in the background art, and further improves the continuous design scheme of the existing improved longitudinal coaming plate. Compared with the existing continuous design scheme, the highest point of the longitudinal continuous component is not increased, and the hatch coaming top plate 1 and one longitudinal continuous component on each side of the ship are additionally added to jointly participate in the total longitudinal strength, which is more convenient in construction compared with the existing scheme, and the total longitudinal strength and local strength of the structure are further improved, achieving a relatively ideal weight reduction effect. The specific description is as follows:

[0029] The design scheme of this new type of continuous longitudinal coaming plate of the embodiment is introduced below, Figure 4 which is a transverse view of the design scheme. Since a pipeline type structure is constructed on the main deck, it belongs to a pipeline type design scheme. Compared with traditional cargo ships, the components participating in the total longitudinal strength of the present application mainly include the hatch coaming top plate 1, one longitudinal coaming plate 2 on each side of the ship, one longitudinal coaming plate 3 on each side of the ship, and the lower longitudinal plate 9 of the longitudinal coaming plate on the side of the ship.

[0030] Relative to the design of the existing improved continuous longitudinal hatch coaming, the components participating in the overall longitudinal strength of the present application mainly increase the hatch coaming top plate 1, the longitudinal hatch coaming 3 on each side of the ship, and the lower longitudinal plate 9 of the longitudinal hatch coaming on the side of the ship. For cargo ships, due to the structural characteristics, the neutral axis position is relatively close to the bottom position, and the main deck is correspondingly far from the neutral axis. According to the relevant knowledge of physics, it can be known that when external bending moment load is borne, the bending stress borne by the position far from the neutral axis is the largest, so the overall longitudinal bending stress of the main deck is the largest, and the overall longitudinal strength of the side top plate and the top edge hatch vertical plate, the plate thickness of the main deck and the size of the bone material on these components play a decisive role. In order to improve the overall longitudinal strength of the components in this area, the plate thickness and the size of the bone material will be large, and the weight of this area accounts for a large proportion in the total weight of the structure. The present application increases the components participating in the overall longitudinal strength in this area, which helps to reduce the weight of the existing components.

[0031] The present application increases several components participating in the overall longitudinal strength. For the longitudinal hatch coaming 2 on each side of the ship, it is a structural component of the traditional scheme and the improved scheme, so there is no change in the structure form in the transverse section, and the form of the longitudinal section is consistent with the improved scheme, as shown in Figure 1 For the added longitudinal hatch coaming 3 on each side of the ship, the traditional cargo ship and the existing improved scheme are as shown in Figure 5 The new hatch design scheme is shown in the A-A section of Figure 6 . Figure 5 VIEW A of is the face plate of the longitudinal rib and knee plate under the hatch coaming top plate. Considering that the local load of the upper hatch cover is relatively large, only the knee plate and the face plate of the knee plate are used to support here, the structure is relatively weak, and the end stress is relatively large, so the specification compulsorily requires that the area 1 in the figure adopts partial penetration welding, and the area 2 adopts full penetration welding to ensure effective stress transfer. The present application makes this face plate into a longitudinally continuous perforated plate, as shown in the A-A section of Figure 6 , which can effectively participate in the overall longitudinal strength and significantly reduce the stress of this area. The welding requirements at areas 1 and 2 will be reduced, and general fillet welding can be used instead of penetration welding; for the lower longitudinal structure of the longitudinal hatch coaming on the side of the ship, the design form of the traditional cargo ship and the existing improved scheme is as shown in Figure 3As shown, the original structure is two longitudinal beams on the main deck and the top edge cabin, which is generally T-shaped section. Since the construction space is small, the T-shaped section is not particularly convenient for construction. The present scheme replaces the original T-shaped section with a longitudinally continuous perforated plate, greatly increasing the convenience of construction. Considering that the height of the web of the T-shaped section in the traditional scheme and the improved scheme plus the height of the panel is not much lighter than the perforated plate scheme of the present invention, it can be considered that the weight increase of this modification of the present invention is not large. In order to ensure the longitudinal continuity of the top plate, the transition section of the top plate at different cargo hatch coaming is a transition form combining flat plate and curvature plate. Longitudinal section of the transition section is shown in Figure 6 , the vertical section of the transition section is shown in Figure 6 , the flat plate part of the top plate is smoothly transitioned to the adjacent inclined plate through a circular arc at a certain distance from the transverse strong frame, and the inclined plate is smoothly transitioned to the flat plate part of the top plate through a circular arc. The three-dimensional view is shown in Figure 7 and Figure 8 .

[0032] The specific structure is shown in Figure 4 , 6 , 7, 8, a hatch coaming structure considering the overall longitudinal strength, the hatch coaming structure on the deck is a continuous pipeline structure; the coaming of the pipeline structure includes: a first longitudinal hatch coaming plate 2 on each side of the ship in the port and starboard at the hatch, a second longitudinal hatch coaming plate 3 on each side of the ship in the port and starboard, a hatch coaming top plate 1 located at the top of the first longitudinal hatch coaming plate 2 and the second longitudinal hatch coaming plate 3, a curvature plate 14 connected with the hatch coaming top plate 1, and a flat plate 13 connected with the curvature plate 14; the first longitudinal hatch coaming plate 2 and the second longitudinal hatch coaming plate 3 are provided with weight reduction holes.

[0033] Referring to Figure 7 , the flat plate 13 is also provided with weight reduction holes.

[0034] Referring to Figure 4 , 8 , the pipeline structure further includes a lower longitudinal plate 9 of the second longitudinal hatch coaming plate 3 on the side of the ship.

[0035] Referring to Figure 4 and 8 , the coaming of the pipeline structure further includes a transverse plate 4, and the transverse plate 4 is provided with a first passage hole 5 for weight reduction, rainwater flow and personnel passage.

[0036] Referring to Figure 4 and 8The first pass-through hole 5 is provided with a second pass-through hole 6 below the first pass-through hole 5 and below the main deck 7 for weight reduction, ballast water flow and personnel passing.

[0037] Continuing to refer to Figure 4 and 8 The second pass-through hole 6 is also provided on the transverse plate 4.

[0038] The present application mainly solves the problem that the longitudinal coaming and the top plate of the coaming do not participate in the overall longitudinal strength and only participate in the local strength in the previous coaming structure design, so that the weight is wasted. The key point is that the coaming top plate, the two longitudinal continuous coamings on the left and right sides, and the longitudinal plate under the deck on the left and right sides jointly participate in the overall longitudinal strength, which is relatively simple in construction compared with the existing scheme, and the overall longitudinal strength and the local strength of the structure are further improved, and the ideal weight reduction effect is achieved. The protection point of the present application is the new design of the longitudinal continuous coaming.

[0039] The above is the preferred embodiment of the present application, and those skilled in the art can make various transformations or improvements on the basis of the above, and these transformations or improvements should be within the scope of protection of the present application without departing from the general concept of the present application.

Claims

1. A hatch coaming structure with total longitudinal strength, characterized in that: the hatch coaming structure on the deck is a continuous pipe structure; the pipe structure coaming comprises: a first longitudinal hatch coaming (2) on each side of the ship in the docking position at the hatch, a second longitudinal hatch coaming (3) on each side of the ship, a hatch coaming top plate (1) on top of the first longitudinal hatch coaming (2) and the second longitudinal hatch coaming (3), a curvature plate (14) connected to the hatch coaming top plate (1) in a smooth transition, a flat plate (13) connected to the curvature plate (14); weight-reducing holes are provided on the first longitudinal hatch coaming (2) and the second longitudinal hatch coaming (3); the pipe structure coaming further comprises a transverse plate (4) with a first passage hole (5) for weight reduction, rainwater flow, and personnel passage; a second passage hole (6) for weight reduction, ballast water flow, and personnel passage is provided below the first passage hole (5) and below the main deck (7); weight-reducing holes are also provided on the flat plate (13); the pipe structure further comprises a lower longitudinal plate (9) of the second longitudinal hatch coaming (3) on the side of the ship.

2. The integrated total longitudinal strength hatch coaming structure of claim 1, wherein: The second passage hole (6) is provided on the transverse plate (4).

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