CN1071666C - Support structure for hatch covers - Google Patents

Abstract

The invention relates to a support structure for a hatch cover (1) of a cargo ship for loading containers on its ceiling, said structure comprising elongated support beams attached to the lower part of the hatch cover (1), arranged substantially parallel to the longitudinal axis of the containers (2) and having a length substantially equal to the length of the hatch cover (1). The invention is implemented in such a way that the supporting beam (4) and the underside of the hatch cover top plate (1) form a structural element (box-section beam) whose substantially closed section consists of two side edges (5) and a bottom web (6), the distance spanned between the side edges (5) of the box-section beam (4) on the underside of the hatch cover top plate (1) being approximately equal to the width of the container (2).

Description

Support structure for hatch covers

The invention relates to a support structure for a hatch cover of a cargo ship on which containers are loaded on the roof, said structure comprising an elongated support beam attached to the lower part of said hatch cover substantially parallel to the direction of the longitudinal axis of said container Align and have a length roughly equal to the length of the hatch.

This hatch cover is especially used on a cargo ship to close the hatch of the transport channel entering the cargo hold, and also as a load-bearing part of the deck, on which the goods on the deck such as containers are stacked. Many such as 12 containers can be placed on each hatch cover, stacked into two layers, so that the containers on each layer are placed into three side-to-side, and two bottom-to-bottom. The total load on the hatch covers of cargo ships is heavy, which requires additional reinforcement of the hatch covers by welding support beams respectively at the bottom of the hatch covers.

The supporting members or beams of such hatch covers traditionally consist of L or T-shaped parts arranged parallel to each other and welded to the underside of the hatch top plate. Each support member is generally parallel to the long side of the container when welded, and the distance from the two sides of one flange to the bottom plate of the hatch cover is the same. Such L or T-shaped parts require extensive surface preparation such as sandblasting, coating and welding. Also the inner corners (90°) of L or T shaped parts tend to accumulate dust and other dirt increasing the risk of corrosion.

The object of the present invention is to provide a new support structure for hatch covers of cargo ships loaded with containers on the roof thereof, which can overcome the above-mentioned disadvantages. The supporting structure of the present invention is characterized in that the supporting beam and the underside of the hatch cover roof form a structural element (box-section beam) whose substantially closed cross-section consists of two sides and a bottom mesh plate, said box-section The distance spanned between the sides of the beams on the underside of the hatch roof is substantially equal to the width of the container.

In a preferred embodiment of the invention, the two sides of the box-section beam are aligned substantially parallel to the long sides of the container.

Another preferred embodiment of the present invention is that the two sides of the box-section beam are vertically arranged and aligned parallel to each other.

Another preferred embodiment of the present invention is that the two sides of the box-section beam are at an angle to the bottom of the hatch cover top plate, so that the two sides extending downward from the bottom of the hatch cover top plate are mutually towards the bottom of the hatch cover top plate. The edges shrink.

The advantage of the present invention is that the surface preparation of the supporting beams is easier than conventional beams, since the structure has no hard-to-reach places and internal dead spots where dirt can accumulate, which can easily lead to corrosion. One box section beam of the present invention can replace two traditional L or T section beams. The number of welded beams is thus halved compared to the prior art. Another advantage of the closed box-section beam as a force distribution unit is that it can balance the stress of the main structure of the hatch cover.

The present invention will be described in further detail below in conjunction with the best embodiment and accompanying drawings.

Figure 1 is a schematic diagram of a load-carrying beam of a conventional hatch cover on which containers are stacked;

Fig. 2 is an embodiment of the present invention, is similar to the view of traditional structure in Fig. 1;

Fig. 3 is an embodiment of the present invention, which is a perspective view obliquely seen from the lower part.

Figure 1 shows a side view of a hatch cover 1 on which containers 2 are stacked. The hatch cover 1 is supported and reinforced by elongated L- or T-section beams 3 below it parallel to each other, which are substantially aligned at the sides of the container 2 . Each component is connected to the underside of the hatch cover 1 by welding, and each side of the component has a weld (not shown).

As shown in Figure 2, in one embodiment of the invention, each pair of components in Figure 1 is replaced by a "box-section" beam 4, the outer edges of both sides of which are welded to the hatch cover 1 The box-section beam with such an opening on the bottom surface and the bottom surface of the hatch cover 1 form a substantially closed box-section structure, thereby preventing dirt from accumulating in corners that are difficult to remove.

The open box-section beam 4 comprises two sides 5 and a webbed base 6 connecting them. The sides 5 are generally vertical, but as can be seen from Figures 2 and 3, they can also be arranged at an angle to the lower part of the hatch cover top, so that the two sides extending downward from the hatch cover top face each other. Its lower edge shrinks. This inclination angle can vary within a certain range, such as 45-90°. Each side 5 is parallel to the side of the container, preferably at said side.

In summary, the invention is characterized in that the width of the box-section beam is approximately equal to the width of the container. In this context, the width of a container is to be understood as the distance between the midpoints of the corner stiffeners (container cages), which are placed under the container, in mutual crossing directions of the containers. However, there may be some dimensional variation in the box-section girder due to the possible differences in the dimensions of the container cages. The substantially equal width of the beams should not be understood here as being equal to the width of the container on the order of millimeters, but a certain error is allowed within the scope of the present invention. The width of the box-section beam 4 is preferably in the range of 1800-2500 mm. The length of the box-section beam 4 is roughly equal to the length of the hatch cover 1, generally between 10-15m. The height of the box-section beam 4, that is, the distance from the bottom mesh plate 6 to the lower surface of the top plate of the hatch cover 1 is preferably between 600-900 mm. The box-section beam 4 in the present invention is preferably made of a steel plate with a material thickness of 7-20mm.

The bottom mesh plate 6 of the box-section beam 4 is substantially horizontal, or in the longitudinal middle portion as shown, while the edge portions are inclined upwards close to the edge of the beam. In other words, the latter embodiment comprises a box section whose height tapers towards its ends, in which case the height of the sides 5 also tapers correspondingly towards the ends of the beam.

Looking at the embodiment in Figures 2 and 3, there are two box-section beams spaced a certain distance below the hatch cover. Other embodiments may also be included without departing from the scope of the present invention. The end of the hatch cover here has a transverse side member 7 extending across the entire width of the hatch cover 1 .

It will be apparent to a person skilled in the art that the invention is not limited to the embodiments described above, but that it can be varied within the scope of the appended claims.

Claims (7)

1. A support structure for a cargo ship hatch cover (1) loaded with containers on its roof, said structure comprising elongated support beams attached to the lower part of said hatch cover (1), substantially parallel to said containers (2 ) and the length is approximately equal to the length of the hatch cover (1), characterized in that: the support beam (4) and the bottom surface of the hatch cover top plate (1) form a structural element (box section beam), which The substantially closed section consists of two sides (5) and a bottom mesh plate (6), between the sides (5) of the box-section beam (4) on the bottom surface of the hatch cover top plate (1). The distance across is approximately equal to the width of the container (2). 2. A structure according to claim 1, characterized in that the two sides (5) of the box-section beam (4) are aligned substantially parallel to the long sides of the container (2). 3. A structure according to claim 1 or 2, characterized in that the two sides (5) of the box-section beam (4) are substantially perpendicular and arranged parallel to each other. 4. A structure according to any one of claims 1 to 3, characterized in that the two sides (5) of the box-section beam (4) are arranged at an angle to the lower part of the hatch cover roof (1) such that the The two side edges extending downwards of the top plate of the hatch cover (1) shrink toward the lower edge of the hatch cover (1) mutually. 5. A structure according to any one of claims 1 to 4, characterized in that the bottom mesh plate (6) of the box-section beam (4) is substantially horizontal. 6. A structure according to any one of claims 1 to 4, characterized in that the bottom mesh plate (6) of the box-section beam (4) is approximately horizontal in the longitudinal middle part, while the edge part slopes upwards close to the edge of the beam . 7. According to the structure described in any one of claims 1 to 6, it is characterized in that the height of the box-section beam 4 is between 600-900mm, the width is between 1800-2500mm, the length is between 10-15m and the box-section The material thickness of the beam (4) is between 7-20mm.

Images