US3359741A

US3359741A - Deep water support system

Info

Publication number: US3359741A
Application number: US533627A
Authority: US
Inventors: Arthur J Nelson
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-03-11
Filing date: 1966-03-11
Publication date: 1967-12-26
Anticipated expiration: 1984-12-26

Description

Dec. 26, 1967 A. J. NELSON DEEP WATER SUPPORT SYSTEM 3 Sheets-Sheet 1 Filed March 11, 1966 FIE-.1.

INVENTOR. ARTHUR J. NELSON ATTORNEYS Dec. 26, 1967 J NELSON 3,359,741

DEEP WATER SUPPORT SYSTEM Filed March 11, 1966 5 Sheets-Sheet 2 F1 Isl--2- INVENTOK er/wk J. NELSON BY W 71! ATTORNEYS A. J. NELSON Dec. 26, 1967 DEEP WATER SUPPORT SYSTEM 5 Sheets-Sheet Filed March 11, 1966 INVENTOR. ARTHUR J NELSON ATTUZNEVS United States Patent 3,359,741 DEEP WATER SUPPORT SYSTEM Arthur J. Nelson, Santa Barbara, Calif. (1998 Broadway, San Francisco, Calif. 94109) Filed Mar. 11, 1966, Ser. No. 533,627 14 Claims. (Cl. 61--46) The present invention relates to a system for supporting objects in submerged condition in a body of liquid, and more particularly is directed to such a system adapted to buoyantly support an elongated array of objects in submerged stable condition. The invention is especially concerned with a systemadapted for use at sea to automatically sustain the absolute position of the objects with respect to an established datum, irrespective of changes in the supported mass and/or adverse sea conditions.

In recent years, it has become increasingly evident that underwater working techniques must be developed to take advantage of the many resources found at sea. Prime among these resources presently known are petroleum and mineral deposits found at or beneath the floor of the sea. It is also anticipated that, as technology develops, other valuable resources will be discovered in the sea.

In order to effectively recover resources from the sea, it is necessary that practical means of supporting various objects in submerged condition be developed. Among the most immediate of these objects which it is necessary to support are conduits facilitated to convey resources from the floor of the sea to convenient collection stations. Although the support ofsuch conduits might seem relatively simple, it has posed extreme problems due to the depths typically encountered at sea and the resultant conduit lengths necessitated. These problems are aggravated by various factors, such as: adverse sea condtions, varying density of the resource productbcing recovered, practical limitations on the strength and capacity of conduit and support components, and unexpected conditions resulting from failure of equipment associated with the conduits.

According to the present invention, it has been found that the foregoing problems and aggravating factors can best be treated by providing a system whereby the conduit or other elongated array desired to be supported is disposed under tension in a substantially vertical orientation. The preferred form of the system employs both intermediate submerged pontoon structure and surface stabilizing structure to effect the support. Ancillary to these structures the invention incorporates monitoring means to continuously sense varying conditions and control means associated with this monitoring means to maintain the structures in a condition effecting support at a selected elevation relative to a fixed datum, such as the ocean floor. Naturally, the invention also provides for the construction of the support system in a manner to withstand the rigors of sea service.

It is, accordingly, a principal object of the present in- I vention to provide a support system to satisfy the needs of modern underwater technology and particularly technology relating to the recovery of resources from locations on or beneath the floor of the sea.

Another and more specific object of the invention is to provide an underwater support system capable of effecting the stable support of submerged objects under continuously varying conditions.

Yet another object of the invention is to provide an elongated underwater support system incorporating elongated support elements which are continuously maintained under relatively uniform tensile loads.

Still another and more general object of the invention 3,359,741 Patented Dec. 26,1961

is to provide an underwater support system well adapted for supporting any of the various objects which it may be desired to dispose in submerged condition at sea. With respect to this object, it is noted that although the exemplary embodiment of the invention disclosed herein is shown cooperating with a harvesting system of the type disclosed inmy co-pending application, Ser. No. 533,623, filed Mar. 11, 1966, the invention will find any number of other applications.

In its more basic aspects, the system of the present invention may be defined as a series of interrelated elements adapted to support an elongated array of objects in a substantially vertically disposed condition submerged at sea. The basic system comprises: a substantially vertically disposed elongated tension transmitting structure secured in supporting relationship to the objects of the array; at least one intermediate pontoon structure secured to the tension transmitting structure intermediate the end portions thereof to support, at least partially, the load of the array disposed therebelow; and, stabilizing structure secured to the upper end portion of the tension transmitting structure to support, at least in part, the composite load of the array unsupported by the intermediate pontoon structure. The intermediate pontoon structure comprises a chamber of selectively variable buoyancy; buoyancy monitoring means to sense the degree of buoyancy of the chamber; and, buoyancy control means to vary the buoyancy of the chamber responsive to the buoyancy monitoring means so as to maintain the intermediate pontoon structure in a condition supporting the portion of the array therebelow to a predetermined partial degree.

The foregoing and other objects and the more specific characteristics of the present invention will become more apparaent when viewed in light of the following description and accompanying drawings, wherein:

FIG. 1 is an elevational view, partially in section, illustrating the overall arrangement of an embodiment of the inventive system;

FIG. 2 is an elevational schematic view illustrating the buoyancy control circuitry employed with the arrangement of FIG. 1;

FIG. 3 is a perspective view, partially in section, illustrating the condition responsive block and tackle structure adjustably securing the stabilizing pontoon structure of the inventive system to the tension transmitting struc ture thereof;

FIG. 4 is a sectional plan view of the equal tensioning arrangement employed in the tension transmitting structure of the invention; and,

FIG. 5 is a sectional view taken on a plane designated by the line 5-5 of FIG. 4. I

Referring now to FIG. 1, therein is shown a body of water 10 having a floor 11 and a surface 12. The surface 12 is designated by phantom lines at 12a and 12b to illustrate deviations therein which may result from wave or tidal action. A barge 13 is buoyantly supported on the surface 12 and has extending therethrough a circular well 14. Closed

buoyant chambers

15 and 16 surround the well 14 and are isolated therefrom to provide for buoy- 'ancy of the barge.

In the exemplary embodiment illustrated in FIG. 1, the buoyancy system of the present invention is shown supporting a conduit 17 extending between the barge 13 and a harvester 20 disposed in proximate contact with the floor 11. The harvester 20 is of the type more fully disclosed in my aforementioned co-pending application, Ser. No. 533,623. It is to be understood that the barge 13, conduit 17 and harvester 20 are shown herein primarily to exemplify an environment in which the inventive support system may be used. From the subsequent discussion,

it will become apparent that the system is not limited to use with these specific components.

The exemplary environment illustrated in FIG. 1 also includes discharge conduit structure supported on the barge 13 and coupled in fluid communication with the conduit 17. This structure includes coupled fluid conveying components comprising: an elbow 21; a first ball joint 22; a first conduit section 23; a second ball joint 24; and, a second conduit section 25. Support of this structure on the barge 13 is provided by a track 26 mounting the ball joint 24 on the barge for free rectilinear movement longitudinally thereof and a rigid arm 27 pivotally secured at the respective ends thereof to the conduit section 23 and a portion of the barge hull. Through the latter arrangement, as the barge 13 is vertically displaced relative to the conduit 17, movement with respect to the ball joint 22 is confined to a substantially vertical line. During this movement, the ball joint 24 slides rectilinearly on the track 26 and the arm 27 pivots about its connection with the barge 13 and the conduit section 23. A more detailed disclosure of this support arrangement is found .in my aforementioned co-pending application Ser. No. 533,623.

Referring now more specifically to the improved inventive support system, a stabilizing pontoon 30 is buoyantly supported at the surface 12 within the well 14 for vertical movement relative to the barge 13. Detailed structure to provide for the guiding of the stabilizing pontoon 30 within the Well 14 is also disclosed in my aforementioned co-pending application Ser. No. 533,623. From the subsequent discussion, it will be seen that the stabilizing pontoon 30, together with submerged intermediate pontoons disposed therebelow and ancillary tension transmitting structure function to support the conduit 17 without transmitting any appreciable degree of support force to the barge 13. In FIG. 1, two intermediate pontoons designated, respectively, by the

numerals

31 and 32, are shown disposed below the stabilizing pontoon 30. Although only two intermediate pontoons have been shown for exemplary purposes, from the subsequent discussion it will become apparent that any number of such pontoons could be utilized without departing from the invention. The specific number of pontoons employed in a particular system would be dependent upon the support capacity of each pontoon and the cumulative load to be supported by the system.

Pontoon structure Each of the

pontoons

30, 31, and 32 comprises an inverted cup-shaped vessel of generally semi-spherical configuration having a closed upper surface and a bottom open to fluid communication With the body of water 10. An open ended conduit section sealingly secured to and extending through the u er surface of each of the pontoons provides for passage of the conduit 17 therethrough. In the stabilizing pontoon 30, the conduit section is designated by the numeral 33 and in the

intermediate pontoons

31 and 32, which are identical to each other, the conduit sections are designated by the numerals 34. The lower support arrangement for these conduit sections is exemplified by the illustration of one of the sections 34 in FIG. 5, wherein it is shown secured to spider-like structure 35 extending across the lower portion of the pontoon. The spider-like structure 35 does not interfere materially with the open bottomed characteristic of the pontoons.

Through the aforedescribed pontoon structure, the stabilizing pontoon 30 and each of the intermediate pontoons are provided with a vessel of selectively variable buoyancy. Specifically, by varying the amount of air, or other gas, contained in the open bottomed pontoons, the buoyancy therefore may be selectively varied. Variance of each pontoon is effected, as will subsequently become apparent, by structure providing for the selective charging and discharging of gas from the pontoons.

At this point it is noted that the harvester 2t} incorporates open bottomed pontoon structure similar in operation to that of the

pontoons

30, 31 and 32. Although the pontoon structure of the harvester is schematically shown herein for the purpose of exemplification, it is to be understood that the specifics of this harvester form part of the subject matter of my aforementioned co-pending application Ser. No. 533,623. Attention is directed to the fact, however, that the harvester 20 is coupled to the conduit 17 by a swingable conduit section 36 mounted for swinging movement by a fluid communicating ball joint 37. From the susbequent discussion, it will be seen that swinging of the conduit section 36 may be use-d, in part, to control the operation of the inventive support system.

The

intermediate pontoons

31 and 32 are each secured in supporting relationship to the conduit 17 through the arrangement illustrated in FIG. 5. This arrangement comprises a frusto-spherical collar 40 fixed to and extending radially from the conduit 17 and a mating annular frustospherical socket member 41 fixed to the conduit sections of each of the pontoons. The support thus provided facilitates a degree of flexibility between the conduits 17 and the intermediate pontoons, since the collars 40 and members 41 may move universally relative to each other.

From the following discussion, it will be seen that the above described support connections between the intermediate pontoons and the conduit 17 function to secure the tension transmitting structure in supporting relationship to the conduit 17. The manner in which the stabilizing pontoon 30 is secured in supporting relationship to the conduit 17 will also be developed in the subsequent discussion.

Tension transmitting structure The tension transmitting structure in the illustrated embodiment comprises

cable segments

42 and 43 secured, respectively, between the

intermediate pontoon

31 and 32 and the stabilizing pontoon 30 and intermediate pontoon 31. Each of the

segments

42 and 43 is comprised of similar elements and, for the sake of simplicity, corresponding elements in each segment will be designated by like numerals. The

segments

42 and 43 each comprise: three

cables

44, 45, and 46; and, a tension equalizing device 47 secured to the uppermost ends of the cables (see FIGS. 3, 4, and 5). The cables of the segment 42 are secured in tension transmitting relationship by connection of the lowermost ends thereof to the pontoon 32 and connection of the equalizing device 47 at the uppermost end thereof to the pontoon 31. The cables of the segment 43 are secured in tension transmitting relationship by connection of the lowermost ends thereof to the pontoon 31 and connection of the equalizing device 47 at the uppermost end thereof to the stabilizing pontoon 30 through a crane mechanism 50. Connection of the equalizing device 47 to the pontoon 31 and crane mechanism 50, respectively, is similarly effected through sleeves 51 fixed to these elements in loose coaxial relationship around the conduit 17.

Each of the equalizing devices 47 comprises: a first substantially horizontally disposed beam 52 pivotally mounted on the sleeve 51 for movement about a first axis 53 extending substantially normal to and through the longitudinal centerline of the conduit 17, said first beam having

cable connectors

54 and 55 on the end portions thereof spaced, respectively, from the first axis by distances in a two to one ratio relative to each other; a second substantially horizontally disposed beam 56 pivotally mounted on the sleeve 51 for movement about a second axis 57 extending substantially normal to and through the longitudinal centerline of the conduit 17 in vertically spaced relationship to the first axis 53, said second beam having

cable connectors

60 and 61 on the end portions thereof spaced, respectively, from the axis 57 in a two to one ratio relative to each other; a third substantially horizontally disposed beam 62 freely suspended by connection of the end portions thereof, respectively, with the

connectors

54 and 60 by

cables

63 and 64, said third beam having a cable connector 65 midway between the connected end portions thereof; and,

bolts

66, 67, and. 68 fixedly secured to the

cables

44, 45, and 46, respectively, and adjustably received in the

cable connectors

61, 65, and 55, respectively. The cable connectors on the respective beams comprise openings extending therethrough.

Cables

63 and 64 are fixed directly to these openings, whereas

cables

44, 45, and 46 are adjustably secured thereto through the

aforedescribed bolts

66, 67, and 68, respectively, and nuts cooperating therewith (see FIG. The adjustable securing of the latter cables is provided to facilitate installation and to compensate for elastic stretch which may take place in the

cables

44, 45, and 46.

Through the geometric interrelationship of the equalizer device components, equal tension is continuously maintained in the

cables

44, 45, and 46. Furthermore, since these cables are symmetrically positioned at equal angularly spaced locations around the conduit 17 (see FIG. 4), imbalance of support for the conduit is avoided. To illustrate the operation of the equalizing device, it is noted that with equal weights, designated as w for convenience, applied to each of the

cables

45, 46, and 47, loads will be transmitted through the following equalizer elements in the indicated units of w.

Crane mechanism The crane mechanism 50 basically comprises a head block support 71 fixedly mounted on the stabilizing pontoon 30; a tail block support 72 fixedly secured to the sleeve 51 of the equalizing device secured to cable segment 43; and, a continuous cable 73 reeved around pulleys 75 and 76 on the respective head and tail block supports to haul drums 74 mounted on the stabilizing pontoon 30 in fixed relationship with respect to the head block 71. From FIG. 3, it will be seen that the crane mechanism comprises a balanced block and tackle system symmetrically disposed on either side of the conduit 17. Since the block and tackle elements to either side of the conduit 17, such as the haul drums 74, correspond identically in structure and operation, like numerals will be used for designation of corresponding elements. It is noted that in the diagrammatic representation of FIG. 3, the haul drums 74 and associated drive train structures cooperating therewith appear mounted on the head block support 71 for purposes of diagrammatic illustration. This illustration technique has been employed for simplification purposes, since the head block support 71 and the haul drums 74 and associated drive train structure are all fixedly mounted on the stabilizing pontoon 30. From FIG. 1, however, it can be seen that the haul drum and its associated drive structure are actually elevated on the stabilizing pontoon relative to the head block support.

From the haul drums 74, the continuou cable 73 is directed first around opposed aligned

sheaves

75 and 76, respectively, on the head block and tail block supports and then around equalizing sheaves 77 mounted beneath the tail block support. The latter sheaves provide for balance continuity between the block and tackle segments to either side of the conduit 17. The drive train structure for the haul drums 74 comprises: a common drive shaft 80 keyed to the drums; a pair of motors 81 drivingly engaged with the shaft 80 through hydraulic clutch and gear box devices (the latter devices are not illustrated); shafts 82 mounted to either end of the shaft 80 in axial alignment therewith; selectively operable clutches 83 interposed between the ends of the shaft 80 and the shafts 82 to establish driving interengagement therebetween; and, counterbalance drums 84 keyed to the shafts 82. The drums 84 each have connected thereto and reeved therearound a counterbalance cable 85 extending to a fixed 1 connection 86 with the stabilizing pontoon 30, which cable has supported intermediate the ends thereof a counterbalance weight 87. The counterbalance cables are reeved around the counterbalance drums cooperating therewith in a direction opposite to that at which the cable 73 is reeved around the haul drums 74. Thus, when the clutches 83 are engaged, the counterweights 87 function to balance the load transmitted to the haul drums 74 by the cable 73.

In the preferred form, the counterweights 87 each have a weight equal to twice the minimum support stress on the cable 73. Thus, since half of the counterbalance Weight is transmitted to the counterbalance drums 84, this weight maintains the drive train assembly statically balanced when the cable 73 is in the condition of minimum support stress. As a result, the crane motors 81 need only provide the energy necessary to overcome stresses in the cable 73 from additional supported load, acceleration, and frictional resistance in the various crane mechanism members.

In operation, the crane motors 81 continuously run to support any residual load applied to the cable 73 in excess of that balanced by the weights 87. Naturally, during this operation, the clutches 83 are engaged to couple the shafts 82 in driving engagement with the shaft 80. The hydraulic couplings incorporated into the motors 81 provide for the continuous running of the motors, even when it is not desired to support residual load therethrough or haul in on the cable 73. This arrangement has the advantage that the motors are always ready for instant use and control thereof may be readily effected through the hydraulic clutches cooperating therewith. The control system for the hydraulic clutches will be developed in the subsequent discussion.

Crane control system The support system of the present invention, as will become more apparent in the following discussion, is designed so that each intermediate pontoon 31 will support slightly less than the load disposed therebeloW..As a result, the composite load unsupported by the intermediate pontoons is transmitted to the stabilizing pontoon 30. This interrelationship of load support is deliberately maintained so that the

cable segments

42 and 43 and the crane mechanism 50 are continuously held under tension. As a result of this interrelationship, however, to maintain the conduit 17 at a fixed elevation relative to the floor 11, it is necessary to provide a crane control system to accommodate elevational variances in both the floor 11 and the surface 12. It is to this system that the present control system applies.

Control of the crane responsive to variances in the surface 12 is accomplished through submergence monitoring structure mounted on the stabilizing pontoon 30 and a control mechanism coupled between this structure and the crane mechanism 50 to provide for operation of the crane mechanism responsive to the condition of the submergence monitoring structure. The submergence monitoring structure comprises: an open ended well 90 sealingly secured to and extending vertically through the stabilizing pontoon 30; a cylindrical float 91 slidably received within the well 90 and having a closed lower end 92 and an open upper end 93; a sheave 94 mounted on the float 91 above the open upper end 93; a cable 95 trained over the sheave 94 and secured at one end to the tail block support 72 and at the other end to the upper end of the float 91; and, a weight 96 sheave supported on the cable 95 within the float 91. Through this arrangement, the float 91 is free to float on the surface 12 irrespective of the submerged condition of the stabilizing pontoon 31. Submergence monitoring is continuously effected through the cable 95, since this cable is drawn into and out of the float 91 as the elevation of the tail block support 72 varies relative to the float.

selsyn transmitter mounted on the float 91 and having a drive sheave 100 in reeved engagement with the cable 95; selsyn receivers 101 mounted on each of the motors 81 in controlling association with the hydraulic clutches incorporated thereinto to effect bypassing of the clutch fluid and resultant clutch disengagement upon the receipt of a signal by the receivers 101 from the transmitter 97; and, conventional control circuitry 102 (schematically illustrated in FIG. 3) controllably coupling the transmitter 97 and the receivers 101. The sprocket 100 is coupled in driving relationship to the selsyn transmitter 97 through a ratchet clutching mechanism (not illustrated) which provides for activation of the transmitter only upon payout of the cable 95 from the float 91. The latter occurrence results whenever the stabilizing pontoon 30 is raised relative to the tail block support 72 in response to tidal or wave action. Upon this occurrence, the selsyn transmitter 97 activates the receivers 101 to bypass clutch fluid in the hydraulic clutches incorporated into the motors 81. The latter operation, in turn, permits the load on the tail block support 72 to payout the cable 73 from the haul drums 74. Thus, the stabilizing pontoon is permitted to be raised with wave or tidal action while the submerged apparatus secured to the tail block support 72 is held steady. Naturally, due to the one way action of the transmitter 97, as wave or tidal action lowers the stabilizing pontoon relative to the tail block support 72, the motors 81 drive the haul drums 74 to take up the cable 73.

Control of the crane mechanism 50 responsive to variances in the floor 11 is effected through means of position monitoring structure adapted to sense variances in vertical displacement between the harvester 20 and the lower end of the conduit 17; and, position control means associating this position monitoring structure with the crane mechanism. The position monitoring structure is schematically represented in FIG. 2 and simply comprises a pair of normally opened vane operated magnetic switches 103 and 104 mounted on the harvester 20 and a vane operator 105 for these switches mounted on the swingable conduit section 36. Through this arrangement, raising of the conduit 17 relative to the harvester 20 functions to close the switch 103. Similarly, lowering of the conduit 17 relative to the harvester 20 functions to close the switch 104. Naturally, as can be seen from FIG. 2, the switches 103 and 104 are spaced apart sufficiently that limited movement of the conduit 17 relative to the harvester 20, and resultant swinging of the conduit section 36, may take place without closing either of the switches.

The control mechanism associating the switches 103 and 104 with the crane mechanism 50 comprises circuitry, 105 and 107, respectively, coupling the switches in controlling relationship with the hydraulic couplings of the motors 81. Although this circuitry is only shown partially in FIG. 3, it is to be understood that it may take any of the forms well known to those skilled in the electrical art. The circuitry is arranged so that closing of the switches 103 and 104, respectively, functions alter natively to either pay out or haul in the cable 73. Haul in is effected by charging the hydraulic couplings with fluid, while payout is effected by bypassing fluid from the hydraulic couplings. As a result of the position monitoring arrangement provided by the switches 103 and 104, the crane mechanism 50 is operated to maintain the conduit 17 within predetermined distances from the floor 11. Thus, it may be said that the support system maintains the conduit at a fixed elevation relative to the datum established by the floor level.

Buoyancy control structure From the foregoing description of the stabilizing pontoon 30 and the

intermediate pontoons

31 and 32, it was seen that these pontoons each comprise open bottomed vessels capable of entrapping a gaseous medium, such as air, therein. Although the details of the harvester 20 are in part the subject of applicants aforementioned copending application Ser. No. 533,623, it is noted that the harvester also incorporates an open bottomed vessel capable of entrapping a gaseous medium therein. The latter characteristic is not, however, intended to form a part of the present invention.

The buoyancy control system of the present invention operates by selectively varying the volume of gaseous medium, namely air, in the exemplary embodiment illustrated, entrapped in each of the

pontoons

30, 31 and 32. The main source of air in the embodiment diagrammatically illustrated in FIG. 2 comprises a compressor having the discharge thereof coupled in fluid communication with a storage tank 111 by a conduit 112. The latter arrangement is conventional in that it includes a check valve 113 interposed in the conduit 112 to prevent the passage of air from the tank 111 to the compressor 110 and a pressure control valve (not illustrated) incorporated into the storage tank 111 to effect control of the compressor 110. The compressor 110 and tank 111 are con nected in fluid communication with discharging and charging conduits for the pontoons through means of

conduits

114 and 115, respectively. The latter conduit has a branch 116 leading to fluid communication with the interior of the stabilizing pontoon 30 through a manually controlled charging valve 117. It is through the valve 117 and a similar manually controlled discharging valve 118 coupled in fluid communication with the pontoon 30 that the volume of air trapped in the vessel of the pontoon is controlled. This control i effected to maintain the pontoon at a predetermined degree of buoyancy under a specific load.

Alternatively operable electrically controlled valves 121 and 122 are interposed in the conduit and provide, respectively, through a conduit 123 for the charging of air into and the discharging of air from the intermediate pontoon 31. Specifically, when the valve 121 is opened, air is charged into the pontoon 31 from the tank 111. Similarly, when the valve 122 is opened, air is discharged therethrough to a conduit 124 leading to the conduit 114. The latter conduit has disposed therein downstream from the connection of the conduit 124 in fluid communication with the atmosphere an electrically operated valve 125 wired to operate opposite the valve 122. Through this arrangement, air is provided to the compressor 110 either from the conduit 124 or from atmosphere and compressed air is recirculated to increase efficiency of the overall system.

The charging and discharging of air from each of the intermediate pontoons is effected through means of buoyancy monitoring structure for each of the pontoons and buoyancy control means operated responsive to the conditions sensed by the monitoring structure. Since the buoyancy monitoring structure for each intermediate pontoon corresponds, like numerals will be used to designate corresponding elements in each intermediate pontoon. Referring now to FIG. 2, the structure in each of the intermediate pontoons is shown therein as comprising: a rod 126 received for free axial movement between a pair of bearings 127; a float 130 fixed to the rod 126 between the bearings 127; a pair of magnetically operated

switches

131 and 132 received loosely around the rod 126 in vertically spaced relationship; a switch actuating blade 133 fixed to the shaft 126 intermediate the

switches

131 and 132; and, a solenoid coil 134 loosely received around the shaft 126. Although the solenoid coil 134 does not perform a part of the monitoring function, it is so structurally related to the monitoring structure that its mention at this time seems appropriate. It is to be understood that, with the exception of the shaft 126 and the elements fixed thereto, the various components of the monitoring structure and the solenoid 13- 1 are fixedly mounted within and on the intermediate pontoons with electrical apparatus above liquid level.

Since the buoyancy control means cooperating with the uppermost intermediate pontoon 31 differs from that of the lower intermediate pontoon 32, the structure and operation of these means will be described separately. It is here pointed out, however, that although only one lower intermediate pontoon has been shown beneath the uppermost intermediate pontoon, any number of lower intermediate pontoons could be utilized without departing from the spirit of the invention. In the event that more lower intermediate pontoons are utilized, the interrelationship of buoyancy monitoring structure and buoyancy control means would correspond identically to that between the uppermost intermediate pontoon 31 and the lower intermediate pontoon 32.

The buoyancy control means for each of the intermediate pontoons is electrically operated through means of a pair of

main leads

135 and 136. These leads extend to an electrical power supply typically supported either on the stabilizing pontoon 30 or the barge 13. Reference is made to FIG. 2 for a schematic illustration of the

leads

135 and 136 and the various circuitry cooperating therewith.

Referring now to the buoyancy control means for the intermediate pontoon 31, this comprises: the valves 121 and 122;

electrical leads

137 and 138 controllably connecting the switch 131 to the valve 121; and, electrical leads 141 and 142 controllably connecting the switch 132 to the valve 122. With this arrangement, when the water level in the intermediate pontoon 31 raises the float 130 to a position wherein the blade 133 closes the switch 131, the valve 121 is opened, thus admitting air into the vessel of the intermediate pontoon 31 and lowering the water level therein. Similarly, when the water level in the intermediate pontoon 31 permits the float 130 to drop to a position wherein the blade 130 closes the switch 132, the valve 122 is opened, thus venting or discharging air from the vessel of the intermediate pontoon 31 and raising the water level therein. It can thus be seen that the water level within the pontoon 31, and the resultant buoyancy thereof, is maintained within predetermined limits. The exact positioning of these limits can readily be adjusted by select positioning of the float 130.

Referring now to the buoyancy control means for the lower intermediate pontoon 32, this comprises: an electrically operable valve 143 interposed in the conduit 123 :beneath the opening thereof into the intermediate pontoon 31; a conduit 144 extending in fluid communication between the interior of the intermediate pontoon 31 and the conduit 123; a compressor 145 and check valve 146 interposed in the conduit 144 to provide one way flow therethrough to the conduit 123; a submersible electric motor 147 coupled in driving relationshi with the compressor 145; a conduit section 150 establishing fluid communication between the conduit 123 and the interior of the pontoon 32; and, electrical circuitry controllably connected between the

switches

131 and 132, respectively, of the pontoon 32 and the motor 147 and valve 143. The latter circuitry comprises

electrical leads

151 and 152 establishing electrical connection between the switch 131 and the motor 147 and

electrical leads

153 and 154 establishing electrical connection between the switch 132 and the valve 143. With this arrangement, when the water level in the pontoon 32 raises the float 130 to a position closing the switch 131, the compressor 145 is activated, thus pumping air from the pontoon 31 into the pontoon 32 and increasing the buoyancy of the latter pontoon. Similarly, when the level of water in the pontoon 32 permits the float 130 to lower to a position wherein the blade 133 closes the switch 132, the valve 143 is opened, thus permitting air to discharge or vent from the pontoon 32 into the pontoon 31. As a result of this arrangement, the buoyancy of the pontoon 32 is maintained within predetermined limits similarly to that of the pontoon 31.

The foregoing charging and discharging arrangement for the lower intermediate pontoon 32 has the advantage that air introduced into the lower intermediate pontoon is compressed in stages. Specifically, the air is first compressed for introduction into the intermediate pontoon 31 by the compressor and then compressed for introduduction into the pontoon 32 by the compressor 145. As a result, the capacity required of each compressor is maintained within reasonable limits. It is to be understood that if additional lower intermediate pontoons are employed, the same stepwise compression arrangement existing between the

pontoons

31 and 32 would be utilized. In such an expanded arrangement, it is preferable to provide each successively lower compressor with slightly less capacity, thus assuring that the lower pontoon will not charge so rapidly as to impart compressive forces to the load being supported.

It is here again noted that the capacity and control structure for each of the intermediate pontoons is so adjusted that each intermediate pontoon is capable of only partially supporting the load therebeneath. Thus, compressive forces in the supported load are avoided and some composite unsupported load is always transmitted to the stabilizing pontoon 30.

The harvester 20 has cooperating therewith buoyancy monitoring structure and buoyancy control means corresponding in structure and operation to that for the intermediate pontoon 32. For the sake of simplicity, the various components cooperating with the harvester 20 which correspond to those cooperating with the intermediate pontoon 32 have been designated by like numerals followed by the subscript a. Specifically, these components are designated as follows: 126a, 127a, 130a, 131a, 132a, 143a, 144a, 145a, 146a, 147a, 150a, 151a, 152a, 153a, and 154m With this arrangement, the buoyancy of the harvester 20 is maintained within predetermined limits and air supply for this buoyancy is obtained through the same stepwise compression arrangement utilized for the lower intermediate pontoon 32. It is to be understood, however, that the harvester 20 is not designed to sup port the load of the conduit 17.

In addition to the aforedescribed buoyancy control structure associated with each of the pontoons, the stabilizing pontoon is provided with support condition monitoring structure to sense the load of the conduit 17 supported thereby and maintain this load within predetermined limits. This condition monitoring structure comprises: a float compartment tank 155 vertcally disposed in the stabilizing pontoon 30 and having a lower port 156 in fluid communication with the body of water on which the pontoon is supported and an upper port 157 communicating with the atmosphere through an upstanding pipe 160; a rod 161 mounted in the tank 155 by bearings 162 for free axial movement; a float 163 fixed to the rod 161 intermediate the bearings; a pair of magnetically operated

switches

164 and 165 received around the rod 161 in vertically spaced relationship; and, a switch actuating blade 166 fixed to the rod 161 intermediate the

switches

164 and 165 for movement into activating condition with respect to either of the switches.

The operation of the support condition monitoring structure is coordinated with that of the buoyancy control structure for each of the intermediate pontoons through electrical circuitry adapted to energize the solenoids 134 to either depress or raise the floats 130 responsive to the condition of the

switches

164 and 165. This circuitry comprises: an electric-a1 lead 167 extending from the switch 164 to one side of the solenoids 134; an electrical lead 170 extending from the switch 165 to the other side of the solenoids 134;

electrical leads

171 and 172 connecting the solenoids 134 to the main power lead 135; and, an electrical lead 173 connecting the

switches

164 and 165 to the main power lead 136. This circuitry is arranged so that closing of the switch 164 functions to raise the rods 126, while closing of the switch 165 functions to lower the rods 126. As a result of this arrangement, when the stabilizing pontoon is in an elevated condition indicating that it is not supporting the desired degree of load, the buoyancy monitoring structure of the

intermediate pontoons

31 and 32 is forced to a position simulating excessive buoyancy and, thus, the buoyancy of the intermediate pontoons is decreased and the composite load transmitted to the stabilizing pontoon for support is increased. When an excessively submerged condition of the stabilizing pontoon is sensed by closing of the switch 164, a condition of insufficient buoyancy is simulated in the

intermediate pontoons

131 and 132 by raising of the rod 136. This, in turn, functions to increase the buoyancy of the intermediate pontoon and decrease the composite load transmitted to the stabilizing pontoon 30.

Through the aforedescribed support condition monitoring structure and the coordinating means cooperating therewith, the load transmitted to the stabilizing pontoon is maintained within predetermined limits. The restricted port 156 in the lower end of the float tank 155 functions to dampen the responsiveness of the float 163, thus avoiding operation of the support condition monitoring structure responsive to sudden variations in the load supported thereby, as might result from sudden wave action. The provision of the extension pipe 160 assures that the tank 155 is continuously vented while the entrance of water through the vent port 157 is avoided.

With the continued admittance of air to the

intermediate pontoons

31 and 32 under the influence of the solenoids 134, the water level in the intermediate pontoons will eventually reach a level where the weight of the float 130' will transfer to the rod 126. This Weight is so designed as to be more than the solenoid can support and, therefore, upon this occurrence the switches 131 will open, thus terminating the charging of air into the intermediate pontoons. The continued venting of air from the intermediate pontoons under the influence of the solenoids 134 similarly eventually results in a con dition where the floats 130 raise the rods 126 to a position opening the switches 132. At this point, the venting of air from the intermediate pontoons responsive to the condition monitoring structure is, naturally, terminated.

At this point it is noted that variations between the buoyant capacity of the intermediate pontoons may result due to different water levels established by variances in the compressor rates and other causes, possibly minor leaks, et cetera. Periodically, this imbalance can be rectified by artificially establishing a light load condition at the stablizer pontoon through utilization of the aforedescribed support monitoring structure. Specifically, this is accomplished by manually depressing the float 163 to a position venting the intermediate pontoons to the maximum water level, thus tensioning the supported load to a maximum. After this condition has been assumed for a period of time, it can be assumed that all pontoons are ballasted to a maximum level. When this condition is reached, release of the float 163 will activate the compressors of the system and return the intermediate pontoons to a balanced condition.

From the foregoing description it is believed apparent that the present invention enables the accomplishment of the objects initially set forth herein. It is to be understood, however, that the invention is not intended to be limited to the specific details of the exemplary embodiment herein described. For example, it is considered well Within the province of the invention that the specific physical characteristics of the system components may be varied and that loads of various types might be supported.

What is claimed is:

1. In an elongated array of objects disposed substantially vertically in a body of liquid, an improved support system comprising:

(a) a substantially vertically disposed elongated tension transmitting structure secured in supporting relationship to the objects of said array;

(b) at least one intermediate pontoon means secured to said tension transmitting structure intermediate the end portions thereof to support, at least partially, the load of said array disposed therebelow, said pontoon means having:

(1) a chamber of selectively variable buoyancy;

(2) buoyancy monitoring means to sense the degree of buoyancy of said chamber; and,

(3) buoyancy control means to vary the buoyancy of said chamber responsive to said buoyancy monitoring means to maintain said intermediate pontoon means in a condition supporting the portion of said array therebelow to a predetermined partial degree;

(c) stabilizing pontoon means secured to the upper end portion of said tension transmitting structure to support, at least in part, the composite load of said array unsupported by said intermediate pontoon means.

2. An improved support system according to claim 1, including:

(a) adjustment means secured to said tension transmitting structure to selectively vary the relative vertical position at which the stabilizing pontoon means is secured to the upper portion of said structure;

(b) submergence monitoring means operatively associated with the stabilizing pontoon means to sense the degree of submergence thereof in said body of water; and,

(c) submergence control means responsive to said submergence monitoring means and controllably associated with said adjustment means to maintain the stabilizing pontoon means secured to the tension structure in a surfaced condition.

3. In an elongated array according to claim 2, further including an element disposed in close proximity to the floor of said body of water, the improved support system further comprising:

(a) linking structure secured between said element and the tension transmitting structure;

(b) position monitoring means operatively associated with said element and tension transmitting structure to sense vertical displacement therebetween; and

(c) position control means responsive to said position monitoring means and controllably associated with said adjustment means to maintain said vertical displacement within predetermined limits.

4. An improved support system according to claim 1,

including:

(a) support condition monitoring means operatively associated with said stabilizing pontoon means to sense the load of said array supported thereby; and,

(b) coordinating means cooperatively associated with said condition monitoring means and the buoyancy control means of said intermediate pontoon means to effect operation of said control means responsive to the load sensed by said condition monitoring means so that said load is maintained within predetermined limits.

5. An improved support system according to claim 1, wherein:

(a) a plurality of said intermediate pontoon means are secured, respectively, to said tension transmitting means at vertically spaced locations intermediate the end portions thereof;

(b) said intermediate pontoon means are each secured in supporting relationship to the objects of said array therebelow; and,

(c) said tension transmitting structure comprises:

(1) first flexible cable segments secured, respectively, between adjacent of said intermediate pontoon means; and,

(2) a second flexible cable segment secured between the uppermost of said intermediate pon- 13 toon means and said stabilizing pontoon means.

6. An improved support system according to claim 5,

wherein, in each of said intermediate pontoon means:

(a) said chamber is defined by an inverted cup-shaped vessel having a closed upper surface and an open bottom;

(b) said buoyancy monitoring means comprises a water displaceable float disposed in said vessel and float position detectors cooperating therewith to detect deviation of said float from predetermined extremities of displacement; and,

(c) said buoyancy control means comprises alternatively operable gaseous medium charging and discharging structure secured in fluid communication with the interior of said vessel and controllably associated with said detectors to selectively charge gaseous medium into or discharge gaseous medium from said vessel.

7. An improved support system according to claim 6,

including:

(a) a prime source of gaseous medium maintained under a pressure sufiicient to facilitate the introduction thereof into the uppermost of said intermediate pontoon means;

(b) first conduit means coupling said source in fluid supplying communication with the charging structure of the uppermost of said intermediate pontoon means; and,

(c) second conduit means coupling the vessel of each of said intermediate pontoon means in fluid communication with the charging and discharging structure of the intermediate potoon means immediately therebelow, whereby:

(1) gaseous medium charged into the vessels of each of the intermediate .pontoon means below the uppermost thereof is supplied from the vessel of the intermediate pontoon means immediately thereabove; and,

(2) gaseous medium discharged from the vessels of each of the intermediate pontoon means below the uppermost thereof is vented into the vessel of the intermediate pontoon means immediately thereabove.

8. An improved support system according to claim 7,

wherein:

(a) the charging structure of the uppermost of said intermediate pontoon means comprises a valve adapted to selectively open and close said first conduit means to fluid communication with the vessel of the uppermost of said intermediate pontoon means; and,

(b) the charging structure of each intermediate pontoon means below the uppermost thereof comprises a pump adapted to selectively compress and convey gaseous medium from the vessel of the intermediate pontoon means thereabove to the vessel thereof through said second conduit means; and,

(c) the discharging structure of each of said intermediate pontoon means below the uppermost thereof comprises a valve adapted to selectively open and close the vessel of the intermediate pontoon means thereabove to thevessel thereof through said second conduit means.

, .9, In an elongated array according to claim 5, wherein the array comprises a continuous member, the improved support system wherein? (a) said first cable segments each comprise:

(1) at least three intermediate cables disposed symmetrically around and extending longitudinally of said member in equal angularly spaced relationship; and,

(2) first equalizing means secured to and continuously maintaining equal tension in said intermediate cables;

(b) said second cable segment comprises:

(1) at least three stabilizing cables disposed symmetrically around and extending longitudinally of said member in equal angularly spaced relationship; and,

(2) second equalizing means secured to and continuously maintaining equal tension in said stabilizing cables;

(0) said adjustment means comprises a block and tackle comprising:

(1) head and tail blocks secured, respectively, to said stabilizing pontoon means and second cable segment; and,

(2) a take-up cable trained around said head and tail blocks.

10. An improved support system according to claim 9, wherein:

(a) the intermediate cables of each of said first segments extend between opposed sides of immediately adjacent intermediate pontoon means;-

(b) the intermediate cables of each of said first segments are secured between opposed sides of immediately adjacent intermediate pontoon means by a fixedly secured connection to one of said intermediate pontoon means and a connection through one of said first equalizing means to the other of said intermediate pontoon means;

(c) on each of saidother intermediate pontoon means said first equalizing means comprise:

(1) a first substantially horizontally disposed beam pivotally secured to said intermediate pontoon means for movement about a first axis extending substantially normal to and through the longitudinal centerline of said continuous member, said first beam having first and second connectors on the end portions thereof spaced, respectively, from said first axis by distances in a two-to-one ratio relative to each other;

(2) a second substantially horizontally disposed beam pivotally secured to said intermediate pontoon means for movement about a second axis extending substantially normal to and through the longitudinal centerline of said continuous member in vertically spaced relationship to said first axis, said second beam having first and second connectors on the end portions thereof spaced, respectively, from said second axis by distances in a two-to-one ratio relative to each other; and,

(3) a third beam substantially horizontally disposed, f-reely suspended by connection of the end portions thereof respectively, with the first connectors of said first and second beams through tension transmitting elements and having a cable connector mid-way between the connected end portions thereof;

(d) the three intermediate cables of each of said first segments are secured through each of said equalizing means by connections, respectively, to said second connector of said first beam, said second connector of said second beam and said cable connector of said third beam.

11. An improved support system according to claim 9, wherein said adjustment means further comprises:

(a) haul means operatively secured to said take-up cable to selectively vary the length thereof trained around said head and tail blocks and thus vary the relative vertical position at which the stabilizing pontoon means is secured to the upper portion of the tension transmitting structure; and,

(b) counterbalance means operatively associated with said haul means to balance, at least partially, the weight supported by said take-up cable.

12. In a system comprising:

(a) a support member;

(b) a suspended member; and,

(c) three tension transmitting support elements secured between said members; an improved structure securing said elements to one of said members to maintain equal tension therein, comprising:

(1) a first beam disposed substantially normal to said tension transmitting support elements and pivotally secured to said one member for movement about a first axis disposed substantially normal to said support elements, said first beam having first and second connectors on the end portions thereof spaced, respectively, from said first axis by distances in a tWo-to-one ratio relative to each other;

(2) a second beam disposed substantially normal to said tension transmitting support elements and pivotally secured to said one member 1n spaced relationship to said first beam for movement about a second axis disposed substantially normal to said support elements, said second beam having first and second connectors on the end portions thereof spaced, respectively, from said second axis by distances in a twoto-one ratio relative to each other;

(3) a third beam freely suspended substantially normal to said tension transmitting support elements by connection of end portions thereof, respectively, to the first connectors of said first and second beams through tension transmitting elements and having an intermediate connector mid-way between the connected end por- .ions thereof; and,

(4) means connecting said three tension transmitting support elements, respectively, to said second connector of said first beam, said second connector of said second beam and said intermediate connector of said third beam.

13. In an installation comprising:

(A) a series of gas containing stations disposed, respectively, at succeedingly greater depths in a body of liquid, said stations each having:

(1) contiguous wall means defining an upwardly closed chamber containing a volume of gas, said wall means being subject, externally, to pressure by said body; and,

(2) opening means disposed through a lower portion of said wall means to establish fluid communication between said body and volume and subject said volume to pressure corresponding, substantially, to the pressure externally of said wall means;

(B) a gas supply source disposed above the uppermost of said stations, said source being capable of providing gas under a pressure suflicient for the introduction thereof into the chamber of said uppermost chamber; and,

(C) means to effect the introduction of gas into the chamber of the uppermost station from said source and the discharging of gas from said chamber responsive to the liquid level therein to maintain said level within a predetermined range;

an improved system for supplying gas and discharging gas from the chambers of said stations comprising:

(a) a single fluid conducting conduit extending between said stations, said conduit having:

(1) first and second conduit means connected thereto for each of said stations above the lowermost thereof, said means extending, independently, into fluid communication with the chamber of the station therefor with said means for each station being disposed with the second thereof connected to said single conduit below the first thereof; and,

(2) third conduit means connected thereto beneath the lowermost connection thereto of said second conduit means and extending into fluid communication with the chamber of the lowermost of said stations;

(b) remotely operable independent shut-off valve means interposed, respectively, in said single conduit between the connection thereto of the first and second conduit means for each of said stations above the lowermost thereof;

(c) remotely operable independent discharge means interposed in each of said second conduit means to selectively effect the pumping of gas therethrough to said single conduit; and,

((1) liquid level control means operatively associated with the chamber of each of said stations below the uppermost thereof, said means being adapted to, selectively:

(1) open and close the valve means immediately thereabove responsive to the attainment of first predetermined liquid level conditions in the chamber operatively associated therewith; and,

(2) activate and de-activate the discharge means immediately thereabove responsive to the attain ment of second predetermined liquid level conditions in the chamber operatively associated therewith.

14. In an elongated array of objects interconnected in tension transmitting relationship and disposed substantially vertically in a body of liquid, an improved support system comprising:

(a) at least one intermediate pontoon means secured to said array in tension transmitting relationship intermediate the end portions thereof to support, at least partially, the load of said array disposed therebelow, said pontoon means having:

(1) a chamber of selectively variable buoyancy;

(b) stabilizing pontoon means secured to the upper end portion of said array in tension transmitting relationship to support, at least in part, the composite load of said array unsupported by said intermediate pontoon means.

References Cited UNITED STATES PATENTS JACOB SHAPIRO, Primary Examiner,

Claims

1. IN AN ELONGATED ARRAY OF OBJECTS DISPOSED SUBSTANTIALLY VERTICALLY IN A BODY OF LIQUID, AN IMPROVED SUPPORT SYSTEM COMPRISING: (A) A SUBSTANTIALLY VERTICALLY DISPOSED ELONGATED TENSION TRANSMITTING STRUCTURE SECURED IN SUPPORTING RELATIONSHIP TO THE OBJECTS OF SAID ARRAY; (B) AT LEAST ONE INTERMEDIATE PONTOON MEANS SECURED TO SAID TENSION TRANSMITTING STRUCTURE INTERMEDIATE THE END PORTIONS THEREOF TO SUPPORT, AT LEAST PARTIALLY, THE LOAD OF SAID ARRAY DISPOSED THEREBELOW, SAID PONTOON MEANS HAVING: (1) A CHAMBER OF SELECTIVELY VARIABLE BUOYANCY; (2) BUOYANCY MONITORING MEANS TO SENSE THE DEGREE OF BUOYANCY OF SAID CHAMBER; AND, (3) BUOYANCY CONTROL MEANS TO VARY THE BUOYANCY OF SAID CHAMBER RESPONSIVE TO SAID BUOYANCY MONITORING MEANS TO MAINTAIN SAID INTERMEDIATE PONTOON MEANS IN A CONDITION SUPPORTING THE PORTION OF SAID ARRAY THEREBELOW TO A PREDETERMINED PARTICAL DEGREE; (C) STABILIZING PONTOON MEANS SECURED TO THE UPPER END PORTION OF SAID TENSION TRANSMITTING STRUCTURE TO SUP-