AU684814B2 - Magnetic handling and cable wrapping system - Google Patents

Description

94E043 9/15/94 SHO/AP1 Page 1 MAGNETIC HANDLING AND CABLE WRAPPING SYSTEM BACKGROUND OF THE INVENTION This invention relates to a facility for handling Steel Hulled Vessels (SHVs) and wrapping cables around them. In particular, it relates to a facility for De-Perming (or degaussing) SHVs which includes a coil of cable (the Z coil) for supporting the horizontal plane around an SHV, and a coil (the X coil) made up of individual turns or wraps for temporarily supporting the SHV in ther vertical plane before it is wrapped. It may also be noted that by construction of a facility along the North-Sough Magnetic Axis, additional coil systems may be eliminated.

This invention permits the Z coil to be permanently installed at all times, without the need for removal after treatment. It also permits the coil to be shortened or lengthened at specific intervals to provide accurate coil size for various length SHVs.

As is well known, to De-Perm a steel hulled vessel, electric currents of differing intensity are passed through independent coils in vertical and horizontal planes around the ship to control the ambient magnetic field and therefore alter the magnetic state of the vessel. It is to be noted that the use of the term "SHV" herein refers to both surface ships and submarines.

By wrapping an insulated electrically conducting coil vertically around the ship's superstructure and hull and passing a current therethrough, the horizontal magnetic field may be controlled. By supporting a horizontal coil (the Z coil) the horizontal plane around the ship and passing an electric current therethrough, the vertical magnetic field may be controlled. The electronic and power supply systems to drive, monitor, model and treat the SHV require the control of D. C. pulsed electricity delivered at high current 2 (typically thousands of Amps) through either or both coils at regular intervals at regulated power outputs.

Although a Drive-In system that automatically wraps the cable around a submarine is known, it is only capable of accommodating a single class submarine, requires a highly trained crew to operate, and consequently is very expensive.

One problem to be faced in providing a facility for wrapping the Z coil around the ship is the weight of the coil, and the difficulty experienced in providing buoyancy while simultaneously attempting to form a perfectly shaped coil which will provide optimum magnetic field homogeneity.

The Z coil typically consists of several turns of copper cable arranged around the perimeter of the facility to enclose the volume of the SHV. The arrangement of this coil so formed may be optimized to provide the best achievable vertical field for the treatment.

Typically, each coil turn may weight in excess of 4 kg per meter and the combination of turns may weigh in excess of 40 kg per meter. The total weight of the Z coil to be supported may therefore exceed 14 metric tons.

Thus, the facility should be able to support such a weight plus the added weight of personnel and mechanized plant on its buoyancy support system during treatment. The coil is required to accurately retain its shape in position around an SHV even in relatively high winds which can create wave action at the water surface and affect the position of the moored ship's mass. The coil is also required to be adequately protected to allow its permanent installation to be achieved.

A further problem relates to the relative position of the Z coil to the ship's hull in Co.: environmental conditions, when the ship is subjected to swell, wind and waves reacting singularly or in combination with the effects of tide. Any variation in the relative distance between the Z coil and the SHV's hull must preferably be minimized to achieve *e.O optimum magnetic field homogeneity. Optimum magnetic field homogeneity is essential to successful treatment results.

Additionally, it may be unsafe to handle heavy cable around an SHV's hull and to superstructure both below and above the surface of the water when the ship is 30 continuously rising and falling due to the wave or swell effect acting on the moored vessel. Accordingly, wrapping may be halted during times of year when heavy swells and waves are prevalent. Thus, it is desirable that the facility be able to cope with the vessel's movement and still allow safe wrapping of the cable.

From the perspective of successful treatment results and economic utilization of assets, inclement weather, squalls and winds causing wave and swell reactions with tidal variations adversely affecting moored vessels, cause detrimental results in treatment activity. Down time from unsafe conditions causes unscheduled delays. Facilities need to provide operational times which include these unsatisfactory conditions.

[N:\IiblI]01050:KEH r 3 BRIEF SUMMARY OF THE INVENTION It is the object of the present invention to overcome or substantially ameliorate at least some of the above disadvantages.

There is disclosed herein a system for magnetically treating a steel hulled vessel (SHV) in water, the SHV being associated with a horizontal magnetic field and a vertical magnetic field extending about vertical and horizontal axes, respectively, of the SHV, the system comprising: a plurality of pontoons coupled together to form a perimeter for receiving the SHV therein, said perimeter comprising: a substantially linear bow section having first and second ends, a first side section coupled to said first end of said bow section, a second side section coupled to said second end of said bow section, said first and second side sections being substantially parallel such that an open end of said perimeter is defined through which said SHV can enter said perimeter, and a gate section adapted to move generally parallel to said bow section between said first and second side sections to close off said perimeter after said ship has entered said perimeter; said system further comprising: first cable means extending about said perimeter below said pontoons so as to form a substantially horizontal coil when said perimeter is closed off, and o. means for passing an electric current through said first cable means.

There is further disclosed herein a method of magnetically treating a steel hulled vessel (SHV) in water, the SHV being associated with a horizontal magnetic field and a vertical magnetic field extending about vertical and horizontal axes, respectively, of the SHV, the method comprising the steps of: S coupling together a plurality of pontoons to form a perimeter for receiving the SHV therein, said perimeter comprising: a substantially linear bow section having first and second ends, a first side section coupled to said first end of said bow section, S 30 a second side section coupled to said second end of said bow cection, said first and second side sections being substantially parallel such that an open end of said perimeter is defined through which said SHV can enter said perimeter, and a gate section adapted to move generally parallel to said bcw section between said first and second side sections to close off said perimeter after said ship has entered said perimeter; extending first cable means about said perimeter below said pontoons so as to form a substantially horizontal coil when said perimeter is closed off, and passing an electric current through said first cable means.

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[N:\AIib11]01050:KEH Each floating pontoon preferably includes a top working platform mounted on one or more flotation elements. The flotation element preferably comprises a polyethylene tank, but other flotation devices could, of course, be utilized.

The floating pontoons may have varying widths and there are preferably two widths of pontoon. The pontoons making up the perimeter are preferably hinged end-toend around the bow and side sections and within the gate section. At least one of the floating pontoons forming the bow and side sections of the perimeter is preferably provided with a roller assembly for fitting to a pile to anchor the perimeter in a horizontal position. The roller assembly preferably comprises a plurality of rollers each having a horizontal axis of rotation, the rollers being mounted on a frame to provide a rolling contact surface on an interior side of an annulus, whereby the roller assembly can be positioned over the pile and move vertically up and down the pile, but is constrained in the horizontal plane.

In a preferred embodiment said downwardly extending member may carry a Z coil below the surface of the water and/or may extend as far as the lowest depth required for a 4* 0 4,O D 0* 9 *ft

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[N:\Iib11]01050:KEH 94EO43 9/15/94 SHO/AP 1 Page Z coil, and preferably includes two or more eyelets to allow one or more cables to be supported at different depths on one or alternative downward members.

In a further preferred embodiment of the invention, electric junction boxes are 5 provided on the ends of the gate section and at intervals along the side sections of the perimeter corresponding to the lengths of different SHVs. A cable running along the side and bow sections of the perimeter can be electrically connected to the junction boxes on the side sections, and the cable running along the gate section can be electrically connected to the junction boxes on the ends of the gate section. By electrically connecting the junction boxes on the ends of the gate section to the appropriate junction boxes on the side sections, the cable can then easily be connected to form a complete coil around the

SHV.

In a further preferred embodiment of the invention, the X coil cables, determined in length from a given point as the distance traveled by a cable closely wrapped around a vessel in the vertical plane to the point of commencement, are delivered to the floating pontoons along with accouterments which include X coil buoys, cable flanges and an assortment of rope lines.

A cable drum trailer is used to control the X coil leading end which is fitted through retaining rings and clamped by a cable flange into a buoy, floated into the waters S encompassed by the perimeter, drawn across to one side by hauling lines securing the S leading end to t, pontoon cleat, while the trailing end is similarly housed and tethered to the opposite side cleats creating a submerged loop over which the incoming vossel can pass. Alternatively, the coil may be temporarily supported by the pontoon perimeter in a space not intruded upon by the vessel, whereupon the berthing being completed, the lines attached to pontoon cleats of the leading and trailing end of the X coils are released and passed onboard the vessel at a prescribed spot, or the cables may be moved to the prescribed position, whereupon the cables are hauled aboard and secured and coupled to

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94E043 9/15/94 S HO/AP Page 6 the fore and aft wraps forming a vertically wound coil around the SHV's hull and superstructure, the action preferably being accomplished without the need for divers.

Furthermore, during cable wrapping, the use of cable buoys which may remain at 5 water level allowing the cables to slide therethrough, perform a secondary function where a cable being secured aboard becomes free and the head weight of the cable creates the energy to move either the leading or trailing end of the cable toward the water, until the cable flange comes in contact with the cable buoy surface affecting a limiting reaction, supporting the cable from total submersion, whereupon the recovery can preferably be effected without the need for divers.

BRIEF DESCRIPTION OF THE DRAWINGS S"One embodiment of a facility according to the invention will now be more fully 15 described, by way of example, with reference to the drawings, of which: Figure 1 shows a schematic plan view of a facility according to one embodiment of the invention; Figure 2 shows a bottom plan view of one pontoon used in the facility of Figure 1.

Figure 3 shows a top plan view of one pontoon of Figure 2.

4 Figure 4 shows a sectional elevation through a pontoon used in the facility of Figure 1.

Figure 5 shows a pontoon connection assembly according to one embodiment of the invention.

i 94E043 9/15/94 SHO/AP1 Page 7 Figure 6 shows an enlarged view of portion A of Figure 4.

Figure 7 shows a roller assembly used in the facility of Figure 1.

Figure 8 shows a side elevation of part of the facility of Figure 1, including one means for supporting a cable.

Figure 9 shows a sectional view through part of the facility of Figure 8.

Figure 10 shows a sectional view of the facility of Figure 1, including one alternative means fur supporting a Z cable, and one alternative method of temporarily supporting the X coil forming the submerged loop.

Figure 11 shows one alternative member for supporting a Z Coil Cable.

Figure 12 shows a sectional view of an alternative method of supporting a Z coil cable.

Figure 13 shows a plan view of an X coil buoy used in the facility of Figure 1.

Figure 14 shows a side elevation of a cable flange used in the facility of Figure 1.

Figure 15 shows an isometric view of the Junction Box Main Frame used in the facility of Figure 1.

Figure 16 shows a cable srain relief assembly as a component of Figure

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94E043 9/15/94 SHO/AP 1 Page 8 DETAILED DESCRIPTION OF THE DRAWINGS Thus, as shown in Figure 1 of the drawings, a facility for receiving and handling SHVs, both surface ships and submarines, and for wrapping both X and Z coils around the SHV comprises a plurality of floating pontoons P1 to P36. The pontoons P1 to P36 are either single width or double width and are hinged together to form two parallel side sections and a bow section and a gate section The structure of one double width pontoon, for example P1, is shown in Figures 2 and 3 of the drawings. It will be appreciated that a single width pontoon, for example P3 of Figure 1, is similar in construction but only includes a single row of flotation tanks As shown in Figure 2 and 3, the floating pontoon P1 comprises nine deck panels made of plywood, to whose lower surface are mounted 18 flotation tanks Each flotation tank is mounted by the means of nylon webbing which passes around the tank and is then connected to a bracket (11) to the under side of the appropriate deck panel The deck panels are attached on each deck edge to an edge beam (10) and in the center to a center beam (13) by means of a beam bolt Each flotation tank (6) also has a bung hole at the bottom thereof for adjusting the amount of flotation with air and water. These flotation tanks can be reversed and have the bung hole on the top surface and function identically.

As shown in Figure 3, the floating pontoon P1 has a location identified for various hinge applications. The varioius locations shown for this embodiment of the invention provides for interconnection of single width and/or double width pontoons. However in any one case two hinges are utilized where two pontoons interconnect either end.

Pontoons P7 with P35 and P36 are structurally interconnected by mechanical means as shown in Figure 3A where the edge beams (10) are connected to each other by means of a fastener (12) as shown in figure 3B installed horizontally securing both beams.

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94E043 9/15/94 S HOAP 1 Page 9 As shown in Figure 3A, deck panels are interspersed throughout with staggered joints over edge beams (10) and double center beams (13) which are also secured by a series of fasteners (12) installed as detailed above.

As shown in Figure 3, road markings are provided on the top surface of pontoon P1 depicting a safe movement corridor enabling crew and equipment to move around the perimeter. It will be appreciated that a single width pontoon would only include space for the road area, whereas a double width pontoon, such as that shown in Figure 3, includes extra deck area, for example for reel and equipment storage.

Returning to Figure 1, it will be seen that bow section is connected to the side sections and by means of removable walkways and all three of those sections are moored in position by attachment to piles MP1 to MP22 driven into the sea bed.

However, to allow the facility to rise and fall with the wave, swell or tide, similarly to the ship, each pontoon which is to be moored to a pile is provided with a roller assembly such as that shown in Figure 7. This roller assembly (15) is in turn fitted into a positioning and holding assembly (16) as shown in Figure 17. The roller assembly (15) comprises eight rollers (17) arranged around an inner perimeter of an octagonal annular frame (18).

Each of the rollers (17) rotates around a horizontal axis and the assembly (15) is positioned over the appropriate pile. Thus, as the facility rises and falls, one or more S of the rollers (17) contacts the pile and rotates, allowing the facility to move vertically, and yet be anchored in the horizontal direction to the pile.

As shown in Figure 1, dolphin pile arrangements D1 to D9 having three or seven piles coupled together are used for the mooring of the vessel independent to the marina piles MP1 to MP22 which support the perimeter of the pontoon system.

c~ 94E043 9/15/94 SHO/API1 Page As shown in Figure 1, side sections and are, in this embodiment, made long enough to enclose the longest SHV to be handled by the facility. The SHV enters between the two side sections and bow first and moves forward until the b ,w of the SHV is a predetermined distance from bow section Gate section is then moved to close off the facility behind the stem of the SHV. As shown in Figure 1, depending on the length of the SHV to be handled, the gate section may have any one of four, or more positions. At each of these positions, corresponding to a pr-,aMc.u length SHV, the gate section is moored and coupled to the side sections a (2i) usirp.

mooring ropes attached to bollards marked X on the ends of the gate section l and in appropriate positions on the side sections and Once a vessel is in position, placed over the center line marked by Dl and the hinge joint of the gate section moored equidistant from the perimeter, a cable carried by the gate section (24) and/or (25) can be connected from one junction box (26) on 15 section 1 to the corresponding junction box (26) on section 2.

The Z coil (24) and (25) extends along the two side sections and and the bow section of the facility as shown in Figure 1, and is connected to junction boxes (26) positioned on the pontoons at predetermined positions corresponding to the lengths of different SHVs to be handled, as shown at Figure 18. Thus, although the cable extends from the bow section along each of the side sections and as far as the farthest end, junction boxes (26) are provided at positions along the cable enabling the length of cable supported on gate section to be connected thereto, this completes the Z coil circuit around the SHV hull. Other connections to the Z coil, for example to the main power supply and the control system, can also be made through the junction boxes.

In Figure 8, cable support members (19) and (20) are mounted to the edge beams by means of hook bolts (21) set into the deck panels at specific intervals along the vertical face of the edge beams The suspension of the Z coil (24) and (25) may be 94E043 9/15194 SHO/AP 1 Page I I incorporated in one of the following positions, the first being from the face of the edge beams (10) on the internal face of the perimeter as per Figure 8. The second being identical but from the face of the edge beams (10) on the external face of the perimeter, and the third being positioned from the underside center of the double width pontoons and 5 the rear edge beam of the narrow width pontoons as shown in Figure 10. Each of the support members (19) and (20) have a series of adjusting eyelets by which the coil may be suspended at various depths. This is shown in (22) of Figure No. 11. Thus, the Z coil may be set at various widths and various lengths according to the need of the embodiment.

Accordingly what has been described is a facility comprising a plurality of floating pontoons forming a working platform, connected end-to-end or side-by-side throughout the system. Buoyancy is maintained by the use of flotation tanks under both double width and single width pontoons, connected by elastomeric hinges. The pontoons are positioned about a vessel permitting the movement of personnel and equipment around the entire perimeter of the vessel.

The facility also enables the X coils which are wrapped vertically around the vessel to be easily positioned. From the pontoon deck, the cables can be pre-positioned in the berth prior to the docking of the vessel by the adaption cable flotation buoy (28) shown in Figure 13, and a cable flange (29) shown in Figure 14 which is retained around the cable by a commercial mechanical band and clip. The cables feed through pre-positioned rings on a buoy (28) which is attached to each end of the cable, and the middle of the cable is suspended from one pontoon face toward the sea floor, across the gap between the two parallel sides and and back up to the opposing pontoon forming the submerged loop (30) shown in Figure 10. Cleats positioned on the pontoons enable the buoys to be tied back to the pontoon face in specific positions obviating a navigational problem for the docking vessel. Alternatively, the buoyed X cables may occupy a position forward of the docking vessel similarly held by cleats on opposite pontoons.

94E043 9/15/94 SHO/API Page 12 When the vessel is docked, the cables are secured to drag lines, and hoisted up around the hull and/or super-structure of the vessel to form the X coil. As the cables pass through the rings in the buoy the cable buoys may remain at water level or at a niche in the ship's hull or super-structure. A cable flange (29) is fitted to each cable end, which prevents the cable from freeing itself from the cable buoy If a cable is accidentally dropped or unsecured, the weight of the cable causes the cable to fall back to the water level where the cable flange engages the surface of the cable buoy preventing the cable from falling to the sea bed. Thus, cable recovery is speedily achieved from the pontoon working platform or from the SHV's deck.

When all of the cables are connected and tested, including the cables connected to the power supply, the pontoons provide the means of safe exit by personnel, their equipment and machinery previously engaged in cable wrapping, via a ramp and wharf (31) shown at Figure 1. which connects the system to the land. When all personnel are secure, the cables can be energized and the treatment continues.

It will be appreciated that, although only one embodiment of a facility according to the invention has been described, a number of improvements and variations can be made without departing from the scope of the invention.

Claims (23)

1. A system for magnetically treating a steel hulled vessel (SHV) in water, the SHV being associated with a horizontal magnetic field and a vertical magnetic field extending about vertical and horizontal axes, respectively, of the SHV, the system comprising: a plurality of pontoons coupled together to fo-in a perimeter for receiving the SHV therein, said perimeter comprising: a substantially linear bow section having first and second ends, a first side section coupled to said first end of said bow section, 1o a second side section coupled to said second end of said bow section, said first and second side sections being substantially parallel such that an open end of said perimeter is defined through which said SHV can enter said perimeter, and a gate section adapted to move generally parallel to said bow section between said first and second side sections to close off said perimeter after said ship has entered said perimeter; said system further comprising: first cable means extending about said perimeter below said pontoons so as to form a substantially horizontal coil when said perimeter is closed off, and means for passing an electric current through said first cable means.

2. The system of claim 1 wherein said first cable means comprises a first cable extending along said first side section, said bow section and said second side section and coupled to opposing ends of a second cable extending along said gate section.

3. The system of claim 2 wherein a plurality of junctions boxes are spaced along each of said first and second side sections, said first cable being coupled to said second cable via a said junction box adjacent each said opposing end of said second cable. V,

4. The system of any one of claims 1 to 3 wherein at least one of said pontoons is adapted to be anchored to a pile to allow said pontoons to move vertically as they float.

The system of claim 4 further comprising roller means coupled to at least one of the pontoons forming the bow and first and second side sections, said roller means being adapted to be fitted to a pile to allow said pontoons to move vertically as S they float.

6. The system of claim 5 wherein said roller means includes a plurality of rollers, each said roller having a horizontal axis of rotation to provide a rolling contact surface with a pile.

7. The system of any one of claims 1 to 5 wherein at least one of said pontoons comprises a top workng platform mounted on a flotation element.

8. The system of any one of claims 1 to 7 wherein said pontoons are hinged end to end around the first and second side and bow and gate sections. [N:\Iibil]01050:KFH 00 OS OS 0*O S~ S. SO *0

9. The system of any one of claims 1 to 8 further comprising second cable means extending about said SHV in a substantially vertical plane for controlling the horizontal magnetic field of the SHV, the second cable nr.eans having two ends.

The system of claim 9 further comprisilng support lines for securing the ends of the second cable means to pontoons on opposing parallel sections of said perimeter such that said second cable means defines a submerged loop over which an incoming SHV may pass.

11. The system of claim 10 further comprising: coil buoys, cable flanges for clamping said second cable means on said cable buoys, and cable control means for controlling said second cable means.

12. The system of claim 11 wherein said cable buoys support said second cable means from total submersion in the water.

13. A method of magnetically treating a steel hulled vessel (SHV) in water, the SHV being associated with a horizontal magnetic field and a vertical magnetic field extending about vertical and horizontal axes, respectively, of the SHV, the method comprising the steps of: coupling together a plurality of pontoons to form a perimeter for receiving the SHV therein, said perimeter comprising: a substantially linear bow section having first and second ends, a first side section coupled to said first end of said bow section, a second side section coupled to said second end of said bow section, said first and second side sections being substantially parallel such that an open end of said perimeter is defined through which said SHV can enter said perimeter, and 25 a gate section adapted to move generally parallel to said bow section between said first and second side sections to close off said perimeter after said ship has entered said perimeter; extending first cable means about said perimeter below said pontoons so as to form a substantially horizontal coil when said perimeter is closed off, and 30 passing an electric current through said first cable means.

14. The method of claim 13 wherein said first cable means is extended by extending a first cable along said first side section, said bow section and said second side section and coupling said first cable to opposing ends of a second cable extending along said gate section.

15. The method of claim 14 wherein said first cable is coupled to said second cable via a junction box adjacent each said opposing end of said second cable.

16. The method of any one of claims 13 to 15 wherein at least one of said pontoons is anchored to a pile to allow said pontoons to move vertically as they float. [NAIibil10105:KEH

17. The method of claim 16 wherein roller means are coupled to at least one of the pontoons forming the bow and first and second side sections, said roller means being adapted to be fitted to a pile to allow said pontoons to move vertically as they float.

18. The method of any one of claims 13 to 17 wherein said pontoons are hinged end to end around the first and second side and bow and gate sections.

19. The method of any one of claims 13 to 18 further comprising the step of extending second cable means about said SHV in a substantially vertical plane for controlling the horizontal magnetic field of the SHV, the second cable means having two ends.

20. The method of claim 19 further comprising the steps of: clamping said second cable means to coil buoys, and securing said second cable means to pontoons on opposing parallel sections of said perimeter such that said second cable means defines a submerged loop over which an incoming SHV may pass.

21. The method of claim 20 further comprising the step of supporting said second cable means from total submersion in the water.

22. A system for magnetically treating a steel hulled vessel (SHV) in water, the SHV being associated with a horizontal magnetic field and a vertical magnetic field extending about vertical and horizontal axes, respectively, of the SHV, the system being 20 substantially as hereinbefore described with reference to the accompanying drawings.

23. A method for magnetically treating a steel hulled vessel (SHV) in water, the SHV being associated with a horizontal magnetic field and a vertical magnetic field extending about vertical and horizontal axes, respectively, of the SHV, the method being substantially as hereinbefore described with reference to the accompanying drawings. Dated 16 September, 1997 ""Rockwell International Corporation Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON s*n~s~ rr~ul 11~1 1 1I1 I- Magnetic Handling and Cable Wrapping System ABSTRACT A system for magnetically treating a steel hulled vessel (SHV) in water comprises first cable means (Z coil) extending about the horizontal axis of the SHV for controlling the vertical magnetic field of the SHV, and a plurality of pontoons (P1-P34) coupled together to form a perimeter for receiving the SHV therein. The perimeter comprises a substantially linear bow section a first side section coupled to the bow section, a second side section coupled to the bow section, and a gate section coupled between the first and seccnd side sections, and movable substantially parallel to the bow section to enclose the SHV within the perimeter. A plurality of electric junction devices (26) are carried along the gate, bow, and first and second side sections. An electric current is passed through the first cable means at predetermined intervals for energizing the electric junction devices such that an energized coil is formed about the perimeter of .the SHV to control the magnetic field and alter the magnetic state of the SHV. (Fig. 1) IL~s