GB2123775A - Mooring ships - Google Patents

Abstract

A ship is fastened to a buoy 3 via a rigid coupling arm 1, so that a constant distance is always maintained between the ship and the buoy. The arrangement enables the coupling arm to be quickly and easily coupled and uncoupled to the buoy. A coupling cone 2 is provided on an upper portion of the buoy 3, the coupling arm 1 is pivotally attached to said coupling cone, said cone has a lower inverse conical portion adapted to fit into a flared hole formed in the upper end of the buoy, and a movable locking member 5 is provided in the coupling cone for detachably locking said coupling cone to said mooring member. Preferably, all the equipment for coupling and uncoupling the cone is installed within the coupling cone so that it can be serviced and maintained on board ship, or on shore when the ship docks. <IMAGE>

Description

SPECIFICATION Apparatus for mooring a ship The present invention relates to apparatus for mooring a ship at sea.

As a means of mooring ships, storage vessels for petroleum products, various other vessels and barge mounted plants (hereinafter all simply referred to as ships) it has been long standing practice to moor the ships to a buoy which is anchored to the seabed using ropes, chains, or the like.

However, the recent trend is to moor the ships in waters far offshore, where ocean and wave conditions can be severe. With the ship simply fastened to the buoy using ropes, as described above, the buoy and the ship will collide with one another if the ropes are loosened or damaged.

Instead of using ropes, therefore, there have been proposed other means for fastening the buoy and -the ship in the form of a rigid construction.

Thus, the ship is fastened to the buoy using a rigid coupling arm, so that a constant distance is always maintained between the ship and the buoy.

Various methods have been proposed for anchoring the buoy in the sea. For example, the buoy may be anchored at a position just underneath it using a chain (or rod, rope or the like), or it may be anchored using several chains (or ropes) which are suspended, or it may be in the form of a pole installed on the sea bed.

Although the use of a rigid coupling arm eliminates the probablity of collision between the buoy and the ship, the size and weight of the coupling arm, or the complex construction of the coupling means which couples the buoy and the ship together, make the mooring semi-permanent.

In other words, a rigid coupling arm makes it impossible to moor or release the ship easily within a short period of time, unlike mooring by chains or ropes.

Therefore, the rigid coupling arms have a serious defect in that the ship cannot be quickly released in case of emergency, such as when fire has broke on the ship or on the surrounding sea, or in icy waters, if the ship is likely to collide with a floating iceberg.

An object of the present invention is to eliminate the abovementioned problem normally inherent in mooring means incorporating a coupling arm by providing apparatus which enables the ship to be moored to, or released from, the mooring quickly.

According to this invention, apparatus for mooring a ship is characterised in that a coupling cone is provided on an upper portion of a mooring member in the form of a mooring pole or a mooring buoy, a coupling arm is pivotally attached to said coupling cone, a lower portion of an inverse conical portion of said coupling cone is fitted into a flared hole which is formed in said upper portion of said mooring member, and a movable locking member is provided in said coupling cone for detachably locking said coupling cone to said mooring member.

Other objects and advantages of the invention will become apparent from the following description of one exemplary embodiment thereof, taken in conjunction with the accompanying drawing, in which~ Figure 1 is a perspective view schematically illustrating the embodiment apparatus, and Figure 2 is an enlarged cross-sectional view of the apparatus.

Referring to Figure 1, the apparatus comprises a coupling arm 1, a coupling cone 2, and a mooring member 3, which may be a mooring pole or a mooring buoy anchored to the sea bed. A ship S is coupled to an upper portion of the mooring member 3 by the coupling arm 1, via the coupling cone 2.

Referring to Figure 2, a lower portion of the coupling cone 2 is of an inverse conical shape which engages with a flared recess that is formed in an upper portion of the mooring member 3.

After they have been engaged together, a locking pin of a movable locking member, which latter is actuated by a hydraulic pressure generator 4 in the coupling cone 2, is located in a groove 6 formed in the inner wall of the flared recess in the upper portion of the mooring member 3. Thus, the coupling cone 2 is locked to the mooring member 3.

The upper surface of the locking pin 5 and the corresponding upper surface of the groove 6 are tapered so that they will engage with each other in the form of a wedge. As the pin 5 moves into the groove 6, the coupling cone 2 is pulled downwardly relative to the mooring member 3, whereby a rubber packing 7 provided under a flange extending circumferentially around a central part of the coupling cone 2 is compressed by a predetermined amount, between said coupling cone 2 and the upper peripheral edge of the mooring member 3. Therefore, after they have been coupled together, water is prevented from entering into the coupling cone 2. The rubber packing 7 also acts to reduce shock when the coupling cone 2 is engaged.

Locking pins 5 are provided in a required number around the circumference of the coupling cone 2. The groove 6, however, is formed continuously around the inner surface of the mooring member 3. Therefore, the coupling cone 2 may be engaged in any rotational position about its axis.

Also, as shown in Figure 2, the coupling arm 1 is pivotablly attached to the upper portion of the coupling cone 2 via a ball and socket joint 8.

The apparatus shown in Figure 2 is intended for use in loading a fluid such as crude oil from the sea bed to the ship, or unloading from the ship to the sea bed and includes a pipeline for the fluid transfer, comprising a rigid pipe 9 for transporting the fluid along the coupling arm 1, which is connected to an annular flow path in a rotatable ring 11 at the top of the coupling cone 2 via a flexible pipe 10, or it may be a foldable pipe with swivel joints. A rigid pipe 12 connects with the annular flow path in the ring 1 1 and hangs vertically within the coupling cone 2 to be connected at its lower end to a foldable pipe 13, this latter pipe 13 being connected via a flange 15 to a further rigid pipe 14 that rises from the mooring member 3.When the coupling cone 2 and the mooring member 3 are to be engaged with each other or disengaged from each other, the pipeline can be attached or detached at the flange 15. In a modification, the foldable pipe 13 with swivel joints may be replaced by a flexible pipe.

Although Figure 2 illustrates only one pipeline system, it is easy to install a plurality of pipeline systems in the same manner.

Furthermore, an entrance/exit port 16 with a water-tight door (or water-tight cover), a handrail 17 and a ladder 18 are provided so that staff can enter into the coupling cone 2 to start or stop the hydraulic pressure generator 4, to attach or detach the flange 1 5, or to check and maintain the equipment.

The operation of the apparatus will now be explained, assuming that the ship S is moored to the mooring member 3 by the coupling arm 1 via the coupling cone 2. Thus, the ship S drifts, tilts, pitches and rolls due to ocean currents, tide, wind and waves, etc. and any forces generated are transmitted to the coupling cone 2 via the coupling arm 1. Here, however, the coupling arm 1 and the coupling cone 2 are rotatable owing to the presence of the ball and socket joint 8. Therefore, no bending moment or twisting moment is produced in this portion; the axial force only is transmitted to achieve the purpose of mooring.

When the mooring member 3 is a buoy which is anchored by anchoring chains only and which is swingable, the ball and socket joint 8 may be replaced by a joint which rotates about the vertical axis only.

Fluid is transported from the sea bed to the ship S through the rigid pipe 14, flange 15, foldable pipe 13 with swivel joints, rigid pipe 12, the annularflow path in the rotatable ring 11, flexible pipe 10 and rigid pipe 9.

Even when relative displacement has taken place between the coupling arm 1 and the coupling cone 2 due to the motion of the ship S or the mooring member 3, the flexible pipe 10 and the ring 11 move to follow the displacement, and the transport of the fluid is not disturbed.

The coupling cone 2 can be separated from the mooring member 3 in the following manner. First, the operator enters into the coupling cone 2 through the entrance/exit port 16. The operator may directly transfer from a workboat (not shown), or may transfer from the ship S which is mooted via the coupling arm 1.

The operator who has entered into the coupling cone 2 disengages the flange 15. A stop valve (not shown) will respectively have been provided at the top end of the rigid pipe 14 and at the lower end of the foldable pipe 13. By closing the stop valves, the fluid in the pipes is prevented from gushing out.

Then, the operator starts the hydraulic pressure generator 4 so that the locking pins 5 are withdrawn by the hydraulic pressure to a position indicated by a dot-dash line.

The hydraulic pressure generator 4 will have a hydraulic pump that is actuated by, for example, compressed air. The compressed air will be supplied from the moored ship via the ring 11 through a pipeline system which is similarly constructed as the above pipeline system for transferring fluid, or from a workboat through the entrance port 16.

Thus, the preparation for separation is completed. When the coupling arm 1 is lifted up, the coupling cone 2 is separated from the mooring pole 3. The coupling arm 1 can then be lifted up by a lifting device (not shown) such as crane, installed at the bow of the moored ship.

The coupling cone 2 and the mooring member 3 are contacted and fastened chiefly via the rubber packing 7. A sufficient gap is maintained between the inverse conical portion at the lower portion of the coupling cone 2 and the flared recess at the upper portion of the mooring member 3.

Therefore, there is no probability that the two members will adhere together. To couple them together, the abovementioned operations are carried out in the reverse order. In this case, since the top end of the mooring member 3 is flared, there is no need to accurately centre the coupling cone 2, and said member. This enables the coupling operation to be easily carried out.

Effects and advantages of the apparatus for mooring ships of the present invention are summarized below.

(1) Movable locking members such as locking pins 5 are installed in the coupling cone 2, and other equipment is also installed in the coupling cone 2. Therefore, the apparatus can be maintained and checked in the dock when the ship is brought into the dock. Accordingly, there is no need to perform maintenance operations in dangerous seas. In other words, the apparatus of the present invention contributes to the enhancement of safety.

(2) No apparatus or moving part necessary for coupling is installed in the mooring member 3 that is left in the sea, after it is disconnected from the coupling cone 2. Therefore, the mooring member 3, after disconnection, requires no maintenance (for preventing the ingress of water or the like).

(3) Since the coupling mechanism is simply constructed, the disconnection or the coupling can be effected within a short period of time.

(4) The ship can be quickly disconnected in an emergency. Therefore, the conditions for disconnection can be set to suitable values with reference to the operation rate, such that the condition of external forces for the mooring apparatus can be reduced to practical ranges.

Claims (3)

1. Apparatus for mooring a ship, characterised in that a coupling cone is provided on an upper portion of a mooring member in the form of a mooring pole or buoy, a coupling arm is pivotally attached to said coupling cone, a lower portion of an inverse conical portion of said coupling cone is fitted into a flared hole which is formed in said upper portion of said mooring member, and a movable locking member is provided in said coupling cone for detachably locking said coupling cone to said mooring member.

2. Apparatus for mooring a ship as claimed in Claim 1, characterised in that driving means for said movable locking member is provided in said coupling cone.

3. Apparatus for mooring a ship constructed, arranged and adapted for use substantially as hereinbefore described with reference to, and as shown in, the accompanying drawing.