WO2011134016A1

WO2011134016A1 - Handling of bulk cargo

Info

Publication number: WO2011134016A1
Application number: PCT/AU2011/000491
Authority: WO
Inventors: Stuart Ballantyne
Original assignee: Asd Marine Services Pty Limited
Priority date: 2010-04-30
Filing date: 2011-04-29
Publication date: 2011-11-03
Also published as: AU2011245072B2; AU2011245072C1; CN102869591A; AU2011245072A1

Abstract

The invention provides a system for loading bulk cargo at sea which includes at least one feeder vessel adapted to carry bulk cargo from a source to a transfer vessel with which it can be associated, a transfer vessel which can receive bulk material from at least one feeder vessel and which has means to deliver such material to a bulk carrier.

Description

HANDLING of BULK CARGO

Area of the Invention

This invention relates to the handling of bulk cargo, such as iron ore, and in particular, to handling this cargo in areas where the infrastructure does not permit the ship to be loaded to be tied to a wharf or where dredging for access is not permitted.

Background to the Invention

This situation of difficulty with cargo handling occurs where infrastructure has not yet been put in place in a particular area. It can also occur where there is shallow water extending some significant distance out from the shore which may make the cost of providing wharf infrastructure prohibitive and where dredging to open access is not permitted.

There have been various proposals for such loading which include the use of a transfer vessel which can be located between a barge into or onto which the ore is loaded, possibly by a shore conveyor which extends outwardly from the shore to the barge itself, or to another transfer vessel from which the ore is passed to the barge, and when loading the bulk carrier, the barge is provided with a conveyor system which can feed its contents to the transfer vessel which in turn has a conveyor arrangement which extends over the deck of the bulk carrier and above the holds of the carrier.

This conveyor system can be controllable to evenly fill the holds and by movement of either the conveyor system, the transfer vessel or both, can obtain access to the various holds of the vessel.

This arrangement can operate up to wind loads of approximately 25 knots. But, beyond this, the system cannot be operated. Usually, there's high demurrage for delays in loading and particularly in areas where high winds or seas are prevalent the result can be detrimental to the ship owners.

Outline of the Invention

It is the object of the present invention to provide a loading system which can operate effectively in low seas and low winds, but which can continue to operate when seas become choppy and the winds reach speeds of higher than 25 knots.

By providing an arrangement which can operate under these conditions, it is believed that under normal average operating conditions, where loading cannot occur for 60 to 90 days per annum, the saving in costs to the ship owner for demurrage and damage can be up to $600,000 per annum.

It is a further object to provide a system whereby bulk cargo can efficiently be provided to a bulk carrier.

The invention is a system to load bulk cargo which includes at least one feeder vessel adapted to carry bulk cargo from a source to a transfer vessel with which it can be associated, a transfer vessel which can receive bulk material from feeder vessels and which has means to deliver such material to a bulk carrier.

It is preferred that this delivery means is conveyor means.

Preferably the transfer vessel is capable of receiving and holding a quantity of bulk material received from feeder vessels which material can be delivered to a bulk carrier.

The transfer vessel is preferably adapted to feed bulk material either from a feeder vessel or from its own holding of the material to the bulk carrier. The feeder vessel(s) may have means whereby they can be connected directly to the transfer vessel to minimise delay in mooring these relative to the transfer vessel.

The means of connection can include an area at the stern of the transfer vessel which is adapted to receive a feeder vessel therein and for the feeder vessel to be connected to the transfer vessel.

In order that the invention may be more readily understood and put into practice we will describe by way of non limiting example one particular form of the invention with reference to the accompanying drawings.

Brief Description of the Drawing Figures

Fig. 1 Shows the loading system of the invention having a feeder vessel engaged with a transfer vessel which is loading a bulk carrier;

Fig. 2 Shows a perspective view of a feeder vessel;

Fig. 3 Shows a feeder vessel engaged with a transfer vessel in an orientation appropriate for moving the transfer vessel;

Description of an Embodiment of the Invention

An embodiment of the invention 10 is shown in Figure.

The invention 10 provides a vessel 20 which can be considered a floating harbour and which in this specification will be called a transfer vessel.

This vessel may include a storage area for bulk material which, for convenience will be called ore, and which vessel has at its rear end 25 an arrangement whereby feeder vessels 40 can be received and held relative to the storage (transfer) vessel, the transfer vessel 20 having means to recover ore from the feeder vessel 40 and to either load this into its own storage area or feed it directly to a bulk carrier 50, adjacent to which the feeder/transfer assembly is located.

The arrangement whereby feeder vessels 40 can be received and held by a transfer vessel 20 ( as shown in Figure 1 ) may include an open space between sides 22 having a width slightly greater than the width of- the feeder vessel and a length equivalent to the storage area in the transfer vessel such that the feeder vessel can back in to the transfer vessel for unloading either directly to a bulk carrier or into the transfer vessel's storage 30 towards the bow of that vessel.

The arrangement is such that the feeder vessel can be backed into the space which can be open to the sea and can have a bottom closure at a depth greater than that of the loaded feeder vessel.

Using the arrangement of the invention, the only restriction on the delivery of ore from the feeder vessels to the transfer vessel, which can hold, say, 35,000 tonnes of ore is the capacity of the transfer vessel. This enables, when a bulk carrier is in connection with the transfer vessel, loading to commence immediately without waiting for feeder vessels to come to the transfer- vessel.

Of course, if the transfer vessel is not carrying ore, a feeder vessel can have its cargo transferred by way of the transfer vessel directly to the bulk carrier.

Thus, the system can provide a much more efficient way of transferring ore to bulk carriers than has previously been the case and can also do this in seas and winds which would normally preclude loading, thus saving or eliminating demurrage as the feeder vessel and the transfer vessel are effectively unitary.

The transfer vessel, in the embodiment described, has its storage 30 at the forward end thereof which may be an enclosed hold or the like and, as described above, at the rear of the vessel, there can be an incursion defined by two side walls and which may be enclosed at the under surface or could be open to the sea.

This incursion is of a width and length to receive the body of a feeder vessel which can be reversed therein and locked relative to the transfer vessel.

The form of inter-engagement is not critical to the invention but it may be that adjacent the forward end of the transfer vessel . which contains the bridge that controls systems, the engines and other facilities and which can be higher than the remainder of the vessel may have inter-engaging members extending each side thereof which can effect locking of the feeder vessel to the transfer vessel.

Preferably there is located along each side of the transfer vessel from adjacent the stern thereof to adjacent the bow, side conveyors 27 which can move the ore forwardly.

There is also be provided along the length, a gantry 28 which, in one embodiment, carries a bucket chain elevator which delivers the ore to the required side conveyor.

In another embodiment of the invention, the gantry can carry a bucket wheel which feeds onto a transverse conveyor which delivers the contents to a side conveyor of the transfer vessel.

The bucket chain elevator or bucket wheel can be movable transversely along the^' gantry, the gantry can of course be moved forwardly and aft relative to the transfer vessel, so the ore carried in the feeder vessel can be readily and rapidly removed by the bucket wheel to its transverse conveyor to the longitudinal conveyor of the transfer vessel.

It is also possible to have the bucket chain elevator or bucket wheel arranged on an arm which is associated with one side of the transfer vessel and which can be moved so that the elevator or bucket wheel can reach basically any part of the transfer vessel and again deliver the ore so gathered to a conveyor which, in turn delivers the ore to the longitudinal conveyor of the transfer vessel.

The ore so delivered can have one of two destinations. The first is direct to a bulk ore carrier to which the transfer vessel is connected.

In this case, the ore being carried by the conveyor along the side of the transfer vessel passes to another conveyor which runs transverse to the vessel and from this, to a load-out boom which extends outwardly from the transverse vessel to above the hold of the bulk carrier which is to be filled and the ore is passed directly to this hold.

Alternatively, if there is no bulk carrier associated with the transfer vessel at the time, the ore is diverted by a transverse conveyor into the storage area of the transfer vessel and as mentioned, this, in one particular embodiment, can hold up to 35,000 tonnes of ore.

As each feeder vessel, can carry some 5000 tonnes, this means that up to seven feeder vessel loads can be held in the transfer vessel whilst awaiting a bulk carrier and once the carrier is in position delivery can commence immediately without having to wait for feeder vessels to bring ore or without holding a number of feeder vessels waiting for sequential unloading onto the transfer vessel.

The transfer vessel is normally not powered and could be moved, as is conventional, by tugs or the like but in the arrangement of the invention, if the vessel is to be moved, a feeder vessel may be moved, bow first, into the position defined by the rear of the transfer vessel and its forward end can be connected to the transfer vessel, preferably by a connection arrangement which enables free movement between the feeder vessel and the transfer vessel in roll, pitch and heave.

The feeder vessel can relocate the transfer vessel in this way, thus obviating the necessity of providing tugs to do this. In addition, should it be required, the feeder vessel can simply tow the transfer vessel in a normal way. As the feeder vessel is adapted to carry up to 5000 tonnes of ore, it has sufficient power for this.

To reiterate the advantages of the system of the invention over previously proposed systems, the transfer vessel, which can be considered to be a floating harbour, can carry in the embodiment described, up to 35,000 tonnes of ore and be ready to deliver these to a bulk carrier with effectively little or no down time from the time that the carrier is associated with the transfer vessel.

At the same time feeder vessels can interconnect with the transfer vessel thus giving a stable connection between these and their carried ore, which in the present embodiment would be of the order of 5000 tonnes, and deliver this direct to the bulk carrier, if the transfer vessel is depleted of ore, or can deliver it to the transfer vessel which can carry up to 35,000 tonnes of ore ready for immediate loading to a bulk carrier.

Whilst as an exemplification of the invention, we have described the feeder vessels as being able to carry 5000 tonnes of ore and the transfer vessel 35,000 tonnes, these are simply preferments and the quantities could vary depending upon the particular application.

For example, if the water level at the rail head or delivery conveyor position is very shallow, it may be desirable to use feeder vessels which carry less than 5000 tonnes or if the water is relatively deep, it may be that larger feeder vessels would be satisfactory.

Also, depending upon the amount of ore to be shipped, it could be desirable that the transfer vessel can hold more than 35,000 tonnes.

At the same time, the feeder vessels can be used to move the transfer vessel, if this is required and with an effective free movement coupling of the type mentioned earlier, can do this in relatively heavy seas and strong winds.

Because the transfer vessel can carry substantial quantities of ore, this means that the feeder vessels can be used effectively to ferry ore to the transfer vessel even if there is no bulk carrier attached thereto, so instead of either waiting adjacent the shore or standing off the transfer vessel, the feeder vessels may be used most efficiently.

At the same time, because there is a minimal delay in transferring ore to a bulk carrier and because this transfer can continue under quite adverse weather conditions, the delay in loading the bulk carrier is minimised.

Whilst there has been described in the specification a particular arrangement and interconnection between the feeder vessels and the transfer vessel, it is to be understood that substantial variations can be made in this, without departing from the scope of the present invention.

In particular, the machinery, or the type of systems to transfer the ore from the feeder vessels to the transfer vessel or direct to a bulk carrier can vary widely and can in fact mirror handling equipment used in the mining industry, but which provide the necessary flexibility as far as transferring material is concerned.

Any variation in these areas are deemed to be part of the invention. ^■

Claims

The claims defining the invention are as follows:

1. A system for loading bulk cargo at sea which includes at least one feeder vessel adapted to carry bulk cargo from a source to a transfer vessel with which it can be associated, a transfer vessel which can receive bulk material from at least one feeder vessel and which has means to deliver such material to a bulk carrier.

2. A system for loading bulk cargo as claimed in claim 1 wherein the transfer vessel is capable of receiving and holding a quantity of bulk material received from a plurality of feeder vessels.

3. A system for Loading bulk cargo as claimed in claim 2 wherein the bulk cargo is subsequently transferred to a bulk carrier.

4. ' A system for loading bulk cargo as claimed in claim 1 wherein the delivery means is conveyor means.

5. A system for loading bulk cargo as claimed in claim 4 wherein the transfer vessel is adapted to feed bulk material either from a feeder vessel or from its own holding of the material to the bulk carrier.

6. A system for loading bulk cargo as claimed in any one of claims 1 to 5 in which the transfer of bulk cargo from feeder vessel to transfer vessel and to bulk carrier takes place at sea.

7. A system to load bulk cargo as claimed in claim 6 wherein a feeder vessel can be interconnected to a transfer vessel.

8. A system to load bulk cargo as claimed in claim 7 wherein the means of interconnection includes an area at the stern of the transfer vessel which is adapted to receive a feeder vessel therein and for the feeder vessel to be connected to the transfer vessel.

9. A system to load bulk cargo as claimed in claim 8 wherein a feeder vessel is backed into the stern of a transfer vessel for unloading the feeder vessel.

10. A system to load bulk cargo as claimed in claim 9 wherein the bow of a feeder vessel can enter the stern of a transfer vessel and engage with it in order to move the transfer vessel.

1 1. A system to load bulk cargo substantially as hereinbefore described with reference to the accompanying drawings.