US3922992A - Single point vessel mooring system - Google Patents

Abstract

A system to facilitate connection of a tanker or similar floating vessel to a single point mooring embodying loading and offloading facilities. The mooring includes a connecting hawser capable of restraining the vessel, and to which one or more fluid carrying conduits are attached. The hawser remote end is provided with a messenger line which is maintained in a substantially upright position above the water''s surface. A catch mechanism depending from the vessel is thereby able, while moving through the water, to engage the messenger line preliminary to retrieving the hawser and fastening the vessel to the mooring.

Description

United States Patent Wilbourn 1 Dec. 2, 1975 [5 1 SINGLE POINT VESSEL MOORING 3.799.097 3/1974 Robertson ll4/206 R SYSTEM Primary ExaminerGeorge E. A. Halvosa [75] Inventor. Li p. wllboum New Orleans Assistant Examiner-Stuart M. Goldstein Attorney, Agent, or Firm-T. H. Whaley; C. G. Ries; [73] Assignee: Texaco Inc., New York, NY. Robert B. Burns [22] Filed: May 29, 1974 [57] ABSTRACT [21] Appl. No.: 474,281

A system to facllltate connecnon of a tanker or s1m1lar floating vessel to a single point mooring embodying [52] U.S. Cl. 114/230 loading and ffl di f ili i Thc mooring includes [5 l 1 Int- CLZ t a connecting hawser capable of restraining the essel [58] Field of Search 1 14/206 R, 230, 221 R; and to which one or more fl id Carrying conduits are 9/8 9 attached. The hawser remote end is provided with a I messenger line which is maintained in a substantially [56] References Cited upright position above the waters surface. A catch UNITED STATES PATENTS mechanism depending from the vessel is thereby able. 3,083,676 4/1963 Anderson 114/230 While moving through the k to engage the 3,279 419 10/1966 D Marco n 9 9 senger line preliminary to retrieving the hawser and 3.466.680 9/1969 Schirtzinger 1 114/230 fastening the vessel to the mooring. 3.492.963 2/1970 Kaiser ll4/230 3.750.723 8/1973 Schirtzinger 114/230 Clams, 14 Drawmg Figures Sheet 2 of4 I 3,922,992

U.S. Patent Dec. 2, 19 75 US. Patent Dec. 2, 1975' Shest 3 of4 3,922,992"

FIG. 4A

FIG. 3A

FIG. 8

SINGLE POINT VESSEL MOORING SYSTEM BACKGROUND OF THE INVENTION The use of single point moorings is becoming more widely prevalent and desirable in offshore waters to facilitate loading and offloading of vessels such as tankers and the like. The advantage of such a mooring is that it is relatively simple in construction, is capable of positioning a vessel away from the ordinary traffic lanes and ship traffic characteristic of a pier type operation. Further, it permits restrained movement of the vessel in response to wind and wave conditions without interrupting a loading or offloading operation.

Normally, a relatively large tanker has but limited maneuvering capability which would permit it to pick up a hawser line from a mooring for making the connection to the latter. The procedure usually followed is that a launch or similar small boat will physically carry the end of the hawser line to the tanker for making the necessary connection. Thereafter the one or more fluid carrying conduits depending from the mooring can likewise be communicated with the unloading facility on a tanker prior to effectuating transfer of liquids or fluids.

Often in the instance of a vessel mooring situation, however, wind and wave conditions are such as to render the use of a small boat to maneuver the hawser line impractical. For example, when the weather conditions result in wave heights of 6 to 8 feet, maneuverability of a small boat is severely limited, and further the safety of personnel as well as the boat are jeopardized during the operation.

Toward minimizing the use of launches and smaller vessels to achieve a mooring connection, means is provided as disclosed herein whereby the single point mooring includes one or more connecting hawsers. The latter can either float or be submerged beneath the waters surface. In either event the remote end of the heavy hawser is provided with a messenger line having an upstanding portion, which is maintained a desired distance beyond the waters surface.

The vessel to be moored is provided with a retractable catch mechanism, preferably attached to the forward end thereof. Said mechanism is operably positioned to engage the messenger line as the vessel, while slowly moving, is steered into contact with the latter. Thereafter, the messenger line can be readily drawn aboard the vessel, thus permitting the hawser to likewise be retrieved, and the physical connection between mooring and vessel completed.

DESCRIPTION OF THE DRAWINGS In the drawings,

FIG. 1 is a vertical elevation illustrating a mooring of the type contemplated prior to being connected to a floating vessel.

FIG. 1A is a top view of FIG. 1.

FIG. 2 is an enlarged segmentary view of the mooring shown in FIG. 1.

FIG. 2A is a top view of FIG. 2.

FIG. 3 is a segmentary view of the forward end of a vessel showing the catcher mechanism in retracted position.

FIG. 3A is a top view of FIG. 3.

FIG. 4 is similar to FIG. 3 illustrating the catch mechanism in the outward position.

FIG. 4A is a top view of FIG. 4.

FIG. 5 is similar to FIG. 1 illustrating the vessel connected to the mooring.

FIG. 5A is a top view of FIG. 5.

FIG. 6 is a segmentary view on an enlarged scale of the connection between the hawser and the messenger line.

FIG. 7 is an enlarged'view of the connector shown in FIG. 2.

FIG. 8 is a top view of FIG. 7.

FIG. 9 is a cross-sectional view taken along 9-9 in FIG. 2A.

Referring to the drawings, FIG. 1 represents an offshore mooring 10 of the type contemplated, which is normally referred to as a single point mooring. The mooring is characterized in general by an upright floating body 11, usually of cylindrical construction, and including flexible conduit means 12 to communicate with an underwater pipeline 13. The latter extends from a shore or submerged installation, to conduct fluids to and from the vessel.

Pipeline 13 is either buried, or can rest on the ocean floor, and terminates adjacent the mooring l0. Said pipeline 13 is connected to the latter by means of one, and usually by a plurality of intermediate, flexible conduits which pass upwardly through the water and are engaged by appropriate valve means to external liquid carrying conduits 14.

Mooring 10 is held in place over a limited area of ocean floor by anchor lines 16 and 17, preferably a plurality thereof being disposed about the mooring, and having their ends fixed or anchored into the ocean floor. Thus, the outwardly radiating pattern of the respective anchor lines permits the mooring to readily vacillate in response to the water movement. However. lateral movement is restrained to a limited distance against displacement in response to water and wind action, as well as to lateral displacement in response to a tanker 18 being connected thereto.

Mooring 10 is provided with a rotatable head 19 into which the respective conduits 14 and one or more hawsers 26 are communicated. Thus, the respective conduits 14 will be freely rotated about the mooring as tanker 18 is rotated by wind, wave and tide action, and yet not interfere with the fluid flow therebetween.

The primary advantage of the present arrangement resides in that, as herein mentioned, tanker 18 can be loaded or offloaded as the case may be while remaining a distance out to sea rather than drawn up to a stationary unloading pier or the like.

Vessel 18 will be referred to for the present descriptive purpose as a tanker adapted to carry crude or refined petroleum products to and from points of use. Tanker 18 is, in the normal manner, provided with a forward end or bow which can also embody the loading and unloading facility in the form of valved connections and manifolds to which external mooring conduits 14 are removably attachable.

To effectuate the initial connection between floating mooring l0 and the moving vessel 18, the latter is provided with a catch mechanism 21 embodying one or more arms 22 and 23. Said arms, when not in use are normally collapsed backward against the sides of vessel 18 as shown in FIGS. 1 and 1A. When in the operating position, the arms 22 and 23 are advanced forward to an open position as shown in FIGS. 4 and 4A to define a converging, line catching area therebetween. Thus, as

one of the open arms 22 or 23 engages an upstanding messenger line 24, the latter can be drawn aboard the vessel and rapidly retrieved by winch 33 to bring the end of the mooring hawser 26 into locked engagement with a connecting means on the vessel.

Mooring as herein noted comprises a cylindrical body 11 which is maintained uprightly in a floating position at the water's surface by internal buoyancy means. Normally body 11 is provided with a circumferential shock absorbing or bumping arrangement 27 to withstand impacts with moving vessels and the like as the latter comes into severe contact with the mooring.

Mooring 10 is provided on its upper side with rotatable or pivotally connected head 19 which can assume a number of embodiments known in the art. The purpose of said head 19 is to permit independent rotatable movement between the head and body 11 as vessel 18 and the connecting conduits 14 are moved in a floating position about the mooring.

The physical structure of rotatable head connection 19 is such that in spite of the amount of relative movement between vessel 18 and mooring 10, a loading or unloading operation can be maintained continuously. External conduits 14 are fabricated to normally float at the waters surface or they can be so maintained by the use of spaced apart buoyancy members 29. While there are presently shown two such conduits 14 which extend from head 19 and connected to the vessel, it is understood that any number of such conduits can be utilized in the practice of the invention.

Preferably, mooring hawser 26 is connected to the respective conduits 14 by means of an elongated bracket 31, as shown in FIGS. 7 and 8. Said bracket engages the respective conduits 14 and mooring hawser 26, whereby to maintain a desired rigid spacing therebetween near the hawser remote end. Thus, as hawser 26 is drawn from the water and onto a vessel during the mooring pick-up operation, conduits 14 can similarly be brought aboard and subsequently fitted to appropriate connections on the vessel.

Each conduit 14 is provided with a flange 32 or similar fitting adapted to removably but rapidly engage the mating portion of such member on vessel 18. With respect to the mooring hawser 26, the latter is fastened at one end to the mooring head 19 and can be supported on the waters surface. The remote end of hawser 26 is provided with a tag line 36 having a loop 34 or similar fitting which accommodates an upstanding messenger line arrangement 24.

Referring to FIG. 2, messenger line 24 includes in effect a connector such as a shackle 37 or the like adapted to removably engage a similar fastening loop 34 on the end oftag line 36. A messenger line cable 24 depends from shackle 37 and is normally maintained in a substantially vertical disposition by any of several means including the presently shown inflatable balloon 41 which rises a predetermined distance above the waters surface as to be readily retrieved.

Preferably, the messenger line 24 includes a flexible cable or rope, although said member can with some degree of advantage assume the form of a rigid structural member such as tubing and the like having appropriate flexing joints. However, in that said member 24 must resist the sudden impact of a vessels catch mechanism engaged therewith, said member is preferably resiliently constructed, or embodies a degree of resilience therein which would permit it to withstand the shock of a pick-up operation.

Messenger line 24 is maintained in its substantially upright disposition by a self-supporting expandable member such as balloon 41 or the like having means to introduce an expanding medium thereto. It is appreciated that when so supported, the messenger line will be free to be deflected in response to the wind force acting against the balloon 41. The balloon is normally maintained in an inflated condition to facilitate a pick-up operation and to identify the position of the buoy, particularly at night. Thus, balloon 41 may be provided with an outer radar beam reflective surface, or alternately with a radar reflecting member attached thereto.

Under such conditions, the vessel can accurately approach its mooring position merely by permitting the reflected balloon to function as a radar reflector.

Toward assisting in the pick-up operation, messenger line 24 can be provided with an outwardly radiating collar preferably in the form of a plurality of discrete, laterally spaced fingers 42. The latter are so curved and constructed that as the outstretched arms 22 and 23 depending from the vessel engage the messenger line 24, forward movement of the vessel will eventually permit the messenger line to be guided along the arms as to be picked up and attached to the winch 33. As a safety measure, the downwardly projecting fingers 42 are so adapted to engage an arm 23, such that the arms will not tend to pass over the balloon thereby freeing it from the intermediate area between the respective arms.

While not presently shown, balloon 41 or messenger line 24 can further be provided with a lighting means. Provision of the latter is usually governed by governmental navigational requirements toward the lighting of a floating or fixed object in any navigable waters.

The presently disclosed arms 22 and 23 are operably connected to the forward end of the vessel 18, but may alternately be attached to the rear or stern end should mooring in such a position be deemed desirable. As shown, the respective arms 22 and 23 are disposed at the bow of the vessel 18, being pivotally connected to the latter such that they may be positioned as shown in FIGS. 3, 3A, 4 and 4A, in either the extended or the retracted position.

Each arm comprises in effect a hinged joint 43 which operably connects the arm to the bow of the vessel for movement in a substantially horizontal plane. Each arm is of a sufficient length such that when in the extended position it covers a substantial intermediate area. The operable range of arms 22 and 23 can be extended if weather deems, by structuring the arms to be telescopically adjustable. This scope in the arms coverage facilitates the pick-up operation even though the balloon 41 is subjected to excessive wind and wave action, and might be forced into a lower altitude due to displacing action of the wind.

While presently shown as being fixed to the bow of vessel 18, the respective arms can also be carried on a carriage or similar apparatus adapted to move in a vertical direction on a track or similar guide means 44 fixed to the bow of the boat. Thus, the entire arm mechanism as shown in FIG. 1, can be preset to a desirable elevation above water level depending on the condition of the vessel whether loaded or unloaded, and on the weather conditions, both of which would affect the disposition of messenger line 24. Functionally, during a mooring operation the vessel advances slowly in a direction toward the upstanding messenger line 24.

At such time as the outspread arms 22 and 23 come in contact with the messenger line, the forward movement of the vessel will tend to guide the line along one arm until it is drawn into contact with the vessel itself.

Thereafter the messenger line is turned onto winch 33 such that the balloon and messenger line can be rapidly drawn aboard the vessel thereby bringing the hawser 26 onto the deck. As the forward end of the hawser is made fast to the deck, the vessel is in effect tethered and ready to be connected to the fluid carrying conduits 14.

Referring to FIG. 7, toward facilitating the connecting operation between the mooring and a vessels tanks, the respective conduits 14 are engaged with hawser 26 by a rigid bracket 31 shown therebetween. As the hawser 26 is drawn onto the boat, it also can be winched in such manner as to lift the remote ends of the respective conduits 14. Since these members are relatively heavy, the lifting of the conduits can be aided through use of a suitable hoist or equipment positioned at the bow of the boat to aid in such an operation.

With the ends of conduits 14 positioned on deck, bracket 31 can be quickly and easily removed thus permitting the respective conduits to be communicated with the appropriate shipboard manifold or connection prior to passing fluid therethrough.

In accordance with the particular structure of the vessel, the loading and unloading manifold stations may be at the forward end of the vessel immediately adjacent to the bow. Alternately, however, these connections can be located toward the boat center. In any event the respective conduits 14 can be positioned with respect to the vessel so as to facilitate the loading and yet permit the vessel to swing freely about its mooring 10.

After a cargo transfer has been completed, the vessel can be readily detached from the mooring and get underway. This is achieved by a reversal of the steps followed in the mooring operation. Thus, the hawser 26 is detached from the vessel and the messenger line 24 is connected to the tag line. With the balloon 41 inflated, the hawser is released so that the vessel can back from the mooring and get underway.

Other modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof, and therefore, only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. System for engaging a vessel floating at the waters surface to a mooring positioned in a body of water, said mooring including a connecting hawser having one end thereof depending from the mooring, and being of sufficient length to position the hawser other end a distance from the mooring,

a messenger line depending from said hawser other end and being supportably elevated to a substantially upright position above the waters surface,

a catch mechanism depending from said vessel to engage and retain said messenger line as the vessel moves into contact therewith,

said catch mechanism including at least two outstanding arms operably carried on the vessel emanating from a common point on said vessel and positioned outwardly of the point to define an area between said arms which converges toward the vessel,

whereby said hawser other end can be drawn onto and connected to said vessel for restraining further movement of the latter.

2. In an apparatus as defined in claim 1, wherein said hawser includes means for maintaining at least a portion of said hawser floatably at the waters surface.

3. In an apparatus as defined in claim 1, wherein said catch mechanism includes a messenger line winch mechanism depending from the vessel and adapted to engage said messenger line end after the latter has been received between said arms, for drawing said messenger line in, and subsequently drawing the hawser onto said vessel.

4. In an apparatus as defined in claim 1, wherein said line catch mechanism includes at least two arms operably connected to the vessel and adapted to be pivotally adjusted outwardly from a position adjacent the vessels sides, to form said area therebetween whereby to engage said upstanding messenger line as the vessel is guided through the water toward the latter.

5. In an apparatus as defined in claim 1, wherein said at least two arms are operably engaged to said vessel bow at a point adjacent to said winch mechanism.

6. In an apparatus as defined in claim 1, wherein said catch mechanism is operably carried on said vessels bow and including means at said bow for adjusting said catch mechanism in a vertical direction.

7. In an apparatus as defined in claim 1, wherein said messenger line includes a collar carried adjacent the line upper end and being adapted to engage said catch mechanism.

8. In an apparatus as defined in claim 7, wherein said collar includes a plurality of fingers depending radially from said messenger line to contact said catch mechamsm.

9. In an apparatus as defined in claim 4, wherein said catch mechanism at least two arms are telescopically constructed.

10. In an apparatus as defined in claim 1, wherein said respective at least two arms when outwardly positioned are disposed in a substantially horizontal plane.

Claims (10)

1. System for engaging a vessel floating at the water''s surface to a mooring positioned in a body of water, said mooring including a connecting hawser having one end thereof depending from the mooring, and being of sufficient length to position the hawser other end a distance from the mooring, a messenger line depending from said hawser other end and being supportably elevated to a substantially upright position above the water''s surface, a catch mechanism depending from said vessel to engage and retain said messenger line as the vessel moves into contact therewith, said catch mechanism including at least two outstanding arms operably carried on the vessel emanating from a common point on said vessel and positioned outwardly of the point to define an area between said arms which converges toward the vessel, whereby said hawser other end can be drawn onto and connected to said vessel for restraining further movement of the latter.

2. In an apparatus as defined in claim 1, wherein said hawser includes means for maintaining at least a portion of said hawser floatably at the water''s surface.

3. In an apparatus as defined in claim 1, wherein said catch mechanism includes a messenger line winch mechanism depending from the vessel and adapted to engage said messenger line end after the latter has been received between said arms, for drawing said messenger line in, and subsequently drawing the hawser onto said vessel.

4. In an apparatus as defined in claim 1, wherein said line catch mechanism includes at least two arms operably connected to the vessel and adapted to be pivotally adjusted outwardly from a position adjacent the vessel''s sides, to form said area therebetween whereby to engage said upstanding messenger line as the vessel is guided through the water toward the latter.

5. In an apparatus as defined in claim 1, wherein said at least two arms are operably engaged to said vessel bow at a point adjacent to said winch mechanism.

6. In an apparatus as defined in claim 1, wherein said catch mechanism is operably carried on said vessel''s bow and including means at said bow for adjusting said catch mechanism in a vertical direction.

7. In an apparatus as defined in claim 1, wherein said messenger line includes a collar carried adjacent the line upper end and being adapted to engage said catch mechanism.

8. In an apparatus as defined in claim 7, wherein said collar includes a plurality of fingers depending radially from said messenger line to contact said catch mechanism.

9. In an apparatus as defined in claim 4, wherein said catch mechanism at least two arms are telescopically constructed.

10. In an apparatus as defined in claim 1, wherein said respective at least two arms when outwardly positioned are disposed in a substantially horizontal plane.

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