Goods hatch

Abstract

The invention relates to a cargo hatch for a bulk cargo ship or other ship and allowing access to a cargo hold. The cargo hatch includes one or more hatch covers disposed on a hatch coaming that surrounds a hatch opening through which the cargo hold can be accessed. In order to prevent water from entering the cargo hold from the external environment, a sealing piece is usually arranged between the hatch cover and the hatch coaming. The seal may be susceptible to deterioration. The invention proposes a cargo hatch for a bulk cargo ship, the cargo hatch comprising a hatch coaming surrounding a hatch opening and a hatch cover configured to be removably positioned on the hatch coaming such that the hatch cover reversibly closes the hatch opening, wherein the cargo hatch includes two sealing systems configured to provide respective and separate seals between the hatch coaming and the hatch cover in use.

Description

Technical Field

[0001] The present invention relates to cargo hatches and, more particularly but not exclusively, to cargo hatches for bulk carriers. Background Art

[0002] Bulk carriers are commercial vessels that transport bulk cargoes such as coal, cement, ore and grain. Typically, bulk cargoes are stacked directly in one or more cargo holds of a bulk carrier without packaging or any additional containers, although bulk carriers can also be used to transport other cargoes (e.g. packaged cargoes). On a bulk carrier, access to the cargo holds is via hatch openings on the deck of the ship, which are covered by one or more hatch covers. The hatch covers are set on hatch coamings (vertically extending flat surfaces / plates) that completely surround the hatch openings and provide a seal to protect the cargo holds from weather and seawater.

[0003] Traditionally, sealing is achieved using compression rods mounted on top of the hatch coaming and mating washers (e.g., rubber washers) mounted within a channel (e.g., a steel channel) at the bottom of the hatch cover. When the hatch cover is in its closed position, the washers are seated on the compression rods so that under the weight of the hatch cover the washers conform to the shape of the compression rods, thereby forming a seal. Prior art arrangements of this type are known to provide protection against rainwater, but can only provide limited protection against the ingress of seawater into the cargo hold (e.g., during heavy weather at sea).

[0004] Furthermore, during the service life of a bulk carrier, the effectiveness of this traditional type of sealing may deteriorate due to damage to components of the cargo hatches, such as hatch coamings, hatch covers, gaskets or compression rods. Such damage may be caused by weathering or corrosion over time, or even by accidents during the loading and unloading of the vessel. Therefore, one of the most common problems in transporting bulk cargoes and other cargoes in bulk carriers is contamination caused by the ingress of seawater or rainwater into one or more cargo holds. This can lead to cargo damage (especially since the cargo is usually unpackaged) and subsequent insurance claims.

[0005] The present invention is designed based on the above considerations. Summary of the invention

[0006] In general, the present invention relates to a cargo hatch for a bulk carrier, the cargo hatch comprising a hatch coaming surrounding a hatch opening and a hatch cover configured to be removably positioned on the hatch coaming so that the hatch cover reversibly closes at least a portion of the hatch opening, wherein the cargo hatch comprises two sealing systems (e.g. a double sealing arrangement) which are configured to provide respective and separate seals between the hatch coaming and the hatch cover during use.

[0007] In a first aspect, a cargo hatch for a bulk carrier is provided, comprising: a hatch coaming surrounding a hatch opening; a hatch cover configured to be removably positioned on the hatch coaming so that the hatch cover reversibly closes at least a portion of the hatch opening; a first sealing system comprising a gasket and a compression rod and configured to provide a seal between the hatch coaming and the hatch cover in use; and a second sealing system comprising an inflatable seal and configured to provide a seal between the hatch coaming and the hatch cover in use.

[0008] As used herein, "in use" refers to when the hatch cover is located on the hatch coaming so that the hatch opening is closed by the hatch cover. In this case, the cargo hatch can be referred to as being in a closed state.

[0009] By providing a cargo hatch according to the first aspect, an improved seal between a hatch cover and a hatch opening (e.g. defined by a hatch coaming) may be achieved. In particular, water ingress into the cargo hold and contamination of the cargo in the cargo hold may be reduced or eliminated. In particular, a second sealing system comprising an inflatable seal may contribute to enhancing the watertightness of the cargo hatch and the cargo hold. Furthermore, by providing a second sealing system comprising an inflatable seal, the cargo hatch may remain watertight during repeated use despite physical changes of the hatch cover and / or the hatch coaming (e.g. its dimensions) over time, e.g. due to weathering and / or corrosion.

[0010] The hatch cover may be configured to be removably positioned on the hatch coaming such that the hatch cover reversibly closes the hatch opening (eg, the entire hatch opening). In other words, a single integral hatch cover may be used to close the hatch opening.

[0011] By providing a hatch cover that reversibly closes the entire hatch opening, fewer paths for potential water to enter the hatch may be provided compared to a conventional roll-down hatch cover that typically includes two cooperating hatch covers that each cover a respective half of the hatch opening and meet at a center seam when closed. In this conventional type of roll-down hatch cover design, the center seam provides an additional path for water to enter the hatch in addition to the area around the edge of the hatch opening where one or more hatch covers abut the hatch coaming. In other words, in embodiments where the hatch cover reversibly closes the entire hatch opening, the length of the one or more sealing systems required for the cargo hatch is reduced.

[0012] The operation of the cargo hatch according to the first aspect is as follows. After cargo is loaded into the cargo hold via the hatch opening, the hatch cover is moved into position so that it is located on the hatch coaming. As a result, the hatch opening is closed by the hatch cover. This process may be referred to as closing the hatch cover. The gasket and the compression rod may be positioned on opposing surfaces of the hatch cover and the hatch coaming. For example, the compression rod may be located on the hatch coaming and the gasket may be located on the hatch cover. When the hatch cover is located on the hatch coaming, the gasket abuts (e.g., is located on) the compression rod, and the gasket is adapted to the shape of the compression rod (e.g., under the weight of the hatch cover) so that a seal is provided between the hatch coaming and the hatch cover. This is a first sealing system.

[0013] When the hatch cover is closed, the inflatable seal is in an uninflated state. When the hatch cover is located on the hatch coaming, the inflatable seal expands to an inflated state. In the inflated state, the inflatable seal abuts both the hatch cover and the hatch coaming and adapts to the shape of the hatch cover (e.g., the skirt of the hatch cover, see below) and the hatch coaming so that the seal is arranged between the hatch cover and the hatch coaming. This is the second sealing system. In the inflated state, the volume of the inflatable seal is greater than the volume of the inflatable seal in the uninflated state.

[0014] When it is necessary to enter the cargo hold, the hatch cover can be moved away from the hatch opening, so that the cargo hold can be entered through the hatch opening. When the hatch cover is moved away from the hatch opening, the cargo hatch can be considered to be in an uncovered state. In the uncovered state, the hatch cover can be adjacent to the hatch opening, and the cargo hold can be entered through the hatch opening.

[0015] The inflatable seal may be a reversible inflatable seal. In other words, the inflatable seal may expand from an unexpanded state to an expanded state, and also (e.g., subsequently) collapse (i.e., reduce in volume) from the expanded state to an unexpanded state. In an embodiment in which the inflatable seal is a reversible inflatable seal, the operation of the inflatable seal may be as follows. When the cargo hatch is in a closed state, the inflatable seal may expand from an unexpanded state to an expanded state to provide a seal between the hatch cover and the hatch coaming, as described above. When the hatch cover is to be removed, the inflatable seal may collapse from an expanded state to an unexpanded state so that a second seal is no longer provided between the hatch cover and the hatch coaming. This may make it easier to remove the hatch cover from the hatch opening in order to open the hatch. This also means that the inflatable seal returns to an unexpanded state, for example, to prepare for the next closure of the hatch cover after new cargo is loaded into the hatch via the hatch opening.

[0016] The inflatable seal can be an inflatable seal. For example, the seal can be inflated from an uninflated state to an inflated state by directing an inflation gas (e.g., air) into an inflatable volume defined within the inflatable seal. In addition, the seal can be collapsed from an inflated state to an uninflated state by venting or removing the inflation gas from the inflatable volume. For example, the inflatable seal can include a bladder surrounding the cavity. The volume of the cavity can be increased (e.g., from an uninflated state to an inflated state) by injecting gas, and in embodiments having a reversibly inflatable seal, the volume of the cavity can be reduced (e.g., from an inflated state to an uninflated state) by removing gas.

[0017] The hatch cover may comprise a bottom surface which faces a hatch opening, for example a cargo hold of a bulk carrier, in use. The hatch cover may comprise a top surface on an opposite side of the bottom surface which faces away from the hatch opening in use. In use, the top surface may form part of a bulk carrier deck.

[0018] The hatch opening may have a main axis. The hatch cover may also have a corresponding main axis. The hatch opening and the main axis and the main axis of the hatch cover may extend in a vertical direction, for example the main axis may be parallel to a vertical axis of the bulk carrier. When the cargo hatch is in a closed state, the main axis of the hatch cover may be colinear with the main axis of the hatch opening.

[0019] The hatch opening may have a width (e.g. in a direction approximately between the port and starboard sides of the bulk carrier) of about 10m to 25m, such as about 15m to 20m, such as about 15m. The length of the hatch opening may be approximately perpendicular to the width, and therefore parallel to the centerline of the bulk carrier. The length of the hatch opening may be less than the width. For example, the length of the hatch opening may be between about 5m and about 20m, such as between about 10m and about 15m, such as about 10m.

[0020] The hatch coaming may include a compression rod of the first sealing system. For example, the hatch coaming may have a top surface (e.g. facing away from the deck of the bulk carrier, e.g. facing in a substantially vertical direction) to which the compression rod is attached. The hatch cover may include a corresponding gasket that abuts (e.g. lies on) the compression rod in use and matches the shape of the compression rod to provide a seal between the hatch coaming and the hatch cover. The seal may be maintained by the downward force of the hatch cover on the compression rod.

[0021] The first sealing system may extend between all connection areas between the hatch cover and the hatch coaming. For example, the compression rod may extend completely around the periphery of the hatch coaming. For example, the compression rod may extend completely around the top of the hatch coaming. In such an embodiment, the gasket of the first sealing system may extend completely around an area of ​​the hatch cover, which area (when the cargo hatch is in a closed state) corresponds to the area where the hatch cover is connected to the compression rod (e.g., via the gasket). For example, the gasket of the first sealing system may extend completely around the periphery of the hatch cover (e.g., on the bottom surface of the hatch cover) and may be spaced inwardly from the peripheral edge of the hatch cover so that the shape of the gasket (when viewed from below) corresponds to the shape of the compression rod on the hatch coaming (when viewed from above).

[0022] In some embodiments, the hatch opening may have a quadrilateral (e.g., rectangular) shape. In other words, the hatch opening may be a quadrilateral hole (e.g., opening) in the bulk carrier deck. Thus, the hatch coaming extending around the entire periphery of the hatch opening may have a quadrilateral shape when viewed from above. Furthermore, the compression rod (e.g., on the top surface of the hatch coaming) may also have a quadrilateral shape when viewed from above, such that it surrounds the periphery of the hatch opening.

[0023] In embodiments where the compression rod has a quadrilateral shape, the corresponding gasket of the first sealing system may also have a quadrilateral shape such that it corresponds to the shape of the compression rod. For example, the gasket of the first sealing system may be located on the bottom surface of the hatch cover such that when viewed from below, the gasket of the first sealing system may form a quadrilateral on the bottom surface of the hatch cover corresponding to the shape of the compression rod.

[0024] The hatch cover may include an inner gasket channel (e.g., a steel channel) configured to accommodate a gasket of the first sealing system. The inner gasket channel may be on the bottom surface of the hatch cover. The inner gasket channel may have a quadrilateral shape so that the gasket of the first sealing system has a quadrilateral shape as described above.

[0025] The hatch coaming may include one or more side surfaces. The one or more side surfaces may face in a direction substantially perpendicular to the main axis of the hatch opening. The inflatable seal may be located on one or more side surfaces of the hatch coaming. For example, the inflatable seal may be located on one or more side surfaces near the top of the hatch coaming, such that in an inflated state, the inflatable seal abuts the hatch cover to form a seal as described above.

[0026] By providing an inflatable seal on one or more side surfaces of the hatch coaming, the inflatable seal may be spaced apart from a first sealing system which may be located on a top surface of the hatch coaming and thereby not interfere with the operation of the first sealing system.

[0027] In some embodiments, the hatch coaming may include a channel (e.g., a semi-tubular channel having a substantially semi-circular cross-section) configured to accommodate the inflatable seal. For example, one or more side surfaces of the hatch coaming may include the channel. For example, the channel may extend around all sides of the hatch coaming (e.g., continuously). The channel may define an outwardly oriented opening. When expanded from an unexpanded state to an expanded state, the inflatable seal may expand through the opening.

[0028] The channel may be connected (e.g., attached) to the hatch coaming via a channel support. The channel support may extend away from the hatch coaming (e.g., in a direction substantially perpendicular to the main axis of the hatch opening) so that the channel is spaced apart from the hatch coaming (e.g., in a direction substantially perpendicular to the main axis of the hatch opening). In some embodiments, one or more side surfaces of the hatch coaming may include the channel support, for example, the channel support may extend around all side surfaces of the hatch coaming (e.g., continuously). The channel may be spaced apart from the hatch coaming (e.g., the channel support extends from one or more side surfaces) by about 100 mm to about 500 mm, for example, about 150 mm to about 450 mm, for example, about 200 mm to about 400 mm, for example, about 250 mm to about 350 mm, for example, about 300 mm to about 350 mm, for example, about 300 mm. The channel may have a depth of about 20 mm to about 100 mm, such as about 30 mm to about 90 mm, such as about 40 mm to about 80 mm, such as about 50 mm to about 70 mm, such as about 50 mm to about 60 mm, such as about 60 mm. Here, "channel depth" refers to the dimension of the channel extending from the opening of the channel, such as in a direction perpendicular to the main axis of the hatch opening and / or in the extension direction of the channel support away from the side surface of the hatch coaming. In an embodiment where the channel is a semi-tubular channel, the semi-tubular channel may have a diameter of about 40 mm to about 200 mm, such as about 60 mm to about 180 mm, such as about 80 mm to about 160 mm, such as about 100 mm to about 140 mm, such as about 100 mm to about 120 mm, such as about 120 mm.

[0029] The one or more side surfaces of the hatch coaming may be one or more outer side surfaces of the hatch coaming, respectively, such that the one or more side surfaces face away from the hatch opening (eg towards the gunwale of the bulk carrier). In other words, the one or more side surfaces may be oriented outwardly.

[0030] By providing an inflatable seal on the outer side surface of the hatch coaming, in use, the second sealing system can provide a seal between the hatch coaming and the hatch cover, which seal separates the first sealing system from the external environment. As a result, the second sealing system can reduce the possibility of damage to the first sealing system due to weathering or corrosion.

[0031] The second sealing system may extend around all connection areas between the hatch cover and the hatch coaming.For example, the inflatable seal (eg, and a channel configured to accommodate the inflatable seal) may extend completely around the hatch coaming and the hatch opening.

[0032] In embodiments where the hatch opening has a quadrilateral shape (as described above), the inflatable seal may extend (e.g., continuously) along each side of the quadrilateral shape. In these embodiments, the hatch coaming may include an inflatable seal (e.g., and a channel to accommodate the inflatable seal) on each side of the quadrilateral shape.

[0033] Bulk carriers (like all ships) have a centerline. In embodiments where the hatch opening is a quadrilateral shape, the quadrilateral shape may be substantially aligned with the centerline of the bulk carrier. In other words, the hatch opening may have four sides facing forward, aft, port and starboard, respectively. In addition, other features having a corresponding quadrilateral shape (as described above) may similarly be aligned with the centerline of the bulk carrier. For example, the hatch coaming may have four outer side surfaces facing forward, aft, port and starboard, respectively.

[0034] The hatch cover may comprise a skirt. The skirt may extend away from the hatch cover, for example from the bottom surface of the hatch cover. For example, the hatch cover may comprise a skirt which, in use, extends from the bottom surface of the hatch cover towards the hatch opening. The skirt may be similar to a plate attached to the hatch cover (for example to the bottom surface of the hatch cover), which is substantially perpendicular to the hatch cover. For example, the skirt may comprise a plate which forms a continuous loop and extends from the hatch cover and is substantially perpendicular to the hatch cover. The skirt may comprise one or more side surfaces facing in a direction substantially perpendicular to the main axis of the hatch cover.

[0035] In use, the skirt may extend around the entire periphery of the hatch opening. The shape of the skirt (when viewed from below) may be mathematically similar to the shape of the hatch coaming (when viewed from above). In embodiments where the hatch coaming is quadrilateral in shape when viewed from above, the skirt may be a complementary quadrilateral in shape when viewed from below.

[0036] In use, the skirt (e.g. one or more side surfaces of the skirt) may overlap the hatch coaming (e.g. one or more side surfaces of the hatch coaming). In preferred embodiments, in use, the hatch coaming may be located on the side of the skirt closest to the hatch opening. In these embodiments, the skirt may be considered to be located outside the hatch coaming because the skirt is located between the hatch coaming and the external environment. The spacing between the hatch coaming and the skirt may be uniform around the hatch opening.

[0037] When the hatch opening is closed by the hatch cover, the inner gasket channel (and the gasket) may be positioned within the skirt so that the skirt is positioned between the inner gasket channel and the edge of the hatch cover. The outer wall of the inner gasket channel (e.g., the wall closest to the hatch cover edge) may be adjacent to (e.g., connected to and optionally aligned with) the skirt so that the gasket of the first sealing system is adjacent to (e.g., connected to) the skirt.

[0038] By providing a hatch cover with a skirt, wherein in use the skirt extends from the bottom surface of the hatch cover towards the hatch opening, seals and sealing systems can be more easily arranged between the hatch cover and the hatch coaming. In addition, a longer and / or more complex path can be provided between the external environment and the hatch opening, so that the possibility of water entering the cargo hold via the hatch opening can be reduced. In particular, by providing the skirt on the outside of the hatch coaming when in use, the path for water ingress requires that the water travel in an upward direction before passing over the top of the hatch coaming. In addition, by arranging the skirt on the outside of the hatch coaming when in use, the first sealing system and the inflatable seal are protected by the skirt from the external environment. This can increase the life of the sealing system by reducing damage caused by weathering and / or corrosion.

[0039] The skirt may extend from about 100 mm to about 400 mm, such as about 150 mm to about 350 mm, such as about 200 mm to about 300 mm, such as about 200 mm to 300 mm, such as about 270 mm, from the bottom surface of the hatch cover.

[0040] The skirt may include one or more reinforcing members. Such reinforcing members may be arranged on one or more side surfaces of the skirt, for example on one or more outer side surfaces of the skirt. The one or more outer side surfaces of the skirt are the one or more side surfaces facing away from the hatch opening when in use. A plurality of reinforcing members may be spaced apart from each other along the skirt. The reinforcing member may extend away from the bottom surface of the hatch cover. The reinforcing member is referred to as a bracket.

[0041] The skirt (eg, one or more side surfaces of the skirt) may include a wedge-shaped notch around its perimeter.Some or all of the plurality of reinforcement members may include corresponding wedge-shaped notches.

[0042] In embodiments where the skirt overlaps the hatch coaming in use, the inflatable seal may abut the skirt (e.g., one or more side surfaces of the skirt) and the hatch coaming (e.g., one or more side surfaces of the hatch coaming) when in the inflated state. For example, in embodiments where the inflatable seal is located on one or more outside surfaces of the hatch coaming and the skirt is positioned to the outside of the hatch coaming, the inflatable seal may abut the skirt and adapt to the shape of the skirt (e.g., the shape of one or more side surfaces of the skirt) such that a seal is provided between the hatch cover and the hatch coaming. In other words, the second sealing system may include an inflatable seal and a skirt such that, in the inflated state, the inflatable seal abuts the skirt to provide a seal between the hatch coaming and the hatch cover.

[0043] By providing a second sealing system comprising an inflatable seal and a skirt, the inflatable seal can abut against the skirt when in an inflated state and adapt to the shape of the skirt so that a seal is provided between the hatch cover and the hatch coaming. The skirt provides a surface against which the inflatable seal can abut to form a good quality seal. Furthermore, the skirt provides protection for the inflatable seal against the external environment.

[0044] As described above, the hatch cover is moved into position so that after cargo is loaded into the cargo hold via the hatch opening, the hatch cover is positioned on the hatch coaming. Before being moved into position, the hatch cover is positioned adjacent to the hatch opening so that the hatch opening is not covered (referred to as the uncovered state). The cargo hatch can be (reversibly) switched between a covered state (wherein the hatch cover is above the hatch opening) and an uncovered state. The hatch cover can be moved between the covered state and the uncovered state in a direction substantially parallel to the centerline of the bulk carrier.

[0045] In the covering state, the hatch cover is positioned above the hatch opening, but not on the hatch coaming. Thus, the cargo hatch can be reversibly moved (e.g. lowered and raised) between the covering state and the closed state.

[0046] In order to ensure that the hatch cover is correctly in its closed position when the cargo hatch is in the closed state, the cargo hatch may comprise means for correctly positioning the hatch cover, such as wedge-shaped slides.

[0047] The hatch coaming may include one or more friction pads (bearing pads) to support the hatch cover. For example, the top surface of the hatch coaming may include a plurality (e.g., four) friction pads to support the hatch cover. The one or more friction pads may be bolted or welded to the hatch coaming. The hatch cover may support the compression rod (or multiple compression rods) described herein via respective washers and also support the friction pads.

[0048] The hatch cover can be mounted on a track, such as a wheel track, so that the hatch cover can move along the track to switch between a covered state and an uncovered state. For example, the cargo hatch can include two tracks. The track can extend approximately parallel to the centerline of the bulk carrier. One track can be located on the starboard side of the hatch opening, and another track can be located on the port side of the hatch opening. The hatch cover can include wheels. One or more wheels can be configured to run along the corresponding tracks, such as being stationary and rolling on the corresponding tracks. For example, the hatch cover can include two wheels configured to be stationary and rolling on the starboard track and two wheels configured to be stationary and rolling on the port track. In some embodiments, the hatch cover can include four such wheels, such as being located near each corner of the hatch cover.

[0049] One or more motors can be used to drive the wheels along the track. The hatch cover can include one or more motors. For example, each wheel can have a corresponding motor. The track and the wheels can have teeth (e.g., so that the track is similar to a rack and the wheels are similar to cooperating pinions).

[0050] When the hatch cover is to be closed, the hatch cover can be moved over the hatch opening, for example by moving the hatch cover along a track. At this stage, the cargo hatch is in a covered state, but not yet in a closed state. The hatch may include means for lowering the hatch cover onto the hatch coaming. For example, one or more hydraulic jacks may be provided to lower the hatch cover onto the hatch coaming. For example, four hydraulic jacks may be provided, for example one hydraulic jack is provided at each corner of the hatch cover. Thus, the hatch cover can be located on the hatch coaming (e.g., so that the hatch is in a closed state), and then the sealing system can be operated as described herein.

[0051] When access to the cargo hold is required, the hatch cover can be raised (e.g., by a hydraulic jack) to transition the cargo hatch from a closed state to a covered state, and then moved away from the hatch opening (e.g., by tracks) to transition the cargo hatch from a covered state to an uncovered state.

[0052] In use, the hatch cover may extend beyond the hatch opening, such as the hatch coaming. For example, in use, the hatch cover may extend beyond the hatch opening in a lateral direction, such as toward the port and / or starboard side of the bulk carrier. In some embodiments, in use, one or more portions of the hatch cover extending beyond the hatch opening may cover a portion of a crew passage and / or a workspace adjacent to the hatch opening. The workspace may be provided between the crew passage and the hatch coaming (e.g., on one or both sides of the bulk carrier).

[0053] In embodiments where the hatch cover extends beyond the hatch coaming, one or more edges of the hatch cover (in use) may be connected to (e.g., located at) a support area of ​​a bulk carrier. For example, the support area may be part of a deck of a bulk carrier. In some embodiments, an additional sealing system may be provided between the hatch cover and the support area (e.g., the deck of a bulk carrier). The additional sealing system may include a gasket and a compression rod. For example, the support area (e.g., the deck) may include a compression rod, and the hatch cover may include an additional gasket for the additional sealing system. In use, the gasket of the additional sealing system may abut (e.g., be located at) a compression rod of the support area and be adapted to the shape of the compression rod, thereby providing a seal between the hatch cover and the support area. The seal may be maintained by the downward force of the hatch cover on the compression rod.

[0054] The support area of ​​the bulk carrier may extend completely around the hatch opening. The additional sealing system may extend between all connection areas between the hatch cover and the support area of ​​the bulk carrier. For example, the compression rod of the additional sealing system may extend completely around the hatch opening. In these embodiments, the gasket of the additional sealing system may extend completely around the area of ​​the hatch cover, which corresponds to the area of ​​the compression rod of the hatch cover connected to the additional sealing system when the hatch cover is closed. For example, the gasket of the additional sealing system may extend completely around the periphery of the hatch cover. The shape of the gasket of the additional sealing system (when viewed from below) may correspond to the shape of the compression rod on the support area, such as the deck of the bulk carrier (when viewed from above).

[0055] The compression rod of the additional sealing system may have a quadrilateral (e.g. rectangular) shape (when viewed from above) such that it surrounds the hatch opening. The corresponding gasket of the additional sealing system may have a quadrilateral shape such that it corresponds to the shape of the compression rod of the additional sealing system. For example, in the case where the hatch cover is quadrilateral in shape, the gasket of the additional sealing system may extend around the edge of the hatch cover on the bottom surface such that it also has a quadrilateral shape.

[0056] The hatch cover may include an outer gasket channel, such as a steel channel, configured to accommodate a gasket of the additional sealing system. The outer gasket channel may be on the bottom surface of the hatch cover. The outer gasket channel may have a quadrilateral shape so that the gasket of the additional sealing system has a quadrilateral shape as described above.

[0057] In a second aspect, a bulk carrier is provided comprising one or more cargo hatches according to the first aspect. In some embodiments, the bulk carrier according to the second aspect may comprise more than one cargo hatch according to the first aspect, each cargo hatch comprising a respective hatch cover configured to be removably positioned on a respective hatch coaming such that the hatch cover reversibly closes the hatch opening (e.g., the entire hatch opening).

[0058] The hatch cover on the bulk carrier according to the second aspect is movable in a direction substantially parallel to the centre line of the bulk carrier so as to cover and uncover the hatch opening.

[0059] In a third aspect, a method for closing a cargo hatch for a bulk carrier is provided, the method comprising the steps of: removably positioning a hatch cover on a hatch coaming of the cargo hatch, providing a first seal between the hatch coaming and the hatch cover using a first sealing system, wherein the first sealing system comprises a gasket and a compression rod (e.g. on opposing surfaces of the hatch coaming and the hatch cover), providing a second sealing system comprising an inflatable seal, inflating the inflatable seal to provide a second seal between the hatch coaming and the hatch cover.

[0060] The step of removably positioning the hatch cover on the hatch coaming of the cargo hatch may include the steps of moving the hatch cover over the hatch opening (eg, so that the cargo hatch is transitioned between an uncovered state and a covered state), and lowering the hatch cover so that it rests on the hatch coaming.

[0061] For accessing a cargo hold of a bulk carrier via the hatch opening, the method according to the third aspect may further comprise the steps of collapsing the inflatable seal to remove the second seal, and moving the hatch cover away from the hatch coaming such that the hatch opening is accessible.

[0062] Moving the hatch cover over the hatch opening may comprise, for example, moving the hatch cover in a direction substantially parallel to a centreline of the bulk carrier.

[0063] The invention includes the combination of the various aspects and preferred features described, unless such a combination is expressly not permitted or explicitly avoided.For example, the method of the third aspect may relate to the method of closing a cargo hatch according to the first aspect.

[0064] Throughout this specification, reference is made to the cargo hatch of the first aspect being on a bulk carrier. However, it will be appreciated that the cargo hatch of the first aspect may also be provided on any type of vessel, not just on a bulk carrier. Therefore, the skilled person will appreciate that references to a bulk carrier are also references to any other vessel.

[0065] In this specification, "viewed from above" means viewing towards the bulk carrier deck. In the context of hatch covers and their components (e.g. skirts, gaskets), "viewed from below" means viewing towards the bottom surface of the hatch cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Embodiments and examples illustrating the principles of the present invention will now be discussed with reference to the accompanying drawings, in which:

[0067] Figure 1A top view of a bulk carrier having a cargo hatch according to the first aspect is shown, wherein the cargo hatch is shown in an uncovered state.

[0068] Figure 2 Shows Figure 1 Aft view of the hatch cover of the cargo hatch shown.

[0069] Figure 3 Shown as viewed from the starboard side Figure 2 Side view of the hatch cover.

[0070] Figure 4 Shows Figure 2 Bottom view of the hatch cover of the cargo hatch shown.

[0071] Figure 5 Shows Figure 1 A top view of a bulk carrier in which the cargo hatches are shown in a covered state.

[0072] Figure 6 Shows Figure 1 Cross-section of the starboard side of a bulk carrier showing the cargo hatch in the covered state.

[0073] Figure 7 Shows Figure 1 Cross-section of a bulk carrier in FIG. 1, showing the cargo hatches in the closed position. DETAILED DESCRIPTION

[0074] Various aspects and embodiments of the present invention will now be discussed with reference to the accompanying drawings. Other aspects and embodiments will be apparent to those skilled in the art. All documents mentioned herein are incorporated herein by reference.

[0075] Figure 1 A top view of a longitudinal portion of a bulk carrier having a cargo hatch 100 according to the first aspect is shown.

[0076] The bulk carrier 1 has a starboard upper water ballast tank 2 and a port upper water ballast tank 3, which are separated by an area of ​​a deck 4 through which a cargo hatch 100 is provided. The two upper water ballast tanks 2, 3 are separated from the area of ​​the deck 4 with the cargo hatch 100 by respective longitudinally extending crew passages 5a, 5b. The cargo hatch 100 is symmetrical about the centerline 91 of the bulk carrier 1.

[0077] Although only one cargo hatch 100 is shown in the drawings, the bulk carrier 1 may have more than one cargo hatch 100, each having a structure identical or similar to the structure of the cargo hatch 100 described herein. Each cargo hatch 100 is typically spaced apart from the other cargo hatches along the centerline 91 of the bulk carrier 1 (i.e., in the longitudinal direction).

[0078] The cargo hatch 100 has a hatch opening 101 which is a rectangular hole in the deck 4 of the bulk carrier 1. The hatch opening 101 allows cargo to be loaded through the hatch opening and into the cargo hold of the bulk carrier.

[0079] The hatch coaming 110 surrounds the hatch opening 101 such that it extends around the entire perimeter of the hatch opening 101. As will be appreciated by a person skilled in the art, the hatch coaming 110 comprises a vertically extending flat surface / plate around the hatch opening 101. Here, the hatch coaming 110 resembles the side of a cuboid such that it surrounds the entire perimeter of the hatch opening 101.

[0080] exist Figure 1 In FIG. 1 , the cargo hatch 100 is shown in an uncovered state, wherein the hatch cover 130 is located near the hatch opening 101 and towards the stern of the bulk carrier, so that the cargo hold can be accessed through the hatch opening 101. For clarity, in FIG. Figure 1 Components below the hatch cover 130 are shown.

[0081] The hatch cover 130 is arranged on two longitudinally extending wheel rails 20a, 20b, which are located on respective sides of the hatch opening 101. When viewed from above, the hatch cover 130 has a larger area than the hatch opening and extends across the crew passages 5a, 5b on the port and starboard sides. Near each corner of the hatch opening 101 and aligned with the wheel rails 20a and 20b, respective hydraulic jacks 120a, 120b, 120c, 120d are provided.

[0082] Figure 2 Shows Figure 1 A rear view of a hatch cover 130 is shown. The hatch cover 130 is a flat plate (e.g., a metal such as steel). In this embodiment, the hatch cover 130 has a thickness of approximately 450 mm (millimeters), a width of approximately 19 m (meters), and a length (in the longitudinal direction) of approximately 11.5 m. Those skilled in the art will appreciate that the dimensions of the hatch cover 130 may vary depending on the dimensions of the cargo hatch 100 and / or the bulk carrier 1.

[0083] The hatch cover 130 includes a skirt 131 extending from the bottom surface of the hatch cover 130. The skirt 131 extends around the periphery of the hatch cover 130 and is spaced inwardly from the edge of the hatch cover 130. The hatch cover 130 has a main axis extending vertically through the center of the hatch cover 130. The skirt 131 includes an outer side surface 134, which faces a direction generally perpendicular to the main axis of the hatch cover in use. The outer side surface 134 of the skirt 131 can be considered to include four continuously connected outer side surfaces 134 facing different directions (forward, aft, port and starboard). Figure 2An outboard surface 134 of the skirt 131 facing in the aft direction is shown. The skirt includes a plurality of reinforcing members 135 spaced apart along the skirt 131 on the outboard surface 134. The reinforcing members 135, which may be similar to ribs, extend away from the bottom surface of the hatch cover 130.

[0084] Figure 3 A side view of the hatch cover 130 from the starboard side is shown. Here it can be seen that the outer surface 134 of the skirt 131 facing the starboard side has reinforcement members 135 spaced therealong.

[0085] The hatch cover 130 includes four wheels 121a, 121b, 121c, 121d underneath (attached to the bottom surface). Each wheel is located between the skirt 131 and the side of the hatch cover 130. Figure 3 As shown, there are two wheels 121a, 121b on the starboard side, which are aligned transversely and spaced longitudinally from each other. There are also two wheels 121c, 121d on the port side, which are aligned transversely and spaced longitudinally from each other in a similar manner (see Figure 4 ). The starboard side wheels 121a, 121b are arranged on the starboard side wheel rail 20a, and the port side wheels 121c, 121d are arranged on the port side wheel rail 20b, so that the hatch cover 130 is movably supported on the wheel rails 20a, 20b. The wheels 121a, 121b, 121c, 121d are configured to roll along the wheel rails 20a, 20b, so that the hatch cover 130 can move along the wheel rails. Each wheel 121a, 121b, 121c, 121d is provided with a corresponding motor 122a, 122b, 122c, 122d, and the motor 122a, 122b, 122c, 122d drives the wheel 121a, 121b, 121c, 121d, so that the hatch cover 130 moves along the wheel rails 20a, 20b.

[0086] Figure 4 The hatch cover 130 is shown viewed from below. Figure 4 In FIG. 1 , all four wheels 121a, 121b, 121c, 121d and corresponding motors 122a, 122b, 122c, 122d can be seen near the corners of the hatch cover 130. Figure 4 As shown, the skirt 131 is rectangular when viewed from below.

[0087] The hatch cover 130 includes an inner gasket channel 132 disposed inside the skirt 131 such that the skirt 131 is positioned between the inner gasket channel 132 and the edge of the hatch cover 130. The inner gasket channel 132 extends completely around the interior of the skirt 131. When viewed from below, the inner gasket channel 132 follows a path having a corresponding rectangular shape. The outer wall of the inner gasket channel 132 is aligned with the skirt 131. The inner gasket channel 132 is configured to accommodate an inner gasket.

[0088] The hatch cover 130 also includes an outer gasket channel 133 that extends around the perimeter of the bottom surface of the hatch cover 130 at the peripheral edge of the hatch cover 130. The outer gasket channel 133 also follows a rectangular path when viewed from below. The outer gasket channel 133 is configured to accommodate an outer gasket.

[0089] Figure 4 The hatch cover 130 is shown in Figure 4 There is horizontal and vertical symmetry in the orientation shown.

[0090] Next, the operation of the cargo hatch 100 will be described.

[0091] As explained above, Figure 1 The cargo hatch 100 is shown in an uncovered state. Figure 5 In FIG. 1 , the cargo hatch 100 is shown in a covered state such that the hatch cover 130 is located above the hatch opening 101 (at Figure 5 130, for the sake of clarity, the components below the hatch cover 130 are shown). Figure 1 The uncovered state shown and Figure 5 This is achieved by moving the hatch cover 130 along the wheel tracks 20a, 20b on wheels 121a, 121b, 121c, 121d driven by motors 122a, 122b, 122c, 122d.

[0092] In the covered state, the hatch cover 130 is located above the hatch opening 101 . Figure 6 A cross-sectional view of the starboard side of a bulk carrier is shown, wherein the cargo hatch 100 is in a covered state (ie the cargo hatch 100 is covered but not yet closed).

[0093] Figure 6 Three sealing systems are shown: a first sealing system 140 ; ​​a second sealing system 150 ; and an additional sealing system 160 .

[0094] The first sealing system 140 includes an inner gasket 141 received in the inner gasket channel 132 of the hatch cover. The first sealing system 140 also includes an inner compression rod 142 located at the top of the hatch coaming 110. The compression rod 142 extends completely around the top of the hatch coaming 110 so that the compression rod 142 is rectangular in shape (similar to the hatch coaming 110) when viewed from above. Figure 6 In the covered position shown, the inner gasket passage 132 is vertically aligned with the compression rod 142.

[0095] The second sealing system 150 comprises an inflatable seal 151 and a skirt 131 of the hatch cover 130. The inflatable seal 151 is housed in a semi-tubular channel 158 which is located on the outer side surface 111 of the hatch coaming 110, near the top of the hatch coaming 110. Specifically, the outer side surface 111 of the hatch coaming 110 has a channel support 159 which extends outwardly away from the hatch coaming 110 (in a direction substantially perpendicular to the main axis 101 of the hatch opening 101). The semi-tubular channel 158 having a semi-circular cross section is located at the end of the channel support 159 so that it is located about 300 mm from the hatch coaming 110. The semi-tubular channel 158 extends completely around the hatch coaming 110. The radius of the semi-tubular channel 158 is about 60 mm.

[0096] The inflatable seal 151 is configured to reversibly expand from an unexpanded state to an expanded state. When expanding from the unexpanded state to the expanded state, the inflatable seal 151 expands through an outwardly facing opening 157 of a semi-tubular passage 158 away from the hatch coaming 110 .

[0097] The additional sealing system 160 comprises an outer gasket 161 received in the outer gasket channel 133 of the hatch cover 130. The additional sealing system 160 also comprises an outer compression rod 162 located on the deck 4 of the bulk carrier 1. When viewed from above, the outer compression rod 162 is rectangular so that when the cargo hatch 100 is in a position such as Figure 6 In the covered state shown, the outer gasket channel 133 is vertically aligned with the compression rod 162. In other words, when the cargo hatch 100 is in the covered state, each portion of the outer gasket channel 133 is vertically aligned with a portion of the compression rod 162. As a result, the outer compression rod 162 surrounds the hatch opening 101 and the hatch coaming 110 and is spaced apart from the hatch opening 101 and the hatch coaming 110.

[0098] Figure 7 A cross-sectional view of a bulk carrier 1 is shown. Figure 7 In the figure, the cargo hatch 100 is shown in a closed state, so that the hatch cover 130 is located on the hatch coaming 110. In order to close the cargo hatch 100, the cargo hatch 100 is opened from Figure 6 The coverage status shown is down to Figure 7 Specifically, the hatch cover 130 is lowered from its position in the covering state to a position in the closed state (on the hatch coaming 110) by hydraulic jacks 120a, 120b, 120c, 120d. As will be appreciated by those skilled in the art, in the closed state, the hatch cover 130 may be fixed in a conventional manner, for example by a clamping plate arranged around the skirt 131.

[0099] In the closed state, the inner gasket 141 of the first sealing system 140 rests on the inner compression rod 142. The inner gasket 141 adapts to the shape of the inner compression rod 142 under the weight of the hatch cover 130, thereby providing a watertight seal between the hatch cover 130 and the hatch coaming 110, thereby sealing the cargo hold from the external environment.

[0100] In the closed state, the outer gasket 161 of the additional sealing system 160 is located on the outer compression rod 162. Under the weight of the hatch cover 130, the outer gasket 161 adapts to the shape of the outer compression rod 162, thereby providing an additional seal between the hatch cover 130 and the deck 4. The additional sealing system thus provides a watertight seal between the passenger passages 5a, 5b and the external environment.

[0101] In the closed state, the skirt 131 of the hatch cover 130 tightly surrounds the hatch coaming 110. When viewed from below, the shape of the skirt 131 is mathematically similar to the shape of the hatch coaming 110 when viewed from above (i.e., a rectangular shape in the illustrated embodiment). The proximity of the hatch coaming 110 to the skirt 131 facilitates the formation of the second sealing system 150.

[0102] In the case of a cargo hatch never covered (e.g. Figure 1 ) to the covered state (as shown) Figure 5 and Figure 6 ), and then to the closed state (as shown Figure 7 140). During the operation of the cargo hatch 100, the inflatable seal 151 remains in an uninflated state. When the cargo hatch 100 is in a closed state, the inflatable seal 151 expands from the uninflated state to the inflated state through the opening 157 of the semi-tubular passage 158, so that it abuts against the skirt 131. When inflated in this manner, the inflatable seal 151 adapts to the shape of the skirt 131 so that it provides a seal between the hatch cover 130 and the hatch coaming 110. Therefore, the second sealing system 150 provides a waterproof seal between the hatch opening 101 and the external environment. In addition, since the second sealing system 150 is located outside the first sealing system 140, the second sealing system 150 protects the first sealing system 140.

[0103] When it is desired to access the cargo hold via the hatch opening 101, the inflatable seal 151 collapses from the inflated state to the uninflated state, and the hydraulic jacks 120a, 120b, 120c, 120d operate to lift the hatch cover 130 so that the cargo hatch 100 is transformed from the closed state to the covered state. The hatch cover 130 then moves along the wheel rails 20a, 20b so that the hatch opening 101 is uncovered (i.e., the cargo hatch 100 is transformed from the covered state to the uncovered state).

[0104] It will be appreciated that the inflatable seal 151 may be inflated in a variety of different ways. In some embodiments, for example, the inflatable seal 151 is pneumatically inflated by inflating, for example, by directing a volume of inflation gas into the interior volume of the inflatable seal 151. In some such examples, the inflation may be air and may be directed into the inflatable seal by a compressor device 180 in a known manner. As will be appreciated, such embodiments may further include a venting device configured to ventilate the interior volume of the inflatable seal 151 to release the inflation air and thereby transition the inflatable seal 151 from its inflated state back to its uninflated state.

[0105] Alternative embodiments are contemplated in which the inflatable seal 151 may alternatively be hydraulically inflated by directing an appropriate amount of hydraulic fluid into the interior volume of the inflatable seal 151. In some such arrangements, the hydraulic fluid may be provided within a closed hydraulic circuit (not shown) including a reservoir and one or more fluid conduits in fluid communication with the interior volume of the inflatable seal 151. A reversibly operable hydraulic pump may be provided to i) pump hydraulic fluid from the reservoir to the interior volume of the inflatable seal 151 to inflate the inflatable seal 151, and ii) pump hydraulic fluid from the interior volume of the inflatable seal 151 to the reservoir to collapse the inflatable seal 151.

[0106] Figure 7 Also shown are working spaces 6a, 6b provided between the hatch coaming 110 and the respective crew passageways 5a, 5b.

[0107] exist Figure 6 and Figure 7 In FIG. 1 , the main axis 92 of the hatch opening 101 is shown. Figure 2 and Figure 3 In the figure, the main axis 93 of the hatch cover 130 is shown. These main axes are parallel to the vertical axis of the bulk carrier. In this specification, references to directions such as vertical, top, bottom, etc. refer to the directions when the bulk carrier is in a normal upright position, such as in a dock. In other words, when the centerline of the bulk carrier is horizontal, the longitudinal axis of the hatch opening is vertical (for example, as shown in the figure). Those skilled in the art will understand that when, for example, the bulk carrier is at sea, the direction of the bulk carrier and the cargo hatch may change. Therefore, any direction mentioned should not be understood as limiting the invention to the orientation of the cargo hatch as shown in the figure.

[0108] The features disclosed in the foregoing description, or in the attached claims, or in the drawings, are expressed in their specific form or as means for performing the disclosed functions or as methods or processes for obtaining the disclosed results, and, as the case may be, may be used alone or in any combination of these features to realize the invention in various forms.

[0109] Although the present invention has been described in conjunction with the above exemplary embodiments, many equivalent modifications and variations will be apparent to those skilled in the art when the present invention is given. Therefore, the exemplary embodiments of the present invention set forth above should be considered illustrative rather than restrictive. Various changes may be made to the described embodiments without departing from the spirit and scope of the present invention.

[0110] To avoid any ambiguity, any theoretical explanations provided herein are intended to enhance the reader's understanding. The inventors do not wish to be bound by any of these theoretical explanations.

[0111] Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0112] Throughout the specification, including in the appended claims, unless the context requires otherwise, the words "comprise" and "comprising" and variations such as "comprises" and "comprising", will be understood to imply the inclusion of stated numbers or steps or numbers or groups of steps but not the exclusion of any other numbers or steps or numbers or groups of steps.

[0113] It must be noted that the singular forms "the" and "said" used in the specification and the appended claims include plural forms unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" one particular value and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, by using the antecedent "about" when a value is expressed as an approximation, it will be understood that the particular value forms another embodiment. The term "about" in relation to a numerical value is optional and has a meaning, for example, of + / - 10%.

Claims

1. A cargo hatch for a bulk carrier, comprising: hatch coaming, surrounding the hatch opening; a hatch cover configured to be removably positioned on the hatch coaming such that the hatch cover reversibly closes at least a portion of the hatch opening; a first sealing system comprising a gasket and a compression rod and configured to provide a seal between said hatch coaming and said hatch cover in use; and A second sealing system comprises an inflatable seal and is configured to provide a seal between the hatch coaming and the hatch cover in use.

2. The cargo hatch according to claim 1, wherein: The inflatable seal is a reversibly inflatable seal.

3. The cargo hatch according to claim 1 or 2, wherein: The expandable seal is an inflatable seal.

4. A cargo hatch according to any one of the preceding claims, wherein: The hatch coaming comprises a side surface, wherein the inflatable seal is located on the side surface.

5. The cargo hatch according to claim 4, wherein: The side surface is an outer side surface facing away from the hatch opening.

6. A cargo hatch according to any one of the preceding claims, wherein: The hatch cover comprises a skirt extending from a bottom surface of the hatch cover towards the hatch opening so as to overlap the hatch coaming in use.

7. The cargo hatch according to claim 6, wherein: In use, the skirt is located outboard of the hatch coaming.

8. A cargo hatch according to claim 6 or 7, wherein: The second sealing system comprises the skirt such that in an inflated state the inflatable seal abuts the skirt to provide a seal between the hatch coaming and the hatch cover.

9. A cargo hatch according to any one of the preceding claims, wherein: The hatch cover is configured to be removably positioned on the hatch coaming such that the hatch cover reversibly closes the entire hatch opening.

10. A cargo hatch according to any preceding claim, wherein: The hatch cover is movable in a direction substantially parallel to a centreline of the bulk carrier between a covering position in which the hatch opening is covered by the hatch cover and an open position in which the hatch opening is uncovered.

11. A bulk carrier comprising one or more cargo hatches according to any one of claims 1 to 10.

12. A method of closing a cargo hatch for a bulk carrier, the method comprising the steps of: removably positioning a hatch cover on a hatch coaming of a cargo hatch; providing a first seal between the hatch coaming and the hatch cover using a first sealing system, the first sealing system comprising a gasket and a compression rod; providing a second sealing system including an inflatable seal; and The inflatable seal is inflated such that a secondary seal is provided between the hatch coaming and the hatch cover.

13. The method according to claim 12, wherein: The step of removably positioning the hatch cover on a hatch coaming of the cargo hatch comprises the steps of moving the hatch cover over the hatch opening in a direction substantially parallel to a centreline of the bulk carrier and lowering the hatch cover such that the hatch cover is positioned on the hatch coaming.

14. The method according to any one of claims 12 and 13, comprising the steps of: collapsing the expandable seal to remove the second seal; The hatch cover is moved away from the hatch coaming such that the hatch coaming is accessible.

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