US3762358A

US3762358A - Apparatus for dragging along a submerged structure

Info

Publication number: US3762358A
Application number: US00146960A
Authority: US
Inventors: G Hinkle
Original assignee: R J BROWN AND ASSOCIATES
Current assignee: R J BROWN AND ASSOCIATES; R J BROWN AND ASSOCIATES NL
Priority date: 1970-05-27
Filing date: 1971-05-26
Publication date: 1973-10-02
Anticipated expiration: 1990-10-02
Also published as: GB1306902A; NL143673B; IT961086B; FR2099744A5; NL7007662A

Abstract

Apparatus for dragging along a structure submerged in a body of water is attached by a pulling cable to the structure and is carried by the lower end of a pole or post which depends from a floating vessel and is mounted by a universal joint on said vessel. A cable extends from a winch on the vessel down over a pulley carried by the lower end of the pole to an anchor towards which the vessel and submerged structure are to be drawn and means are provided for moving the pole upwardly or downwardly to adjust the position of the lower end of the pole relative to the floor of the body of water.

Description

United States Patent 1 1 Hinkle l l Oct. 2, 1973 APPARATUS FOR DRAGGING ALONG A SUBMERGED STRUCTURE George S. Hinkle, Wassenaar, Netherlands lnvcntor:

Assignee: R. J. Brown and Associates Filed: May 26, 1971 Appl. No.: 146,960

Foreign Application Priority Data May 27. 1970 Netherlands 7007662 US. Cl. 115/7, 6l/72.3 int. Cl B63b 21/56 Field oiSearch 115/7; 61/723, 72.4

7 References Cited 0 UNITED STATES PATENTS Stimson (H/72.3

3590,58) 7/l97l Smulders t. (ii/72.4

Primary Examiner-Milton Buchler Assistant Examiner-Stuart .M. Goldstein Att0rneyYoung & Thompson [57] ABSTRACT Apparatus for dragging along a structure submerged in a body of water is attached by a pulling cable to the structure and is carried by the lower end of a pole or post which depends from a floating vessel and is mounted by a universal joint on said vessel. A cable extends from a winch on the vessel down over a pulley carried by the lower end of the pole to an anchor towards which the vessel and submerged structure are to be drawn and means are provided for moving the pole upwardly or downwardly to adjust the position of the lower end of the pole relative to the floor ofthe body of water.

7 Claims, 1 Drawing Figure Pmmanw m 3.782.358

INVENTOR 650665 6. H/NKME BY M ATTORNEY$ 1 APPARATUS FOR DRAGGING ALONG A SUBMERGED STRUCTURE The invention relates to an apparatus for dragging along a structure which is either directly or indirectly resting on the floor of a body of water by means of a cable connected with said structure.

It is known in the art, for instance, to drag pipe-laying devices along the pipeline. In that instance, the device is dragged along by means of a cable extending from a vessel which may or may not be at anchor. The power required for energizing said pipe-laying device is in that instance supplied by tubes or cables extending from the vessel as well. The disadvantage of this known apparatus is that the cable does not always pull in the desired vertical or horizontal direction, while the movements of the vessel due to the wash of the waves is an interfering factor. Moreover, the orientation of the vessel with respect to waves, currents and wind may be unfavorable.

It is therefore an object of the present invention to provide an apparatus for dragging along a submerged structure in which said disadvantages are eliminated. This object is achieved by the fact that the pulling cable is secured to a member which is permitted to swing and adapted to be kept above the floor of a body of water in front of the structure from a vessel or a similar floating installation and by the fact that a second cable extends from said member, which is retained at some distance from and in front of said member and roughly in the direction of movement, means being provided to haul in said second cable with respect to said member.

In this manner it is achieved that under all conditions the structure is subjected to a pulling force in the desired direction, whereby the vertical component of said force may be adjusted as desired, while the orientation of the vessel can be chosen independently from the direction in which the force is exerted.

The member may be secured to the lower portion of a pole suspended from the vessel, which pole is universally pivotable and is connected with the vessel in a vertically adjustable manner, the second cable being passed via a sheave mounted on the member to a winch drum for hauling in said cable, which drum is mounted on the vessel.

In order to make it possible to adjust the pulling force to the desired extent, means for controlling said force may be provided at the second cable.

In order to maintain the position of the member at a constant level above the floor of a body of water, the pole may be suspended via means for the compensation of vertical difi'erences in height. Means may be pro vided for lowering the pole.

In applying the apparatus for dragging along a structure according to the invention, which has to be eiiergized, the tubes or cables for the supply of the power are passed through the pole. Due to the fact that in the apparatus according to the invention there is a constant distance between the structure to be dragged along and the lower portion of the pole, there is no danger that said tubes may become entangled.

The invention will now be explained in more detail with reference to the single FIGURE of the drawing, wherein a diagrammatic fragmentary view of an embodiment of the invention is shown.

The drawing shows a vessel 1 floating on the surface of the water. From the vessel 1 is suspended a pole 2 which is passed through the universal joint 3 mounted on the vessel 1 and down through the opening la. The universal joint 3 is positioned in the proximity of the central axis of rotation of the vessel 1 so that the lower end of the pole 2 and the member 11 carried thereby will be positioned in the proximity of the central axis of rotation of said vessel. To the top of the pole are connected a hoisting rope 4 and a rope 4a for pulling the pole 2 down, which enable the pole to be moved upwardly and downwardly by means, not further shown, disposed on the vessel. At the lower portion of the pole is secured a member 11 to which is attached a cable 5 which, at its other end, is attached to the structure to be dragged along, which is not shown and may consist of a pipeline burying device passed over the pipeline 6. At the other side of the member 11 carried by the lower portion of the pole 2 is mounted a sheave 7, over which sheave a second cable 8 is passed, the front end of which, not shown, is anchored in the floor of a body of water, said cable extending upwardly via the sheave 7 to the power control means 9 and finally to the winch drum 10 mounted on the vessel.

When the pulling forces on cable 8 are great and/or the weight of pole 2 is light there is a tendency for pole 2 to move upwardly. Rope 4a serves to prevent pole 2 from moving upwardly.

For reasons of safety, member 11 is attached to pole 2 by a fracture joint so that if the structure to be dragged along should become stuck, for instance, member 11 can break off, said member being secured to a buoy 12 to make it possible to find the broken-off portion again.

The vessel is moreover provided with an echo sounder 13 which makes it possible to adjust the distance between the lower portion of the pole and the bottom, which echo sounder may cooperate with an adjusting device for theadjustment of vertical differences in height, so that the lower portionof the pole remains at a uniform level above the floor of a body of water.

The structure to be dragged along is energized through the cables or tubes 14 which extend from said structure to the lower portion of the pole 2 and are subsequently passed through the pole 2 to the vessel.

In accordance with the present invention there is pro? vided an apparatus by means of which an underwater structure can be dragged along from a vessel in a simple manner. The movements of the vessel do not interfere with the process, while the longitudinal orientation of the vessel can be substantially independent of the'direction of pull, so that it is, for instance, nearly always possible to carry out operations while meeting the waves bow on.

Having described my invention, I claim:

1. Apparatus for dragging along a structure submerged in a body of water by means of a pulling cable connected with said structure, comprising a member to which the pulling cable is connected, said member being carried beneath a vessel or a similar body floating on said body of water and which is permitted to swing and adapted to be kept in front of said structure, said pulling cable extending rearwardly from said member to said structure, a second cable one end of which is retained at some distance from and in front of said member and roughly in the direction of movement, and means on said vessel for hauling in the other end of said second cable to draw the vessel and structure towards the retained end of the second cable, said member being secured to the lower end of a pole suspended from said vessel, which pole is universally pivotally and vertically adjustably connected with said vessel, and said other end of said second cable being passed over a sheave mounted on said member to a winch drum mounted on said vessel, in order to haul in said cable.

2. Apparatus for dragging along a structure submerged in a body of water by means of a pulling cable connected with said structure, comprising a member to which the pulling cable is connected, said member being carried beneath a vessel or a similar body floating on said body of water and which is permitted to swing and adapted to be kept in front of said structure, said pulling cable extending rearwardly from said member to said structure, a second cable one end of which is retained at some distance from and in front of said member and roughly in the direction of movement, and means on said vessel for hauling in the other end of said second cable to draw the vessel and structure towards the retained end of the second cable, said member being positioned relative to the vessel in the proximity of the central axis of rotation of said vessel, said member being secured to the lower end of a pole suspended from said vessel, which pole is universally pivotally and vertically adjustably connected with said vessel, and said other end of said second cable being passed over a sheave mounted on said member to a winch drum mounted on said vessel, in order to haul in said cable.

3. Apparatus according to claim 1, in which there is provided a control device for controlling the pulling force of the second cable.

4. Apparatus according to claim 2, in which there is provided a control device for controlling the pulling force of the second cable.

5. Apparatus according to claim 1, in which there is provided a device for the compensation of vertical differences in height of the pole, so that, the elevation of said member above the floor of the body of water remains constant.

6. Apparatus according to claim 1, in which there are provided means for pulling down the pole.

7. Apparatus according to claim 5, in which the structure has to be energized, and means for the supply of power to the structure from the vessel are passed through the pole.

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