Tug barge lightering connection system

Abstract

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.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] 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.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] 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. [0004] 2. Description of the Prior Art [0005] 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 fro...

AI Technical Summary

Benefits of technology

[0012] 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.

[0014] 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.

Problems solved by technology

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.

As the barge is loaded, the weight of the load will cause the barge to sit lower in the water.

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.

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 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.

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