US 20080105185 A1
A lightering connection system is provided for coupling a tug boat to a barge, where the connection permits relative vertical movement between the tug and barge while maintaining horizontal movement control between the vessels. The tug boat has port and starboard retractable rams having coupler heads which engage the barge along inboard port and starboard vertical receiver channels. The coupler heads and vertical receiver channels are provided with waveform surfaces to permit interlocking engagement between the tug boat and barge. The waveform surfaces also permit smooth relative movement of the surfaces as the ram disengages in performing the lightering operation. The coupler heads and vertical channel receivers have a mating angular construction to maintain horizontal movement control between the tug and barge during the lightering operation.
1. A coupler and receiver assembly for connecting a pusher vessel within a stern notch of a barge, the assembly comprising:
a pair of rams provided on lateral sides of the pusher vessel, a coupler head attached to each of the rams,
receiver channels for receiving each coupler head provided on the barge,
each receiver channel comprising first and second generally opposed sidewalls,
each of the coupler heads comprising lateral edges, at least one of the lateral edges of each coupler head having a primary waveform surface with a plurality of rounded, non-angular projections, at least one of the first and second sidewalls of each of the receiver channels having similar secondary waveform surfaces adapted to mate with the lateral edge of the coupler heads having the primary waveform surface.
2. The coupler and receiver assembly of
3. The coupler and receiver assembly of
4. The coupler and receiver assembly of
5. The coupler and receiver assembly of
6. The coupler and receiver assembly of
7. The coupler and receiver assembly of
8. The coupler and receiver assembly of
9. The coupler and receiver assembly of
10. The coupler and receiver assembly of
11. A coupler and receiver assembly for maintaining a water level position of a pusher vessel within a stern notch of a barge during a lightering operation, the assembly comprising:
a pair of rams provided on lateral sides of the pusher vessel,
a coupler head attached to each of the rams, the coupler head having lateral edges angularly disposed towards each other at the front end of the coupler head,
receiver channels for receiving each coupler head provided on the barge,
each receiver channel comprising first and second generally opposed sidewalls, the sidewalls being angularly disposed away from each other at the longitudinal opening of the receiver channel, the angular disposition of the sidewalls being equal but opposite to the angular disposition of the lateral edges of the coupler head,
each of the coupler heads comprising lateral edges having a primary waveform surface with a plurality of rounded, non-angular projections, each of the first and second sidewalls having similar secondary waveform surfaces with a plurality of rounded, non-angular projections adapted to mate with the lateral edges of the coupler heads, the rams being adapted for extraction and retraction to maneuver the coupler heads into engagement with and disengagement from the receiver channels, whereby the primary waveform surfaces of the lateral edges of the coupler heads are capable of being brought into mating engagement with the secondary waveform surfaces of the first and second sidewalls of the receiver channels to secure the pusher vessel within the stern notch of the barge.
12. The coupler and receiver assembly of
13. The coupler and receiver assembly of
14. The coupler and receiver assembly of
15. The coupler and receiver assembly of
16. The coupler and receiver assembly of
17. An assembly for coupling a first vessel with a second vessel, the assembly comprising:
a ram provided on the first vessel;
a coupler head attached to the ram; and
a receiver channel provided on the second vessel for receiving the coupler head, with the receiver channel including first and second sidewalls,
wherein the coupler head includes first and second lateral edges, with at least one of the lateral edges having a primary waveform surface presenting a plurality of curved, non-angular projections, and at least one of the first and second sidewalls of the receiver channel having a similar secondary waveform surface adapted to mate with the lateral edge of the coupler head having the primary waveform surface.
18. In a system for selectively coupling a first vessel with a second vessel, wherein the system includesó
a first ram including a first coupler head, the first ram being mounted on the first vessel so as to be selectively extendable outwardly from a first side of the first vessel;
a first receiver channel provided on a first side of a notch in the second vessel, oriented substantially vertically, and operable to receive the first coupler head when the first vessel is located within the notch and the first ram is extended;
a second ram including a second coupler head, the second ram being mounted on the first vessel so as to be selectively extendable outwardly from a second side of the first vessel; and
a second receiver channel provided on a second side of the notch in the second vessel, oriented substantially vertically, and operable to receive the second coupler head when the first vessel is located within the notch and the second ram is extended;
the improvement comprising:
the first and second coupler heads each having left and right sides, with each of the left and right sides including a coupler head surface presenting a first plurality of low amplitude, rounded projections; and
the first and second receiver channels each having left and right sides, with each of the left and right sides including a receiver channel surface presenting a second plurality of low amplitude, rounded projections,
wherein the first and second pluralities of low amplitude, rounded projections interact so as to allow for vertical sliding movement between each coupler head and its respective receiver channel without requiring full withdrawal of the coupler head from the receiver channel, thereby allowing for relative vertical movement between the first and second vessels while substantially eliminating other relative movement.
This present continuation patent application is related to and claims priority benefit of an earlier-filed non-provisional patent application of the same title, Ser. No. 11/345,792, filed Feb. 2, 2006, and an even earlier filed provisional patent application Ser. No. 60/649,849, filed Feb. 2, 2005. The identified earlier-filed applications are hereby incorporated by reference into the present application.
1. Field of the Invention
The present invention relates to the field of marine equipment, particularly, the art of connecting tugboats or pusher vessels with barges or other non-powered vessels which are equipped with a notch in the stern of the barge for receiving a tug or pusher vessel therein.
2. Description of the Prior Art
Barges are used to transport cargo on water, but have no self-propelling mechanisms, and rely primarily on tugboats or other pusher vessels for movement from one location to another. There exist many types of connections for coupling tugboats to barges, and the particular form of connection used depends on the marine environment in which the transportation takes place. As can be expected, a more secure coupling arrangement is required to maintain the connection of the tugboat to the barge in rough waters. For example, when a barge is used to transport oil, the coupling of the tugboat to the barge, the loading of the barge, and the actual pushing of the loaded barge take place out in open sea and are subject to substantial waves. It is imperative that the tug boat be securely connected to the barge to prevent the tug boat from being tossed about against the barge, or substantial damage and injury can occur.
A stable form of connection is provided through the use of extendable ram devices on the tug boat which interconnect with receivers on the barge. An example of this extendable ram and receiver configuration is shown in
This type of connection is suitable when the barge maintains a fixed load and the tug boat merely transports the barge. However, a tug boat must frequently transport a barge to a first destination where it receives a load, and then transport the barge to a second destination where the barge is unloaded. During the two operations, the respective water levels of the tug boat and barge will change relative to each other as the load weight is affected. For example, when the barge is empty, it will sit in the water relatively high. As the barge is loaded, the weight of the load will cause the barge to sit lower in the water. However, because no weight change is made to the tug boat itself, the water line of the tug boat remains constant. If the tug boat were to remain fixedly connected to the barge during the loading operation, the weight load would push the tug boat down into the water, with possibly disastrous consequences. The tug boat must, however, maintain some degree of connection with the barge during loading, otherwise the waves from the rough waters may prevent realignment and re-attachment. Therefore, the connection must permit the relative levels of the tug boat and barge to change as the weight load varies. The process by which the tug boat adjusts its position to the coupled barge as the weight load is changed is called lightering.
As shown in
To permit the relative vertical movement of the barge with respect to the tug boat, the rams are retracted a sufficient distance so that the teeth 26 of coupler head 22 come out of interlocking engagement with the teeth 24 of vertical channel receiver 20. The distance of retraction must be enough so that the tips of teeth 26 can clear the tips of teeth 24 so relative vertical movement can occur. Any contact between the tug coupler head and the barge during vertical motion with this type of connection causes the tug ram to turn and makes reengagement difficult. Full disconnection is required to allow relative vertical movement between the tug and barge. The operation of the rams is mechanically and electrically controlled as fully explained in the Kuhlman et al U.S. Pat. No. 4,688,507 and is now well known to those having skill in the art.
Full disconnection results in loss of longitudinal and tug roll control. Any time the ram disengages from secure engagement with the receiver, there is potential for mishap, especially in the heavy waters out at sea. Specifically, anytime that the coupler becomes disengaged, the tug boat is allowed to roll.
Accordingly, it is desirable to minimize the degree of disengagement of the ram from the receiver channel during the lightering operation so that the ability for respective vertical movement between the tug boat and barge is maximized, while the potential for tug boat roll and loss of longitudinal control is minimized. It is also desirable to minimize the amount of time it takes to disengage the ram coupler head from engagement with the receiver channel long enough for the lightering adjustment to be made, then to reengage the ram coupler head with the receiver channel to reestablish a secure connection.
In accordance with one embodiment, the invention comprises a tug barge lightering connection system of the type comprising a ram equipped with a coupler head for engagement with a vertical receiver channel of a barge, which is adapted to minimize the degree of disengagement of the ram from the receiver channel during the lightering operation so that the ability for achieving respective vertical movement between the tug boat and barge during the lightering operation is maximized, while the potential for unintentional longitudinal movement is minimized. The coupler head of the tug boat ram is wedge shaped and its lateral edges are provided with a waveform surface. The vertical receiver channels of the barge have a complementary wedge shape for receiving the ram coupler heads. The opposing side walls of the vertical receiver channels also have a waveform surface that mates with the lateral edges of the ram coupler heads as they come into engagement with the receiver channels. The waveform surface of the respective coupler heads and sidewalls of the receiver channels thus permit an interlocking engagement to provide a secure vertical connection between the tug boat and barge. The smooth curves and the absence of angular edges in the waveform surface of the respective coupler heads and sidewalls permit smooth incremental relative vertical movement of the tug boat to the barge during the lightering operation. The low amplitude of the waves also minimize the degree of ram disengagement from the receiver channels necessary to effect vertical movement. The wedge shape entry point of the receiver channels provide sufficient area for the retraction of the waveform surface of the coupler heads to disengage from interlocking connection with the waveform surface of the receiver sidewalls while still providing longitudinal control of the connection between tug boat and barge.
In accordance with another aspect of the invention, the shape of the waveform on the lateral edges of the coupler heads and the sidewalls of the vertical receiver channels may vary depending upon the weight load to which they are subjected. The greater the load transported by the barge, the greater the amplitude of the wave may be desired at any given level of ram engagement pressure. The waveform surface of the vertical channels may be comprised of discrete sections which can be attached onto the sidewalls of vertical receiver channels in barges.
Accordingly, it is an object of the present invention to provide a lightering connection system between a tug boat and a barge for maximizing the vertical relative movement efficiency between a tug boat and a barge during the lightering operation, while minimizing the loss of secure connection between the tug boat and the barge during the lightering operation. There has thus been outlined herein, rather broadly, certain embodiments of the invention in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.
Referring now to the drawings in more detail,
Waveform surfaces 32 and 34 are provided on the lateral sides 36 and 38 of coupler head, or helmet, 40, respectively, as shown in
The interaction between the waveform surfaces on the ram coupler head and sidewalls of the vertical channel receiver can be understood by viewing the operation as referenced in the drawings and aided by the following description. In the usual barge transportation scenario, a tug boat 14 enters the notch 12 of a barge 10 equipped with port and starboard vertical receiver channels of the type well known in the art, as shown in
The waveform surface also permits vertically controlled movement as a function of friction. With the rounded surfaces provided by the waveform, the transition between the point where a wave crest emerges out of a trough (as in
As shown in
One embodiment of the waveform surface of the present invention comprises a coupler head whose lateral sides have the waveform surface integrated therein. This enables existing rams using a helmet incorporating the tooth-edged coupler to be switched with a helmet incorporating the waveform surface coupler. Similarly, the vertical channel receiver may have the waveform surface integrated into its sidewalls. Alternately, the waveform surface could be connected to an existing surface by welding or bolting or the like. Another embodiment provides for the waveform surface to be installed on vertical channel receiver side walls by installing in individual sections as shown in
In the foregoing description, certain terms have been used for brevity, clearness and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed. Moreover, the description and illustration of the inventions is by way of example, and the scope of the inventions is not limited to the exact details shown or described.
Certain changes may be made in embodying the above invention, and in the construction thereof, without departing from the spirit and scope of the invention. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not meant in a limiting sense. Having now described the features, discoveries and principles of the invention, the manner in which the inventive tugboat and barge connector and receiver combination is constructed and used, the characteristics of the construction, and advantageous, new and useful results obtained; the new and useful structures, devices, elements, arrangements, parts and combinations, are set forth in the appended claims.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.