GB1586835A - Fluid transferring apparatus - Google Patents

Description

(54) FLUID TRANSFERRING APPARATUS (71) We, FMC CORPORATION, a corporation organised and existing under the laws of the State of Delaware, United States of America, of 200 E. Randolph Drive, Chicago, Illinois, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following state ment The present invention relates to fluid transferring apparatus, and more particularly to fluid transferring apparatus especially designed for use in loading and unloading marine tankers.

Various types of fluid transferring devices are used in conveying fluids between a dock, buoy, or floating barge and a marine tanker or other transport vessel. Some of these devices are large articulated pipe structures referred to as marine loading arms, such an arm generally comprising two or more arm sections mounted on an upstanding riser and pivotally interconnected by swivel joints in a manner to allow the arm to accommodate itself to movements of the buoy, barge and/or tanker while fluid transfer is in progress.

In referring herein to fluid transferring having two pivotally-interconnected arms or conduit members mounted on a support, the arm or conduit member adjacent the support will be referred to as the 'inner' arm or member and the other will be referred to as the 'outer' arm or member.

According to the present invention, there is provided apparatus for transferring fluid from one fluid handling means to another comprising a rigid inner conduit members, means mounting said inner conduit member for pivotal movement about a first horizontal axis, a rigid outer conduit member pivotally connected at one of its ends to the outer end of said inner conduit member for movement about a second horizontal axis, a drive mechanism connected between said mounting means and said inner conduit member for moving said inner conduit member about said first horizontal axis, a drive means connected between said mounting means and said outer conduit for rotating said outer conduit member with respect to said inner conduit member; said drive means being operable throughout its full range of operation for movement independent of the movement of said inner conduit member; and means for counterbalancing said inner and outer conduit members including means for applying a force to said inner conduit member at a radial distance from said first axis that varies as the centre of gravity of said conduit members alters its horizontal distance from said first axis, and wherein said drive means comprises a first sheave concentric with said first horizontal axis and fixed to prevent rotation thereof about said first axis, a second sheave rotatable about said second horizontal axis and fixed to said outer conduit member, and cable means fixed to said first sheave and trained around said second sheave, said cable means being operable to rotate said second sheave to effect movement of said outer conduit member.

The invention will now be particularly described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a side elevation of a fluid transferring apparatus according to the present invention, with an articulated conduit shown in an extended position; Figure 2 is a plan of a portion of the apparatus of Figure 1, viewed in the direction of the arrows 2-2 of Figure 1; Figure 3 is a side elevation of the apparatus of Figure 1, with the articulated conduit in a stowed position; Figure 4 is an enlarged fragmentary side elevation of the apparatus shown in Figures 1 and 2, with certain portions broken away; Figure 5 is a vertical section taken along line 5-5 of Figure 4; Figure 6 is a plan of a portion of the apparatus of Figure 1, viewed in the direction of the arrows 6-6 of Figure 1; Figure 7 is a rear elevation of the apparatus viewed in the direction of the arrows 7-7 of Figure 3; Figures 8 and 9 are diagrammatic views showing a counterbalancing mechanism in different positions; Figure 10 is a fragmentary side elevation of a second embodiment of the present invention, with the articulated loading arm in its stowed position.

Figure 11 is a fragmentary front elevation of the apparatus of Figure 10, viewed in the direction of the arrows 11-11 of Figure 10.

A fluid conveying apparatus in accordance with the first embodiment comprises an articulated loading arm, designated A in Figure 1, with rigid inboard and outboard conduit members B and C, respectively, these members being pivotally interconnected in substantially end-to-end relation for relative movement about a horizontal axis Z. The inner end of the inboard member B is pivotably mounted on an upstanding riser conduit E for universal movement about intersecting vertical and horizontal axes V and Y, respectively. A structure 10, which includes one or more rigid frame members 12 and 14 interconnected by one or more horizontal members 16, supports the riser E, and hence the loading arm members B and C on a dock or marine vessel deck D to which the structure 10 is fixed. The riser E is connected to a pipeline or other conduit F that extends to a fluid storage facility (not shown) for supplying fluid to the loading arm, or conducting fluid from it, during its use in a loading or unloading operation. When not in use the loading arm A is stowed in the position illustrated in Figure 3. From this position the arm is moved into the position shown in Figure 1, and subsequently coupled to a fluid receiving means such as a manifold conduit G located on a marine tanker or other floating vessel T when fluid transfer operations are to be performed. If desired, however, the arrangement may be reversed, i.e., the loading arm A may be mounted on the tanker T and the conduit G may be located on the dock or deck D.

The fluid transferring apparatus of Figures 1-9 further comprises a T-shaped carriage 18 mounted on the support structure 10 for pivotal movement about the vertical axis V.

The carriage 18 includes a stem or upright member 19, a cross member 20 rigid with the upper end of the stem, and bottom plate 22 (best seen in Figure 4) that is rigid with the lower end of the stem 19. The bottom plate 22 is pivoted on and supported by a thrust bearing 24 that is mounted on a footplate 26 secured to the marine vessel deck or dock D.

A pair of vertical plates 27 and 27a (Figure 7) are connected between the bottom plate 22 and the stem 19 to provide support between these two carriage members. The vertical riser pipe E extends through and is rigidly secured to the cross arm 20, and is held in vertical alignment with the thrust bearing 24 on the axis V by a sleeve bearing 28 which is rigidly connected to the support structure 10.

Thus, the bearings 24 and 28 secure the riser E and the carriage 18 in vertical position and permit them to pivot in unison about the axis V.

To permit the T-shaped carriage 18 and the riser pipe E to pivot about the vertical axis V, the riser E is provided at its lower end with a swivel joint 30 (Figs. 1 and 3) which provides a fluid-tight yet pivotable connection with the stationary conduit F, thus permitting the fluid to be transferred from the conduit F to the inboard and outboard conduits B and C.

A double acting horizontally-disposed hydraulic cylinder 32 (Figs. 1, 3, 4 and 7) for pivoting the carriage 18 about the vertical axis V is pivotally connected to the carriage by a pair of pivot pins 34a and 34b (Fig. 4).

The lower pin 34b is connected to the bottom plate 22 and the upper pin 34a is connected to a bracket 36 rigidly secured to stem 19 and to a vertical rod 37. The hydraulic cylinder 32 has a piston rod 39 that is connected by a pin and clevis assembly 40 (Figs.

1 and 3) to a bracket 42 that is mounted on the footplate 26. Suitable hydraulic lines (not shown) connected to the hydraulic cylinder 32 provide fluid pressure to extend or retract the piston rod 39 with respect to the cylinder 32, thus pivoting the loading arm about the axis V in a counterclockwise or clockwise direction, respectively, as viewed from above the apparatus.

A 90" elbow 44 (Fig. 5) that is welded, bolted or otherwise fixed to the upper end of the riser pipe E with its horizontal leg 46 projecting laterally, establishes communication between the riser pipe E and a laterally projecting leg 48 of another 90" elbow 49 (Figs. 1-5) which constitutes a part of the inboard conduit B of the articulated loading arm A. The two elbows 44 and 49 are interconnected by a trunnion pipe swivel joint 51 (Fig. 5) that maintains a fluid-tight connection between the riser E and the inboard conduit B while facilitating pivotal movement of the conduit B about the horizontal axis Y (Figs.

1 and 3). The inboard conduit B also includes an elongated rigid pipe 53 which is rigidly secured to the other leg 55 of the elbow 49.

The inboard conduit B terminates at its outer end in an elbow 57 (Figs. 1 and 6) which is secured to the pipe 53 so that the outer leg 59 of the elbow 57 is parallel to the leg 48 of elbow 49.

The outboard conduit C of the articulated loading arm A includes an elongated rigid pipe 60 (Figs. 1, 3, 6 and 7) with a 900 elbow 61 at its inner end and another 90" elbow 62 at its outer end. The elbow 61 is connected to the leg 59 of the elbow 57 by a swivel joint 63 that maintains fluid-tight communication between the conduits B and C while permitting pivotal movement of the conduit C about the horizontal axis Z.

The outboard conduit C carries at its outer end a triple pipe swivel joint assembly 66 (Figs. 1, 3 and 7) comprising first, second and third swivel joints 67, 68, and 69, respectively, and first, second, third, and fourth 90" pipe elbows 70, 71, 72, and 73, respectively. As perhaps best seen in Figure 7, the swivel joint 67 interconnects elbows 62 and 70, the joint 68 interconnects elbows 70 and 71, and as best seen in Figures 1 and 3 the elbows 71, 72 and 73 are welded or otherwise rigidly fixed together in an end-to-end manner. The swivel joint 69 is mounted on the outer end of the elbow 73, and interconnects this elbow with a suitable coupling assembly 74 that functions to releaseably connect the loading arm A to the flange 75 (Fig. 1) of a tanker manifold G. The swivel joints 67, 68 and 69 permit pivotal movement about three mutually perpendicular axes J, K, and L so that the coupling assembly 74 can be brought into alignment with the flange 75, thus facilitating connection of the outer end of the articulated loading arm to the tanker manifold G. This triple swivel joint assembly 66 also enables the loading arm A to follow the movements of the marine vessel T to which it is coupled, and to accommodate to movements of the deck D of another marine vessel upon which it is mounted, so that vessel-to-vessel fluid transfer at sea can be safely and efficiently accomplished.

The loading arm A further includes a pair of transversely spaced cam plates 76 and 76a (Figs. 1-5) mounted at the top of the riser in vertical parallel planes for pivotal movement about the horizontal axis Y. Annular outer bearings 78 and 78a (Fig. 5), which are welded or otherwise fixed to the plates 76 and 76a, respectively, are rotatably engaged upon coaxial inner bearings 80 and 80a, respectively, which are integral with or fixed to the elbow 44 at the upper end of the riser conduit E with their common axis coincident with the axis Y. The plates 76, 76a extend forward from the riser E towards the junction of the conduits B and C, and are rigidly joined together at or near their forward ends and secured to the inboard conduit B by a pipe clamp 77 or other suitable means to provide support for this conduit so that the elbow 49 can be removed for servicing the swivel joint 51 without having to remove the conduit B from its supporting structures.

The means for pivoting the inboard and outboard conduits B and C about the horizontal axis Y include annular cable guides 91 and 91a (Figs. 1, 3-5) respectively, of channel-shaped cross-section. These guides are welded or otherwise fixed to the plates 76, 76a with their axes coinciding with those of the bearing members 78, 78a. The guides 91 and 91a serve as reels upon which actuating cables 92 and 92a, respectively, are trained, one end of each cable being secured to the associated reel so that the reel, and with it the conduit B, can be pivoted about the horizontal axis Y by imposing tension upon the other end of the cable. The two cables 92, 92a are trained in opposite directions about their respective reels, the cable 92 being adapted to pivot the conduit B clockwise as viewed in Figs. 1, 3 and 4, whereas the cable 92a is adapted to pivot the conduit B in the opposite direction.

The cables 92, 92a extend downward from their respective reels into guiding engagement with sheaves 94, 94a (Figures 5 and 7) respectively, and from there to sheaves 95, 95a (Figure 7) which are secured to the outer ends of piston rods 96, 96a, respectively. The cables 92, 92a extend around their respective sheaves 95, 95a and then upward to the cross member 20 of the T-shaped carriage 18 to which they are secured as by U-bolt clamps 97, only one of which is shown (Figs. 1, 3 and 4). The piston rods 96, 96a are operatively engaged within and extend slidably through the upper ends of hydraulic cylinders 98, 98a, respectively, which cylinders are anchored at their lower ends to the respective vertical plates 27, 27a by pin and clevis assemblies 99, 99a, the clevis elements being welded to the vertical plates 27, 27a. The cylinders 98, 98a are of the single-acting type so that when the source of fluid under pressure (not shown) is connected to the hydraulic cylinder 98 and fluid is permitted to discharge from the other cylinder 98a, tension is imposed upon the cable 92 by the piston rod 96 to pivot the inboard conduit B clockwise. Such movement of the conduit B winds the other cable 92a onto the reel 91a, withdrawing the piston rod 96a from its cylinder 98a. Conversely, by connecting the hydraulic fluid under pressure to the cylinder 98a and by relieving the pressure in the cylinder 98, the conduit B is caused to pivot in the opposite i.e., counterclockwise, direction, and the piston rod 96 is withdrawn from within its cylinder 98. The hydraulic system which powers the cylinders 98, 98a is conventional, and is widely used in a variety of fluid conveying apparatus.

As illustrated in Figures 1, 3-5 and 7, the outboard conduit C is pivoted relative to the inboard conduit B about the axis Z by means of a pantograph assembly comprising sheaves 82 and 83, cables 84, 85 and 86 and 87, and hydraulic cylinders 88 and 89. The sheave 82 (Fig. 5) is fixed to the riser elbow 44 coaxially with the axis Y, and the sheave 83 (Figs. 6 and 7) is fixed to the elbow 61 at the inner end of the outboard conduit C coaxially with the axis Z. A portion of each of the cables 84, 85 is trained around the sheave 82, and the inner ends of both cables are secured to this sheave. In like manner, a portion of each of the cables 86 and 87 is trained around the sheave 83, and the outer ends of each of these cables is secured to this sheave. The cylinders 88 and 89 are attached to the outer ends of the cables 84, 85, and the piston rods 88a, 89a of these cylinders are attached to the inner ends of the cables 86, 87, respectively.

Accordingly, when the piston rod 88a is retracted into its cylinder 88, and simultaneously therewith the piston rod 89a is extended from its cylinder 89, the sheave 83 and the outboard conduit C are pivoted counterclockwise about the axis Z as viewed in Figures 1 and 3, i.e., the conduit C is elevated. Correspondingly, the conduit C is lowered, i.e., pivoted clockwise about the axis Z, when the piston rods 88a, 89a are extended and retracted, respectively, in a simultaneous manner.

Since the turning moment resulting from the attitude of the outboard conduit C is transmitted by means of this pantograph system directly to the riser elbow 44, the attitude of the outboard conduit C with respect to the inboard conduit B does not have any effect on the counterbalancing of the loading arm A, and thus the loading arm A remains balanced regardless of the attitude of the outboard conduit C. The hydraulic system which is used to control the operation of the hydraulic cylinders 88, 89, and for that matter hydraulic cylinders 98, 98a is not critical to the present invention. Suitable hydraulic systems for these purposes are described in detail in U.S. patents numbers 3,382,893 and 2,980,150, respectively.

The apparatus includes counterbalancing system so designed that it neutralizes the tendency for the articulated loading arm A to pivot about the horizontal axis Y regardless of the position of the arm. This system comprises a counterweight 100 in the form of an appropriate weight that is guided for vertical movement on a rod 37 extending between the forward end of the crossarm 20 and the bottom plate 22 (Figs. 1 and 4) of the T-shaped carriage 18. A plurality of rollers 103 (Figs. 1, 3 and 4), attached to the weight 100, cooperate with the vertical rod 37 and the stem 19 to guide the weight as it moves in a vertical direction.

The weight 100 is suspended by a pair of cables 101 and lOla (Figs. 1, 3-5 and 7) from a pair of axially aligned sheaves 102 and 102a that are rotatably mounted on opposite sides of the forward end of the crossarm 20. The cables 101, lOla are trained about the sheaves 102, 102a, as well as around another pair of axially aligned sheaves 104 and 104a that are rotatably mounted upon opposite sides of the after end of the crossarm 20. From the sheaves 104, 104a, the cables 101 and lOla extend upward and forward to positions closely adjacent the inner faces of the cam plates 76 and 76a, respectively, where they are connected to these plates. The connection of the cable 101 to the plate 76 will be described with the understanding that the cable lOla is similarly connected to plate 76a.

As seen best in Figure 4, the plate 76 carries two cable guides 106 and 107, respectively, secured to the inner face of the plate 76. The guide 106 is formed from a suitable length of flat stock bent to the desired longitudinal curvature and secured along one edge to the plate 76 so that it projects laterally and inwardly therefrom. The inner end portion of the guide 106, i.e., that portion nearest the axis Y curves clockwise away from this axis, while the remainder of the guide 106 curves counterclockwise so that its other end smoothly merges at 108 into the web 109 of a channel-shaped guide 110 that is secured to and extends along the periphery of the plate 76. In a clockwise direction (Fig. 4) from the point of convergence with the guide 106, the web 109 is slotted as indicated at 112, and the cable 101 extends through the slot 112 thus provided so that the upper end of this cable can be securely attached to the cam plate 76 as by U-bolt clamps 114.

From its point of convergence with the guide 106, the channel shaped guide 110 extends counterclockwise (Fig. 4) in a curve gradually increasing in radius to a point P on the periphery of the plate 76 at a maximum radial distance from the axis Y. The curvature of the channel shaped guide 110 and that of the guide 106 are such that the two cooperate to form a curve of gradually decreasing radius from the point P in a clockwise direction (Fig. 4) to the inner end of the guide 106.

The guide 107 also is formed of a suitable length of flat strip stock bent longitudinally into an arcuate configuration. This guide 107 extends from the web 109 of the channel guide 110 at the opposite end of the slot 112 from that at which the guide 106 smoothly merges with the web, as shown in Fig. 4.

That portion of the guide 107 which projects outward from the web 109 is provided with auxiliary flanges along its lateral edges to form a channel in cross-sectional configuration.

The parts are so proportioned and arranged that when the loading arm A is in a position of neutral equilibrium, i.e., when the inboard conduit B slopes rearward a few degrees from the vertical (Figure 8), the region of the plate 76 with which the inner end portion of the guide 106 is associated is disposed toward the sheave 104 permitting the cable 101 to extend in a straight line from its point of tangency with the sheave 104 toward the axis Y. It will be understood, therefore, that when the loading arm A is in the described position of neutral equilibrium, wherein the gravitational forces imposed upon the conduit are neutralized and consequently exert no turning moment upon the conduit, the cable lox is incapable of exerting any counter-torque upon the loading arm A. As the inboard conduit B rotates counterclockwise from the vertical position toward the position shown in Figure 3, the cable guide 107 engages the cable 101 in a manner producing a progres sively greater deflection of the cable as the displacement of the conduit B from the verti cal increases. Consequently, as the loading arm A is displaced progressively further from its point of neutral equilibrium and the turn ing moment induced by gravity becomes pro gressively greater, the cable 101 exerts a progressively greater counter-torque, thus effectively counterbalancing the loading arm A regardless of how far the arm is displaced counterclockwise from its neutral position.

When the outboard conduit drive cylinders 88 and 89 are not actuated, the outboard 'conduit C remains substantially fixed in relation to the horizontal as the inboard conduit B is pivoted about the axis Y from the position shown in Figure 1 to the position shown in Figure 3. Consequently, the center of gravity of the loading arm A remains at a inconstant radial distance from the axis Y as the arm is rotated from its operative position shown in Figure 1 to its stowed position in .Figure 3. It is apparent, therefore, that the center of gravity is to the right of the axis Y as shown in Figure 1 and gradually moves to a point above the axis Y, and from there to the left of the axis Y as shown in Figure 3.

The force imposed by gravity upon the load ing arm increases regularly as the assembly rotates from its position illustrated in Figure -8 rearward to its stowed position of Figure 3, and the cable guide -107 is designed to increase the counter-torque exerted by the cable 101 against the plate 76 at the same rate However, when the loading arm rotates forwardly, i.e., clockwise, from the position shown in -Figure 8, the center of gravity shifts to a greater distance from the axis Y because the outboard conduit C is suspended from 'the opposite end of the inboard conduit B in a manner permitting the-angles between these two conduits to increase as the inboard conduit B approaches the horizontal position.

Therefore, the turning moment imposed on the loading arm A by its own weight increases at a faster and irregular rate than when the arm is pivoting counterclockwise from the neutral position as seen in Figure 8, and this faster rate of increase is compensated for by the volute curvature of the cable guides 106 and 110 on which -the - cable-JO-i-.

winds as the' arm pivots clockwise from the neutral position of Figure 8. As the inboard conduit B approaches a horizontal - position (Fig. 9), the cable 101 makes tangential engagement with the guides 106 and 110 at points spaced progressively further from the Y axis, as clearly illustrated in Figures 8 and 9, reaching a maximum when the conduit B is in a horizontal position as shown in Figure 9.

When loading arm is pivoted to the stowed position shown in Figure 3, the inboard con duit B comes to rest upon the support 120, thereby reducing the stress on the support structure 10. The support 120 includes one or more upright rigid frame members 122 and 123 interconnected by one or more horizon tal members 125 and 126. The support 120 may also include suitable cross bracing for increasing the strength and rigidity of the structure. A jack 128 is used to support the counterweight 100 to further reduce the stress on the structure 10 when the loading arm is in the stowed position. Another sup port 129, fastened to the inboard conduit B, supports the outboard conduit C so that the hydraulic cylinders 88 and 89 can be de energized while the arm remains in the stowed position.

Thus, the foregoing embodiment provides an improved fluid transferring apparatus having a cam-suspended and operated coun terweight which balances the articulated loading arm in all positions while that coun terweight remains at all times in an operating location much closer to the deck of a ship or barge on which the apparatus is mounted than loading arms with counterweights mounted at the riser trunnion. By using this invention the center of gravity of a fluid transfer apparatus can be significantly low ered, thereby greatly reducing the stress on the apparatus and correspondingly increas ing the safety thereof.

Figures 10 and 11 disclose another embodi ment of the present invention wherein the counterweight 100 of Figures 1-9 has been replaced by a pair of hydraulic cylinders 130 -and 130a, a hydraulic pump 132, a constant pressure relief valve 134, and a source of hydraulic fluid 136. The hydraulic cylinder 130 is secured to the vertical rod 37 by a pair of clamps 140 and 141, while the cylinder 130a is secured to the rod 37 by a pair of clamps 140a, 141a. The hydraulic pump 132 and the relief valve 134 provide fluid under a constant pressure to an inlet port 137 and 137a of each of the cylinders 130 and 130a.

This fluid exerts a constant downward force on the pistons (not shown) of these cylinders and thus provides a constant downward force on each of the cables 101 and 101a that are connected to the piston rods 131, 131 a, respectively. This downward force thereby counterbalances the turning moment induced by gravity on the articulated loading arm A about the horizontal axis - Y. The counter balance"' apparatus disclosed in Figures 10 and 11 has the advantage of eliminating counterweights, and thereby reduces the stress on the support structure 10, the stem 19, and the vertical rod 37 when the marine vessel rolls in heavy seas. The operation of the sheaves 102, 104 and the cam plates 76, 76a of the apparatus is the same as has been described hereinbefore with respect to Figures 1-9.

WHAT WE CLAIM IS:- 1. Apparatus for transferring fluid from one fluid handling means to another comprising a rigid inner conduit member, means mounting said inner conduit member for pivotal movement about a first horizontal axis, a rigid outer conduit member pivotally connected at one of its ends to the outer.end of said inner conduit member for movement about a second horizontal axis, a drive mechanism connected between said mounting means and said inner conduit member for moving said inner conduit member about said first horizontal axis, a drive means connected about said first horizontal axis, a drive means connected between said mounting means and said outer conduit for rotating said outer conduit member with respect to said inner conduit member; said drive means being operable throughout its full range of operation for movement independent of the movement of said inner conduit member; and means for counterbalancing said inner and outer conduit members including means for applying a force to said inner conduit member at a radial distance from said first axis that varies as the centre of gravity of said conduit members alters its horizontal distance from said first axis, and wherein said drive means comprises a first sheave concentric with said first horizontal axis and fixed to prevent rotation thereof above said first axis, a second sheave rotatable about said second horizontal axis and fixed to said outer conduit member, and cable means fixed to said first sheave and trained around said second sheave, said cable means being operable to rotate said second sheave to effect movement of said outer conduit member.

2. Apparatus according to claim 1 wherein means for rotating said second sheave comprise at least one fluid-powered cylinder and piston assembly.

3. Apparatus according to claim 1 wherein said drive means includes means for pivoting the outer end of said outer conduit member under a portion of said inner conduit member and means for extending the outer end of said conduit beyond the outer end of said inner conduit member to provide an articulated conduit having a length substantially equal to the sum of the lengths of said inner conduit member and said outer conduit member.

4. Apparatus according to any preceding claim including a weight mounted below the level of said first horizontal axis to provide a relatively low centre of gravity for said apparatus.

5.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. the sheaves 102, 104 and the cam plates 76, 76a of the apparatus is the same as has been described hereinbefore with respect to Figures 1-9. WHAT WE CLAIM IS:-

1. Apparatus for transferring fluid from one fluid handling means to another comprising a rigid inner conduit member, means mounting said inner conduit member for pivotal movement about a first horizontal axis, a rigid outer conduit member pivotally connected at one of its ends to the outer.end of said inner conduit member for movement about a second horizontal axis, a drive mechanism connected between said mounting means and said inner conduit member for moving said inner conduit member about said first horizontal axis, a drive means connected about said first horizontal axis, a drive means connected between said mounting means and said outer conduit for rotating said outer conduit member with respect to said inner conduit member; said drive means being operable throughout its full range of operation for movement independent of the movement of said inner conduit member; and means for counterbalancing said inner and outer conduit members including means for applying a force to said inner conduit member at a radial distance from said first axis that varies as the centre of gravity of said conduit members alters its horizontal distance from said first axis, and wherein said drive means comprises a first sheave concentric with said first horizontal axis and fixed to prevent rotation thereof above said first axis, a second sheave rotatable about said second horizontal axis and fixed to said outer conduit member, and cable means fixed to said first sheave and trained around said second sheave, said cable means being operable to rotate said second sheave to effect movement of said outer conduit member.

2. Apparatus according to claim 1 wherein means for rotating said second sheave comprise at least one fluid-powered cylinder and piston assembly.

3. Apparatus according to claim 1 wherein said drive means includes means for pivoting the outer end of said outer conduit member under a portion of said inner conduit member and means for extending the outer end of said conduit beyond the outer end of said inner conduit member to provide an articulated conduit having a length substantially equal to the sum of the lengths of said inner conduit member and said outer conduit member.

4. Apparatus according to any preceding claim including a weight mounted below the level of said first horizontal axis to provide a relatively low centre of gravity for said apparatus.

5. Apparatus according to claim 4 including guide means for preventing lateral movement of said weight while freely permitting vertical movement of said weight.

6. Apparatus according to any preceding claim including support means for relieving said means mounting said inner member of a substantial portion of the weight of said inner and said outer conduit members when said apparatus is in a stowed position.

7. Apparatus according to any one of claims 1 to 5 wherein said means mounting said inner conduit includes a rigid plate, mounted on said inner conduit member to support said inner conduit member for pivotal movement about said first horizontal axis.

8. Apparatus according to any preceding claim wherein the force applying means comprises fluid-powered-cylinder and piston means connected to said inner conduit member.

9. Apparatus according to claim 8 wherein the cylinder and piston means comprises at least one hydraulic-powered cylinder, and a fluid pressure circuit for providing hydraulic fluid to said cylinder at a pressure sufficient to restrain movement of the piston in the cylinder when the moment of force exerted by the inner and outer conduit members about the first horizontal axis is imposed on said piston.

10. Apparatus according to claim 9 including a source of fluid under pressure, said source being effective to supply fluid to said cylinder at a constant pressure so that said cylinder and piston means can maintain a constant counterbalancing force on said inner and outer conduit members.

11. Fluid transferring apparatus substantially as hereinbefore described with reference to the accompanying drawings.