WO2015001776A1

WO2015001776A1 - A hatch cover for an ocean-going ship

Info

Publication number: WO2015001776A1
Application number: PCT/JP2014/003443
Authority: WO
Inventors: Ragnar E. HANSEN
Original assignee: Oshima Shipbuilding Co., Ltd.
Priority date: 2013-07-03
Filing date: 2014-06-27
Publication date: 2015-01-08
Also published as: CN105358426A; JP2016527114A; KR101879960B1; CN105358426B; NO20130932A1; PH12015502845A1; KR20160019519A; PH12015502845B1; NO338137B1; JP6100929B2

Abstract

A hatch cover (1) comprising a cover body (17) and a circumferential skirt (4) depending from the cover body (17). The skirt (4) is provided with a support portion (8) for supporting the hatch cover (1) on a hatch coaming (2) of a ship and the support portion (8) is provided with a central elongate groove (9). A resilient lower sealing member (10) is provided in the central elongate groove (9) such that it protrudes out of said groove (9) for sealing against the hatch coaming (2). The lower sealing member (10) is configured such that it is deformable into the central elongate groove (9) upon pressing together of hatch cover (1) and ship at normal use. A plurality of stiffening bodies (18) is provided on the inside of the cover body (17). The cover body (17), the skirt (4) and the stiffening bodies (18) are made from fiber-reinforced plastics.

Description

A HATCH COVER FOR AN OCEAN-GOING SHIP

The present invention relates to a hatch cover suitable for an ocean-going ship, such as a Panamax bulk carrier. Specifically, the present invention relates to a hatch cover made of fiber-reinforced plastic and to a ship provided with such hatch covers.

Typically hatch covers for ocean-going ships are made from steel. Such hatch covers are heavy, requires sturdy supporting structures and strong and expensive lifting and handling arrangements for moving the hatch covers. Further, such covers do not always provide adequate sealing to the ship for protection of cargo carried. Also, due to the high weight of conventional large hatch covers, the cargo loading capacity of the ship is reduced.

Korean Patent Application Publication No. 20090087658 British Patent Application Publication No. 913497 Korean Patent Application Publication No. 20110102530 International Publication No. WO 2009/0064175

It is an object of the present invention to provide a light-weight hatch cover for a ship providing reliable protection of cargo carried.

This and other objects are achieved by a hatch cover according to a first aspect of the invention. The hatch cover comprises a cover body, and a circumferential skirt depending from the cover body. The skirt is provided with a support portion for supporting the hatch cover on a hatch coaming of a ship and the support portion is provided with a central elongate groove. A resilient lower sealing member is provided in the central elongate groove such that it protrudes out of said groove for sealing against the hatch coaming. The lower sealing member is configured such that it is deformable into the central elongate groove upon pressing together of hatch cover and ship at normal use. A plurality of stiffening bodies is provided on the inside of the cover body. The cover body, the skirt and the stiffening bodies are made from fiber-reinforced plastics.

The combination of providing of stiffening bodies and using fiber-reinforced plastic for cover body,skirt and stiffening bodies, provides for a strong, light and corrosion resistant hatch cover capable of evenly distributing load from on top of the hatch cover, and down to the underlying ship with sustained good water sealing capabilities all around the support portion of the circumferential skirt. The cover body provides cover for a hatch of the ship, thereby preventing water from entering the hatch. The skirt supports the hatch cover on top of the ship via the support portion of the skirt, typically on a hatch coaming around the hatch. When the hatch cover is positioned for covering the hatch, the lower sealing member is pressed against the hatch coaming such that it seals against the coaming and prevents water from passing the seal and entering the hatch.

Upon pressing the hatch cover against the ship, the sealing member will be deformed and pressed into the elongate groove of the support portion, such that the support portion of the hatch cover eventually is supported directly on the underlying surface. The sealing member is thus protected from being too heavily loaded, thereby preventing excessive wear and breaking of the lower sealing member. In other words, the maximum pressure on the lower sealing member is controlled. This effectively provides for a more dependable protection of goods carried below the cover.

The hatch cover may be substantially rectangular with opposite longitudinal and transversal skirt portions, wherein the stiffening bodies extend across the cover body between opposite transversal or longitudinal portions of the skirt, and wherein opposite ends of each respective stiffening body are connected to the skirt. The connection between skirt and stiffening bodies improve structural integrity of the hatch cover, thus enabling use of thinner and lighter skirt and cover body whilst distributing load from the cover body to the hatch coaming via the stiffening body, and the skirt.

The stiffening bodies may be spaced apart at their ends. This allows attachment of fittings and opening holes for ventilation in the spaces formed between the ends of adjacent stiffening profiles.

A plurality of stiffening plates may be provided on the inside of the skirt and extending substantially perpendicularly to the inside of the skirt. The stiffening plates provide improved structural integrity for the skirt, for example along portions of the skirt not connected to a stiffening body.

Stopper members may be provided on at least some of the stiffening bodies, said stopper members having protrusions engageable into corresponding recesses of stopper sockets attached to the ship to prevent relative motion between ship and hatch cover. When the hatch cover is positioned over a hatch, the stopper members engage into corresponding recesses of the stopper sockets, such that the stopper members cannot move longitudinally or transversally relative to the ship along the respective portion of hatch coaming adjacent each respective stopper socket. Thus, the stopper members prevent excessive wear of the lower sealing member by preventing certain movement of each respective portion of the skirt to which each respective stopper member is attached. However, the stopper members and sockets typically do not prevent vertical relative movement between hatch cover and ship, such that the hatch cover can still be easily raised and lowered. Also, this configuration of the stopper members and sockets is such that outwards and inwards movement of the skirt portions adjacent each respective stopper member, normal to each respective skirt portion, is allowed to a certain degree.

This improve resiliency of the hatch cover, such that proper sealing is ensured. A further effect is that local stresses are mitigated, thereby allowing design of a lighter cover with adequate robustness. The stopper member may be made of metal. That gives better wear resistance for hatch covers made from fiber-reinforced plastics.

The hatch cover may be provided with cleat brackets on outer side portions of the skirt. The cleat brackets allow for releasable connection of the hatch cover to cleats mounted on the ship. The provision and positioning of the cleat brackets on the hatch cover gives control over compression of the seal and where loads are applied to the hatch cover, such that excess stress on the hatch cover can be avoided. This is especially important for light-weight structures, such as structures from fiber-reinforced plastics.

Cleat brackets may be provided on top of the cover body. Such positioning of cleat brackets enables releasable connection of adjacent hatch covers, such as to form a larger cover structure comprising several hatch covers.

At least one outer side portion of the skirt is provided with at least one side ridge. The side ridge is provided with a central elongate groove, and a resilient side sealing member is provided in the central elongate groove of the side ridge such that it protrudes out of said groove for sealing against an adjacent hatch cover. The side ridge and side sealing member provides a unitary member capable of sealing anywhere on an opposing flat surface onto which it pressed, without being sensitive to relative movements between the opposing surface and the side ridge. Similarly to the lower sealing member, the side sealing member is protected from being too heavily loaded, thereby preventing excessive wear and breaking of the lower sealing member. The side ridge and sealing member effectively provides for a more dependable protection of goods carried below the cover.

According to an aspect of the invention a pair of the above described hatch covers is provided. Adjacent side ridges of the pair of hatch covers may be configured to extend parallel to each other when said pair of hatch covers are positioned adjacent each other for covering of a hatch. Since the respective ridges extend parallel to each other, their relative movement in a first direction is limited, which is of advantage since it ensures proper sealing.

According to a further aspect of the invention, a hatch cover system is provided. The system comprises a ship and one or more hatch covers as described above. Each hatch is surrounded by a hatch coaming, and the hatch covers are configured to fit over a respective one of said hatch coamings such that the lower sealing member fits sealingly to the respective hatch coaming. The hatch cover system of the invention provides for a more dependable protection of goods carried below the cover.

An inner support ridge may be provided on the respective hatch coaming for preventing the skirt of the respective hatch cover from moving inwards. The inner support ridge improves control of movement of the skirt, thereby enabling design of lighter hatch cover without risking excessive deformation of hatch cover and without risking poor sealing performance.

An outer support ridge may be provided on the hatch coaming for preventing the skirt of the respective hatch cover from moving outwards, thereby improving structural integrity of the hatch cover. A further effect is that sideways displacement of the hatch cover is prevented, such that it will not be displaced off the hatch coaming or to a non-sealing position.

The system may comprise stopper sockets attached to the ship and corresponding stopper members as described above. The stopper members and the stopper sockets are configured for mutual engagement to prevent relative movement at least along the skirt by each respective stopper socket. The combination of stopper member and stopper socket functions as described above. The stopper member engages into corresponding recesses of a corresponding stopper socket, such that relative movement is controlled.

This prevents the hatch cover from unintentionally sliding and keeps it in place. When the hatch cover is to be moved, such as when sliding open a hatch cover to enable access to a hatch, the hatch cover is first lifted such that the stopper member and stopper socked do not engage each other.

The present invention will now be described in more detail, with reference to the appended drawings showing an embodiment of the invention.

Fig. 1 shows a perspective view of a hatch cover according to an embodiment of the invention. Fig. 2 shows a top view of the hatch cover also shown in Fig. 1. Fig. 3 shows a transversal side view of the hatch cover also shown in Figs. 1-2. Fig. 4 shows a longitudinal side view of the hatch cover also shown in Figs. 1-3. Fig. 5 shows a cross sectional view of the hatch cover also shown in Figs. 1-4, taken along the line A-A of Fig. 2. Fig. 6 shows a transversal cross sectional view of the support portion of the hatch cover also shown in Figs. 1-5, taken along the line B-B of Fig. 2. Fig. 7 shows a longitudinal cross sectional view of the support portion of the hatch cover also shown in Figs. 1-5, taken along the line C-C of Fig. 2. Fig. 8 shows a perspective view of a portion of a plurality of stiffening bodies, the closest one provided with web plates for attachment to the skirt of a hatch cover. Fig. 9 shows a perspective view from below of a portion of a hatch cover according to an embodiment, provided stiffening plates, web plates and with ventilation openings. Fig. 10 shows a perspective view of a plurality of web plates according to an embodiment. Fig. 11 shows a perspective view from below of a portion of a hatch cover according to an embodiment of the invention. Fig. 12 shows a perspective view of a portion of a skirt of a hatch cover provided with a plurality of stiffening plates. Fig. 13 shows a perspective view of a portion of the hatch cover also shown in Figs. 1-7, said portion being provided with openings for ventilation of the hatch. Fig. 14 shows a perspective view of a portion of the hatch cover also shown in Figs. 1-8, said portion being provided with rounded corners. Fig. 15 shows a side view in cross section of a portion of two adjacent hatch covers connected using a cleat and sealingly abutting each other by means of a respective sealing member and side ridge. Fig. 16 shows a longitudinal cross sectional view of a portion of the hatch cover resting on top of a hatch coaming and fastened by means of a cleat, taken along the line C-C of Fig. 2. Fig. 17 shows a perspective view of a stopper socket according to an embodiment fitted in recesses of a hatch coaming. Fig. 18 shows the stopper sockets also shown in Fig. 17. Fig. 19 shows a perspective view of a stopper member according to an embodiment suitable for engaging the stopper sockets also shown in Figs. 17-18. Fig. 20 shows a perspective view from below of a hatch cover seated on a hatch coaming and provided with the stopper members and stopper sockets also shown in Figs. 17-19. Fig. 21 shows a perspective view from above of front side of a cleat bracket according to a first embodiment. Fig. 22 shows a perspective view from above of the back side of the cleat bracket also shown in Fig. 21. Fig. 23 shows a perspective view from above of front side of a cleat bracket according to a second embodiment. Fig. 24 shows a perspective view from above of the back side of the cleat bracket also shown in Fig. 23. Fig. 25 shows a side view of a transversal end portion of a hatch cover according to an embodiment of the invention, with a transversal portion of the skirt hidden to show a cross-section of a longitudinal portion of the skirt. For illustration clarity, the corrugations (stiffening body (18)) have been removed from the view. Fig. 26 shows a transversal side view of a cross section of a hatch cover according to an embodiment of the invention, wherein the hatch coaming is provided with an inner support ridge. Fig. 27 shows a corner portion of a hatch coaming provided with inner and outer support ridges, a rail, and a draining hole.

A hatch cover 1 according to a first embodiment of the invention is shown in Fig. 1 positioned on a hatch coaming 2. The hatch cover 1 comprises a cover body 17, and a circumferential skirt 4 depending from the cover body 17. The skirt 4 is provided with a support portion 8 for supporting the hatch cover 1 on a hatch coaming 2 of a ship.

The ship and ship data used together with this embodiment of the fiber-reinforced plastic hatch covers is:
Oshima Shipbuilding Co., Ltd. hull no: 10692
77,000 DWT Bulk Carrier
Ship size: 220m x 32.26m x 19.79m x 12.20m
Type of freeboard: B-60
Of course the hatch cover of the invention may, within the scope of the invention, be adapted to other ships and sizes of hatches and hatch coamings.

The hatch cover 1 is made from fiber-reinforced plastics and has an overall size of 8.01m x 17.10 m. The height of the hatch cover 1 varies from 0.83 to 1.03 m. As shown in Fig. 1, the cover body 17 has two slanted portions joined by a central 1250 mm wide flat portion. In the described embodiment, material thickness of the hatch cover 1 varies between 10 and 40 mm. The total weight of fiber-reinforced plastic for one hatch cover 1 is about 14000 kg, which is about 40% of the weight of a corresponding steel hatch cover. Further optimization of material thickness is possible. Two hatch covers 1, 1b are used together for covering one hatch of the ship.

As shown in Figs. 2, 3, 8, 13, 14, 20 and 26, a plurality of stiffening bodies 18 is provided on the inside of the cover body 1 for strengthening the cover body 17 and distributing stress from loads carried on top of the cover body 17 to the skirt 4. The stiffening bodies 18 extend across the cover body 17 between opposite longitudinal portions of the skirt 4, and opposite ends of each respective stiffening body 18 are connected to the skirt 4. As shown in Fig. 8, the stiffening bodies 18 are shaped like trapezoid corrugations. The opposing walls of the stiffening body may be made from single skin web, or as a sandwich material with core material covered on both sides with a fiber-reinforced plastic web.

As shown in Figs. 2, 3 and 26 inner and

outer support ridges

19, 3 are provided on the hatch coaming 2 for preventing the skirt 4 of the hatch cover 1 from moving inwards and outwards, respectively. When cleats are tensioned to pull the skirt downwards, the lower sealing member 10 is pre-stressed by pressing against the hatch coaming 2. The inner and

outer support ridges

19, 3 prevent inward/outward movement of the skirt 4, thereby preventing excessive wear on the lower sealing member 10 and support surfaces. Please note that stiffening bodies 18 are not shown in Fig. 25 although they exist in this embodiment.

The hatch cover 1 is provided with cleat brackets 5 on outer side portions of the skirt 4. The cleat brackets 5 are bolted to the skirt 4 of the hatch cover 1. Figs. 21-24 show two different embodiments of cleat brackets 5. The first cleat bracket 5 shown in Figs. 21-22, comprises an inner plate and an outer plate. The outer plate has through holes for a respective bolt, and the inner plate comprises corresponding threaded parts for each bolt to engage. In the other embodiment, shown in Figs. 23-24, the outer plate has bolts welded on its inside, wherein the inner plate has corresponding through holes for the bolts. Each bolt is instead engaged using conventional nuts on the inside of the inner plate. As shown, the inner plate is split in two, for enabling attachment of the cleat bracket symmetrically over a portion of the skirt provided with an inner stiffening plate extending normal to the inside of the skirt.

Moving devices 6 are attached to transverse sides of the hatch cover 1. Each moving device 6 comprises a wheel mounted on an arm, an electric screw jack (not shown) configured optionally raise or lower the wheel by rotating the arm, and an electric motor configured to rotate the wheel for movement of the hatch cover 1 back and forth on rails 7 on the ship (see Figs. 1 and 25).
When movement of the hatch cover is desired, the wheels of the moving devices 6 are lowered such that the hatch cover 1 is lifted free from any support ridges 3. Once lifted, the hatch cover 1 can easily be moved rolling on the wheels driven by the motors. For emergency operation, when no electric power supply is functioning, the screw jacks may be manually operated by turning the jacking screw to raise or lower the hatch covers, and a simple chain pulley winch may be used to winch the hatch covers sideways.

Optionally, the hatch cover 1 may in an embodiment (not shown) be provided with pre-fitted eyes such that the hatch cover 1 may easily be handled using a crane. It goes without saying that any cleats attaching the hatch cover 1 to the ship must be released before the hatch cover 1 can be lifted and moved. This simple movement system comprising the movement devices described above, would not be feasible for conventional hatch covers made from steel, since they are too heavy.

As shown in Figs. 6, 7, 15 and 16, the hatch cover 1 is provided with a sealing system for sealing between hatch coaming 2 and hatch cover, and for sealing between adjacent hatch covers 1, 1b.

As shown in Fig. 6, 7, 16, 25 and 26, the skirt 4 is provided with a support portion 8 for supporting the hatch cover 1 on the hatch coaming 2. The support portion is 40 mm thick up to a height of 100 mm from its open end. The lower thicker portion of the support portion 8 is provided with a central elongate groove 9. A resilient lower sealing member 10 made from rubber is provided in the central elongate groove 9 such that it protrudes out of said groove 9 for sealing against the hatch coaming 2. The lower sealing member 10 is configured such that it is deformable into the central elongate groove 9 upon pressing together of hatch cover 1 and ship at normal use, normal use being biasing the hatch cover 1 to the hatch coaming 2 using the cleats, and loading goods also on top of the hatch cover 1.

As shown in Fig. 15, the skirt 4 is provided with a side ridge 11 provided with a central elongate groove 12. A resilient side sealing member 13 is provided in the central elongate groove 12 of the side ridge such that it protrudes out of said groove 12 for sealing against an adjacent hatch cover 1b. The side ridge 11 and side sealing member 13 provide a unitary member capable of sealing anywhere on an opposing flat surface onto which it pressed, without being sensitive to relative movements between the opposing surface and the side ridge 11.

In an embodiment, the lower sealing member and the side sealing member is one continuous rubber element extending through both central elongate grooves all around the hatch cover 1 for sealing both to the hatch coaming and to an adjacent hatch cover 1b.

As shown in Fig. 15, an upper ridge 14 may be provided on the hatch cover for draining water away. Further, the upper ridge 14 functions together with the side ridge 11 to limit movement of the opposing side ridge 11b positioned for sealing against a surface between the side ridge 11 and the upper ridge 14. The upper ridge 14 and

side ridges

11, 11b may be provided with an upper recesses forming a respective channel for leading water away, for example directly to outside of the hatch cover, or to draining holes 15 in the hatch coaming 2 and via scupper pipes (not shown) to outside of the hatch cover.

Draining holes 16 may also be provided in the bottom of the stopper sockets 20, as shown in Fig. 18. Fig. 19 shows an embodiment of a stopper member 21 matching the two stopper sockets 20.

The fiber-reinforced material used in the embodiments shown in the figures and described above is glass fiber-reinforced polyester resin according to acceptance criteria for fiber-reinforced plastic construction from Pt.3 Ch.4 of the DNV Rules For High Speed Light Craft.

The materials properties of the GRP single skin plates are given in Table 1 below. The properties assumed in this work are for resin infused laminate with a fiber volume of about 55%. In the Rules there is no minimum amount of reinforcement value specified for a hatch cover application but a value of 5400 g/m (i.e. cargo deck) is considered as an indicative minimum level for the top plating, sides and bottom plating, Pt. 3 Ch. 4, Sec. 6 A202 of the DNV Rules For High Speed Light Craft.

Laminate

1 and 2 is made of E-glass and vinyl ester resin with fibers oriented at (0/90/45/-45degrees) with a percentage of fibers of respectively (40/40/10/10%). The bottom plate is the flat, mid-portion of the strengthening bodies 18. Laminate 3 is made of E-glass and vinyl ester resin with fibers oriented at (0/90/45/-45degrees) with a percentage of fibers of respectively (10/10/40/40%). Laminate 4 is made of E-glass and vinyl ester resin with fibers oriented at (0/90/45/-45degrees) with a percentage of fibers of 25% in all direction i.e. (25/25/25/25%).

It should be understood that the above described laminate is only one of many possible choices of laminates available to the skilled person. Any other fiber-reinforced plastic laminate could be used within the scope of the invention.

The web plates 22, shown in Figs. 8, 9, 10 and 11 are provided along a skirt portion which will be connected to a similar skirt portion of an adjacent hatch cover. The connected hatch covers typically cover a large hatch requiring multiple hatch covers for covering the hatch. When using multiple hatch covers for covering a large hatch, there is no central hatch coaming for supporting the skirt portions in the middle of the hatch opening. Thus, more momentum and stress will occur in the connected skirt portions than in skirt portions supported on hatch coaming, and therefore the web plates 22 are provided for joining the respective skirt portion and adjacent stiffening bodies 18 such that the stiffening body 18 helps supporting the skirt portions. The increased strength brings better control of the shape of the hatch covers and therefore also of the seal between adjacent hatch covers, effectively providing more reliable protection of cargo carried.

The stiffening plates 23 shown in Figs. 9, 10 and 11, are provided on other portions of the skirt, not needing connection to nearby stiffening bodies, such as skirt portions under which a hatch coaming will be present when in use.

This application claims the benefit of Norwegian Patent Application No. 20130932, filed on July 3, 2013, the entire disclosure of which is incorporated by reference herein.

1 hatch cover
2 hatch coaming
3 outer support ridge
4 skirt
5 cleat brackets
6 moving devices
7 rails
8 support portion
9 central elongate groove (of support portion)
10 resilient lower sealing member
11 side ridge
12 central elongate groove (of side ridge)
13 resilient side sealing member
14 upper ridge
15 draining hole (of hatch coaming)
16 draining hole (of stopper sockets)
17 cover body
18 stiffening bodies
19 inner support ridge
20 stopper socket
21 stopper member
22 web plates
23 stiffening plates

Claims

A hatch cover(1) for a ship comprising
a cover body(17) and a circumferential skirt(4) depending from the cover body(17),
wherein the skirt(4) is provided with a support portion(8) for supporting the hatch cover(1) on a hatch coaming(2) of a ship,
wherein the support portion(8) is provided with a central elongate groove(9),
wherein a resilient lower sealing member(10) is provided in the central elongate groove(9) such that it protrudes out of said groove(9) for sealing against the hatch coaming(2),
wherein the lower sealing member(10) is configured such that it is deformable into the central elongate groove(9) upon pressing together of hatch cover(1) and ship at normal use,
wherein a plurality of stiffening bodies(18) is provided on the inside of the cover body(17), and
wherein the cover body(17), the skirt (4)and the stiffening(18) bodies are made from fiber-reinforced plastics.
A hatch cover(1) according to claim 1,
wherein the hatch cover(1) is substantially rectangular with opposite longitudinal and transversal skirt portions, wherein the stiffening bodies(18) extend across the cover body(17) between opposite transversal or longitudinal portions of the skirt(4), and wherein opposite ends of each respective stiffening body are connected to the skirt(4).
A hatch cover(1) according to claim 2,
wherein the stiffening bodies are spaced apart at their ends.
A hatch cover(1) according to claim 2,
wherein the stiffening bodies(18) are spaced apart along their whole length.
A hatch cover(1) according to any one of claims 2-4,
wherein a plurality of web plates is provided on the inside of the skirt(4) and extending substantially perpendicularly to the inside of the skirt(4).
A hatch cover(1) according to any one of claims 2-5,
wherein stopper member(21)s are provided on at least some of the stiffening bodies(18), said stopper members(21) having protrusions engageable into corresponding recesses of stopper sockets(20) attached to the ship to prevent relative motion between ship and hatch cover(1).
A hatch cover(1) according to claim 6,
wherein said stopper members are made of metal.
A hatch cover(1) according to any one of the preceding claims,
further provided with cleat brackets on outer side portions of the skirt(4).
A hatch cover(1) according to any one of the preceding claims,
further provided with cleat brackets on top of the cover body(17).
A hatch cover(1) according to any one of the preceding claims,
wherein at least one outer side portion of the skirt(4) is provided with at least one side ridge,
wherein the side ridge(11) is provided with a central elongate groove(12), and
wherein a resilient side sealing member(13) is provided in the central elongate groove(12) of the side ridge(11) such that it protrudes out of said groove(12) for sealing against an adjacent hatch cover(1b).
A pair of hatch covers(1) according to claim 10,
wherein the respective side ridges(11,11b) of the hatch covers(1,1b) are configured to extend parallel to each other when said pair of hatch covers(1,1b) are positioned adjacent each other for covering of a hatch.
A hatch cover system comprising:
a ship; and
one or more hatch covers(1) according to any one of the preceding claims,
wherein said ship is provided with one or more hatches,
wherein each hatch is surrounded by a hatch coaming(2), and
wherein the hatch covers(1) are configured to fit over a respective one of said hatch coamings(2) such that the lower sealing member(10) fits sealingly to the respective hatch coaming(2).
A hatch cover system according to claim 12,
wherein an inner support ridge(19) is provided on the respective hatch coaming(2) for preventing the skirt(4) of the respective hatch cover(1) from moving inwards.
A hatch cover system according to any one of claims 12-13,
wherein an outer support ridge(3) is provided on the hatch coaming(2) for preventing the skirt(4) of the respective hatch cover(1) from moving outwards to thereby keep the respective hatch cover(1) in place.
A hatch cover system according to any one of claims 12-14 when dependent directly or indirectly on claim 6,
wherein said system comprises stopper sockets(20) attached to the ship, wherein the stopper members(21) and the stopper sockets(20) are configured for mutual engagement to prevent relative movement at least along the skirt(4) by each respective stopper socket(20).