US3889728A

US3889728A - Marine loading arm for bunkering vessels

Info

Publication number: US3889728A
Application number: US353843A
Authority: US
Inventors: Robert M Riche
Original assignee: TECH ET COMMERCIAL D INSTALLAT
Current assignee: TECH ET COMMERCIAL D INSTALLAT; Technique Et Commercial D'installations Industrielles 'luceat'fr197204287215421 Ste
Priority date: 1972-04-28
Filing date: 1973-04-23
Publication date: 1975-06-17
Anticipated expiration: 1992-06-17
Also published as: FR2181584A1; HK13776A; JPS49116786A; SU583729A3; SE399223B; OA04373A; JPS5316594B2; GB1399060A; ZA732689B; FR2181584B1

Abstract

A compactly stowable marine loading arm especially suitable for mounting on the deck of relatively small or coaster-type marine tankers to facilitate transfer of fluids, and especially petroleum products such as bunker fuel, from the tankers to other ships, particularly container-carriers. The loading arm comprises an inboard arm section mounted on a riser for pivotal movement about horizontal and vertical axes, and an outboard arm section joined to the inboard section for pivotal movement about two additional horizontal axes and another vertical axis. The loading arm is arranged to be stowed in a horizontal attitude with the outboard section extending back toward the riser and overlying the inboard section. When the arm is used, the outboard section is pivoted about the vertical axis at its juncture with the inboard section until it extends forward from the inboard section in the desired functional direction. A counterweight carried by the inboard section provides a counterbalancing force for the arm about the riser''s horizontal axis, and a sheave and cable system maintains the outboard section''s elevational attitude, i.e., with respect to the vertical, as the inboard section is raised or lowered, this attitude being variable by a suitably mounted hydraulic cylinder or equivalent means.

Description

United States Patent [1 1 Riche 1 MARINE LOADING ARM FOR BUNKERING VESSELS [75] Inventor: Robert M. Riche, Sens, France [73] Assignee: Societe Technique et Commercial dlnstallations lndustrielles Luceat, Sens, France [22] Filed: Apr. 23, 1973 [21] Appl. No.: 353,843

[30] Foreign Application Priority Data Apr. 28, 1972 France 72.15421 [52] US. Cl. 141/387; 9/15; 137/236; 137/615 [51] Int. Cl B651) 3/04; 865g 67/00 [58] Field of Search 9/8 P, 8 R, 15; 61/46,

[ June 17, 1975 Primary Examiner-Richard E. Aegerter Assistant Examiner-Frederick R. Schmidt Attorney, Agent, or FirmW. W. Ritt, Jr.; C. E. Tripp 5 7 ABSTRACT A compactly stowable marine loading arm especially suitable for mounting on the deck of relatively small or coaster-type marine tankers to facilitate transfer of fluids, and especially petroleum products such as bunker fuel, from the tankers to other ships, particularly container-carriers. The loading arm comprises an inboard arm section mounted on a riser for pivotal movement about horizontal and vertical axes, and an outboard arm section joined to the inboard section for pivotal movement about two additional horizontal axes and another vertical axis. The loading arm is arranged to be stowed in a horizontal attitude with the outboard section extending back toward the riser and overlying the inboard section. When the arm is used, the outboard section is pivoted about the vertical axis at its juncture with the inboard section until it extends forward from the inboard section in the desired functional direction. A counterweight carried by the inboard section provides a counterbalancing force for the arm about the risers horizontal axis, and a sheave and cable system maintains the outboard sections elevational attitude, i.e., with respect to the vertical, as the inboard section is raised or lowered, this attitude being variable by a suitably mounted hydraulic cylinder or equivalent means.

12 Claims, 3 Drawing Figures PATENTED JUN 1 7 I975 ea n S @N No 08 Nm. m 0m 69 Q9 m mm mm mm no. 2. 8mm 80m mm 0.1L m m mm 6m @m o .NN I 8 H m- HIH I mlmv SHEET PATENTEDJUN 17 1975 N m-HIP PATENTEDJUN 17 I975 SHEET mu mHll u l MARINE LOADING ARM FOR BUNKERING VESSELS BACKGROUND OF THE INVENTION This invention relates to apparatus for transferring fluid from one container to another and, more particularly, to marine loading arms for transferring fluid petroleum or products thereof between a storage reservoir and a marine vessel. In a specific sense, the invention relates to shipboard-mounted marine loading arms of the pantograph and counterweighted variety for use on relatively small bunkering vessels.

Many of the more modern large cargo ships, such as container-carriers, have high deck levels especially when they are not loaded to capacity, and often this characteristic makes bunkering them from the wharf quite difficult. When insufficient harbor depth prevents bringing the ships to the wharf, bunkering operations are conducted from a coaster or other small marine tanker that has a very low deck level. For many years whart-mounted marine loading arms have been highly satisfactory for delivering bunker fuel to ships moored alongside within their reach, but in order to install and safely use these arms on board a coaster or similarly small tanker they must be extensively modified to adapt them to that new non-stationary mounting. Many considerations, including overall dimensions, inertia, wind forces, movements of various types, and variations in the tankers loaded water-line, are involved in accomplishing the adaptation, and even then the result may not be entirely satisfactory.

Accordingly, prior to the present invention there was a genuine need for a marine loading arm oflow inertia, of dimensions small enough for compact stowage yet large enough for efficient transfer of bunker fuel, that has adequate reach for bunkering high-decked ships from low-decked tankers, that can be maneuvered with ease and accuracy, and that is otherwise suitable in every way for use aboard a floating marine vessel.

SUMMARY OF THE INVENTION The present invention solves the foregoing problems and fulfills the foregoing needs by providing a marine loading arm that satisfies all the requirements for shipboard mounting and use. An arm according to this invention comprises an inboard section mounted on a riser for pivotal movement about the risers vertical and horizontal axes, and an outboard section pivotally joined to the inboard section through three swivel joints oriented about two horizontal axes and one vertical axis. In the arms stowed position both inboard and outboard sections are horizontally oriented with the outboard section extending back towards the riser and overlying the inboard section.

A sheave and cable pantograph system extends between the risers horizontal axis and the first of the horizontal axes at the juncture of the inboard and outboard sections. The inner sheave of this system is nonrotatable, while the outer sheave can rotate with respect to the inboard section about the aforementioned first horizontal axis. The outboard section is pivotable about the junctures first horizontal axis along with the outer sheave, but also is independently pivotable about the junctures second horizontal axis and its vertical axis.

At the area of juncture between the arms inboard and outboard sections, hydraulic means, such as a cylinder, are employed to pivot the outboard section about the junctures second horizontal axis, thereby changing this sections elevational attitude independent of any movement of the inboard section. When this cylinder is locked against operation and the inboard section is raised or lowered, the outboard section pivots with the outer sheave about the junctures first horizontal axis without any change in its elevational attitude. Hydraulic means, such as a rotatable cylinder or hydraulically powered swivel joint, also are employed to pivot or slew the outboard section about the junctures vertical axis.

At the riser area, additional hydraulic means, again such as cylinders, are provided to elevate the inboard section and to slew the arm about the risers vertical axis. Furthermore, a counterweight is mounted on the inboard section at a suitable position behind the riser to at least partially counterbalance the arm about the risers horizontal axis.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a marine loading arm according to the present invention, showing it mounted on the deck of a marine tanker and in an elevated position.

FIG. 2 is a side elevation, on an enlarged scale, of the loading arm of FIG. 1, showing it in its stowed position.

FIG. 3 is a plan view of the loading arm of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT As illustrated in the drawings, a marine loading arm 10 according to the present invention comprises a riser 12 mountable on the deck 14 of a coaster or other marine vessel 16, an inboard arm section 18 pivotally mounted on the riser l2, and an outboard arm section 20 pivotally joined to the inboard section at a juncture area 22 and terminating in a conventional coupling assembly 24 providing universal movement about three mutually perpendicular axes. The riser and both inboard and outboard arm sections are of rigid, tubular construction to conduct a flow of fluid from the coaster 16 to another marine vessel to which the coupling assembly 24 is connected during bunkering operations, and the riser is connected by suitable piping 26 to the coasters cargo tanks in the usual manner.

The riser 12 includes a vertical swivel joint 28 that facilitates slewing the arm about a vertical axis A, and terminates in a horizontal trunnion swivel joint 30 (FIGS. 2 and 3) that connects it and the inboard section 18 together and provides for elevational pivotal movement of the inboard section about a horizontal axis B. An hydraulic cylinder 32 is supported on the risers nonrotatable lower portion 12a by a suitable bracket 34, and has its piston rod connected to the rotatable element 28a of the swivel joint 28, thereby to provide the force for the slewing movement. The inboard section 18 is pivotally elevated about the axis B by means of an hydraulic cylinder 36 that is supported by a bracket 38 mounted on the risers rotatable upper section 12b, and that is connected at the end of its piston rod to the inboard section 18. Accordingly, by proper manipulation of the

cylinders

32 and 36, as by a suitable control system (not shown), the arm can be raised and lowered about the axis B and slewed about the axis A into any operating position as required.

The arms outboard section 20 is joined to the inboard section 18 through an assembly of three swivel joints and two 90 elbows that facilitate pivotal movement of the outboard section with respect to the inboard section about two horizontal axes and one vertical axis. This assembly comprises a first horizontal swivel joint 40 disposed on a horizontal axis C at the outer end of the inboard section 18, a first elbow 42 extending from the swivel joint 40 to a vertical swivel joint 44 disposed on a vertical axis D, and a second elbow 46 extending from the vertical swivel joint 44 to a second horizontal swivel joint 48 disposed on a hori zontal axis E. The inner end of the outboard section 20 is connected to the swivel joint 48, and is pivoted about the axis E by means of an hydraulic cylinder 50 that extends from the outboard section to a suitable bracket 51 mounted either on the elbow 46 or on the element of the swivel joint 48 that is non-rotatably connected to the elbow 46. Pivotal or swinging movement of the outboard section 20 about the vertical axis D can be accomplished in various ways, as for example by means of an hydraulically powered swivel joint at 44, a rotating cylinder (not shown), or other means that will be obvious to those familiar with this type of equipment. Accordingly, by appropriate powering of the hydraulic cylinder 50 and swivel joint 44 the outboard section can be maneuvered about the axes E and D, respectively, independently of any movement of the inboard section 18.

In order to maintain the elevational attitude of the outboard section 20 with respect to the inboard section 18 during pivotal movement of the inboard section about the risers horizontal axis B and also while the inboard section is stationary, a sheave and cable pantograph system, comprising an inner sheave 52, outer sheave 54, and an interconnecting endless cable-rod assembly 56, is included on the arm 10. The inner sheave 52 is non-rotatably mounted on the riser 12, as for example by securing it to the non-rotatable element of the trunnion swivel joint 30 so that the sheave is coaxial with the risers horizontal axis B. The outer sheave 54 is rotatably mounted on the outer end of the inboard section 18, as by securing it to the rotatable element of the swivel joint 40 that is secured to the elbow 42, so that the sheaves axis of rotation corresponds to the horizontal axis C. The cable-rod assembly 56 comprises a pair of

flexible cables

56a, 56b interconnected by a pair of

rods

56c, 56d, the rods preferably running through guiding rollers 58 mounted on suitable supports 59 fastened to the inboard section 18. The

cables

56a, 56b are trained around the

sheaves

52, 54, respectively, so that as the inboard section is raised or lowered by the cylinder 36 the outer sheave 54 is prevented from rotating about the horizontal axis C into a different position relative to the inner sheave 52. Since the outer sheave is thus maintained in its rotational orientation about the axis C, so too are the elbows 42 and 46 and the vertical axis D maintained. Accordingly, when the cylinder 50 is locked, i.e., its piston rod prevented from extending or retracting, elevational change of the inboard section 18 about the risers horizontal axis B will cause no change in vertical (elevational) attitude of the outboard section 20.

The loading arm further is provided with a counterweight assembly 60 mounted in a suitable manner on a strut or other type of support structure 62 that extends rearwardly from the inboard section 18 behind the riser 12. The mass of the counterweight is sufficient to at least partially counterbalance the arm 10 about the risers horizontal axis B, all in the conventional manner. Where needed, auxiliary support structures such as diagonal, etc. braces 66 can be employed to lend strength to and prevent bending of, the inboard section 18, which herein is shown as comprising three

decreasing pipe sections

18a, 18b and 18c.

When the arm 10 is at rest in its stowed position. as shown in FIGS. 2 and 3, and also in phantom in FIG. 1, the outboard section 20 extends horizontally and rearwardly from its juncture with the inboard section 18 towards the riser 12, overlying the inboard section and resting on a suitable support 70. The outer end of the inboard section also rests in a horizontal attitude on a suitable support 72 (FIG. 1), so that when stowed the arm 10 is in a compact condition with an exceedingly low center of gravity, presenting wind forces with a minimum area against which to act, and otherwise being exceptionally stable with respect to movements of the deck 14.

As should be evident from the foregoing, when the arm 10 is in operation, i.e., when fluid is being transferred from the tanker 16 to another vessel, the

hydraulic cylinders

32 and 50 are in a free-wheeling mode whereas the cylinder 36 is locked. This enables the arm to follow all relative movements between the tanker 16 and the vessel being refueled, while also maintaining support of the inboard section in the most desirable functional attitude. Operation of these cylinders preferably is coordinated by safety hydraulic or electrical circuits (not shown) that are manually or automatically operated, and corrected with ancillary circuits of any of the known appropriate types, according to changes in deck level between the tanker and the vessel being refueled during bunkering operations.

Although the best mode contemplated for carrying out the present invention has been herein shown and described, it will be apparent that modification and variation may be made without departing from what is regarded to be the subject matter of the invention.

What is claimed is: 1. A tubular loading arm comprising: a riser, an inboard arm section mounted on the riser for pivotal movement in a generally vertical plane about a generally horizontal axis through the riser,

an outboard arm section, and

means pivotally interconnecting the inboard and outboard arm sections having three pivot axes, whereby the outboard section can be pivoted with respect to the inboard section in both a generally horizontal direction and a generally vertical direction independent of movement of said inboard section, and the outboard section can be moved between a forwardly extending operational attitude and a rearwardly extending stowed attitude wherein the outboard section generally overlies the inboard section and extends toward the riser.

2. A loading arm according to claim 1 wherein the pivotally interconnecting means comprises three swivel joints interconnected through elbows, with the first and third swivel joints oriented on generally horizontal axes and the second swivel joint oriented on a vertical axis.

3. A loading arm according to claim 2 including a pantograph system for maintaining the axis of the second swivel joint vertical throughoutelevational movements of the inboard section, said pantograph system comprising an inner sheave non-rotatably mounted on the riser, an outer sheave connected to the outboard arm section and mounted on the inboard arm section for rotation about the axis through the aforesaid first swivel joint, and means interconnecting the inner and outer sheaves to rotate the outer sheave as the inboard arm section is pivoted in a vertical plane about the horizontal axis through the riser.

4. A loading arm according to claim 3 wherein the outer sheave and the second swivel joint are connected in a manner that precludes relative movement between said outer sheave and the axis through said second swivel joint.

5. A loading arm according to claim 2 wherein the outboard section is connected to the third swivel joint for pivotal movement about the generally horizontal axis through said third swivel joint independently of movement of the inboard section.

6. A loading arm according to claim 2 including means to pivot the outboard section about the generally horizontal axis through the third swivel joint independently of movement of the inboard section.

7. A loading arm according to claim 2 including means for pivoting the outboard section about the vertical axis through the second swivel joint independently of movement of the inboard section.

8. A loading arm according to claim 1 including first means to pivot the inboard section on the riser, and second means to pivot the outboard section horizontally and vertically with respect to the inboard section, said first and second means functionable independently of each other.

9. A loading arm according to claim 1 wherein the inboard section is mounted on the riser for pivotal movement also about a generally vertical axis through said riser.

10. A loading arm according to claim 1 including means to at least partially counterbalance the inboard and outboard sections about a generally horizontal axis through the riser.

11. A loading arm according to claim 1 including means to connect the outer end of the outboard section to a marine vessel for delivering fluid thereto.

12. A loading arm according to claim 11 wherein said connecting means comprises a plurality of swivel joints interconnected by elbows to provide pivotal movement about three mutually perpendicular axes.

Claims

1. A tubular loading arm comprising: a riser, an inboard arm section mounted on the riser for pivotal movement in a generally vertical plane about a generally horizontal axis through the riser, an outboard arm section, and means pivotally interconnecting the inboard and outboard arm sections having three pivot axes, whereby the outboard section can be pivoted with respect to the inboard section in both a generally horizontal direction and a generally vertical direction independent of movement of said inboard section, and the outboard section can be moved between a forwardly extending operational attitude and a rearwardly extending stowed attitude wherein the outboard section generally overlies the inboard section and extends toward the riser.

3. A loading arm according to claim 2 including a pantograph system for maintaining the axis of the second swivel joint vertical throughout elevational movements of the inboard section, said pantograph system comprising an inner sheave non-rotatably mounted on the riser, an outer sheave connected to the outboard arm section and mounted on the inboard arm section for rotation about the axis through the aforesaid first swivel joint, and means interconnecting the inner and outer sheaves to rotate the outer sheave as the inboard arm section is pivoted iN a vertical plane about the horizontal axis through the riser.