WO2017091860A1

WO2017091860A1 - Super shallow draft bulk carrier

Info

Publication number: WO2017091860A1
Application number: PCT/AU2016/051180
Authority: WO
Inventors: Marcantonio Lucido
Original assignee: Transmarine Holdings Pty Ltd
Priority date: 2015-12-03
Filing date: 2016-11-30
Publication date: 2017-06-08
Also published as: KR20180088900A; CN108367797A; JP2018535894A; AU2016363678A1; BR112018011167A2

Abstract

A super shallow draft bulk carrier (SSD-BC) (10) comprises a hull (12), sponsons (16) attached to the opposite sides of the hull (12) to provide additional buoyancy and thereby reduce the dead weight tonnage draft of the SSD-BC (10). A bulk materials (5) handling system (30a) is also provided which enables transfer of commodities onto or off of the SSD-BC (10). The bulk materials handling system (30a) is arranged to transfer material discharged from a bottom of cargo holds (14). The bulk materials handling system (34) includes a conveyor disposed in one of the sponsons (16) that carries the material discharged from the cargo holds (14) up to a weather deck (31) of the SSD-BC (10).

Description

SUPER SHALLOW DRAFT BULK CARRIER

Technical Field This specification discloses a super shallow draft bulk carrier ("SSD-BC"). Background Art

Bulk commodities such as mined ore, building materials and agricultural produce are often transported by marine vessels such as bulk carriers. Limiting factors in the transport of such commodities using bulk carriers include, but are not limited to, the deadweight tonnage (DWT) of the bulk carrier, the draft at DWT, and the berth configuration at the loading and unloading ports. It is critical that the draft at the DWT does not exceed the maximum permitted draft by the relevant port authority at the loading or unloading port. When the draft available at the load and unload ports are different then in order to enable direct port to port transport various solutions are possible. Firstly one can limit load of the bulk carrier to below the DWT to ensure the carrier draft can be accommodated at the shallowest port. In this event the profit available to the exporter of the bulk commodity is restricted because tonnage of goods transported is less than the DWT of the vessel. A second solution is to schedule the berthing and/or departure of the vessel to take advantage of tide conditions. However this can restrict the throughput of the port and requires vessels to anchor and wait their turn to load or unload. Again this incurs additional costs thus reducing profit to the exporter of the bulk commodity.

The above problem also exists where both the end ports have the same depth but a vessel is required to traverse a shallower channel between the two ports.

To provide context to the above problems reference is made to Port Hedland in Western Australia which is used for the transport of iron ore from Australia to foreign countries. More iron ore is exported per year from Port Headland than any other port in the world.

The vessel movement guidelines of the Port Hedland Port Authority are prescribed in relation to vessels up to 330m length overall (LOA) with a 60m beam. Vessels over 330m LOA may be given permission to navigate the channel at the discretion of the Harbour Master and in certain tidal and weather conditions may be restricted to daylight berthing and sailing.

Some of the berths at Port Hedland enable a bulk carrier to be loaded to a DWT resulting in a maximum draft of 19m. However the main shipping channel between the berths and the open sea permits only a maximum draft of 14m. Economically it is preferable to load a bulk carrier to a DWT providing the maximum allowable draft. In the instance of Port Hedland in order to enable a vessel with a 19m draft to depart from the berth and traverse the main shipping channel departures are timed in accordance with high tide. While this permits the maximum possible DWT this results in delays in arrival and departure of vessels. This in turn substantially increases transport costs and therefore has substantial impact on profit.

The ability to overcome this problem by building bulk carriers with increased beam while maintaining draft is limited at least by the beam of the main shipping channel. The Port Headland Port Authority does have discretion to allow vessels of greater than 60m beam to traverse the main shipping channel. However this is generally conditional on the daylight and tide conditions. Accordingly there is great risk that vessels of a beam substantially greater than 60m, for example 80m or more may be delayed for long periods for entry to or departure from a berth, or indeed prevented from sailing in main channel all together.

There has been a long felt need to increase the bulk carrier DWT without varying the bulk carrier draft or beam to the extent to lie outside of the prescribed vessel movement guidelines of the Port Hedland Port Authority. Notwithstanding the substantial commercial benefits in increasing the tonnage of bulk commodities through Port Headland, and the substantial financial and intellectual resources of the bulk commodities exporters for at least the last 30 years this problem has remained unsolved.

The above reference to the background art is not intended to limit the application of the SSD-BC as disclosed herein. Specifically, embodiments of the disclosed SSD-BC may be used at other ports to facilitate the transport of bulk commodities. Summary of the Disclosure

In one aspect there is disclosed a super shallow draft bulk carrier (SSD-BC) comprising:

a hull provided with a cargo hold for receiving a bulk commodity; and at least one buoyancy device attached on each side of the hull, each buoyancy device configured to reduce the dead weight tonne (DWT) draft of the SSD-BC.

Thus, by way of example a laden Cape Size vessel which ordinarily has a draft of say 19m without the buoyancy devices may have the draft reduced to about 13.3m.

In one embodiment the buoyancy devices comprise steel structures attached to the hull. In one embodiment the buoyancy devices extend between respective perpendiculars of the hull.

In one embodiment the buoyancy devices comprise a substantially continuous outer surface extending along each side of the hull.

In one embodiment an end of a buoyancy device closest to the bow is tapered to reduce in transverse width toward the hull in a direction from the stern to the bow.

In one embodiment an end of a buoyancy device closest to the stern is tapered to reduce in transverse width toward the hull in a direction from the bow to the stern. In one embodiment the buoyancy devices are made of steel.

In one embodiment the buoyancy devices are permanently fixed to the hull.

In one embodiment the SSD-BC comprises a bulk commodities handling system on at least one of a port and a starboard side of the SSD-BC, the bulk commodities handling system arranged to transfer bulk commodities between an off-board location and one or more on-board locations.

In one embodiment the super shallow draft bulk carrier comprises a bulk commodities handling system that enables unloading of bulk commodities from a bottom of the cargo holds. ln one embodiment the super shallow draft bulk carrier comprises a bulk commodities handling system that enables unloading of bulk commodities through at least one of the buoyancy devices. In one embodiment the super shallow draft bulk carrier comprises a bulk commodities handling system that enables unloading of bulk commodities from a bottom of the cargo holds and through at least one of the buoyancy devices.

In a second aspect there is provided a method of constructing a super shallow draft bulk carrier, the method comprising:

attaching at least one buoyancy device along each side of a hull of a vessel.

In one embodiment the method comprises: determining a desired reduction of draft at DWT; and designing at least two buoyancy devices which when attached to the SSD- BC provide the desired reduction of draft at DWT.

In a third aspect there is provided a super shallow draft bulk carrier (SSD-BC) comprising:

a hull provided with a cargo hold for receiving a bulk commodity; and at least one buoyancy device attached on each side of the hull, each buoyancy device configured to reduce the dead weight tonnage (DWT) draft of the SSD-BC; and a bulk commodities handling system that enables transfer of bulk commodities from a bottom of the cargo holds and through at least one of the buoyancy devices. In one embodiment each buoyancy device is configured to reduce the dead weight tonne (DWT) draft of the SSD-BC.

In a fourth aspect is provided a super shallow draft bulk carrier (SSD-BC) comprising: a hull provided with a cargo hold for receiving a bulk commodity; and a bulk commodities handling system that enables transfer of bulk commodities from a bottom of the cargo hold.

In one embodiment the bulk commodities handling system comprises a first conveyor arranged to transfer material sourced from the bottom of the cargo holds through one of the buoyancy devices. ln one embodiment the bulk commodities handling system comprises a ship loader/unloader supported on a weather deck of the SSD-BC and arranged to traverse along the weather deck. In one embodiment the ship loader/unloader is able to rotate or pivoted through 360°.

In one embodiment the bulk commodities handling system further includes a deck conveyor arranged to transfer material along the weather deck to the ship

loader/unloader.

In one embodiment the bulk commodities handling system further includes a link conveyor arranged to transfer material from the first conveyor to the deck conveyor.

In one embodiment the bulk commodities handling system further comprises one or more cranes supported on the weather deck.

In one embodiment the buoyancy devices arranged to receive and discharge ballast material. Brief Description of the Drawings

Notwithstanding any other forms which may fall within the scope of the super shallow draft bulk carrier and method of constructing the same as set forth in the Summary, specific embodiments will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a side view of one embodiment of the disclosed super shallow draft bulk carrier (SSD-BC);

Figure 2 is a plan view of the SSD-BC shown in Figure 1 ;

Figure 3 is a section view of the SSD-BC shown in Figures 1 and 2;

Figure 4a is a top elevation of a second embodiment of the disclosed super shallow draft bulk carrier (SSD-BC);

Figure 4b is a top elevation of the tank top of the SSD-BC shown in Figure 4a;

Figure 4c is a side view of the SSD-BC shown in Figure 4a;

Figure 4d is a section view of the SSD-BC shown in Figure 4a;

Figure 4e is an enlarged view of a portion of the SSD-BC shown in Figure 4a showing a part of a materials unloading subsystem; Figure 5a is a top elevation of a third embodiment of the disclosed SSD-BC;

Figure 5b is a side view of the SSD-BC shown in Figure 5a;

Figure 6 illustrates an embodiment of the disclosed SSD-BC been directly loaded by a conveyor; and

Figure 7 illustrates an embodiment of the disclosed SSD-BC during transshipment of bulk commodities to a cape size vessel.

Detailed Description of Specific Embodiments Figures 1 - 3 illustrate a first embodiment of the disclosed SSD-BC 10. The SSD-BC 10 comprises a hull 12 configured to receive a bulk commodity such as but not limited to iron ore, coal, other mined minerals; agricultural products; building materials, etc. In this embodiment the hull 12 is provided with nine separate cargo holds 14a - 14i (hereinafter referred to in general as "cargo holds 14"). While nine separate cargo holds 14 are disclosed it is to be understood that embodiments of the SSD-BC 10 may comprise any number of cargo holds including only just one. The SSD-BC 10 is also provided with buoyancy devices 16a and 16b (hereinafter referred to in general as "buoyancy devices 16") one of each being attached to opposite sides of the hull 12. In particular the buoyancy device 16a is attached, for example by welding, along the port side of the hull 12 while the buoyancy device 16b is attached along the starboard side of the hull 12. In this particular embodiment each buoyancy device 16 is in the form of a sponson. The buoyancy devices 16 are configured to reduce the deadweight tonnage (DWT) draft of the SSD-BC 10 As a non-limiting example the SSD-BC 10 in the present embodiment may comprise a cape size vessel to which the devices 16 are retrofitted. The cape size vessel for which the hull 12 is an integral part may have for example an overall length (LOA) of about 292m, a beam of about 45m and a draft of 19m at a DWT of 185,000T. The devices 16 are configured so that for the SSD-BC 10 the draft at DWT of 185.000T can be arranged to be in the order of 14m or less such as, for example 14m-12 m. Indeed the buoyancy devices/sponsons 16 can be designed to provide the SSD-BC with a draft to match the shallower of the loading port and the unloading port.

Accordingly the problems that have existed for over 30 years in handling the export of iron ore from Port Hedland can be solved by embodiments of the present SSD-BC10. Utilisation of embodiments of the SSD-BC 10 enable substantially around the clock loading and sailing of bulk carriers at their DWT. There is now no need to queue and wait suitable tidal conditions or alternately to load a bulk carrier to less than its DWT.

Looking at the SSD-BC 10 in more detail it will be noted that in this particular embodiment a single continuous buoyancy device 16 (i.e. sponson) is provided on the port and starboard sides respectively. Each device 16 extends from a forward end 18 near a bow 20 to an opposite rear end 22 near the stern 24. In this embodiment each device 16 is tapered near the ends 18 and 22. The direction of the taper is such that the width of the device 16 reduces toward the hull 12.

It will be noted from Figure 3 that the provision of the devices 16 extends the beam of the SSD-BC 10 over that for identical SSD-BC 10 without the devices 16. Without the buoyancy devices 16, the SSD-BC 10 would have a beam of B1 . The devices 16a and 16b have a respective transverse width or beam of Ba and Bb respectively. Ordinarily the beam of each device 16 is the same so that Ba = Bb. In any event the overall beam B of the SSD-BC 10 is B = B1 + Ba + Bb. The percentage increase in the beam of the SSD-BC in comparison to the same SSD-BC without the devices 16 is: (Ba + Bb) + B1 x 100%. In one example B1 may be in the order of 40m, and Ba and Bb may each be in the order of 10m. Thus the percentage increase in beam arising from the addition of the devices 16 is (10+10) + 40 x 100% = 50%.

Thus in this example the SSD-BC 10 fitted with the devices 16 has a draft of 14m at a DWT of 185.000T and a beam of 60m. Accordingly such an embodiment of the SSD- BC 10 would be within the normal operating parameters of the Port Hedland Port Authority for berthing and subsequent sailing through the main shipping channel without the need for special permission. In order to assist in the loading and unloading of bulk commodities the SSD-BC 10 is provided with a bulk commodities transfer system 30. In this embodiment the transfer system 30 is provided on both the port and starboard sides. However in other embodiments it is possible to provide the system 30 on one side only. The transfer system 30 is arranged to transfer bulk commodities between an off-board location (for example a stock pile or bulk containers located at a port) and one or more aboard locations; in this instance the cargo holds 14. The system 30 comprises a mobile hopper 32 and associated rails 34. The rails 34 are provided on each of the port and starboard sides. A bulk loader (not shown) at a port is able to transfer the bulk commodities to the hopper 32 on the closest side of the SSD-BC 10. The hopper 32 can then traverse its rails 34 to load particular cargo holds 14. Depending on whether the port or starboard side of the SSD-BC 10 is adjacent the berth will determine which of the hoppers 32 will be used during a loading or unloading action. In the event that the transfer system 30 comprises only a single hopper 32 and associated rails 34 then the corresponding side of the SSD-BC 10 will need to be adjacent the berth for the loading and unloading actions. One method of manufacturing the SSD-BC 10 comprises attaching the buoyancy devices/sponsons 16 along each side of an existing bulk carrier such as a cape size vessel. One aspect of this method is designing the respective devices 16 to provide the required reduction in draft at DWT. This may be determined relatively easily by use of the Archimedes principle. Once the devices 16 have been designed they may be constructed from steel or other metals and permanently fixed for example by welding to the existing hull of the bulk carrier to which they are retrofitted. The bulk commodity transfer system 30 is also fitted to the weather deck 31 of the SSD-BC 10.

The buoyancy devices/sponsons 16 can be partially or completely fabricated off-site and subsequently attached by way of any one, or any combination of two or more, of: welding; bolting; and, riveting onto the sides of the hull 12. When prefabricated off-site the buoyancy devices/sponsons 16 can be made in a plurality of sections or portions which are subsequently attached onto the sides of the hull 12. The separate sections of portions may be fluidically isolated from each other. Alternately, the

devices/sponsons 16 can be fabricated in situ directly on the sides of the hull 12. Irrespective of their method of construction the buoyancy devices/sponsons 16 can also be arranged carry and discharge ballast material such as but not limited to water. In this way the ballast of the buoyancy devices/sponsons 16 can be varied to provide an optimum draft dependent on the DWT of the SSD-BC 10.

In this particular embodiment of the SSD-BC 10 the sponsons 16 are configured to have a base 36 which is coplanar with the bottom 40 of the hull 12; vertical sidewalls 38, and an inclined upper wall 40. The wall 40 lies below the weather deck 31 of the hull 12. However other configurations of the sponsons 16 are possible including but not limited to configurations where the various walls are at different levels or different inclinations. For example the base 36 may be inclined as shown by phantom line 36' in Figure 3. Constructing the SSD-BC 10 in the above manner by using an existing bulk carrier has a further benefit in providing or generating a new market for such existing bulk carriers. To this end, there is currently a substantial under-utilisation of such bulk carriers. Indeed many are on the market for scrap value.

Figures 4a-4e depict a second embodiment of the disclosed SSD-BC, designated as SSD-BC 10a. All features of the SSD-BC 10a which are the same or have the same or similar structure or function as in the SSD-BC are designated with the same reference numbers but with the addition of the suffix "a". As will be apparent from the following description the second embodiment of the SSD-BC 10a is enhanced over the first embodiment and has features which provide substantial commercial and economic value not only to the operator of the SSD-BC but also to producers of bulk commodities and the providers of port infrastructure.

The SSD-BC 10a is similar to the SSD-BC 10, but differs by the replacement of the bulk commodities handling system 30 with an upgraded bulk commodities handling system 30a that enables unloading of bulk commodities from the bottom of the cargo holds. Indeed the bulk commodities handling system 30a provides the SSD-BC with a self-loading/unloading capability.

The SSD-BC 10a comprises a hull 12, buoyancy devices/sponsons 16a and 16b on the port and starboard sides of the hull 12, and a plurality of cargo holds 14 as in the first embodiment of the SSD-BC 10. However the SSD-BC 10a includes the bulk commodities handling system 30a which provides remarkable versatility and greatly expands the application of the SSD-BC 10a the extent of opening markets which previously did not exist.

The bulk commodities handling system 30a comprises a number of interrelated and cooperating materials handling subsystems. These subsystems includes: an unloading subsystem 56; a first conveyor 58 that transfers materials sourced from the holds 14 to the deck 31 ; and a ship loader/unloader 60 (hereinafter referred to for convenience as "ship loader 60"). The unloading subsystem 56 comprises one or more, but in this embodiment three, endless conveyors 62a, 62b and 62c (hereinafter referred to in general as "conveyors 62") which run underneath the cargo holds 14; a transverse conveyor 64 at one end of the conveyors 62; hoppers 66a, 66b and 66c (hereinafter referred to in general as "hoppers 66); a further hopper 68, and discharge chutes 70a, 70b and 70c (hereinafter referred to in general as "chutes 70"). The unloading system 56 operates to unload the bulk materials from the bottom of the holds 14 and transfer them to the conveyor 58. The discharge chutes 70a, 70b, and 70c are formed in the bottom wall of each of the holds 14. The endless conveyors 62a, 62b and 62c are arranged in the hull 12 beneath their respective discharged chutes 70a, 70b, and 70c. The conveyors 62 run so that material discharged from the chutes 70 is carried in the direction toward the hoppers 66. The material carried by the conveyors 62 is fed into respective hoppers 66 under which the conveyor 64 runs. Thus the conveyors 62 carry material discharged from the holds 14 into the respective hoppers 66, and the material is subsequently fed by the hoppers 66 onto the conveyor 64 which in turn conveys the material to the hopper 68.

The hopper 68 feeds the material onto the conveyor 58. The conveyor 58 is located within the sponson 16a and runs along an inclined path up to the weather deck 31 . Locating the conveyor 58 in sponson 16a uses otherwise dead space and accordingly does not take up valuable cargo space. It may also be noted that in this embodiment the sponsons 16 have a slightly different configuration to those in the first embodiment. Specifically the sponsons 16 in present embodiment have an upper surface 40 that lies in a horizontal plane and is flush or coplanar with the weather deck 31.

The conveyor 58 runs to a hopper 72 on the weather deck 31 located adjacent the cargo hold 14i near the bow. A link conveyor 74 is provided to receive material discharged from the hopper 72 and feed this to another hopper 76. A deck conveyor 78 runs along the weather deck 31 from beneath the hopper 76 to a location adjacent the cargo hold 14a and near the stern. The ship loader 60 is associated with the deck conveyor 78 so that it can either (a) unload material by receiving material fed by the deck conveyor 78 and discharging it to a location off the SSD-BC 10a; or (b) load material fed by the conveyor 78 into selected holds 14. To this end the ship loader 60 is mounted on rails on the weather deck 31 allowing it to traverse along the length of the weather deck 31 between the holds 14a and 14i. The ship loader 60 has an extendable arm or boom 80 that can be operated to either extend beyond the side of the SSD-BC 10a as shown in Figure 4a in order to offload material; or to extend inwardly in order to load material into the holds 14. The ship loader 60 also includes a tripper to transfer material between the conveyor 78 and the boom 80. Additionally or alternately the ship loader 60 may be formed with a boom 80 that can swivel or pivot through 360°. It will be understood that when the boom 80 can swivel through 360° an end of the boom can be positioned to lie over the side of the vessel in order to unload material, or over an opening of a hold 14 in order to load material into the vessel.

In one possible loading process material may be transferred by a third party loader into either the hopper 72 or the hopper 76 and subsequently transferred by the conveyor 78 to the ship loader 60 with its boom 80 positioned to transfer material into one of holds 14. If the third party loader initially loads into the hopper 72 then the conveyor 74 is also operated to transfer the material from hopper 72 to the hopper 76 which then feeds material to the conveyor 78.

In one possible unloading process the chutes 70 are opened to allow material from within the holds 14 to drop onto the conveyors 62 of the unloading subsystem 56. The material is transferred by the conveyors 62 to the chutes 66, fed onto the conveyor 64, transferred to the chutes 68, fed onto the hold to deck conveyor 58, carried to and dumped in the chute 72, carried by the conveyor 74 and dumped into the chute 76 and fed onto the conveyor 78. Now the ship loader 60 is positioned so that the boom 80 extends over the side of the SSD-BC 10a and operated to unloaded the material onto a wharf or directly onto land adjacent to the berthed SSD-BC 10a.

Those skilled in the art will acknowledge or otherwise understand that ordinarily in order to transfer bulk materials onto or off of a bulk materials transport vessel a berthing wharf or jetty would be provided with loader is similar to loader 60. Thus the loader at the wharf or jetty is used to transfer bulk onto or off of visiting bulk materials transport vessels. It is no longer necessary for the berthing wharf or jetty to have such a loader to enable unloading of material from the SSD-BC 10a.

One method of constructing the buoyancy device/sponson 16a which includes the conveyor 58 is to initially construct and fix the conveyor 58 directly onto a side of the hull 12 and subsequently fix the sponson 16a to the same side of the hull 12 over the conveyor 58. The sponson 16a can be prefabricated off-site as either a single structure or a plurality of superstructures and subsequently fixed to the hull 12. Alternately the sponson 16a can be directly fabricated on the hull 12.

Figures 5a and 5b illustrate yet a further embodiment of the disclosed SSD-BC 10b, in which the same reference numbers as those in relation to the earlier embodiments are used to denote the same features. The SSD-BC 10b in essence is identical to the SSD-BC 10a but with the addition of a plurality of travelling cranes 82. The cranes 82 are mounted on rails that extend along the weather deck 31 on a side of the hull 12 opposite the ship loader 60. The rails for the cranes 82 run from the hold 14a near the stern to the hold 14i near the bow. Each crane 82 is provided with a grab/bucket 84. The cranes 82 enable the loading of the SSD-BC 10b from barges or other adjacently located stockpiles.

The materials handling system 30a of the embodiments of the SSD-BC 10a and 10b, enables material to be loaded or unloaded at a rate of up to 10,000 tonnes per hour. Therefore a SSD-BC with a load carrying capacity of 185,000 tonnes can be loaded or unloaded in space of 18.5 hours compared about 15 days for prior art methods. This provides a massive time saving and consequently massive cost savings in vessel hire and berthing costs.

Since the embodiments of the SSD-BC 10a and 10b are provided with a materials handling system 30a which includes the ship loader 60, they are not limited to transporting bulk materials between wharfs, jetties or port having which have loading and unloading infrastructure. When combined with the shallow draft of a fully laden SSD-BC 10a, 10b this provides unique capabilities, non-limiting examples of which are discussed below.

Cape size bulk carriers with 185,000 DWT require a draft for about 19 m including clearance under the keel. However the vast majority of global export ports on a draft of 14 m or less. Embodiments of the SSD-BC open draft limited ports around the world on a 24/7 basis to any size vessels including the 400,000 DWT Valemax. (This of course is also the case with the first described embodiment of the SSD-BC 10.)

• Dredging of current port facilities which would otherwise be required to enable berthing of a 185,000 DWT vessel is avoided. This not only has substantial cost savings but also avoids adverse environmental issues and legislative issues. Naturally this benefit also arises with the first described embodiment of the SSD-BC 10.

Due to provision of the provision of the bulk commodities handling system 30a costs associated with providing materials transfer infrastructure at loading and destination ports is avoided. Moreover the bulk commodities handling system 30a enables embodiments of the SSD-BC to load cargo directly from a shore conveyor. This can for example make mines which would not be economically viable due to logistics costs, viable because the mined material can be transferred directly by way of long conveyors onto the SSD-BC. There would be no need for building of roads or rail, cranes and other bulk handling material machinery, and no need for stockpiling. An example of this is shown in Figure 6. This Figure illustrates a SSD-BC 10a berthed adjacent a dolphin 86 constructed near a shore line 88. A conveyor 90 loads mined material from a mine, which can be up to tens of kilometres away, directly into the hopper 76. The mined material can then be loaded into the holds 14 using the bulk materials handling system 30a. It should be understood that there is no need in this circumstance to construct the normal port materials handling systems and infrastructure to support the loading of mined material from the mine to the SSD-BC 10a. Of course the materials transfer operation shown in Figure 6 can also be performed by the SSD-BC 10b.

The bulk commodities handling system 30a enables the loading and distribution of cargo from a shore conveyor to all of the holds 14, and also enables unloading the cargo to any oceangoing vessel or at an unloading port. Figure 7 illustrates an example of use of the SSD-BC 10b in a trans-shipment operation in open water, transferring materials onto a cape sized oceangoing vessel 92. This operation may be employed for example where loading port has a draft too shallow to receive the Cape size vessel 92 but the offloading port does have adequate draft. Here the SSD-BC 10b is used to load the material from the loading port and then trans-ship the material to the Cape size vessel 92. Of course the materials transfer operation shown in Figure 7 can also be performed by the SSD-BC 10a. The SSD-BC 10b also enables transshipment from barges using the cranes 82. One application may be for example where a mine produces bulk mined material which is loaded onto river barges with say a maximum capacity of about 2000 tonnes. The barges can be sailed to a moored SSD-BC 10b and have their cargo transferred into the cargo holds 14 using the cranes 82. After the SSD-BC 10b has been fully loaded by transferring the bulk materials from a plurality of barges, it may then be sailed to a destination or unloading port. · As previously mentioned the very shallow draft of the SSD-BC 10, 10a and 10b enables around-the-clock loading and unloading without the need to hide for favourable tide conditions.

It may be recognised from the above discussion that the bulk commodities handling system 30a can indeed be used on other cargo/bulk commodity shipping vessels without incorporating the buoyancy devices/sponsons 16. For example the commodities transfer system 30a can be provided on a regular cape size vessel with a 19 m draft notwithstanding that such vessel is limited to berthing at wharfs/jetties which can accommodate this draft. Therefore even though such a vessel would not have the same berthing options due to the need for a 19 m draft the vessel would nonetheless has the same benefits in relation to the materials handling capability. When modifying a cape size vessel to include the bulk commodities handling system 30a (but without the sponsons 16), the conveyor 58 may be fixed to the outside of the hull or alternately could be provided on the inside of the hull. The conveyor 58 may additionally be formed with a bend in order to feed material into the equivalent of the hopper 76. Alternately an additional link convey similar to the conveyor 74 can be provided to receive material discharged from the end of the conveyor 58 to transfer that to the hopper 76. In the event that the conveyor 58 is fixed to the outside of the hull can be enclosed by a steel cover fixed to the hull. Naturally the cape size vessel fitted with the disclosed bulk materials handling system 30a will require modification to the cargo holds in order to enable material to be discharged onto the underlying conveyor is 62.

Whilst specific embodiments of the super shallow draft bulk carrier and method of construction has been described, it should be appreciated that the bulk carrier and method of construction may be embodied in many other forms. For example while the embodiment of the SSD-BC 10a and 10b are shown with an unloading subsystem 56 having three separate conveyors 66a, 66b and 66c, it can have any number of conveyors including one, two or four or more. The holds 14 would be configured to have the same number of chutes 70 as the number of conveyors 66. Additionally embodiments of the SSD-BC can be provided with mechanical systems to assist in moving material through the chutes 70 onto the underlying conveyor 62. The mechanical systems may include for example augers or vibrators. ln the claims which follow, and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word "comprise" and variations such as "comprises" or "comprising" are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the SSD-BC and method of construction as disclosed herein.

Claims

Claims:

1 . A super shallow draft bulk carrier (SSD-BC) comprising:

a hull provided with a cargo hold for receiving a bulk commodity; and at least one buoyancy device attached on each side of the hull, each buoyancy device configured to reduce the dead weight tonnage (DWT) draft of the SSD-BC

2. The super shallow draft bulk carrier according to claiml wherein the buoyancy devices comprise steel structures attached to the hull.

3. The super shallow draft bulk carrier according to claim 1 or 2 wherein the buoyancy devices extend between respective perpendiculars of the hull.

4. The super shallow draft bulk carrier according to any one of claims 1 to 3 wherein the buoyancy devices comprise a substantially continuous outer surface extending along each side of the hull.

5. The super shallow draft bulk carrier according to any one of claims 1 to 4 wherein an end of a buoyancy device closest to the bow is tapered to reduce in transverse width toward the hull in a direction from the stern to the bow.

6. The super shallow draft bulk carrier according to any one of claims 1 to 5 wherein an end of a buoyancy device closest to the stern is tapered to reduce in transverse width toward the hull in a direction from the bow to the stern.

7. The super shallow draft bulk carrier according to any one of claims 1 to 6 wherein the buoyancy devices are made of steel.

8. The super shallow draft bulk carrier according to any one of claims 1 to 7 wherein the buoyancy devices are permanently fixed to the hull.

9. The super shallow draft bulk carrier according to any one of claims 1 to 8 comprising a bulk commodities handling system on at least one of a port and a starboard side of the SSD-BC, the bulk commodities handling system arranged to transfer bulk commodities between an off-board location and one or more on-board locations.

10. The super shallow draft bulk carrier according to any one of claims 1 to 8 comprising a bulk commodities handling system that enables unloading of bulk commodities from a bottom of the cargo holds.

1 1 . The super shallow draft bulk carrier according to any one of claims 1 to 8 comprising a bulk commodities handling system that enables unloading of bulk commodities through at least one of the buoyancy devices.

12. The super shallow draft bulk carrier according to any one of claims 1 to 8 comprising a bulk commodities handling system that enables unloading of bulk commodities from a bottom of the cargo holds and through at least one of the buoyancy devices.

13. A method of constructing a super shallow draft bulk carrier, the method comprising:

attaching at least one buoyancy device along each side of a hull of a cape size vessel.

14. The method according to claim 13 comprising:

determining a desired reduction of draft at DWT; and

designing at least two buoyancy devices which when attached to the SSD-BC provide the desired reduction of draft at DWT.

15. A super shallow draft bulk carrier (SSD-BC) comprising:

a hull provided with a cargo hold for receiving a bulk commodity; and at least one buoyancy device attached on each side of the hull, each buoyancy device configured to reduce the dead weight tonnage (DWT) draft of the SSD-BC; and a bulk commodities transfer system that enables unloading of bulk commodities from a bottom of the cargo holds and through at least one of the buoyancy devices.

16. A super shallow draft bulk carrier (SSD-BC) comprising:

a hull provided with a cargo hold for receiving a bulk commodity; and a bulk commodities handling system that enables unloading of bulk commodities from a bottom of the cargo hold.

17. The super shallow draft bulk carrier (SSD-BC) according to any one of claims 9- 12 and 15 wherein the bulk commodities handling system comprises a first conveyor arranged to transfer material sourced from the bottom of the cargo holds through one of the buoyancy devices.

18. The super shallow draft bulk carrier (SSD-BC) according to any one of claims 9-12, 15 -17 wherein the bulk commodities handling system comprises a ship loader/unloader supported on a weather deck of the SSD-BC and arranged to traverse along the weather deck.

19. The super shallow draft bulk carrier (SSD-BC) according to claim 18 wherein the ship loader/unloader is able to rotate or pivoted through 360°.

20. The super shallow draft bulk carrier (SSD-BC) according to claim 18 or 19 wherein the bulk commodities handling system further includes a deck conveyor arranged to transfer material along the weather deck to the ship loader/unloader.

21 . The super shallow draft bulk carrier (SSD-BC) according to claim 20 wherein the bulk commodities handling system further includes a link conveyor arranged to transfer material from the first conveyor to the deck conveyor.

22. The super shallow draft bulk carrier (SSD-BC) according to any one of claims 9-12 and 15-21 wherein the bulk commodities handling system further comprises one or more cranes supported on the weather deck.