US2947148A

US2947148A - Jacking mechanism for seadrome

Info

Publication number: US2947148A
Application number: US439589A
Authority: US
Inventors: Einar T Young
Original assignee: Sun Oil Co
Current assignee: Sunoco Inc
Priority date: 1954-06-28
Filing date: 1954-06-28
Publication date: 1960-08-02
Anticipated expiration: 1977-08-02

Description

Aug. 2, 1960 E. T. YOUNG JACKING MECHANISM FOR SEADROME 4 Sheets-Sheet 1 Filed June 28, 1954 mum-Eb-I INVENTOR. EINAR T. YOUNG ATTORNEYS FIG. 4.

Aug. 2, 1960 E. T. YOUNG JACKING MECHANISM FOR SEADROMB 4 Sheets-Sheet 3 Filed June 28, 1954 RESERVOIR INVENTOR. EINAR T. YOUNG BY FIG. 7.

ATTORNE Aug. 2, 1960 Filed June 28, 1954 E. T. YOUNG JACKING MECHANISM FOR SEADROME 4 Sheets-Sheet 4 ATTORNEYS States "2341143 JA'CKING MECHANISM non snAnnoME Einar T. Young, Newtown Square, Pa., assignor to Sun Oil Company, Philadelphia, Pa., a corporation of New Jersey 9 Filed June28, 1954, Ser; No. 439,589 reclaims. c1. 6'1 46.5)

example, where olfshore well drilling is to be performed, 7

may be solidly founded on the ocean bottom by self-docking apparatus in water of depths up to and exceeding 80 feet.

The seadrome includes a plurality of buoyancy tanks framed into a truss structure. The deck is mounted on the truss structure and is, for example, adapted to support facilities and equipment necessary for drilling operations such as a drilling derrick and rig, living quarters, storage area, power plants, mud and other liquid storage vessels, etc. Alternatively, the seadrome may be formed of a solid walled barge structure which floats by virtue of its own displacement;

In addition to the foregoing, foundation columns are provided which are adapted to be jackeddownwardly into engagement with the ocean bottom whereupon continued jacking will serve to raise the seadrome structure a suficient heightabove the surface of the water so that the structure is above the level of waves normally encountered except during extreme storm conditions.

It is the primary object of this invention to provide apparatus for jacking the foundation columns downwardly and upwardly with respect to the seadrome structure.

When it is considered that the seadrome structure may be approximately 220 feet in length, 134 feet in width and may have a deck level normally approximately 28 feet above the surface of the water, and that the entire structure is jacked upwardly on the foundation columns so that the lower portion of the structure will be above the largest waves normally encounteredexcept possibly during extreme storm conditions, it will be evident that the supporting columns will'be distributed over a considerable area of the ocean bottom which will, in many instances, be unlevel, and it will also be evident that synchronizing the lifting movements of the jacking systems on each of the columns in order to maintain not only a level seadrome structure during jacking but also to maintain uniform load distribution over the columns during the substantial length of jacking involved in raising and lowering the seadrome must be considered.

2,947,148 Patented Aug. 2, 1960' 2 ments are housed in a single enclosure in the location of the jacking elements and in'which the remaining portions of the apparatus involved in the electrical control circuit are housed in a control station which may, if desired, be remote from the mechanical jacking elements. These and other objects of the invention will become apparent from the following description when read in} conjunction with the accompanying drawings, in which: Figure 1 is a diagrammatic perspective showing of the entire seadrome structure; 7 Figure 2 is a fragmentary longitudinal section through a portion of a foundation column and a buoyancy tank showing the jacking apparatus; a i v Figure 3 is a section taken on the trace 33 shown in Figure 2; a Figure 4-is a vertical section through a fragmentary portion of the apparatus shown in Figure 2;

Figure 5 is a diagrammatic showing of the hydraulic circuit employed with the jacking apparatus for each foundation column;

Figure 6 is a diagrammatieshowing of the electrical circuit employed with the jacking apparatus for each foundation column; and. V,

- Figure 7 is a Vertical elevationpartly in section showing a fragmentary portion of apparatus shown diagrammatically in Figure 1.

In Figure 1 there is shown generally at Z a perspective diagrammatic showing of the complete seadrome structure. The seadrome structure includes an open supporting truss structure 4 into which buoyancy tanks 6 and 8 are framed. The buoyancy tanks 6 each extend upardly above an associated buoyancy tank 8 and are a of lesser outer diameter than their associated buoyancy v tanks 8. Thus, there is provided astep 10 on which-the It is a further object of the invention to provide a jacking system by means of which, when all of the columns are resting on the ocean bottom, the jacking of each of the columns can be commenced simultaneously.

It is a further object of the invention to provide a truss structure 4 rests. are of annular form and a foundation column 12 ex; tends through each pair of buoyancy tanks. A foundation -tank 14 'is affixed to the lower end of each foundation column 12 and provides a footing for the column on the ocean bottom. As will be evident by viewing the figure, the seadrome truss structure may be supported above the surface of the water by the foundation columns when the foundation tanks are resting on the ocean bottom. It will also be evidentthat while the figure shows six foundation columns the number and arrangement of buoyancy tanks and foundation columns may be selected in accordance with the structural proportions of any particular seadrome involved.

The seadrome truss structure is provided at one endv with a slot 16 which is adapted to be positioned around' or above a drilling location. A platform may be mounted on the seadrome extending across the slot and be adapted to support a conventional type of drilling derrick. Alternatively, a separate drilling platform may be mounted on pilings or other suitable structure fixed to the bottom of the ocean and a slot 16 positioned around the StI'UC-rture While drilling operations'are being conducted;

In Figure 2 there is shown a fragmentary section through a buoyancy tank and its associated foundation column. Between the upper buoyancy tank. 6 and the foundation column 12 there are positioned two hydraulically operated principal piston and cylinder type jacks 18' and 2h. The two jacks are positioned one above the 32 are aflixed to the outer wall of the foundation column The buoyancy tanks 6 andS 12 adjacent to the jacks ;18 and 20. The upper end of the piston rod of the upper jack 18 is provided with a clevis 34 within which there is pivotally mounted a cross pin having its ends 36 adapted to engage transversely aligned recesses in the rack bar 30. The lower jack 20 is provided at the upper end of its piston rod with a clevis 38 within which'there is pivotally mounted a pin having its outer ends 40 adapted to engage the transversely aligned pairs of recesses in the rack bar 30. V A guide roller 42 is rotatably mounted on a pin which is rotatably mounted between the brackets 24. The guide roller 42 is positioned to bear against the outer wall of the foundation column 12 A similar guide roller is desirably provided between the lower foundation tank- 8 and the column 12. 1 V

It will be evident that four of the rack and jack ass'emblies thus faidescribed aredesirably provided in association with each of the foundation columns. In this manner the load transfer between the seadrome platform and the foundation columnis accomplished with adequate load distribution. If desired, additional guide rollers, such asthe-rollers 42, may be provided intermediately of the various jack and rack assemblies in order to further insure the maintenance of the foundation column in proper alignment with the buoyancy tanks. A support post 46 extending upwardly from the top of the buoyancy tank supports a swing or auxiliary jack 48 the base of the cylinder of which is pivotally mounted at 50 to the upper end of the support'post. A swing jack piston rod is pivotally connected at 52 to the upper end of the jack cylinder 18. A spring 54 is mounted between the end of the piston rod and the cylinder 48 and serves to urge the piston rod outwardly, thus to move the jack 18 toward the rack 30.

, Within a recess 56 in the buoyancy tank 6 a swing or auxiliary jack 58 is pivotally mounted to a suitable bracket at 60. The outer end of the swing jack piston rod is pivotally connected at 62 to the upper end of the jack cylinder 20. A spring 64 positioned between the outer end of the piston and the cylinder 58 serves to urge the swing jack 20 toward the racks 30.

A case 66 is mounted on a plate 67 affixed to a framework 68 which alsoserves to assist in supporting the post,46. Within the case 66 there are mounted a plurality of limit switches responsive to the positions of the jacks as will be hereinafter described. These limit of

pulleys

70 and 72 mounted on concentric shafts extending out of the case 66. One end of a cable 74 is affixed to andextends partly around the periphery of the pulley 70. The other end of the cable 74 is affixed to the pin 36. One end of a cable 76 is afiixed to and extends partly around the periphery of the pulley 72. The other end of the cable 76 is afiixed to the pin 40. One end 'of a cable 78 is afixed to an arm 80 extending from a rotatable shaft 82 extending through the wall of the case 66. The other end of the cable 78 is affixed to a pin 84 attached to and extending outwardly from the portion of the jack 20 adjacent to the mounting pin 26. A bar 86 is affixed to and extends outwardly from the cylinder of jack 18. The outer end of the bar 86 is adapted to engage a blade 88 afiixed to and extending from a rotatable shaft 90 extending through the wall of the case 66.

"Refen'ing to Figure 4, the

pulleys

70 and 72 are mounted on

concentric shafts

92 and 94, respectively. A shaft 92 is rotatably mounted in the wall of the case adjacent to the pulley 70 and terminates at 93 in a position midway through the case. in the shaft 92 and extends through to the opposite side of the case wherein it is rotatably mounted as indicated at 95. Cam segments 96, 98-and 100 are afiixed to the shaft 92 and

cam segments

102, 104 and 106 are afiixed to the shaft 94. A spring 108 has its ends, affixed to the cam segment196 and the adjacent wall of the case. 'A

The shaft 94 is rotatably mounted second spring 110 has its ends affixed to the cam segment 106 and the adjacent wall of the case. The limit switch 112 is mounted on a support bracket 114 and positioned so as to have its-actuating roller 116 in engagement with the peripheral surface of the cam segment 96.

Similar limit switches

118, 120, 122, 124 and 126 are positioned to be responsive to motion of their associated

cam segments

98, 102, 104 and 106, respectively. Limit switch 128 is positioned to be responsive to motion of a cam segment 130 afiixed to the rotatable shaft ,82. Limit switch 132 is positioned to be res ponsive to rotation of a cam segment 134 afiixed to the rotatable shaft 90.

Expansion of the jack 18 will draw the cable 74 upwardly and cause rotation of the pulley 70, the shaft 92 and the

cam segments

96, 98 and 100. Rotation of these segments will actuate their associated

limit switches

112, 118 and 120, respectively, as will be hereinafter described. Upon contraction of the jack 18 the spring-108 will cause the shaft 92 to rotate maintaining tension on the cable 74 and rotating the cam segments to the degree allowed by the contraction of the jack 18. Similarly, contraction of the jack 20 will cause rotation of the pulley 72 and

thecam segments

102, 104 and 106. Expansion of the jack 20 will permit the spring 110 to rotate the shaft 94 to the degree'allowed by the expansion of the jack 20. Actuation of the swing jack 48 pulling the jack 18 away from the column 12 will cause the bar 86 to engage the blade 88, rotating the shaft 90 and actuating the limit switch 132. Actuation of the swing jack 58 will move the jack 20 away from the column 12, moving the pin 84 downwardly thus pulling downwardly on the cable 78 and causing the shaft 82 to rotate resulting in actuation of'the limit switch 128.

As has been previously stated, the apparatus described in conjunction with Figures 2, 3 and 4 represents one set of jack cylinders and associated limit switches. In order to provide for the most desirable. jacking conditions, four sets of jacking cylinders and associated limit switches are desirably provided with each column. The hydraulic and electrical control systems employed with the four sets of jack cylinders associated with a single column will now be described. In Figure 5 there is shown a hydraulic pump which pumps hydraulic fluid from a reservoir 142 into a supply line 144 at a pressure determined by the setting of a pressure relief bypass Valve 146. This pressure is indicated by a conventional pressure gauge 148.

Four solenoid operated

hydraulic control valves

150, 152, 154 and 156 are connected to the supply line 144 and are connected to a return line 158. Conventional throttling valves may be employed in the supply and return line connected to these valves if desired. The valve is connected through

lines

160 and 162 to the cylinders of the upper jacks 18. The line 160 is connected to the jack cylinders so as to provide supply liquid for expanding the jacks and the line 162 is connected to the jack cylinders so as to supply liquid for contracting the jacks. It will be evident that, while only two jacks are shown in the drawing, any number of jacks may be connected in parallel arrangement, as indicated by the construction line 164 breaking 01f the drawing.

,The valve 150 is a three position valve having springs 166 for centering the valve in a completely shut-off condition and having

solenoid coils

168 and 170 for positioning the valve in either of its two operative positions. When the valve is deenergized it will assume the position shown with all of the hydraulic lines closed off. If the coil 168 is energized, the valve will assume a position in which hydraulic fluid under pressure is supplied to the cylinders of the jacks 18 to expand the jacks and, if the solenoid coil 170 is energized, the valve' will assume a position in which hydraulic fluid pressure is supplied to'the cylinders of the jacks 18 in I s'uch a manner .as to cause contraction. of thejacksl The electricalcontrol circuit for energizing the

solenoidcoils

168 and 170 will be hereinafter described;

The Valve 152 is connected through line 172.to the cylinders of the swing jacks 48 The line is connected to the swing jack cylinders so as to supply liquid for contracting the jacks. The control valve 152 is a twoposition valve having a return spring 174 normally urg ing the valve to assume a position in which the line 172 is connected to the return line 158. The valve includes a solenoid coil 176 which, when energized, causes the valve to assume a position in which hydraulic fluid under pressureis delivered to the line 172 and causeslthe swing jack cylinders 48 to be contracted.

The control valve 154 is connected to the jack cylinders of the lower jack through

lines

178 and 180. The line 178 is connected to the jack cylinders so as to supply liquid for expanding the jacks and the line 180 is connected to the cylinders so as to supply liquid for contracting the jacks. The valve 154 is a three-position valve identical to the valve 150 and is provided with two

solenoid coils

182 and 184. When the coil 182 is energized, the valve is positioned so as to deliver hydraulic fluid under pressure to the cylinders of the jacks 20 so as to expand the cylinders, and when the coil 184 is energized the valve delivers fluid-under pressure to the cylinders 20 so as to cause contraction of the cylinders.

When neither of the

coils

182 or 184 are energized, the

valve will assume a neutral position in which all of the hydraulic lines are shut off.

The valve 156 is connected through line 178 to the cylinders of the swing jacks 58. The valve is so at" ranged that when the coil 183 is deenergized the valve straits is positioned by the spring 181 and the line 178 is connected to the drain line 158. When the coil 183 is energized, the valve is positioned so as to deliver hydraulic fluid under pressure to the cylinders of the swing jacks 58.

The two swing jacks 48 and 5S and their associated

springs

54 and 64 are so arranged that when no fluid pressure exists in the swing jack cylinders their associated springs urge the

jacks

18 and 20 into engagement with the rack 30. When either of the swing jack cylinders is receiving oil under pressure, the piston in the cylinder is retracted and-acts to compress its associated spring and draw its associated jack cylinder out of engagement with the rack 30. a

' In Figure 6 there is shown the electrical diagram involved in the control systememployed for controlling the operation of four sets of jack cylinders associated with a single column. The control circuit includes a plurality of relays, the coils of which are indicated at R1, R2, R3, R4, R5, R6 and R7, and their associated only one switch 120 and one. switch 122, which are actuated at the mid points of the strokes of the

jacks

18 and 2 0,respectively, are required for the control system associated with each column.

The coil of the relay R7 is connected in series with a push button 196 between a pair of conductors 199 and 192 which are connected to a suitable source of power. The push button 196 is manually controlled and is of the type which must be held closed by an operator. The coil of the relay R6 is connected in series with a second push button 194 between the

power lines

198 and 192. The push button 194 is also of the type which must be held closed by an'operator. The push button 196 serves to initiate operation of the control system through a cycle which is eifective to move the column upwardly with respect to the seadrome platform and the push button 194 initiates operation of the control system through a sequence of operations elfective to lower the column with respect to the seadrome structure. These sequences of operations will be hereinafter'described. A normally open relay 6 contact R6-1 is connected between the conductor 190 and a conductor 198. A similar relay 7 contact R7-1' is connected between the conductor 190 and the conductor 198.

The coil of relay Rl is connected in series with a' series arrangement of the contacts of limit switches 112 between the conductors198 and 192. The contacts 112 are closed when the jack 18 is in an expanded or upper position. Thus, when all four of the jacks 18 have reached their uppermost positions, the four

contacts

112, 112, 112" and 112" will be closed and the coil of the relay R1 will be energized if contact 194 or contact 1% is closed. The normally open relay contacts 122-1 and R3-1 are connected in parallel arrangement and in parallel arrangement with the four limit switch contacts 112.

One side of the relay coil R2 is connected to the con ductor 192. The other side of therelay coil R2 is connected to a parallel arrangement of the limit switch contacts 118. The limit switch contacts 118 are open when switch contacts 124 are open when the lower jack Ztiis contacts indicated at R1-1, etc. The relay R5 is a time delay relay of conventional type in which operation is delayed for a two second interval after it is energized. The circuit also includes a pair of single pole double throw switches 240 and 246, a pair of interlocked single pole three-position switches 200 and 204, and a second pair of interlock three-position single pole switches 220 and 224. The coils of the solenoids associatedwith the

hydraulic valves

158, 152, 154 and 156 described in connection with Figure 5 are indicated at 176, 18.3, 168,

170, 182 and 184 in the wiring diagram. Also included in the wiring diagram are the contacts of the various limit switches described in connection with Figure 4. Except for

switches

120 and 122, the arrangement shown in Figure 4 is the arrangement of limit switches" associ ated with each of the four sets of jacks associated with each column. Thus, in the wiring diagram of Figure 6, there are shown the various sets of four contacts-having identifying numerals corresponding with the numerals of the limit switches shown in Figure '4. These contacts are distinguished bytheir primenumbers as each' being associated with one of the four sets of jacking cylinders. As will be hereinafter described more fully,

expanded to its upper position. The other sides of the

contacts

118 and 124 are connected through a series arrangement of normally open contacts R1-1 and R4-1 to I the conductor 198.

One side of the coil 176 of the solenoid-valve 152 controlling the swing jack 48 is connected to the conductor 192. The other side of the. coil 176 is connected to the movable arm of the single pole double throw switch 240. When the switch 240 is positioned on the contact 242, the coil 176 is connected directly across the

power lines

190 and 192. When the switch 240 is connected to the contact 244, the coil 176 is connected to the movable arm of a single pole doublethrow switch arm 122 positioned to close with

contact points

121 or 123. Contact 121 is connected in series with one side of a normally open contact R6-3. The contact 123 is connected in series with one side of a normally closed contact 116-4. The other sides of the contacts R6-3 and R6-4 are connected together and through four limit switch contacts 128 'to conductor 198. The limit switches 128 are closed when the jack 20 is in engagement with the rack.

One side of the coil 183 of the hydraulic control valve 156 controlilng the flow of hydraulic fluidrto the lower swing jack' 58 is connected to the line 192. The other 7 side of thexc'oil 183 is connected to the movable arm of coil 183 is connected .to the movable arm of a single pole double throw switch positioned to close'with contact points117 or 119. The contact 117 is connected in series with one side of a normally open contact R7-3,

and are provided with only one of the jacking assemblies with each column. These two contacts change their positions at approximately the half-way point-of the jack strokes. The contact 122 moves to the contact point 123 when the contracting jack 20 passes to the'lower half of its stroke. The contact arm 120 switches to the contact point 117 when the contracting jack 18 passes to the lower half of its stroke.

One side of a normally closed contact R 1 of the time delay relay is'connected to the junction between the relay coil R3 and the'switch contacts 124. The other side of the contact R5-1 is connected to a parallel arrangement of normally open contacts R6-2 and R7-2. The other side of the contact R6-2 is connected between the contacts 132 and the contact R73. The other side of the contact R7-2 is connected between the contacts 128 and the contact R63.

One side of the relay coil R4 is connected to the line 192. The other side of the relay coil R4 is connected through the series of arrangement of the contacts 126 to the conductor 198. The parallel arrangement of normally open relay contacts R2-2 and R3-2 is connected in parallel with the series arrangement of contacts 126.

The relay contacts 126 are closed when the jack 20 is contracted to its lowermost position.

The coil' of the time delay relay R5 is connected directly across the

conductors

192 and 198. Thus,.upon depression of either of

the'push buttons

194 and 196, the coil R5 is energized and the contact R5-1 remains closed for approximately two seconds and is thereafter opened.

One side of the coil 168 of the hydraulic control valve 150 is connected to the line 192. The other side of the coil 168 is connected to the movable arm of the single pole three-position switch 200. When the switch 200 is in contact position 208, the coil 168 is isolated from the circuit. When the contact 200 is positioned on the contact point 212, the coil 168 is connected directly across the

power lines

190 and 192. In this position, operation of a control valve is manually controlled by the switch 200. When the switch 200 is positioned on the contact 210, the coil 168 is connected through the normally closed contact R1-2 to the conductor 198. Similarly, one side of the coil 170, which is the other coil of the hydraulic control valve 150, is connected to the line 192, and the other side of the coil 170 is connected to the movable arm of the switch 204; When the switch 204 is on contact position 218, the coil 170 is isolated from the circuit. When the switch 204 is on contact 214, the-coil 170 is connected directly between the line 190 and the line 192. When the switch 204 is connected to the contact 2 16, the coil 170is connected through the normally open relay contact R2-3 to conductor 198. The

interlock, indicated at 206, is provided to insure that when either of the

coils

168 or 170 is connected directly across power supply the other coil is isolated from the circuit. j

One side of each of the

coils

182 and 184 of the hydraulic control valve 154 controlling thelower. jack 20 is connected to the line 192. The other side of thejcoil 182 is connected to the movable arm of switch 220., When the switch 220 is positioned on contact 228, the,

coil 182 is isolated from the circuit. When the arm 220 is positioned on contact 232, the coil 182 is connected directly across the

power lines

190 and 192. When the arm 220 is positioned on the contact 230, thecoil 182 is connected through a normally open relay contact R3-2 to the conductor 198; The otherside' of the coil 184 is connected to contact to arm 224. When the 'contact arm 224 is positioned on the contact 238, the coil 184 is isolated from the circuit. When the arm 224 is positioned on contact 234, the coil 184 is connected directly across power lines and 192. When the contact arm 224 is positioned on the contact 236, the coil 184 is connected through a normally closed contact R4-2 to the conductor 198. ;The interlock arrangement, indicated at 226 be tween the contact arms 220 and 224, is provided to insure that when either of the contact arms is positioned to con nect its associated coil directly across the power lines, the other coil is isolated from the circuit.

,During normal operation'of'the jack system, the arm 20%) is positioned on contact 210, the arm 204 is positioned on contact 216, the arm 220 is positioned oncontact 230 and the arm 224'is' positioned on c'ont'act236; With these arms in these positions, the relays R1, R2, R3 and R4 control operation of the hydraulic control valve solenoid coils 168,170, 182 and 184, respectively. The

coils

176 and 183 of thehydraulic control valve delivering hydraulic fluid to the swing jack members are controlled by relays R6 and R7 and by the

limit switch contacts

128 and 132 which are open when the jacks 20 and the jacks 18, respectively, are in engagement with their associated racks.

Before proceeding further with adescription of the operation of the control'system, it should be noted'that the active stroke of the jacks has been selected to be ten inches. This stroke length is controlled, of course, by the setting of the various limit switches. Thus, when one'of the jacks is in'engagement with the rack, it will move the rack for a distance of ten inches and, when one of the jacks is disengaged from the rack, it will move for a distance of ten inches with respect to the jack mounting but will move a distance of twenty inches with respect to the rack which is being moved ten inches by the other jack. It should also be noted that while the jack stroke is ten' inches the pitch of the rack recesses 32, as indicated at 31, is sixteen inches. The sixteen inch pitch allows jack motion suflicient to provide jack travel into the socket forming portions 33 of the rack recesses.

During the operation of a jacking cycle, the two jacks will both be engaged in the rack recessesonly for those time intervals for which the one jack'is fully expanded and the other jack is fully contracted, or vice versa. The remainder of the time when one jack is in engagement with the rack and is moving the rack in one direction, the other jack will be disengaged from the rack and will be moving in the-opposite'direction.

Referringnow to the wiring diagram of Figure 6 and assuming that it is desired to raise the seadrome platform with respect to the supporting columns, the push button 194 is closed to initiate the sequence of operation of the control system which will serve to move the column downthe rack and thus the solenoid coil 183, is deenergized.

Relays R1, R2, R3 and R4 remain dcenergized because of the positions of their associated series contacts as shown in Figure 6. 'The solenoid coil 168-isenergized through relay contact R1-2 and the solenoid coil 184 is energized through 'relay contact R4-2. Thus hydraulic fluid under pressure is fed to the upperjacks'18 in such ajdirection as to expand the jacks and hydraulic fluid under pressure is fed tothe lower jacks 20 in such a direction as to contract the jacks.

column.- When all four of thelower jacks20 are fully contracted, the four limit switches126'will close, energizing-the relay R4; Closure of the relay 'R4 will deener- Contraction of the' 'jacks 20 will raise the seadrome withrespect to the .gize the Selene-M184 permitting the hydraulic control valve 154 toassume aneutralposition with all of the hydraulic lines shutoff; Prior to completion of the contraction of each of the lower jacks 20, each .of the upper jacks 18 will become fully extended and will have dropped into a rack recess 32 in response to the urging of the swing jack springs 54. When the four upperjacks 13 are each in engagement with a rackrecess, the fourlimit switches 132. will beclosedandrthe solenoid coil 183 will be energized through the relay -contact.R7-4 and the switch am 1.20. Closure of this contact positions the hydraulic contro1'valve156 so ast o supply fluid under pressure to the swing jacks, 58 urging the lower jacks 2% out Qf'611'.

gagerhentfwith the rack. At this time, however, the pins 40 of'thejacks 20 areengaged inthe sockets 33 of the racks preventing the jack from being retracted.

When the upper jacks 18 reach their uppermost position, I the limit switches 112 are closed and the relay R1 isenergiZed, and contact R1-2 opened, deenergizing the solenoid coil 168 of the control valvelEtl, this permitting the control valve 150; toassume a neutral position with all of theiconnections shut ofi'. Uponclosure of the relayfcontactsRl-l andR4-1, therelay coils R2 and R3 are energized through limit switches 1'18 and 124, respectively, whereupon relay coil R1 is connected to power through relay coilsRZ-l and R341. 7

Thus when the lower jacks 20 are in their lowermost positions and when the upper jacks 18 are in their uppermost positions and engaged withthe'rack's, the relays R1, R2,;R3. and R4 are all energized and the solenoid valve coil 168 is deenergized and the coil 17% is energized thus positioning the hydraulic control valve 159 so as to move the upper jacks 18v downwardly, Solenoid coil 182] is energized and solenoid coil 1% is deenergized thus positioning the hydraulic control valve 154 to move the lower jacks 20 upwardly. As the upper jacks move ,downwardly, the; column is moved downwardly with'r'espect to the 'seadrome platform. As the lower jacks 2t} move upwardlyptheirpins 40 become disengaged from their associated sockets 33 in the racks and the swing cylinciers 58 pull the lower jacks 20 out of engagement with. the racks. The upper jacks lttcontinue to contract drawing the column downwardly and the lower jacks continueto expand while disengaged from the racks until they each pass the midpoint positions in their respective strokes at whichtime the

contacts

120 and 122 shift and the. contact 122 moves to contact point 121 and the contact 120 moves ,to contact point 117; This movement of the contact'120 deenergizes the solenoid coil 183 of the hydraulic control valve 156 draining the hydraulic 'iluid from the swing jacks 58 and permitting the springs 64 to urge the lower .jacks 20 into engagement with their racks. As the lower jacks 20 continue to expand, they ultimately reach the next rack recess and drop into engageinent therewith. At approximately the same time this occurs, the upper jackslS have reached the lowermost portions of their strokes. i i

When the lower jack cylinders 21] move into engage ment with the rack recesses, limit switches 128 close and the solenoid coil 176 of the hydraulic control valve 152 is energized through the closed contact R6-3. This actuates the valve 152 so as to deliver hydraulic fluid under pressure to the swing jack 48 to urge the upper jack 1% out of engagement with the racks.

At this point in-the cycle when the upper jacks 18 are in their lowermost positions and thelower jacks 29 are in their uppermost positions, the switches [118 and 124 are open-and therelay'coils RZand R3 are deenergized. Furthermore, the limit switches 112 are only closed when the jacks 18a1fe in their uppermost position and, therefore, in this point in the cycle, the relay'coil R1 is denergizedfl Additionally, the limit switches 126 are only closed when the lower jacks 20 are contracted.

Thus," at this point in the cycle, the limit switches 126 are open, the contact R24 is open and the contact R3-2 i s-open. Thus the relaycoil R4 is deenergized. With the relay coils R1, R2, R3 and R4 deenergized, the jacks 18 are moved upwardly and the jacks 20 are moved downwardly. Upon commencement of the upper motion by the jacks E8, the pins 36 of the jacks move clear of the sockets inthe racks and the swing jacks 48 move the cylinders out ,ofengagement with the racks.

The jacks now continue to move with the jacks: 18 expanding while out of engagement with the racks and the jacks 20 contracting while in engagement with the racks. The jacks cross the mid-points of their strokes and the

switches

122 and 120 again shift and the coil 176 is deenergized permitting the spring 54 to urge the upper jack cylinders 18 back into engagementwith the racks. Thus a cycle of operation has been completed. .Ihese cycles of operation will continue in sequence until the push button 194 is open.

The time delay relay R5 and its contact R5-1 are provided in order that the cycle of operation will start in the proper direction regardless of jack position. Thus with the jacks in position as shown in Figure 2, if the push button 196 is closed, the relay R7 is energized and the coil R3 is immediately energized through the circuit formed by the limit switches 128, the contact R7-2 and the contact RS- I. The coils R1 and R2 are also energized and the coil R4 is energized. Thus substantially immediately upon the depression of the down button 196, the four relays R1, R2, R3 and R4 are each energized and each of the jack cylinders immediately begins movement in the operates and the contact R5-1 opens and remains open until the sequence of operation is interrupted by the release ofthe button 196. I

It is believed unnecessary to burden this disclosure with a recitation of the sequence of operation of the control circuit when eachof the

push buttons

194 and 196 is depressed at any possible point in the operating cycle. It should be noted, however, that the arrangement of

limit switches

128 and 132 prevent both of the swing jack solenoid control valves l52 and 156 from being operated simultaneously. However, the

switches

240 and 246 permit manual operation of the swing jacks 48 and 58 if desired. The interlocked switches 200 and 204 permit manual operation of the upperjacks 18 and the interlocked switches 220 and 224 permit manual operation of the lower jacks 2t The up and down

push buttons

194 and 196 are provided in the form shown in order that-it is necessary for an operator to hold the buttons closed manually during the jacking of any one column. This. type ofdead man control is provided to prevent the possible occurrence of unattended operation of the jacking system. The conductor 262 is connected between the up button 194 and the relayR6 and a conductor264 is connected between the down button 196 and therelay R7. These two connections are provided in order that the control circuit for operating the jacking system at one column may be connected to a master point at whichpoint the jacking systems of each of the columns on the seadrome may be centrally controlled if desired. This central control permits at a central station a control of all of the jacking systems in response to inclination or load indicating means in order that the jacking of all or the columns of the seadrome may be coordinated in such a manner that the load is sufiiciently uniformly distributed among the columns during jacking and that the seadrome is maintained 7 one column as a result of greatly unbalanced loadings among thevarious columns, it will be evident that lifting 11 of the jacking system of that one column will be arrested untillsuch time as the load distribution among the various columns becomes more uniform as a result of continued jacking of the other columns.

Heretofore, it has been noted that a convenient length of active jack stroke of ten inches has been selected. If the actual stroke of the jack cylinders is, for example, twenty inches, there is provided ample overrun at each end of the normal active stroke in which unbalanced'load conditions, such as might arise very rapidly in emergency conditions, may be compensated for through the pressure relief valves 146. The twenty inch stroke of the cylinders provides an additional desirable feature in that in the event ofmaloperation of one of the jacks resulting in the jack cross pins failing to engage the rack that particular jack may be operated manually and placed into engagement with the nearest rack recess even though this jack position be displaced from the normal jack position with regard to the positions of the other jacks of that column.

From the foregoing it will be evident that the jacking system described serves to commence the jacking of the columns immediately upon the depression of the up or down

switches

194 and 196, respectively. It will further be evident that the system provides for an inherent load balancing and additionally admits of operation of the various column jacking systems from a remote central 7 member, a body member having said column member extending therethrough, said members being movable vertically relative to one another, and means operable for moving one of said members selectively upwardly or downwardly relative to the other member including rack means fixedly mounted upon said column member and extending longitudinally thereof, a first pair of extensible fluid motors mounted directly upon said body memher for swinging movement respectively about horizontal control station at which station apparatus for indicating the level of the seadrome structure may be provided. I

Apparatus for indicating'the level of the seadrome structure is shown in Figures 1 and 7. It will be evident that a structure the size of the seadrome structure described herein will suffer a certain amount of deflection if the loading at the various columns is non-uniform. This problem will exist in a solid barge type structure as well as in the truss type structure disclosed. The level indicating system which is hereinafter described may be employed with any type of seadrome structure to indicate the relative elevations of the structure adjacent to each of the support columns.

In Figure 1 there is shown adjacent to each of the columns 12 a container 270. Pipe lines 272 extend between each of the containers to a central station 274. At the central station each of the pipe lines terminate in a vertically extending tube 278 as indicated in Figure 7. Each of the containers 270 is provided with liquid as indicated at 280, the level of which is adjusted with regard to some predetermined portion of the seadrome structure in the vicinity of its associated column. It will be evident that if the level of the liquid in each of the containers is adjusted to be related to similar predetermined portions of the seadrome structure adjacent to each column the levels 282 of the liquid in the upturned ends of the various pipe lines connected to the containers 270 will indicate at the central station the degree of deviation from level of these various portions of the seadrome structure. The capacity of each of the containers 270 is selected to be such that the quantityof liquid in each of the containers is great with respect to the variation in the quantity of' liquid occurring in its corresponding tube 278. Thus only negligible errors will be introduced in the indications of level provided by the tubes 278 at the central control station as a result of displacement of liquid into or out of V prevent the occurrence of excessive load unbalance among the various columns. a e

It should be noted that the use of the seadrome is not limited to use at sea and that when the word sea is axes and detachably engageable with said rack means for transmitting a downwardly acting load from one of said members to the other member, and means for controlling the extension and contraction and positioning of said motors in'predetermined sequence and eflecting operation thereof in repeated cycles whereby to controllably shift one of said members vertically relative to the other member selectively upwardly or downwardly including a second pair of extensible fluid motors mounted directly upon said body member for swinging movement about horizontal axes and operable for swinging said first pair of motors respectively about their pivotal axes thereby to position each motor in detachable load supporting engagement with said rack means While the other motor is free of said rack means.

) 2. The combination defined in claim 1 wherein each motor of the first pair thereof is disposed in an upright position, each motor of the second pair thereof is disposed in a horizontal position and pivotally connected to the associated one of said first pair of motors, and the axes of the pivotal connections of said first pair of motors to the body member and of said second pair of motors respectively to said first pair of motors are all paralleltoone another.

3. The combination defined in claim 2 wherein one motor of the first pair thereof and its associated motor of the second pair thereof are disposed in vertically spaced relation to the other motor of said first pair" the same rack face.

operatively interconnecting said limit switches with said motors for actuation of said limit switches in response to extension, contraction and swinging movements of saidmotors.

6. The combination defined in claim 5 wherein the I electric circuit includes switch means operable for 'permitting manual operation of the motors.

7. The combination defined in claim 5 whereineach motor of the first pair thereof is adapted for actuating one of the limit switches when it engages therack means, and the motor of the second pair thereof associated with the other motor of the first pair thereof is actuated in response to actuation of said switch for freeing the other motor of said first pair thereof from the rack means.

8. The combination defined'in claim 1 wherein the fluid motors are connected in a hydraulic circuit including a pair of valves operable for controlling the flow of pressure fluid respectively to the first pair of said 13 motors, each of said control valves has two valve positioning coils, and the latter are connected in an electric circuit including relay means operable for energizing said coils thereby to position said valves for supplying fluid pressure for selectively extending and contracting said motors. 1

9. The combination defined in claim 1 wherein the fluid motors are connected in a hydraulic circuit including valves operable for controlling the flow of pressure fluid respectively to said motors, each of said control valves associated with one of the motors of the first pair thereof has two valve positioning coils, and the latter are connected in an electric circuit including relay means operable for energizing said coils thereby to position said valves for supplying fluid pressure for selectively extending and contracting said motors, switch means for initiating an automatic cycle of operation for shifting one of said members selectively upwardly or downwardly relative to the other, and time delay means for ensuring shifting of said member in the selected direction regardless of the positions of said motors when said shifting commences.

10. A seadrome comprising a plurality of laterally spaced upright column members, a floatable platform structure having said column members extending freely therethrough, said platform structure and column members being movable vertically relative to one another, and means operable for moving said columns selectively upwardly or downwardly relative to said platform structure including rack means fixedly mounted respectively upon said column members and extending longitudinally thereof, two groups of principal extensible fluid motors mounted directly upon said platform structure for swinging movement respectively about horizontal axes and detachably engageable with said rack means for transmitting column loads to said platform structure when said column members are not engaged with the ocean bottom.

and for transmitting platform loads to said column members when said column members are engaged with the ocean bottom, and means for controlling the extension and contraction and positioningof said principal motor groups in predetermined sequence and efiecting operation thereof in repeated cycles to controllably shift said column members selectively upwardly or downwardly relative to said platform structure including two groups of auxiliary extensible fluid motors mounted directly upon said platform structure for swinging movement about horizontal axes and operable for swinging said groups of principal motors respectively about their pivotal axes thereby to position each principal motor group in detachable load supporting engagement with said rack means while the other principal motor group is free of said rack means..

11. The combination defined in claim wherein the fluid motors are connected in hydraulic circuit, electrically actuated valves are connected in said circuit to control fluid flow, said valves are connected in electric circuit with limit switches mounted upon said platform structure adjacent to said motors, and means is provided operatively interconnecting said limit switches with said motors for actuation of said limit switches in response to extension, contraction and swinging movements of said motors.

12. The combination defined in claim 11 wherein the electric circuit includes switch means operable for permitting manual operation of the motors.

13. The combination defined in claim 11 wherein each principal motor of either group thereof is adapted for actuating one of the limit switches when it engages the rack means, and the auxiliary motor associated with a principal motor of the other group thereof is actuated in response to actuation of said switch for freeing the principal motor of said other group thereof from the rack means.

14. The combination defined in claim 10 wherein the fluid motors are connected in a hydraulic circuit including a pair of valves operable for controlling the flow of pressure fluid respectively to the two groups of principal motors, each of said control valves has two valve positioning coils, and the latter are connected in an electric circuit including relay means operable for energizing said coils thereby to position said valves for supplying fluid pressure for selectively extending and contracting said groups of motors.

15. The combination defined in claim 10 wherein the fluid motors are connected in a hydraulic circuit including valves operable for controlling the flow of pressure fluid respectively to said groups of motors, each of said control valves associated with a principal motor group has two valve positioning coils, and said coils are connected in an electric circuit including relay means operable for energizing said coils thereby to position said valves for supplying fluid pressure for selectively extending and contracting said motors, switch means for initiating an automatic cycle of operation for shifting said column members selectively upwardly or downwardly relative to said platform structure, and time delay means for ensuring shifting of said column members in the selected direction regardless of the positions of said groups of principal motors when said shifting commences.

References Cited in the file of this patent UNITED STATES PATENTS 2,308,743 Bulkley Ian. 19, 1943 2,334,992 Crake Nov. 23, 1943 2,407,796 Page Sept. 17, 1946 2,558,401 Voigt June 26, 1951 2,540,679 Latfaille Feb. 6, 1954 2,673,064 Patterson et a1. Mar. 23, 1954 2,764,133 Pegard Sept. 25, 1956