AU2009317866B2

AU2009317866B2 - Coupling for pusher tug

Info

Publication number: AU2009317866B2
Application number: AU2009317866A
Authority: AU
Inventors: Stuart Edward Ballantyne
Original assignee: ASD MARINE SERVICES Pty Ltd
Current assignee: ASD MARINE SERVICES PTY Ltd
Priority date: 2008-11-21
Filing date: 2009-11-19
Publication date: 2015-01-22
Anticipated expiration: 2029-11-19
Also published as: AU2009317866A1; WO2010057252A1

Abstract

A coupling for pusher tugs whereby the connection permits the tug freedom to heave pitch and roll semi-independently from the motion of the barge whilst retaining full control of the barge as far as steering is concerned. The coupling includes two rails attached to the barge, each rail having two cars which can move along the rail and connecting rods attached to the tug the ends of which are engagable with the cars of the adjacent rails thus permitting driving and turning force to be transmitted from the tug to the barge and permitting relative vertical movement therebetween. Preferably one rod is connected to the upper car on one rail and the lower car of the other rail and the other rod is connected to the other two cars so that there can be relative rotational movement between the tug and the barge.

Description

-1 COUPLING FOR PUSHER TUG Technical Area This invention relates to a coupling for coupling a pusher tug to a barge and is particularly suited to a coupling for catamaran pusher tugs. Background to the Invention Whilst pusher tugs have been in use for many years, it has been difficult to provide couplings which enable to the tug to operate efficiently in that its attitude remains optimum for operation, whilst retaining full control of the barge being pushed and at the same time ensuring the safety of the barge under normal operating conditions. It is also necessary that any coupling be such that it can readily be broken in case of emergency and deteriorating weather. Outline of the Invention The object of the invention is to provide a coupling to couple a pusher tug to a barge in which the weight of the coupling is carried by the barge and the tug retains freedom of movement relative to the barge so as to operate in its most efficient matter and which, at the same time, enables rapid release of the tug from the barge should this be required. The invention includes a coupling for pusher tugs whereby the coupling permits the tug freedom to heave pitch and roll semi-independently from the motion of the barge whilst retaining full control of the barge as far as steering is concerned. The invention further includes a coupling for pusher tugs whereby the coupling permits a tug freedom to move semi-independently from the motion of a barge whilst retaining steering control of the barge, the barge having one or more rails -2 mountable thereto, wherein the coupling includes at least one car being attachable to one of the rails and able to move along the rail, the at least one car being engagable with a pin located on the tug, the coupling in use permitting driving and turning forces to be transmitted from the tug to the barge and permitting relative heave, pitch and roll therebetween. Preferably, the coupling includes one or more rails mountable to the barge. In a particularly preferred form of the invention, the coupling includes two rails mountable to the barge and a car attachable to each rail, each car being able to move along a rail and being engagable with a pin located on the tug, the coupling in use permitting driving and turning forces to be transmitted from the tug to the barge and permitting relative heave, pitch and roll therebetween. It is preferred that the at least one pin is able to be retracted to permit the at least one pin to engage with the at least one car. Preferably, means are provided to permit rapid disengagement of the at least one pin from the at least one car. In at least one preferred form of the invention, each rail has a web and a flange extending outwardly from each side of the web. Preferably, the at least one car has a body member having a pair of spaced members between which a car wheel is locatable for rotation about an axle transverse to the vertical axis of the barge. It is preferred that the body member is attachable to the rail by extensions from the spaced members to permit the car wheel to maintain contact with the rail. Preferably, the car wheel has a peripheral groove in which is locatable a tyre which is contactable with the rail. It is preferred that the body member includes a socket to receive the at least one pin, the socket being pivotally located to permit angular rotation of the at least one -3 pin relative to the body member. Preferably, in use the at least one pin is able to move axially relative to the at least one car. Preferably, the at least one car includes a bearing for enabling the axial movement of the at least one pin relative to the at least one car. It is also preferred that axial movement of the pin relative to the at least one car permits relative roll movement between the tug and the barge. Preferably, in use the at least one pin is able to rotate within the at least one car. It is also preferred that the rotation of the pin permits relative rotation between the tug and the barge. Preferably, rotational movement between the tug and the barge is bounded by the at least one car's range of movement along the rail. In another preferred form of the invention that the coupling includes two rails mountable to the barge, each rail having two cars which can move along the rail and pins attached to the tug the ends of which are engagable with the cars of the adjacent rails thus permitting driving and turning force to be transmitted from the tug to the barge and permitting relative vertical movement therebetween. In this preferred form of the invention, it is also preferred that one pin is engageable to the upper car on one rail and the lower car of the other rail and the other pin is engageable to the other two cars. It is preferred that the pin is permitted to move axially in the coupling to thereby permit relative heel and roll movement between the tug and the barge. It is also preferred that there can be rotational movement between the pin and the car to permit rotation between the tug and the barge. In order that the invention may be more readily understood, a specific embodiment -4 of the invention will be described in relation to the accompanying drawings, in which: Fig 1 shows the arrangement at the bow of the tug showing the rails attached to the barge and the cars on the tug and barge being in a more or less neutral situation; Fig 2 shows a side elevation similar to that of Fig 1 showing the relationship between one of the rails and its associated cars; Fig 3 shows the relationship between the tug and the barge in a more or less neutral position; Fig 4; shows an arrangement similar to that of Fig 3 with the tug riding very much higher than the barge; Fig 5 shows the interconnection between the cars on the adjacent rails; Fig 6 gives an indication of the range of movement between the barge and the tug which can be accommodated by the arrangement of the invention; and Fig 7 shows the arrangement of the car at the bow of the tug. Description of an Embodiment of the Invention Referring to Figs 1 and 2 of the drawings, the coupling between the tug 50 and the barge has three components, a pair of rails 10 which are mounted on the stern of the barge, a car 20, which rides on each rail and pins 40 located on the tug whereby the car can engage with the pin so that the tug can provide driving and steering control over the barge and roll between the tug and the barge can be controlled. A feature of the invention is that the rails 10 and the cars 20, which are the heavy components of the coupling, are on the barge 60 and if the barge is provided with counter weighting means the rails and the cars do not add to the weight of the tug with any consequent degradation of the performance of the tug, although this is not essential.

-5 A further feature which will be described further herein is that the tug has freedom to heave pitch and roll relative to the barge motion which ensure that the tug propellers maintain the best immersion for operating efficiency and also eliminate the high rolling forces due to high GM of the tug if it is forced to move with the barge. At the same time the tug and barge are locked in yaw motion which ensures an immediate steering response of the barge when the tug's direction of movement is changed. These controls will be described generally with relation to Figs 1 to 6 and a particular arrangement of the cars will be described in relation to Fig 7 but it is to be appreciated that there may be variations in the form of the car. Referring to Figs 1 and 2 the rails 10 are connected to the stern of the barge 60 and depending on the relative sizes of the tug 61 and the barge 60 so these are positioned to permit the cars 20 to be located along their length at the required extremes of movement as can be seen from Figs 3 and 4. As can be seen from Fig 5, the tug pins 40 are engageable with the cars 20 on the adjacent rail 10. As the cars 20 can move along the rails 10, this permits roll between the tug and the barge permitting the tug to retain stability along its horizontal axis. The degree of available movement is illustrated in Fig 5 and Fig 6 although the particular degree of movement shown could vary as required. Thus, there is a permissible degree of pitch and roll between the tug 50 and the barge 60 which enables to the tug to operate in its optimum condition, but there is no freedom of movement in yaw which means that the steering between the tug and the barge is direct and there can be no lack of control of the steering of the barge. As can be seen in Figure 7, each rail 10 comprises a web 11 which is attached to -6 the barge and has a flange 12 extending outwardly from each side thereof. The rail is of stainless steel or, at least the flange 12 has stainless steel bearing surfaces. Each car 20 has a body member which, in part, includes a pair of spaced members 21, 21' between which the car wheel 30 is located for rotation about an axle 31 transverse to the vertical axis of the barge. The wheel is a solid bronze or stainless steel wheel in either one or more pieces having a peripheral circumferential groove which carries a solid rubber tyre 32 which is in the form of an O-ring part of which is received in the groove used to cushion shock loads. The wheel preferably has a bronze bush bearing and the axle 40 comprises a stainless steel bearing pin which passes through the wheel and is located in the spaced members, the arrangement providing a self lubricating bearing. The body is readily dissembled to enable replacement of the tyre and the bush, when required. The body also has, rearwardly of the wheel, in the direction of forward movement, a socket 25 to receive the tug pin 42. This includes a stainless steel socket 25 which is located in bronze bearing blocks which, in turn are pivoted on yokes 42 to permit movement of the pin relative to the rail. Thus, the socket 25 is able to pivot via yoke 42, which permits angular rotation of the pin 40 relative to the body of the car 20. The pivot range of the socket 25 relative to the car 20 is depicted in Figure 6. The socket 25 includes a plastic inner bearing for the tug pins 40 and the pins 40 can move axially relative to the socket with stop members 26,27 to limit the amount of available movement. The stop members 26, 27 depicted in Figure 7 comprise the end boundaries of the tug bracket 43.

-7 The tug pins 40 are located above the tug 50 foredeck height 51 to minimise salt water immersion and the rails 10 are thus located on the barge 60 at a height whereby the car 20 will be substantially centrally thereof in still water. The tug pins 40 are located in the tug brackets 43 and are moveable axially relative to the tug brackets 43 normally by a hydraulic ram. Means are provided whereby the tug 50 can be disengaged from the barge 60 which are operable from with the tug or the barge. Under normal operation the pins 40 can be retracted, either manually or hydraulically to permit location in the socket 25 and there can also be provided, for emergency operation a spring/air loaded pull out mechanism with local and remote triggering to retract both pins simultaneously. When the tug 50 is to be coupled to the barge, there can be a trace connected to the car 20 which can be caught with a boat hook and pulled through the tug's pin centre or a separate centering system, the tug is then nudged into position between the barge rails 10, the cars are pulled into vertical alignment with the tug pins 40 which are then simultaneously engaged when the cars are aligned. When the barge 60 is being moved, it will be understood that the cars 20 will be permitted to rise and fall on the rails 10 thus permitting the tug 50 to be in its optimum position to transfer energy through its propellers. At the same time, there can be a degree of movement of the pins 40 relative to the sockets 25 and the sockets themselves have a degree of movement about the yoke pivots 42. Thus, there can be a substantial degree of independent movement between the barge 60 and the tug 50 whilst, at the same time any change in direction of the tug is directly reflected in the direction of movement of the barge. Whilst there has been described herein one particular arrangement of the invention, it will be understood that the various components could be made substantially differently without in any way departing from the spirit and scope of the invention.

Claims

1. A coupling for pusher tugs whereby the coupling permits a tug freedom to move semi-independently from the motion of a barge whilst retaining steering control of the barge, the barge having one or more rails mountable thereto, wherein the coupling includes at least one car being attachable to one of the rails and able to move along the rail, the at least one car being engagable with a pin located on the tug , the coupling in use permitting driving and turning forces to be transmitted from the tug to the barge and permitting relative heave, pitch and roll therebetween.

2. A coupling as claimed in claim 1, wherein the coupling includes the one or more rails mountable to the barge.

3. A coupling as claimed in claim 1 or claim 2 wherein the coupling includes two rails mountable to the barge and a car attachable to each rail, each car being able to move along a rail and being engagable with a pin located on the tug, the coupling in use permitting driving and turning forces to be transmitted from the tug to the barge and permitting relative heave, pitch and roll therebetween.

4. A coupling as claimed in any one of the preceding claims wherein the at least one pin is able to be retracted to permit the at least one pin to engage with the at least one car.

5. A coupling as claimed in claim 4 wherein means are provided to permit rapid disengagement of the at least one pin from the at least one car.

6. A coupling as claimed in any one of the preceding claims wherein each rail has a web and a flange extending outwardly from each side of the web. -9

7. A coupling as claimed in any one of the preceding claims wherein the at least one car has a body member having a pair of spaced members between which a car wheel is locatable for rotation about an axle transverse to the vertical axis of the barge.

8. A coupling as claimed in claim 7 wherein the body member is attachable to the rail by extensions from the spaced members to permit the car wheel to maintain contact with the rail.

9. A coupling as claimed in either claim 7 or claim 8 wherein the car wheel has a peripheral groove in which is locatable a tyre which is contactable with the rail.

10. A coupling as claimed in any one of claims 7 to 9 wherein the body member includes a socket to receive the at least one pin, the socket being pivotally located to permit angular rotation of the at least one pin relative to the body member.

11. A coupling as claimed in any of the preceding claims wherein in use the at least one pin is able to move axially relative to the at least one car.

12. A coupling as claimed in claim 11 wherein the at least one car includes a bearing for enabling the axial movement of the at least one pin relative to the at least one car.

13. A coupling as claimed in claim 11 or claim 12 wherein the axial movement of the pin relative to the at least one car permits relative roll movement between the tug and the barge.

14. A coupling as claimed in any of the preceding claims wherein in use the at least one pin is able to rotate within the at least one car. -10

15. A coupling as claimed in claim 14 wherein the rotation of the pin permits relative rotation between the tug and the barge.

16. A coupling as claimed in any of the preceding claims wherein rotational movement between the tug and the barge is bounded by the at least one car's range of movement along the rail.

17. A coupling substantially as herein described with reference to any one of the accompanying figures.