US3236267A - Method and apparatus for transferring fluid offshore - Google Patents

Description

P. J. BiLY Feb. 22, I966 METHOD AND APPARATUS FOR TRANSFERRING FLUID OFFSHORE 7 Sheets-Sheet 1 Filed Feb. 20, 1963 INVENTOR PETER .1. am

BY W

ATTORNEY P. J. BILY Feb. 22, 1966 7 Sheets-Sheet 2 Filed Feb. 20, 1963 m. m milh ll om KNQ elll w m. QN ww NN INVENTOR PETER J. BILY BY my, 0? @WWM ATTORNEY Feb. 22, 1966 P. J. BlLY 3,236,267

METHOD AND APPARATUS FOR TRANSFERRING FLUID OFFSHORE Filed Feb. 20, 1963 7 Sheets-Sheet 5 PETER J. BILY ATTORNEY Feb. 22, 1966 P. J. BlLY 3,236,267

METHOD AND APPARATUS FOR TRANSFERRING FLUID OFFSHORE Filed Feb. 20, 1963 '7 Sheets-Sheet 4.

INVENTOR PETER J. BILY ATTORNEY P. J. BILY Feb. 22, 1966 METHOD AND APPARATUS FOR TRANSFERRING FLUID OFFSHORE '7 Sheets-Sheet 5 Filed Feb. 20, 1963 NTN mmm

mhm NN INVENTOR PETER J. BILY ATTORNEY P. J. BILY 3,236,267

METHOD AND APPARATUS FOR TRANSFERRING FLUID OFFSHORE Feb. 22, 1966 '7 Sheets-Sheet 6 Filed Feb. 20, 1 963 Nmm HWH P H-H-HHI -52 PETER J. BILY a M ATTORNEY P. J. BILY Feb. 22, 1966 METHOD AND APPARATUS FOR TRANSFERRING FLUID OFFSHORE Filed Feb. 20, 1963 7 Sheets-Sheet 7 u RI. 8 J V mm T E P ATTORNEY United States Patent 3,236,267 METHOD AND APPARATUS FOR TRANS- FERRING FLUID OFFSHURE Peter Si. Bily, Sunset Beach, Calif., assignor to FMC Corporatlon, San Jose, Caiifi, a corporation of Delaware Filed Feb. 20, 1963, Ser. No. 259,847 18 Claims. (Cl. 141-1) The present invention relates to method and apparatus for transferring fluid offshore and more particularly to the offshore loading and unloading of tanker ships through submerged pipelines.

The proposal to load and unload tankers anchored offshore, that is without being berthed at a pier or wharf, is by no means new, but few, if any, satisfactory means have been proposed which allow for normal movement of the ship with wind and tide during loading and unloading operations. It has been suggested, for example, that a mooring pillar erected at the berthing place of the tanker could mount one end of an underwater pipeline, connection being made to the ship via flexible hoses to allow for the ships movement. Not only would such an arrangement be unable to adequately compensate for tanker drift because of the difficulty of supporting long lengths of flexible hose, but the pillar would create a navigational hazard. Furthermore, the flexible hoses would have to be used and stored for long periods of time while exposed to the weather. Another system that has been proposed would utilize a permanently anchored buoy having submerged piping connected thereto but, again, any movement of the ship relative to the buoy would have to be accommodated by flexible hosing and, unlike the first mentioned proposal, relative movement of the buoy with respect to the sea bed also would have to be accommodated by flexible hosing. Both systems, however, would be prone to accident and storm damage.

The extensive use of flexible rubberized hosing in the above mentioned proposals alone renders them impractical since such hosing is expensive, is subject to mechanical damage during handling, and chemically degenerates through prolonged weathering. Furthermore, when a hose being used in this type of service bursts, it is not always possible to shut off the flow of oil promptly and mop-up operations can become most expensive. On the other hand, self-supporting swivel-jointed pipe lengths cannot be satisfactorily used to accommodate the entire movement of the ship because of the distance of and variations in the span.

An object of the present invention is, therefore, to provide a generally improved system for offshore loading and unloading of fluid-carrying ships.

Another object of this invention is to provide a method of loading a tanker ship moored offshore which will allow for the normal movement of the ship without the need for long lengths of flexible rubberized hosing.

Another object is to provide means for the offshore loading of tankers which, when not in use, will not create a navigational hazard to shipping.

Another object of the present invention is to provide a simple and economical system whereby a tanker may be simultaneously loaded and/or unloaded through a number of separate pipelines, while offshore.

Another object of the present invention is to provide an offshore tanker loading system wherein flexible hosing and its complex handling equipment are eliminated.

Another object of the present invention is to provide apparatus whereby tankers may be loaded and unloaded while moored offshore and which does not involve the use of machinery that is permanently exposed to the sea or which must remain in an offshore location for long periods of time.

Another object of this invention is to provide apparatus 3,235,267 Patented Feb. 22, 1966 for the offshore loading of a tanker which is not subject to accidental damage when not in use but which, when in use, will efficiently transfer liquid to and from the tanker.

Another object of the invention is to provide means whereby a tanker may be loaded and unloaded offshore and wherein change in draft due to loading or unloading, as well as the normal movement of the tanker with the wind and tides, may be accommodated by normal flexing of rigid wall pipelines.

Another object of the present invention is to provide means whereby a tanker may be loaded and unloaded offshore and wherein pipelines to the ship are connected with struts which assist in mooring the ship.

Another object of the present invention is to provide an offshore loading system which will permit a tanker to align itself with the prevailing tide or wind while being loaded or unloaded.

Another object of the present invention is to provide an offshore loading system which will allow a tanker to drift about a point in the berthing area during loading or unloading operations.

It should be noted that, in this specification, the term moored is used to indicate that the tanker is tied to buoys, anchors, fixed anchor blocks or piles while offshore. In this way, no distinction is drawn between anchoring and mooring. Also, it should be noted that the term berth is used to indicate the space or positions that a tanker may occupy when it is moored and while it is being loaded or unloaded. In order to distinguish between flexible hosing designed to have great flexibility in short lengths, or between a pipeline formed from short lengths of pipe coupled together by swivel joints, and a pipeline formed by rigidly securing, as by welding, a number of uniform metallic tubes end to end, the latter pipeline will be termed a rigid-wall pipeline since, because of the intrinsic properties of the metal, it will be rigid in short lengths but flexible in long lengths (relative to its diameter). Finally, although the term sea-bed will be used, the system is equally applicable to other bodies of water, such as rivers or lakes and this term should not be interpreted in a limiting manner.

Further objects, advantages and features of the present invention will be apparent from the following description of particular forms thereof made with reference to the accompanying drawings, in which:

FIGURE 1 is a diagrammatic elevation of a tanker being loaded or unloaded by the system of this invention while moored at an offshore berth.

FIGURE 2 is a diagrammatic plan of the tanker and system of FIGURE 1, indicating the tanker drift which can be accommodated.

FIGURE 3 is :an enlarged side elevation, with parts broken away, of the main buoyancy tank employed in the system of FIGURES 1 and 2.

FIGURE 4 is an enlarged end elevation, with parts broken away, of one of the minor pipeline buoyancy tanks shown in FIGURES l and 2.

FIGURE 5 is a schematic view of the oil and air piping of the system illustrated in FIGURES 1 and 2.

FIGURE 6 is a diagrammatic elevation of a modified form of the apparatus for offshore loading and unloading of tankers according to the present invention.

FIGURE 7 is a diagrammatic plan of the system illustrated in FIGURE 6, showing the degree of permissible ship movement.

FIGURE 8 is an enlarged side elevation, with parts broken away, of the offshore end portion of one of the combined strut and oil pipelines indicated in FIGURE 7.

FIGURE 9 is a similar view to FIGURE 8 but depicts the inshort end portion of the strut.

FIGURE is a diagrammatic plan of a tanker being loaded or unloaded by another system also formed in accordance with this inevntion.

FIGURE 11 is a diagrammatic elevation of the system and tanker shown in FIGURE 10.

FIGURE 12 is a diagrammatic elevation similar to FIGURE 11 showing the system as it appears when it is not in use.

FIGURE 13 is an elevation similar to FIGURES 11 and 12 but shows the system as it appears when it is about to be used by a tanker at the berth.

FIGURE 14 is a diagrammatic elevation similar to FIGURE 11 showing the system in use when a small tanker is at the berth.

FIGURE 15 is an enlarged perspective from above the pipeline of the system of FIGURES 10 to 14, showing the manner in which the pipeline is anchored to the sea bed by the anchor block.

FIGURE 16 is an enlarged perspective from above the pallet and a portion of the pipeline employed in the system shown in FIGURES 10 to '14.

Diag-rammatically represented by FIGURES 1 and 2 is a tanker 10 which is discharging and/ or loading oil to and/ or from a shore storage represented by tanks 12 and a pump and valve house 14. A plurality of parallel, rigid wall steel pipelines 16 run from the pump and valve house 14 along the sea bed 17 to the berth at which the tanker 10 is moored by anchor chains or cables 15. Thus, as is common practice in wharf loading and unloading of marine tankers, the multiple oil lines 16 enable different oil grades to be separately and simultaneously loaded and/or unloaded and, Where a single grade of oil is being handled, permit the loading and unloading of this grade to proceed more rapidly. In the example illustrated in FIGURES land 2, four oil pipelines 16 are employed and means are provided in the pump and valve house 14 for making the appropriate connections and, if necessary, for connecting pumps (not shown) into the various lines.

The pipelines 16 are formed from high tensile, corrosion resistant steel, suitably covered or coated in a conventional manner to further inhibit corrosion and abrasion. For the purpose of description, the pipelines 16 may be considered to include an inshore section 18 and an offshore section 19. There need not be, of course, any joints between these sections, although such joints may be convenient from the standpoint of maintenance. Section 18 of pipelines 16 may be buried under the sea bed 17 to reduce the likelihood of mechanical damage but, as such damage is unlikely, it may simply be laid on the sea bed as indicated in FIGURE 1. Section 19, however, lies freely upon the sea bed 17 so that it can be raised to the position shown, as hereinbelow described. A concrete anchor block 20 creates a firmly fixed point at the junction of the pipeline sections 18 and 19, and serves to anchor the inshore end of section 19 against movement with respect to the sea bed and section 18. When a tanker is moored at the berth and is ready for connection to the pipelines 16 (as broadly indicated in FIGURES 1 and 2), the offshore end of pipeline section 19 is raised by means of a main buoyancy tank 22 and minor tanks 24 spaced along the offshore section 19 of the pipelines so that the end of each pipeline 16 is presented to the tanker 10 for connection to the ships tanks. To facilitate such connections, each pipeline 16 communicates with a riser pipe 28 (FIG. 3) which is mounted 'by and forms part of the main tank 22. The tanks 24 are provided to prevent the pipelines from kinking since the pipeline section 19 is of considerable length.

Referring to FIGURE 3 in which the main buoyancy tank 22 is shown partially buoyant but surfaced, the main tank consists basically of a hollow body 30 pierced by generally vertical tubes 32 through each of which one of the riser pipes 28 passes freely from the offshore end of the associated pipeline 16. The body 30 is fabricated from steel plate, as by welding, and the tubes 32 form an integral part thereof opening through the top or deck 34 and the bottom 36 of the body 30. To provide some measure of protection for that portion of each riser pipe 28 which projects above the deck 34, and also to facilitate the manual connection to the riser pipe 28, a gunwale 38 upstands from the periphery of the deck 34 and is provided with scuppers 40 to drain the water from the deck. Spaced at intervals around the sides of the body and near or on the gunwale 38, are a number of brackets 42 which facilitate the attachment of the tank 22 by means of chains 44 to similar brackets (not shown) provided on the tanker 10.

A collar or pipe clamp 46 secures the offshore ends of the pipes 16 together in spaced apart relationship and, by means of a central upper lug 48, enables the offshore end of the section 19 to be suspended, as by a shackle 50, from a lug 51 on a reinforcing plate 52 fixed to the bottom 36 of the tank 22. Inside the tank 22, a chain 54 is secured to a lug 56 on the upper surface of plate 52 and extends upwardly to connect with an eye-bolt 57 held by a nut 58 to an upper reinforcing plate 59. Thus, the eyebolt may be adjusted vertically to keep the chain 54 taut so that the pipeline is not borne by the bottom 36 of the tank alone. In this manner, more of the weight of the pipelines 16 is supported by the collar 46 than by the riser pipes 28.

The connection between the lower end of each riser pipe 28 and the offshore end of the corresponding pipeline 16 is effected by a right-angle elbow 60 secured to the lower end of the riser pipe and a second right-angle elbow 61 secured to the end of the pipeline 16, the elbows being interconnected for relative swiveling movement about a horizontal axis A by a conventional swivel pipe joint 62. Thus, each pipeline 16 may move about the axis A with respect to its riser pipe 28 so that the riser pipe can remain substantially vertical to facilitate connection thereof to the ships tanks, as by tubular coupling rig 63 indicated in FIGURE 1. To prevent the riser pipe from chafing within the tube 32, a collar 64 of relatively soft material is pressed into the top of the tube 32 to space the riser pipe 28 from the sides of the tube. Again, to relieve unnecessary load on the swivel joint 62 between the elbows 60 and 61, a flange 66 is welded to the outer periphery of each riser pipe just above the level of the deck 34 to support the weight of the associated tubular coupling rig 63 on the deck. This is achieved by arranging the lug' 51 and the tubes 32 so that the center of buoyancy of the tank lies therebetween but considerably closer to the lug than to the tubes so that the great majority of the weight of the pipelines 16 is borne by the lug 51. If this is the case, when the tank 22 is fully buoyant and surfaced, it will tend to tip clockwise (in FIGURE 3) about lug 51 but be restrained by the abutment of flanges 66 with the deck 34, the tubes 28 therefore being held in tension before connection of the loading rigs 63. When the rigs are connected, the tank 22 will tip slightly counterclockwise and the Weight of the rigs will be supported, at least partially, by the flanges 66.

In order to connect the loading rigs 63 to the riser pipes 28, a conventional shipboard cargo boom 70 (FIG. 1) may be employed to suspend the rigs over the tank 22 so that the lower end of a lowermost pipe length 72 of each rig is just above the level of the tanks deck 34. A flange 74 (FIG. 3) is provided on the bottom of each lowermost pipe length 72 whereby it may be bolted, as by quick acting bolts 76, to a connecting flange 78 provided on the upper extremity of the corresponding riser pipe 28. Whenever any one of the riser pipes 28 is not connected to a loading rig 63, its open end is sealed by bolting a cover plate (not shown) thereover to prevent loss of oil from, and ingress of water to, the pipeline.

The main buoyancy tank 22 is made buoyant by supply-- ing of air under pressure to the interior thereof. In the; embodiment illustrated in FIGURES 1-5, compressed air is supplied to the tank 22 through an air pipeline. 3.0 which runs along one of the pipelines 16 and is secured thereto at intervals by means of straps 82. The offshore end of the air line 80 includes an elbow 84 which is swivel jointed to an elbow 85 secured to the lower end of an air riser pipe 86. The elbow 85 is immediately below the bottom of the tank and somewhat inshore from the clamp 46. The riser pipe 86 extends upward into the body 30 of the tank 22 and is welded to the tank bottom 36 at $8. The distance between the elbow 84 and the farthest offshore strap 82 should be such that sutficient flexibility of the air line 80 is obtained to accommodate normal pivotal movements of the tank relative to the pipelines 16 about the shackle 50. The air riser pipe 86 terminates close to the underside of the deck 34, the upper end of the pipe 86 being provided with a downwardly turned collar 90. Concentric with the pipe 86 and welded at its upper periphery to the underneath of the deck 34 is a short length of tubing 92 the lower end of which lies in the same horizontal plane as the lower lip of the collar 90. Similarly, an upwardly turned collar 93 is secured about the lower end of the pipe 86 above the tank bottom 36 and a short length of tubing 94 is welded to the upper surface of the bottom of the tank so as to be concentric with air riser pipe 86, the upper periphery of the tube 94 being coplanar with that of the collar 93. Spaced at intervals around the riser pipe 86 and formed in the bottom of the tank within the perimeter of the tube 94 are a plurality of drain holes 96 through which water may be admitted to or drained from the body 30 of the tank 22. Finally, a fiat annular float 98 is located around the riser pipe 86 in free sliding engagement therewith, the float being formed from a plastic material which is both unafiected by sea water and is resistant to attack by marine growths. The material of the float is also sufficiently resilient so that a substantially liquid-tight seal may be formed between the float and the tube 92 and collar 90, or the tube 94 and collar 93.

Therefore, when the tank 22 rests on the sea bed 17, it is substantially filled with water which has entered through holes 96, expelling air from the tank through the air riser pipe 86, and the float 98 will bear against tube 92 and collar 90 to prevent water from passing into the riser pipe 86. If it is desired to raise the tank to the surface, air is supplied under pressure through the line 80 to the riser pipe 86 and presses the float 98 from its seating on the tube 92 and collar 90 so that air is admitted into the body 30 of the tank 22 and water is expelled therefrom through the drain holes 96. As the Water level within the tank 22 falls, the tank becomes more buoyant and will gradually rise to the surface of the water, the process continuing until the water level within the tank falls to the top of the tube 94 and until the float 98 bears against tube 94 and collar 93, preventing substantial loss of air from the tank 22. At that time, however, the tank 22 will be fully buoyant and the offshore end of the pipelines 16 will be supported with the upper ends of the riser pipes 28 exposed and ready for connection to the loading rigs 63.

Referring now to FIGURE 4 in which one of the minor buoyancy tanks 24 is illustrated. as appears when fully buoyant, it will be noted that each minor tank 24 is similar in construction to the main tank 22 except that no oil riser pipes penetrate it. Again, the tank is formed by conventional methods from steel plates to provide a rectilinear hollow body 100. As in the case of the main tank 22, a pipeline clamp 102 is employed both to hold the pipelines 16 in spaced relation and to provide a connection between the pipeline section 19 and the tank. The clamp 102 consists of upper and lower members 103 and 104, respectively, which are secured together by two sets of outer bolts S and a single set of inner bolts 106 so as to locate the pipelines 16 in place. A tubular bracket 107 forms the connection between the tank bottom 108 and the clamp 102, the bracket having an upper flange 109 secured to the tank bottom 108, as by rivets 110, and a lower flange 112 secured to the upper clamp member 103 by the bolts 106. A central hole 115 is formed within 6 the clamp member 103 concentric with bore 116 of the bracket 107 to provide a passage for the water to pass to and from the tank body and for an air riser pipe 118 to pass from a T-joint 120 in air line 80 into the tank 24. Because the tank 24 is firmly secured to the clamp 102, there is no need for a swivel joint between the air riser pipe 118 and the air line 80.

As indicated for the tank 22, the pipe 118 terminates at its upper end close to the deck 122 of the tank 24 and a downwardly turned collar 124 is secured to its upper end. The riser pipe 118 is encircled by a short concentric tube 126 which depends from the under surface of the deck 122 of the tank, but, in place of a corresponding lower tube, the tubular body of the bracket 107 is extended. upwardly to provide an integral annular projection 128. However, an upwardly facing collar 130 is secured to the pipe 118 near its lower end so that the upper face of the collar is coplanar with that of the projection 128 so as to provide a seat for an annular float 132 which slides on pipe 118. Expulsion of water from the tank 24 is achieved in the same way as described for the tank 22, except that the water from the body 100 of the tank 24 passes down the bracket 107 and through the hole 115 in the clamp member 103.

An anchor block (FIGURES l and. 2) is situated on the sea bed 17 beneath the tanker 10 and farther oifshore than the tank 22. A tethering chain 142 connects the anchor block 140 with a lug 144 on the pipeline clamp 46 (FIGURE 3). The position of block 140 and the length of the chain 142 are arranged so that the chain 142 does not restrict the motion or movement of the tank 22 and the offshore end of pipelines 16 unless the pipelines 16 are flexed to their safe stress limits in either direction indicated in FIG. 2. The anchor block 140 and chain 142 also prevent the tank 22 from being pushed shoreward by the tanker beyond a safe distance determined by the flexibility of the pipelines 16. Thus, the block 140 and chain 142 ensure that no part of the pipelines 16 is stressed beyond the elastic limit of the material. The anchor block 140 provides a convenient means whereby a marker buoy 146 may be anchored by a line 148, the buoy 146 serving to identify the tanker berth and to indicate the approximate position of the offshore end of the submerged pipeline.

Referring now generally to FIGURES l and. 2 and particularly to FIGURE 5, the procedure for loading and unloading a tanker will now be described. When the tanker 10 approaches its berth prior to loading or unloading operations, the pipelines 16 and tanks 22 and 24 are resting on the sea bed. Then, the tanker 10 is anchored by lines 15 or moored to appropriate mooring buoys (not shown) so that it is positioned correctly with respect to the marker buoy 146. Once the tanker is moored at its berth, operators within the pump and valve house 14 supply air under pressure to the air line 80; for example, by opening valve 150 (FIG. 5) which connects the air line 80 at the valve house 14 to an air reservoir 152 which, in turn is connected to an air compressor 154 driven by a motor 156. An air pressure gauge 157 is connected in the air line 80 downstream from valve 150 so that the pressure in line 80 may be measured. Water will be expelled from the main buoyancy tank 22 and from the minor buoyancy tanks 24 at varying rates due to the varying depths and volumes of these tanks but, when any tank is filled with air its floats (98 or 132) will substantially prevent further air from escaping from that tank and. the supply of air will be maintained to the other tanks. When all tanks have been filled with air, the pipelines 16 will take the position shown in FIGURE 1 and, since comparatively little air will then continue to escape past the floats (98 or 132), the valve 150 may be closed and the compressor 154 shut down. Alternatively, if air leaks from the line 80 or its fittings at a slow but significant rate, the valve 150 may be left open and the compressor 154 may be operated by a suitable pressure switch 158 which controls the compressor motor 156. The appropriate shore connections are then made to the oil pipelines 16 by suitable valving controls in a distribution center 160, and the chains 44 are made fast to connect the tank 22 to the tanker 10 as indicated in FIGURE 1.

Once the tank 22 has been made fast the coupling rigs 63 are hoisted over the side and connection is made to the riser pipes 28 after first removing the cover plates. When the rigs have been connected to the ships pipe header, transfer of oil from ship to shore or from the shore to the ship may be initiated. When the transfer has been completed the rigs 63 are disconnected from the riser pipes 28 and the cover plates are bolted onto the flanges 78 of the riser pipes. If the valve 150 is open, it is closed and a valve 162 is opened to exhaust the air line 80 to atmosphere to permit water to enter the tanks 22 and. 24 and allow the tanks and the pipelines 16 to submerge.

During loading or unloading of a tanker by the system described, normal movements of the tanker at its berth which result from winds or tides are accommodated by the elastic flexing of the steel pipelines 16. It has been found that a pipeline of 6 to 10 inches in diameter which measures at least 400 feet from the anchor block 20 to the tank 22 will accommodate a 150 foot fore and aft movement of the tanker and will move from the sea bed to the surface in 65 feet of water without being stressed.

v beyond its elastic limit.

In FIGURES 69 of the drawings another system for the offshore loading of tankers is illustrated which also embodies the features and advantages of the invention hereinbefore indicated. As will subsequently become evident, many of the components of this system are the same as or similar to corresponding parts in the above described system and, where this is so, similar reference numerals, with the suflix a applied to them, will be used.

Thus, as before, oil is conveyed between a ship 10a and a shore storage comprising tanks 12a and valve house 14a, by means of the pipelines 16a, as shown in FIG- URES 6 and 7. The pipelines 16a are anchored as before by blocks 20a, but the manner in which their offshore ends are raised differs in this example. Again, however, tanks 22:: are employed to raise the offshore ends of the pipelines 16a and to present riser pipes 28a (FIG. 8) for connection to the ship 10a, the flow of water into or out of the float 22a being controlled by compressed air and a float valve as described with respect to FIGURES 1-6.

One of the principal differences between this system and that previously described lies in the manner in which the ship 10a is moored at its berth during loading and unloading operations. In order to more positively control the sideways movement of the ship 10a while it is berthed, the ship is drawn by its forward and after mooring cables 200 and 201 against a forward fendering strut assembly or frame 202 and an aft fendering strut assembly or frame 204. For the purposes of description, it will be assumed that the two strut assemblies are substantially identical and only the forward assembly 202 will be described, although, where parts of the aft strut assembly 204 are referred to specifically, they will be given the same reference numerals as the corresponding parts of the forward strut assembly together with the suffix 17. Another difference between the system illustrated in FIGURES 1-5 and that illustrated in FIG- URES 69 is that, in the latter system, the pipelines 160 are separated into two pairs, one pair being supported by each strut assembly. Other differences and modifications will become apparent in the following description.

The forward strut assembly 202 consists basically of an anchor block 205 and a pair of parallel tubular struts 206 spaced laterally apart by means of transoms 207. The anchor block 205 is of concrete and is firmly located on the sea bed by one or more piles 208 so as to provide a secure base for a cylindrical steel bearing housing 209 which is let into its upper surface and held in place by studs 210 (see FIGURE 9). The housing 209 locates two sealed bearing units 211 one above the other in vertically spaced relation which, in turn, axially locate a vertically disposed pintle 212 for rotation about its vertical axis. Thus, by rotatably pinning the inshore ends of the struts 206 to an upstanding lug 213 which forms the upper portion of pintle 212, the struts may swing about the horizontal axis of pin 214 which secures them to the pintle as well as about the vertical axis of the pintle 212. It will be noted that the lower end of the tubular housing 209 is closed by coverplate 215 which is secured in place by bolts 216 and that vertical movements of the pintle from the housing is prevented by nut 217 threaded onto the lower end of the pintle. The offshore ends of the struts 206 are pivotally connected to a fender 218 by a horizontal pin 220 which passes through lugs 222 on the back of the fender. However, the offshore end surface of each strut 206 is shaped so that the fender 218 can move through only a limited angle with respect thereto (see FIGURE 8).

A clamp 46:: (FIGURE 8) is employed to secure the tubular struts 206 and the offshore ends of the associated pair of pipelines 16a together in spaced relation and, by means of a lug 48a and a shackle 50a, to connect the struts 206 and the pipelines 16a with a lug 51a on the bottom of tank 22a. A lug 144a depends from the clamp 46a and provides means whereby an anchor chain 142:! may be secured to the clamp 46a to restrict the movement of the offshore end of the strut assembly 202 within safe limits, the chain 142a being fixed to an anchor block 140a (FIGURE 6). Each of the two riser pipes 28a on the strut assembly 202 is secured by a swivel joint 62a mounted between elbows 60a and 61a at the end of the corresponding pipeline 1601, the riser pipes 28a ex tending through the float 22a and terminating in a connecting flange as in the first described system.

Although the air riser pipe 86a extends upwardly into the body of the float 22a from a swivel joint by which it is connected to the offshore end of the air line a as before, a T connection 223 is included in the line 80a just inshore of the outermost strap 82a. A branch air line 224 extends from the connection 223 to the clamp 46a where the air line divides and continues to the offshore extremity of each tubular strut 206 to connect through a union 226, to a ball valve seat 228 screwed through the wall of the strut 206. From FIGURE 8 it will be noted that the ball valve seat 228 faces downwardly from the top of the strut wall and includes integral downwardly depending ball locating prongs 230 which guide a ball float 232 for substantially vertical movement therebetween to and from the tubular seat member 228. The ball 232 is formed from a durable resilient material, or covered with such material, and is substantially less dense than sea water.

A similar ball valve is located at the inshore end of each tubular strut 206 (FIG. 9). Again, the ball valve has a tubular seat 236 with ball retaining prongs 238 extending therefrom and guiding a ball 240 for vertical movement therebetween. However, the inshore ball valve is mounted in the lower side of the strut wall and its seat 236 faces upward, so that when the ball 240 is raised from its seat, the valve provides a passage between the interior of the strut 206 and the sea. A filter screen 242 is included within the bore 244 of valve seat 236 to prevent solid bodies from entering the hollow strut 206.

The shore facilities for the last described system may be substantially identical with that indicated in FIGURE 5. Thus, when compressed air is supplied along the pipeline 80a on each pair of oil lines 16a, is passes into the buoyancy tanks 22a and also to the offshore b-all valve in each tubular strut 206 of assemblies 202 and 204. Both the tanks 22a and the strut assemblies 202 and 204 are therefore emptied of water, loss of air from the tanks 2201 being prevented by the float previously described with respect to FIGURE 3, while loss of air from the struts is prevented by means of the inshore ball valves which close when there is no water within the struts. YVhen the tanks and struts are filled with air they assume the position indicated in FIGURE 6 and the ship may therefore be pulled against the fenders 218 and 21% as described. As before, the ship is guided to its berth by the placement of the marker buoys 146a, but in this case it is drawn into firm engagement with the fenders 218 and 21819 by means of the mooring lines 200 and 201 which are crossed and secured to the strut anchor blocks 205k and 205 respectively, the blocks being located and connection being made thereto by additional marker buoys 254.

Although the second system described may not permit as much drift of the tanker as the first system because the mooring lines 200 and 201 secure the tanker a more positively at its berth, the flexing and pivoting of the strut assemblies 202 and 204 (as indicated in phantom lines in FIGURE 7), together with normal cable slack and stretch, will permit some 70 to 90 feet of fore and aft movement. As the tanker and struts move, the oil lines 16a will follow freely by flexing along their lengths as shown by phantom lines in FIGURE 7. If loading and unloading is to be undertaken while the tanker is more positively located, the horizontal movement of the struts about the anchor blocks 205 and 2051) may be eliminated by casting the pintles 212 into the concrete of the blocks, In such a case, once the cables 200 and 201 have drawn the tanker into firm contact with the strut assemblies 202 and 204, the principal movement (fore and aft) is accommodated by the flexing of the tubular struts 206 along their lengths.

Thus, in both systems, the normal movements of the tanker at its berth are accommodated by the rigid-wall pipelines without the need of lengths of flexible hosing which must be exposed to the weather or sea water for longer periods of time. On the other hand, neither system involves the use of pipeline connections which are permanently located on the surface of the water or on pillars fixed to the sea bed and, therefore, neither system is a hazard to navigation or is prone to storm damage because, during bad weather, the pipeline struts and tanks rest on the sea bed.

In either of the above described embodiments of this invention, connection between the float riser pipes and the ship may be effected by a liquid cargo handling apparatus 250 (FIGS. 6 and 7) such as that disclosed in the United States Patent to P. J. Bily, No. 2,980,150, which may be mounted on a barge 252. So long as the weather permits, the barge may remain in suitable position to permit the transferring apparatus to remain connected to the pipelines 16, 16a and when heavy weather threatens, the apparatus may be disconnected from the float riser pipes, permitting the piping to be submerged as hereinabove described, and the barge 252 with its cargo handling apparatus to be towed to a safe harbor. However, if under the circumstances of any particular installation the use of such a barge should be undesirable, other means of connecting the float riser pipes to the ship may be employed, such as the hereinabove described cargo rig handled by the ships booms.

It will be noted that the various offshore loading systems described with respect to FIGURES 1 to 9 involve the use of a submerged pipeline lying transversely of the berth and that the offshore drift of the tanker may therefore be restricted by the pipeline itself, although all other movements of the tanker must be accommodated by bending of the pipeline and limited by other means. The invention envisages other offshore loading systems, however, in which the submerged pipeline extends longitudinally from the berth and bears the mooring forces to a greater or lesser extent than before described. To exemplify these alternative forms of the invention, a further embodiment 1 b has been chosen and will presently be described with respect to FIGURES 10 to 16 of the drawings.

Referring particularly to FIGURES 10 and 11 of the accompanying drawings, a tanker ship 310 is shown at a berth 311 (indicated by phantom lines in FIGURE 10) as it would appear during loading or unloading of fluid, for example oil, to or from the shore (not shown) through a single pipeline 312. Some distance inshore of the bow end 313 of the berth 311, the pipeline 312 is anchored securely to the sea bed 314 by a concrete anchor block 316 and its deadman or auxiliary anchors 318. A bow mooring cable 319 is permanently secured at its inshore end to the anchor block 316 and extends toward the berth 311 for connection to a bow winch 320 on the tanker and sup ports, by means of two hanger cables 322 and 323, that portion of the pipeline 312 which lies between the tanker 310 and the anchor block 316. In addition to hanger cables 322 and 323, a truss 324 and support cable 326 assist in supporting the weight of pipeline 312, the truss 324 however being slidable along the pipe line 312 and the support line 326 being independently secured to another bow winch 328.

The pipeline 312, at its offshore end, terminates in a pallet structure 330 which (in FIGURE 11) has been hauled up from the sea bed 314 by a pallet cable 332 on each side of the ship 310 into firm contact with the bottom of the ships hull. Two branch pipelines 334 (shown dotted in FIGURE 10) form part of the pallet structure 330 and each extends laterally from the offshore end of pipeline 312 to communicate with a swivel jointed loading arm 336 that extends up the corresponding side of the ship and is connected to a shipboard pipeline terminal connection 338. The pallet 330 and the branch lines 334 and the manner in which they are raised into place will hereinafter he described in detail with respect to FIGURE 16.

As shown best by FIGURE 10, the tanker 310 is moored at the berth 311 by means of the single bow cable 319 and by two stern cables 340, the bow cable 319 being secured to the pipeline anchor block 316 as previously indicated and the stern cables 340 being secured to separate mooring buoys 342 arranged one on each side of stern end 343 of berth 311. Under normal conditions, there will be more than suflicient slack in the mooring lines to allow for tides and changes in tanker draft and the tanker will therefore be able to yaw within limits as indicated by phantom lines in FIGURE 10. The berth 311 is arranged to face the prevailing wind or sea current so as to keep the strain on the stem cables 340 at a minimum and keep the bow cable 319 and pipeline 312 taut. It should be noted, therefore, that the terms, inshore and offshore as applied herein are general terms only and may not be strictly accurate where the prevailing wind or current is nearly parallel with the shore line.

FIGURES 12 and 13 illustrate the state of the system apparatus when it is not in use and when the initial steps of preparing it for use have been taken respectively. In either case, the only portions of the apparatus which are not submerged are the marker buoys. These comprise a bow cable buoy 344, six pallet buoys 346 (only 3 of the latter buoys being shown in these figures) and two stern buoys 342 which serve to mark the tanker berth 311 and to provide means whereby the cables 319 and 332 may be raised and connected to the ship 310. The marker buoys 346 are omitted in FIGURES 10 and 11 for the sake of clarity. Bow buoy 344 is connected by a cable 348 to the bow cable 319 so that its free end may be raised from the sea bed 314 and connected to a ships bow cable 350 by a shackle connector 352 permanently attached to the bow cable 319. Similarly, another buoy cable 354 reaches from the bow buoy 344 to the free end of support cable 326 so that the latter cable can be hauled to the surface and connected by shackle 356 on the end thereof to another ships bow cable 358. Therefore, reverting to FIG- URES 10 and 11, it will be noted that the bow cable 350 is connected to bow winch 320 while bow cable 358 is connected to the second bow winch 328. In this example, six pallet buoys 346 are employed because each pallet cable 332 is attached at three points to the ship 310: each end of each cable 332 is connected by a shackle 360 to a short buoy cable 362 by which it is secured to the corresponding corner buoy 346, while the center of each pallet cable 332 is connected by a shackle 364 to a buoy cable 366 connected to the corresponding center pallet buoy 346. Thus, on each side of the tanker, a forward side ships line 368 may be connected to the forward shackle 360 and an aft side ships line 370 may be connected to the stern shackle 360 so that the pallet assembly 330 can be raised by fore and aft side winches 372 and 374 (shown in FIGURE only).

In berthing, the tanker 310 is steered between the stern buoys 342 toward the bow buoy 344 so as to pass between each side group of pallet marker buoys 346. The ships bow cables 350 and 358 are then paid out so that, by hauling in the bow buoy cables 348 and 354, they may be connected to the shackles 352 and 356 as indicated. At the same time, the ships stern cables 340 are paid out and connected to the stern buoys 342 so that substantial tanker drift will not occur while the pallet connections are being made. Then, the ships fore and aft side cables 368 and 370 on each side are connected to corresponding shackles 360 while another ships cable (not illustrated) is connected to shackle 364, the latter cable being hauled in after connection while the former cables are simultaneously paid out. As will subsequently be more clear, each pallet cable 332 is connected to the corners of the corresponding side of the pallet in a manner such that it may slide with respect to the pallet. However, when the center shackle 364 has been raised to deck level, it is passed over a deck bollard 376 so that the weight of the pallet assembly 330 may be partially supported thereby, although at this stage, the pallet 330 still lies on the sea bed 314 because side cables 368 and 370 were paid out as the shackle 364 was raised. Once the center shackle 364 has been secured to the bollard 376, the side cables 368 and 370 may be hauled in on each side of the ship to raise the pallet into firm abutment with the ships hull. Finally, after the pallet 330 has been raised, the bow cables 350 and 358 are hauled in to provide support for the pipeline 312 as previously described with respect to FIGURE 11. Connection with the pipeline 312 may then be made by raising the loading arm 336 on each side of the ship and connecting it to the corresponding ship-board connection 338 as before indicated.

The truss 324 will slide along the pipeline 312 to find its own rest point when the cable 358 is hauled in. However, if the tanker is small, the truss 324 will tend to slide along the pipeline 312 to a position relatively close to the pallet and remote from the support cable 323 so that a considerable length of pipeline would be supported. To meet this contingency, a stop collar 375 is secured to the exterior of pipeline 312 at a suitable point between the pallet and the support cable 323 so that the truss 324 will be prevented from sliding too far aft. This situation is illustrated in FIGURE 14 where a small tanker 310a is shown at the berth 343 and the position which the truss might take in the absence of the stop 375 is indicated by phantom lines. Naturally, the small tanker 310a will be considerably more narrow than the larger tanker 310 and the pallet 330 will project transversely well beyond each side thereof; but this will not appreciably effect the procedure for fixing the pallet in place or for mooring the tanker. Whether the tanker to be served is large or small the swivel jointed loading arms 336 are unfolded from their normal position (FIGURES 12, 13 and 16) and raised so that the free end of each may be connected to the ship as previously indicated. Comparison of the loading arm in FIGURE 11 and in FIGURE 14 clearly indicates how they are able to compensate for different sizes of ship.

Although the principles and operation of the system shown by FIGURES 10-14 have been described, the details of the manner in which the pipeline 312 and cable 319 are secured to the anchor block 316 will now be described with reference to FIGURE 15 and the details of the pallet assembly 338 will be described with reference to FIGURE 16.

Referring, therefore, to FIGURE 15, that portion of pipeline 312 which lies between the anchor block 316 and the pallet 330 is considerably larger in diameter than that portion which lies inshore of the anchor block 316 because the former portion includes a buoyancy casing 373 formed about liquid conducting tube 377 to increase the buoyancy and strength of the pipeline as a whole. The space between the tube 377 and casing 373 may be filled with a light cellular material, or as indicated in FIGURE 15, it may be left empty and sealed at the forward end by a frustro-conical end cap 378 which is welded to both tube 377 and casing 373. A collar 379 is welded to the exterior of the casing 373 adjacent cap 378 so as to provide a firm abutment for a split clamp 380. The clamp 380 is held together by bolts 381 and has a hole 382 formed in the lower portion of each half through which a pin 383 of shackle 384 is passed. The shackle 384 is also passed through a ring 385 which is permanently attached to a lug 386 cast into upper face 387 of anchor block 316. Also secured to ring 385 is a shackle 388 having a pin 389 that is passed through eye 390 of the bow mooring cable 319.

It is therefore evident that, when the tanker 310 is connected to the pipeline 312 in the manner described, any tendency for the tanker to drift away from the anchor block 316 will be resisted by tension forces in the pipeline 312 as well as is in the bow cable 319. Usually, the greater portion of the mooring forces will be borne by the pipeline 312 rather than the bow cable 319 since the primary function of this cable is to support the weight of the pipeline 312.

The pallet assembly 330, as shown in FIGURE 16, is fabricated by welding from tubular steel components, each component being sealed to exclude water and to thereby increase the buoyancy of the whole assembly. The assembly basically consists of forward and after transom structures 392 and 394, respectfully joined together by cross bracing 396. As each transom is substantially identical with the other, only the forward one has been fully illustrated and both will therefore be described together so that the same reference numerals will be assigned to corresponding parts of both.

The casing 373 of pipeline 312 is secured to each transom structure 392 and 394 by two saddle members 398 and 400 through which the casing passes longitudinally and to which it is secured as by welding. The saddle members are cast or forged and are either secured together at their lowermost point or actually formed together so that, in longitudinal vertical section, they form an upright V-shape structure. Each transom structure may be considered as formed by three parallel and transversely extending main tubular members; that is, a forward member 402, an after member 404, and a lower central member 406. Each of these main members is formed in two parts, a port half and a starboard half, disposed in the same vertical plane but angled with respect to each other from the horizontal plane at an angle set by transverse sockets in the saddles within which the main member halves are secured. Thus, each transom is generally V-shaped so that it may contact the ships hull more positively.

Each main transom member 402, 404 and 406, is positively positioned and secured to its fellow members by the saddles 398 and 400 and by the casing 373 which is secured to the saddles; by bracing runs 488, 410 and 412 which respectively connect main members 402 and 484, 402 and 406, 464 and 406 together along their lengths; and by a pair of triangular starboard end plates 414 and 415 and a pair of port end plates 416 and 417. The inner end plate 414, 416 of each pair is welded at its corners to the outer ends of the main transom members and thereby secures these members firmly together. On the other hand, the outer plate 415, M7 of each pair of end plates is arranged parallel to the inner plate of the pair but is spaced outwardly therefrom by three studs 418 and is secured in this spaced position by means of nuts 420 which engage the outer ends of the studs 418.

As previously indicated, the pallet structure 330 is hauled from the sea bed 314 into contact with the tanker hull by means of the pallet cables 332 which are slidingly engaged with each corner of the pallet structure. For this purpose, therefore, a sheave 422 is rotatably mounted between each pair of triangular end plates 414, 415 and 416, 417 on each transom assembly 392 and 394 by the two studs 418 which are in line with member 402 of transom assembly 392 and the two studs 418 which are in line with member 404 of transom assembly 394. Thus, as indicated in FIGURE 16, each pallet cable 332 is passed beneath the two sheaves 422 on the corresponding side of the pallet assembly 330 and enables the assembly to be raised into position in the manner previously described.

FIGURE 16 also illustrates the branch pipelines 334 and the loading arms 336 more clearly. Branch pipelines 334 extend laterally from the portion of pipeline 312 which lies between the saddles 39S and 40%, the branch lines passing through the casing 373 and communicating with the oil conveying line 377. In the embodiment illustrated the branch pipelines 334 are associated with the forward transom structure 392 only, no such branch lines being incorporated in the after transom structure 394. Each branch line extends outwardly through the corresponding pair of end plates 414 and 415, or 416 and 417, being welded thereto, and terminates in a swivel joint v426 that permits the entire corresponding loading arm 336 to swing as a whole about the axis of the branch pipe.

Each loading arm 336 basically comprises a relatively .long lower pipe member 428, a shorter intermediate member 450, and an upper member 452 having a length -approximately equal to the difference in the lengths of the lower and intermediate members. An elbow 454 is .weldedto the lower end of lower member 428 and is swivelly connected to another elbow 456 which, in turn, is swivelly connected to the corresponding branch pipe 334 by the associated swivel joint 426. Similarly, the upper en of member 428 has elbow 458 welded thereto which is swivelly connected to an elbow fitting 460 that is also swivelly connected to an elbow 462 welded to the lower end of intermediate member 450. An elbow 464 is welded to the upper end of intermediate member 458 and is swivelly connected to elbow 465 welded to the lower end of the upper member 452. Finally a terminal fitting hooked over the stud 418 which is in line with the transom member 464 and lies on the corresponding side of the forward transom assembly 392. As previously indicated, when the loading arms 336 are in use (FIGS. 11 and 14), they extend upwardly to the deck of the tanker, the lower and intermediate pipe members 428 and 450 providing adjustment for various sizes of tanker (both in beam and height dimension), while the upper pipe member 452 passes inboard over the deck to enable the loadingarm to be connected conveniently to the tanker pipeline terminals 338 (FIGURE While particular embodiments of the present invention have been shown and described it will be understood that the offshore tanker loading systems described are capable of further modification and variation without departing from the principles of the invention and it will be understood that the scope of the invention should be limited only by the scope and proper interpretation of the claims appended hereto.

The invention having thus been described, that which is believed to be new and for which protection by Letters Patent is desired is:

1. A method of establishing a fluid conductive connection between a ship moored at an offshore berth and a shore fluid storage while allowing for the normal sideways drift and the normal up and down motion of the ship at its moorings, said method comprising the steps of: arranging a submerged, rigid-wall pipeline to extend along the sea bed from the shore storage to an end of the berth; fixing said pipeline with respect to the sea bed at a point spaced from the berth by a distance such that the pipeline between said berth and said point is able to bend to permit the offshore end thereof to be raised to the ships hull and then moved with the ship during normal sideways movements of the ship at the berth without exceeding the elastic limit of the pipeline material; securing the offshore end of said pipeline to a pallet structure; connecting the ships tackle to said pallet structure to raise the offshore pipeline end and to secure the pallet structure firmly to the ships hull so that it moves therewith; establishing a fluid conductive connection between the ship and the offshore end of the pipeline; and ethering said offshore end of the pipeline to the sea bed to prevent the pipeline from being bent beyond its elastic limit.

2. A method of establishing a fluid conductive connection with a ship at an offshore berth, said method comprising the steps of: positioning a submerged rigidwall pipeline on the sea bed with one end secured to a pallet normally disposed beneath the berth and with an opposite end anchored to the sea bed at a point remote from said pallet, raising the pallet and said pipeline end up from the sea bed into adjacent relation with the ships hull so that the pipeline assists in mooring the tanker at its berth, and connecting the raised end of the pipeline in fluid conducting relationship with the ship.

3. A method of establishing a fluid conductive connection between a tanker moored at an offshore berth and a fluid storage facility spaced from the berth while allowing for the normal sideways and up and down motion of the tanker at its moorings, said method comprising the steps of: arranging a submerged rigid-wall pipeline to extend from the storage facility to the bow end of the berth; fixing said pipeline with respect to the sea bed at a point spaced from the berth by a distance such that the pipeline between said berth and said point is able to bend to permit the offshore end thereof to be raised and secured to the hull of the tanker and then moved with the tanker during said normal movements without exceeding the elastic limit of the pipeline material; securing the offshore end of said pipeline to a pallet structure normally lying on the sea bed substantially in the center of the berthing area; hauling the pallet structure, by cable means provided thereon and to which ships tackle may be connected, from the sea bed into firm contact with the tankers hull; raising a swivel-jointed, tubular fluid conducting loading arm from the pallet and securing one end of said loading arm to the tanker in fluid conducing relation therewith, the other end of said loading arm being connected in fluid conducting relation with the ofishore pipeline end; and mooring the tanker to limit its movement with respect to the sea bed to prevent the pipeline from being bent beyond its elastic limit.

4. A system for establishing a fluid conductive connection with a ship moored at an offshore berth comprising: a submerged fendering strut arranged on one side of the berth and projecting outwardly therefrom; an anchor block fixed with respect to the sea bed and pivotally anchoring the end of the tendering strut remote from the berth for movement in a substantially vertical plane; a buoyancy tank secured to the fendering strut near the end thereof adjacent the berth; buoyancy control means connected to said buoyancy tank for supplying air thereto and exhausting air therefrom, the buoyancy control means thereby controllably increasing and decreasing the buoyancy of said tank so as to effect the raising of the end of the strut adjacent the berth substantially to the surface of the water and the lowering of said strut end to the sea bed; at least one rigid-wall pipeline having substantial rigidity and limited flexibility in fluid conductive connection with a fluid storage facility and extending along the sea bed to the strut, the offshore end of said rigid-wall pipeline being secured to the end of the strut adjacent said berth for conjoint movement therewith, the movement of the offshore end of said pipeline being accommodated by the resilient bending of said pipeline; cable means whereby the tanker may be drawn into fender-ing relation with said strut when said strut is raised to the surface of the water; and means whereby fluid connection between the tanker and the offshore ends of said pipeline may be established when the strut is in the raised position.

5. A system for establishing a fluid conductive connection between a ship at an offshore berth and a shore fluid storage, said system comprising: two parallel laterally spaced and submerged tendering strut assemblies arranged on one side of the berth and projecting outwardly therefrom, one end of each of said struts being disposed adjacent said side of the berth and the other end of each of said struts being spaced from said berth, an anchor block associated with each strut fixed with respect to the sea bed and pivotally anchoring said other end of the associated strut so that said strut is free to move about a vertical and a horizontal axis from a normal position on the sea bed to a raised position wherein said one end is substantially at water level at said one side of the berth; a buoyancy tank secured to said one end of each strut and having an opening therein through which water may enter and leave said tank, each buoyancy tank normally containing sufficient water to prevent it from raising the said one end of the associated strut from the sea bed; air supply means disposed on the shore and connected to the buoyancy tanks for supplying air under pressure to said buoyancy tanks to thereby expel the water from the buoyancy tanks so as to render each tank sufficiently buoyant to raise the associated strut to the raised position; a submerged, rigid-wall pipeline extending along the sea bed from the berth toward the shore storage, said pipeline having an inshore end connected with said shore storage and an offshore end fixed to said one end of one of the struts for movement therewith, a pipeline anchor block fixed with respect to the sea bed and disposed at predetermined distance from the berth along said pipeline so as to anchor said pipeline to the sea bed; a riser pipe secured in fluid conductive relationship with the offshore end of the rigid-wall pipeline so that, when said offshore end of the pipeline is raised to the surface of the water by said one strut, the riser pipe will extend above the surface of the water for fluid conducting connection with the tanker at said berth; and tanker mooring means disposed on said one side of the berth to which the tanker may be moored so that when the struts are in their raised position the tanker may be drawn into fendering relation with said one end of each strut, the struts thereby assisting to hold the tanker at its berth, said one end of each strut being rigidly held in contact with the tanker while said tanker moves normally at its berth, the raising of the offshore end of the pipeline by the strut and the lateral movement of the offshore end of the pipeline with the tanker and strut being accommodated by resilient bending of the pipeline between the offshore end thereof and said pipeline anchor block.

6. A system for establishing a fluid conductive connection with a ship moored at an offshore berth, said system including: a rigid-wall pipeline extending from one end of the berth toward the shore, said pipeline normally resting on the sea bed with its offshore end extending longitudinally beneath the bow end of the berth; a pallet structure rigidly secured to the offshore end of the pipeline and normally lying on the sea bed beneath said berth; means on said pallet structure whereby said structure may be secured to the tanker at said berth and hauled up from the sea bed into firm contact with the hull of the tanker while resiliently bending the pipeline along its length; a fluid conducting swivel jointed loading arm connected at one end of the offshore end of the pipeline and normally resting on the pallet structure; and means whereby the free end of said loading arm may be raised from said pallet structure, when the offshore end of the pipeline and the pallet structure are raised into contact with the ship, to connect said pipeline in fluid conductive relation with said ship, the normal drifting movements of the tanker at its berth being accommodated by the resilient flexing of said rigid-Wall pipeline along its length.

7. A system for establishing a fluid conductive connection between a tanker moored at an offshore berth and a shore storage, said system comprising a submerged, rigid-iwall pipeline normally lying on the sea bed so that the offshore end thereof extends beneath the bow end of the berth and the inshore end thereof is connected in fluid conductive relationship with the shore storage; an anchor block anchoring the pipeline to the sea bed at a point spaced a predetermined distance from the berth; a pallet structure secured rigidly to the pipeline at the offshore end thereof; cable means secured to each side of said pallet and adapted to be connected to the ships tackle so that the pallet may be raised thereby from the sea bed and drawn into firm contact with the hull of a tanker at the berth, the raising of the pallet causing the pipeline to bend along its length over said predetermined distance; and a fluid conducting swivel jointed loading arm mounted on one side of the pallet having one end connected to the offshore end of the pipeline and secured to the pallet and having the other end normally resting on the pallet but adapted to be raised from said pallet side and connected to the tankers pipeline connection, the tanker being moored at the berth by means of the pipeline and at least one stern mooring cable adapted to limit the sideways drift of the tanker during loading and unloading so that the bending of the pipeline between said pallet and the point at which it is anchored to the sea bed may take place Without generating stresses which exceed the elastic limit of the material of the pipeline.

8. In an apparatus for establishing fluid communication with a vessel floating in a body of water, elongated conduit means having opposite end portions and being of such diameter, length, and material that when it is suspended at points spaced more than one hundred feet apart, it is of sufficient rigidity that it is self-supporting and sufficiently flexible that it bends transversely within a limited range, said conduit means being located in a predetermined submerged position in said body of water with one of its end portions being free for elevational movement in the water, means for raising said free end portion of the conduit means to a position off the seabed with said conduit means being flexed in a smooth curvature between said end portions, and means for establishing fluid communication between said free end portion of the conduit means and said vessel, said conduit means yieldably resiliently resisting movement of said vessel in a path toward and away from the other end portion of the conduit means and transversely of said path Whereby said conduit means maintains said vessel in a predetermined berthing area spaced from said other end ortion of the conduit means.

9. The apparatus of claim 8 including means for limiting the amount of flexing of said conduit means.

10. The apparatus of claim 8 wherein said conduit means is made of high tensile corrosion resistant metal.

11. The apparatus of claim 8 wherein said raising means includes a rigid frame underlying said free end portion of the conduit means, said frame having a supporting end adjacent to the free end portion of said conduit means and a mounting end spaced longitudinally of said conduit means from said supporting end, and means pivoting the mounting end of the frame at a predetermined location with respect to the bed of the body of water for elevational adjustable movement of said frame, said free end portion of the conduit means being supported on said frame for elevational movement therewith.

12. In an apparatus for establishing fluid communication with a vessel floating in a predetermined berthing area in a body of water, anchoring means submerged in the water and fixed with respect to the bed of said body of water in spaced relation to said berthing area, substantially rigid support means pivoted to said anchoring means and projecting from said anchoring means toward said berthing area for elevational adjustable movement in the water with respect to said anchoring means, an elongated flexible conduit having a portion borne by said support means and a portion projecting away from said anchoring means on the opposite side thereof from said berthing area, said conduit being disposed transversely of the pivot axis of said support means, and means for elevationally adjusting said support means, and thus said portion of the conduit borne by said support means, with respect to said anchoring means.

13. The apparatus of claim 12 wherein said support means is mounted on said anchoring means for generally horizontal swinging movement.

14. The apparatus of claim 12 including mooring lines having ends connected to the vessel at fore and aft positions and opposite ends located closely adjacent to said anchoring means and in fixed positions with respect to the axis about which said elevational movement of the support takes place.

15. The apparatus of claim 12 wherein said support means has an upper end portion in engagement with said vessel when said support means is raised by said elevationally adjusting means.

16. In an apparatus for establishing fluid communication with a vessel floating in a body of water, an anchor submerged in the water; an elongated non-articulated rigid-walled normally straight conduit means having opposite end portions, said conduit means being characterized by an ability to flex down between its end portions when said conduit means is supported only at said end portions and by an ability to resiliently return to a substantially straight condition when the entire conduit means is supported in a common plane, said conduit means normally lying on the bottom of the body of water, one of the end portions of the conduit means being secured to said anchor, said other end portion being spaced from the anchor; and means for raising said other end portion of the conduit means off from said bottom and supporting said other end portion adjacent to a vessel, said conduit means being thereby resiliently flexed between its end portions and generally horizontally between said anchor and said vessel while remaining substantially entirely submerged in said water, said other end portion of the conduit means being in fluid communication with the vessel when said other end portion is supported adjacent to the vessel, said vessel being subject to movement in a path toward and away from said anchor and transversely of said path, said conduit means resiliently yielda-bly resisting movements of said vessel in said path and transversely of said path whereby said conduit means maintains said vessel in a predetermined berthing area While in fluid communication in said vessel 17. A method of establishing a fluid conductive connection between a storage facility on shore and a tanker subject to limited movement at an offshore berth, said method comprising the steps of: pivotally anchoring one end of a tendering strut at a point on the sea bed spaced from one side of the berth so that the other end of said strut is free to rise from the sea bed into a fendering position adjacent to the tanker, rendering said strut buoyant so that it is raised into said tendering position, moving the tanker into firm contact with said strut and maintaining said contact, and arranging a submerged rigidwall, resiliently flexible pipeline along the strut such that said pipeline flexes resiliently along its length when the strut is raised to said tendering position and moves with the normal movement of the tanker at its berth.

18. In combination with a vessel floating in the water, an elongated pipeline having inner and outer end portions, said pipeline being submerged in the water and having weight and resilient flexibility substantially equal to that provided by a high tensile steel conduit having a diameter from six to ten inches and a length of several hundred feet, means for raising and lowering the outer end portion of the pipeline While the remainder of the pipeline is supported on the bottom of the body of water so that the pipeline has a generally catenary shape in its raised position, means for attaching the pipeline to a vessel in the raised position of the pipeline so that movements of the vessel cause resilient flexing of the pipeline and so that the weight and resilience of the pipeline yieldatbly resists movements of the vessel toward and away from said inner end portion of the pipeline and in a path disposed transversely of the pipeline so as to maintain said vessel in a predetermined area spaced from said inner end portion of the pipeline, and means for establishing communication between the vessel and the pipeline.

References Cited by the Examiner UNITED STATES PATENTS 1,188,426 6/1916 Fairfield 14l382 1,736,293 11/1929 Van Den-burg 138-97 2,374,249 4/1945 Wadsworth 14l-382 2,955,626 10/ 1960 Hartley 141279 3,118,155 1/1964 Sicgel 9-8 FOREIGN PATENTS 683,547 11/1939 Germany.

LAVERNE D. GEIGER, Primary Examiner.

Claims (1)

1. A METHOD OF ESTABLISHING A FLUID CONDUCTIVE CONNECTION BETWEEN A SHIP MOORED AT AN OFFSHORE BERTH AND A SHORE FLUID STORAGE WHILE ALLOWING FOR THE NORMAL SIDEWAYS DRIFT AND THE NORMAL UP AND DOWN MOTION OF THE SHIP AT ITS MOORINGS, SAID METHOD COMPRISING THE STEPS OF: ARRANGING A SUBMERGED, RIGID-WALL PIPELINE TO EXTEND ALONG THE SEA BED FROM THE SHORE STORAGE TO AN END OF THE BERTH; FIXING SAID PIPELINE WITH RESPECT TO THE SEA BED AT A POINT SPACED FROM THE BERTH BY A DISTANCE SUCH THAT THE PIPELINE BETWEEN SAID BERTH AND SAID POINT IS ABLE TO BEND TO PERMIT THE OFFSHORE END THEREOF TO BE RAISED TO THE SHIP''S HULL AND THEN MOVED WITH THE SHIP DURING NORMAL SIDEWAYS MOVEMENTS OF THE SHIP AT THE BERTH WITHOUT EXCEEDING THE ELASTIC LIMIT OF THE PIPELINE MATERIAL; SECURING THE OFFSHORE END OF SAID PIPELINE TO A PALLET STRUCTURE; CONNECTING THE SHIP''S TACKLE TO SAID PALLET STRUCTURE TO RAISE THE OFFSHORE PIPELINE END AND TO SECURE THE PALLET STRUCTURE FIRMLY TO THE SHIPS HULL SO THAT IT MOVES THEREWITH; ESTABLISHING A FLUID CONDUCTIVE CONNECTION BETWEEN THE SHIP AND THE OFFSHORE END OF THE PIPELINE; AND TETHERING SAID OFFSHORE END OF THE PIPELINE TO THE SEA BED TO PREVENT THE PIPELINE FROM BEING BENT BEYOND ITS ELASTIC LIMIT.

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