Abstract: An offshore system of the articulated tower type is provided, which utilizes chain devices extending in different directions from the upper portion of the tower to the seabed to help maintain the tower in a largely vertical orientation. In one system wherein the tower must be held close to the vertical orientation, as where the system is used for drilling underwater hydrocarbon wells, an inclinometer is utilized to measure small angles of tilting of the tower, to operate one or more winches that pull on the chain devices. The chain devices can be in the form of heavy chains extending in loose curves. In another system, the chain devices are lines of highly stretchable material such as nylon, and which may be nearly neutrally buoyant, and with the lines extending in almost straight lines between the tower and seabed.

Abstract: A compliant concrete structure which is supported by using a compliant pile system consisting of piles and pile sleeves so that the platform may yield to large oscillations when the structure is installed in a body of water. The invention comprises attaching the pile sleeve guides (6) and the pile sleeves (3) to a rotation symmetrical concrete shell which forms the basic structure. The pile sleeves are rigidly connected to the lower end portion (2) of the structure.

Abstract: A tension-restricted articulated platform tower for offshore oil and gas production. Two or more tower segments of increasing lateral dimension (proceeding toward the ocean floor) are stacked and articulated by means of a resilient joint. The platform tower behaves as a fixed tower under normal quiescent conditions with each of the segments above the base segment sitting thereabove in an at rest position. When forces sufficient to unseat the compressed resilient joint element are directed against the platform tower (e.g., from wind, waves, or water current), the tower behaves complaintly with tension elements secured to each corner post providing a restorative force proportional to the amount of tower movement.

Abstract: An improved keyhole latch is provided for securing offshore structures in place. The back flange of the flex joint and latch assembly has a male portion and the load ring of the receptacle has a female portion. By matching the male and female portions, rolling of the load ring and flex joint and latch assembly is minimized and the noncontinuous surface on the load ring is strengthened.

Abstract: A stress-limiting device for a flexible riser which stress-limiting device glides in a set of guides rigidly attached to an articulated structure emplaced in the deep sea. The device includes an elastic guide tube element coaxial to the riser, with the stiffness of the guide tube increasing progressively from the top to the bottom of said guide tube, whereby the stiffness characteristic is appreciable in the lower region of the guide tube, which lower region is affixed to a structure attached to a wellhead or the like via an aligned fitting, whereby the guide tube is held in contact with the riser by the intermediary of a plurality of support mechanisms one of which includes a fitted bushing which glides in the lower, rigid part of the guide tube. The device makes it possible to shut down and resume operation of offshore wells which have been equipped for production.

Abstract: An offshore multiple tendon compliant buoyant tower construction for well operations in which a plurality of tendons are arranged in parallel, vertical, closely spaced assembled relation and have top and bottom ends, the bottom ends being connected to a base module at the sea floor, the top ends being connected to a buoyant structure which includes conductor tubes therein for each of said tendons and which serves to restrict bending of the top portion of said tendons to provide a relatively stiff, unbending, noncompliant tendon top portion which extends below the sea surface, the portion of the assembled tendons below the stiff to portion being relatively compliant; the buoyant structure imparting tension to said plurality of assembled tendons at the top ends thereof whereby the tensioned tendons provide lowering of the effective center of gravity of the tower construction below the center of buoyancy and whereby cyclic stresses in the assembled tendons resulting from roll or bending of the tower construction

Abstract: A jacket adapted to be mounted in an upright position in water depths in the range of 1000 to 1500 feet or more. The jacket has a number of spaced, generally parallel legs coupled together by braces, each leg being tubular to contain a plurality of sleeves and/or guides rigidly secured to the inner surface of the leg. Each sleeve has a tubular pile therewithin, the upper end of each pile being rigidly connected to the upper end of the sleeve, the piles extending downwardly through respective sleeves and into the sea bottom to provide a foundation for the jacket. Each pile serves as a compression spring to present tension-compression couples to withstand lateral forces during rocking motion of the upper end of the jacket relative to the lower end thereof. Each pile is further adapted to house a well for transfer of hydrocarbon or mineral products from the sea bottom to the platform on the upper end of the jacket.

Abstract: Emergency escape platform apparatus including an escape platform disposed in spaced apart relation from a drilling platform and joined to the drilling platform by escape bridge apparatus. Two flexible base cables are connected in tension horizontally adjacent between the escape platform and the drilling platform. Two flexible hand cables are connected in tension horizontally adjacent to one another and vertically adjacent respectively above the base cables. A plurality of vertical spacer bars are vertically connected between a respective base cable and a respective hand cable at selected intervals. Cable tensioning apparatus connects the base cables and the hand cables for maintaining the cables under selected tension while permitting relative movement between the escape platform and the drilling platform. Light weight walkway structure is horizontally disposed between and connects the base cables to provide a walkway for individuals between the drilling platform and the escape platform.

Abstract: A flexible structural joint of "flex joint" for use in an articulated structure is disclosed. The articulated structure has a first section and a second section which are located along a longitudinal axis of the structure, the first section being subject to lateral or transverse loads. The flex joint is located between the first and second sections and accommodates lateral pivoting of the first section with respect to the second section through elastic flexing or bending of certain of its members. No moving parts are used. In a first embodiment, the flex joint consists of an elongated axial load member and at least three shear and torsion links oriented so as to lie substantially in a plane perpendicular to the longitudinal axis of the structure. Each of the links is connected at one of its ends to the first section and at its other end to the second section.

Abstract: A connection system between a main body and a superstructure, usable in a sea environment, comprising an arrangement for moving the main body relatively to the superstructure and, guide means cooperating with said moving arrangement. The moving means arrangement is inscribed on a cylindrical surface, was the guide and moving arrangment being adapted to allow at least a swinging movement of main body relatively to said superstructure.

Abstract: The present invention provides a vessel mounted mooring system and a method for its installation. The method involves the construction of a vertical well in the vessel extending from the deck through the bottom plates of the vessel. A lower bearing ring which circumscribes the well is connected to the underside of the bottom plates. A lower turret unit is laterally guided by the lower bearing ring and is restrained against uplift forces by the lower bearing ring. A middle turret unit is placed into the well and connected to the lower turret unit. An upper bearing ring which circumscribes the well is mounted to the deck. The upper turret unit is connected to the middle turret unit whereupon the weight of the assembly of the upper, middle and lower turret units is supported by the upper turret unit and is guided by the upper bearing ring.

Abstract: The present invention provides a vessel mounted mooring system and a method for its installation. The method involves the construction of a vertical well in the vessel extending from the deck to the bottom plates. A lower bearing ring which circumscribes the well is connected to the underside of the bottom plates and extends beyond the keel. A lower turret unit is supported substantially within the bearing ring. A middle turret unit is placed into the well and connected to the lower turret unit. An upper bearing ring which circumscribes the well is mounted to the deck. An upper turret unit is connected to the middle turret unit whereupon the assembly of the upper, middle and lower turret units is supported and guided by the upper bearing ring and further guided by the lower bearing ring.

Abstract: An articulated, compliant offshore structure having a base portion establishing a gravity-type foundation on the ocean bottom, a tower extending upward from the base portion and a deck seated on the tower a spaced distance above the ocean surface. The tower is secured to the base portion by an articulated joint which permits the tower and deck to undergo limited pivoting about the base. This provides compliancy in response to forces imposed on the structure by wind, waves and ocean currents. A set of tensioned members, preferably cables, are secured between anchorages on the base and at an elevated position on the tower to provide controlled resistance to pivoting of the tower. In the preferred embodiment the tower and base are concrete shell structures.

Abstract: A flexible structure of controlled yieldability for use as a hydrocarbon drilling and production platform in deep seas, or as a mooring point for oil tankers, constituted by a foundation base assembly, a vertical cylindrical tubular element placed under tension by a buoyancy chamber disposed at its top in proximity to the water surface, and an overlying lattice which at its top supports the plant platform.The tubular element is connected at its lower end to the base and at its upper end to the buoyancy chamber by means of suitable profiled tapered terminal elements able to withstand the bending loads which are generated at said connections.The entire structure is constituted by four separate pieces, namely the foundation base assembly with the lower terminal element, the lower half of the cylindrical tubular element, the upper half thereof, and the upper buoyancy chamber which is connected at one end to the upper terminal connection element and at the other end to the top lattice.

Abstract: An offshore structure for deepsea production of this invention is designed for achieving economy both in installation and in operation. It consists mainly of a base to be founded on a sea-bed, a buoyant body having a separator segregated from the sea for storing and separating the produced fluids and an elongate tensioned member for connecting the base and the buoyant body and transporting the produced fluids from the well through the base to the separator near the surface of the sea. The separator has a compartmentalized outer wall for controllably variable ballasting and deballasting.

Abstract: Flexible piles (5) are arranged close to the center of the tower (1) and evenly spaced apart on a circumference the area of which is about 10% of the area of the tower. The product of the total buoyancy of the tower by the arm level between the buoyancy center and the center of the articulation is at least equal to 1.25 times the product of the weight of the platform by the arm level between the center of gravity and the center of the articulation.

Abstract: Disclosed is a deep water anchoring system including a structural body floating at the surface of a body of water and with an intermediate floating member directly under and spaced from the floating structural body, the intermediate floating member being submerged below the surface of the water a distance sufficient to be unaffected directly by surface winds and waves. A gravity anchor along the bed of the body of water is coupled to the intermediate floating member via multiple cables which perferably extend angularly outwardly from the intermediate floating member. The anchoring system is provided with at least three separate and rigid rods, each of which are rotatably coupled at one end to the intermediate floating member and rotatably coupled at the other end to the floating structural body.

Abstract: An offshore mooring system is provided which is especially useful for mooring ships in moderately shallow seas such as on the order of 300 feet. The system is of the type which includes a tower having a lower end pivotally mounted to the sea floor and an upper end lying above the sea surface and connected through a hawser to a ship. A group of long chains have lower ends anchored at locations spaced about the tower, and upper ends connected to an upper portion of the tower. The chains extend in loose catenary curves, with most of the chain lengths lying on the sea floor in the vertical tower condition, to permit the tower to tilt in any direction by at least 20.degree. from an initial vertical orientation before one of the chains is pulled taut.

Abstract: A method of alleviating problems with high stresses above fatigue failure levels due to vibrations modes caused by vortex shedding during the lowering and jetting-in of a large diameter surface string in deep water having a current characterized by the inclusion of a moment reducing device in the suspension conduit holding the surface string of conduit during lowering and jetting-in. Also disclosed are preferred embodiments where the moment reducing device is either a ball joint or a flex joint.

Abstract: An improvement in an offshore well having a main casing penetrating subterranean formations below the bottom of the water and protruding upwardly through the water with a wellhead affixed above the surface of the water and a boat landing connected with the main casing. The improvement comprises a plurality of at least three anchor piles driven into the bottom at respective azimuths and distances about the well with the well anchored thereto via cables, the cables running upwardly through pulleys disposed a predetermined distance, such as 15 feet, below the surface of the water so as to anchor the well against lateral forces, yet satisfy Marine Maritime Service regulations and allow maneuvering of boats about the well. Also disclosed are typical and preferred structures including sizes and the like.

Abstract: The apparatus of the present invention comprises a compliant structure for use in reducing bending stress at the ends of an elongated cylindrical tether which may, for example, be used to connect a floating platform supported by a body of water to the floor thereof. The apparatus comprises a plurality of tubular support members concentrically arranged about the elongated cylindrical tether at the tether's end connection. Each tubular support member is connected to each adjacent tubular support member in a manner that allows the entire assembly of tubular members to deflect in unison as the cylindrical tether deflects.

Abstract: A flexure joint is formed at the base of a buoyant tower structure by piles driven into the ocean floor. The geometric arrangement of these piles increases the buoyant tower's resistance to lateral forces at the base, while allowing rotational displacement about any horizontal axis, and also allows wells to be directed through the piles to formations located a substantial distance from the tower.

Abstract: A hybrid offshore structure for conducting petroleum drilling and producing operations in very deep waters is disclosed. The structure consists primarily of a substantially rigid lower section extending upwardly from the bottom of the body of water to a pivot point located intermediate the bottom and the surface of the body of water, a compliant upper section extending upwardly from the pivot point to a deck located above the water surface, pivot means located proximate the pivot point and adapted to permit the compliant upper section to pivot laterally in response to environmental loads, and torsion means adapted to transmit torsional loads from the compliant upper section to the substantially rigid lower section. The lower section may comprise either a conventional trussed steel frame fixed to the bottom of the body of water by a plurality of piles or a concrete or steel gravity base. The compliant upper section may optionally be either a guyed tower or a buoyant tower.

Abstract: A movable joint device for coupling a column to a base resting on the sea bed and comprising a male member and a female member each including associated assembling means allowing the joint to be obtained by assembling both members in fitting relationship with positive unilateral connection, the said members being maintained in the assembled position by means for ballasting the column to ensure a constantly downwardly directed load, whereas the said members are disassembled by merely modifying the ballasting means so as to reverse the load and impart it in an upward direction.

Abstract: Method and apparatus for use in drilling a well from an offshore drilling vessel having a riser extending from the vessel down to a subsea wellhead. The apparatus of the invention comprises a flexible coupling installed in the riser's upper elements, with a tensioned cable connected between the flexible coupling and the vessel. The angle of misalignment of the riser's upper elements due to ocean currents impacting the riser and/or vessel may be maintained within acceptable limits by adjusting the tension applied to the flexible coupling.

Abstract: System for drilling from a water surface, of the type having means for exerting and maintaining on the drilling tool a bearing stress, which is constant and normal to the surface to be perforated, no matter what the effect of the swell, wherein it comprises in combination: a base having a central passage for the drill pipe string of a drilling apparatus, which is intended to rest on the sea bed and is elastically connected to means for receiving a cylindrical box; a column formed by a cylindrical tubular central guide, for permitting the passage and guidance of the drill pipe string of the drilling apparatus, the column being surrounded by an external cylindrical tubular envelope, the hollow annular space formed between the central guide and the envelope being subdivided into a tight member constituting the lower ballast, a tight intermediate member of variable length determined as a function of the mean value of the section of water under which drilling takes place, a tight member constituting an upper balla

Abstract: A monolithic structure for off-shore mooring composed of a broadened foundation (2) and an emerging vertical structure (1) having a very slender character and a flexural resistance modulus decreasing from the bottom towards the surface. This structure has a buoyancy chamber (15) placed in a submerged position and close to the top end.

Abstract: A production riser assembly includes a controlled bending guide and base assembly having a curved bend control surface which cooperates with a tension and bend shaft member associated with a riser pipe, whereby movement of the riser pipe is controlled by the movement of the tension and bend shaft member into an abutting relationship with a portion of the bend control surface of the guide and base assembly.

Abstract: The invention provides a flexible off shore platform comprising a base fi to the sea bed by means of a foundation and supporting a flexible column extending over almost the whole height of the platform and at the top of which is located a stabilizer connected by a short column to the deck of the platform; the flexibility of the column allows a basic natural bending period greater than that of the largest waves and always greater than 25 seconds.

Abstract: A self-levelling underwater structure receivable on an upright support implanted in the floor of a body of water and including a hollow unit fitting over the upright support and having a pivot device thereon engaging the upright support so that the hollow unit gravitates to a level position, and a securing assembly for securing the hollow unit to the upright support in the levelled position. A locking assembly is also provided to prevent relative axial movement of the hollow unit and the upright support once the structure is levelled.

Abstract: An oscillatable marine installation comprises a concrete and steel lattice shaft supported by means of a demountable pivot joint on a base fixed to the-sea-bed and including an anti-torque device. The pivot joint is made up of three parts: a casing fixed to the shaft, a part-spherical housing fixed to the base, and a pivot member. The pivot member has an upper part cooperating with the casing, a flange which can be fixed to the casing, and a lower part-spherical part housing which supports a resilient assembly and a bush fixed on the housing. The anti-torque device comprises a universal joint, concentric with the pivot joint. Two opposite pivots of the crosspiece of the universal joint are supported by the lower part of the shaft and the other two pivots by the base. At least two opposite pivots have damping devices and the pivots supported by the base are mounted on supports the height of which can be adjusted.

Abstract: A multiple tube production riser system includes interconnected first and second sets of parallel tubes, each set of tubes being flexibly supported by a frame. The first frame is vertically suspended from a floating platform and allows a relative displacement between the tubes of the first set in a vertical direction. The second frame is inclined to the horizontal and allows warping of the second set of tubes.

Abstract: A sea anchoring system for anchoring floating sea stations to a sea bed floor such as on a foundation or a stay block comprises a tension member connected between a floating station and the sea bed foundation or block with a plurality of tension members connected between the bed foundation and the floating station through universal joints. The universal joints include an assembly comprising an inner spherical body and an outer spherical body arranged over and slightly embracing the inner spherical body. The outer spherical body includes an opening on one side and a pin connected to the inner spherical body and extends through this opening and is connected, for example, to the foundation or to the floating body. The outer spherical body has a connection for example to the tension member. The inner and outer spherical bodies have spherical surfaces facing each other and at least one of these surfaces has a lining of a material which permits sliding interengagement with a minimum friction and wear.

Abstract: The device comprises two concentric swivels, a first or mooring swivel being arranged on the outside of the second or bearing swivel, the second swivel being fixed to the end of a cartridge held in a movable manner in a tube forming a projection at the lower end of the shaft and an extension of an axial passage in the shaft. The cartridge is formed by a cage fitted with openings in which keys are housed. A ring is lowered between the keys and immobilizes them against the wall of the tube which forms an extension of the axial passage in the shaft. The method consists of lowering or raising the cartridge carrying the bearing swivel by means of a set of rods.

Abstract: In apparatus for connecting a tension member, such as an element of a leg of a tension leg platform, to an underwater anchoring base, actual connection to the anchoring base is accomplished by a connector which is joined to the tension element by a flex joint which is spaced above the connector but surrounded by a tubular element rigid with the anchoring base, the flex joint carrying an annular stop surface which is closely embraced by the tubular element. Lateral loads applied to the flex joint by the tension element are transferred directly to the tubular element and the anchoring base rather than to the connector.

Abstract: A diverless system for levelling a template adjacent the floor of a body of water comprising a plurality of fluid-pressure activated gripping assemblies pivotally coupled to the template and receiving the supporting piles therein, with portions of the piles extending above the template; and a jacking assembly capable of being lowered down each of the piles, releasably connected to the template adjacent the associated gripping assembly and raising or lowering the template in the area each of each pile to level the template. The jacking assembly comprises an outer housing, and a double acting hydraulic piston slidably received in the housing, with a pile gripping assembly being coupled to the piston. The gripping assembly in the jacking assembly and those in the template are each formed from a plurality of ring segments that are serrated on the inside and have tapered ribs on the outside, these segments being received in a bowl having corresponding tapered ribs.

Abstract: An arrangement for supporting a well pipe emerging from the sea bottom adjacent a drilling platform which is articulated on a base by means of a universal joint, the base being mounted on the sea bottom adjacent the point where the well pipe emerges. A second base surrounds the portion of the well pipe emerging from the sea bottom, and supports a cylindrical seat by means of a universal joint at a point vertically aligned with the well pipe and horizontally aligned with the universal joint which supports the drilling platform. The upper part of the cylindrical seat surrounds the well pipe in such a manner that the well pipe can slide longitudinally within the seat. A generally horizontal arm is articulated at one end to the drilling platform at a point vertically above the universal joint which supports the platform.

Abstract: An anchor connector incorporating a flexible joint (16) for securing the tension legs (14) of a tensioned leg platform. A latch dog head (34) engages a first recess (26) on the fixed member (22) of the flexible joint and a template recess (30) to prevent disconnection when the dog heads (34) and latch carrier (40) are in a lower position. With the latch carrier (40) in an upper position the latch dog heads (34) fit within a second recess (44) in the fixed member with the dog heads claring shoulder (32) of template recess (30), whereby the connector may be released.

Abstract: In a ball joint accessible for inspection and connecting the service tower of an offshore station to the foundation on the sea bottom, one side of a spherical joint part is firmly connected through a neck to the foot of the tower, and the other side of the spherical part is mounted for universal motion within a joint casing which is anchored to the foundation. The two parts of the joint are connected to each other by a tension member. The spherical joint part is seated on exchangeable supporting bearings 11 which are provided within the joint casing and are well accessible. The top of the joint casing is formed by a cover ring having a collar designed as a spherical zone. From above, the ball joint is sealed and protected by a spherical cap in which an air cushion is maintained. The gap between the cover ring and the spherical joint part is sealed by a stuffing box.

Abstract: Combination tension connector and flex joint for underwater tension elements, such as the tension elements of a leg of a tension leg platform. The flex joint is of generally ball and socket type, with the ball member connected to the lower end of the tension element and the socket member connected to an upwardly projecting annular portion of the male member of the connector.

Abstract: A compliant offshore drilling and producing structure is disclosed. Axial piles extend from articulated joints on a pile base at the sea floor to above the water's surface and are enveloped by sleeves extending downwardly from a rigid platform. Buoyant chambers attached to the sleeves support most of the platform weight and provide righting stability. The platform weight is supported by the axial piles through hydraulic means.

Abstract: An adjustable two-piece rope guiding device [21, 26], particularly adaptable for use on offshore guyed tower drilling and production structures [11]. On such structures it is necessary to deflect a taut guy rope [14] into a direction that may not be precisely known, or that may vary with time. Such deflection must not damage the rope by excessive static or cyclic straining or by wearing. To minimize problems of clearance within the structure the guiding is performed in two parts: (1) a permanent deflection into a direction that satisfies the foregoing clearance requirements and (2) a variable deflection occurring beyond clearance problems that completes the required total deflection.

Abstract: A compliant offshore drilling and producing structure is disclosed. Axial piles extend from articulated joints on a pile base at the sea floor to above the water's surface and are enveloped by sleeves extending downwardly from a rigid platform. Buoyant chambers attached to the sleeves support most of the platform weight and provide righting stability. The platform weight is supported by the axial piles through hydraulic means.

Abstract: A system for levelling a template adjacent the floor of a body of water comprising a plurality of gripping assemblies pivotally coupled to the template and receiving the supporting piles therein, with portions of the piles extending above the template; and a jacking assembly capable of being lowered down each of the piles, releasably connected to the template adjacent the associated gripping assembly and raising or lowering the template in the area of each pile to level the template. The jacking assembly comprises an outer housing, and a double acting hydraulic piston slidably received in the housing, with a pile gripping assembly being coupled to the piston. The gripping assembly in the jacking assembly and those in the template are each formed from a plurality of ring segments that are serrated on the inside and have tapered ribs on the outside, these segments being received in a bowl having corresponding tapered ribs.

Abstract: A subsea connection unit for securing an offshore structure to a marine bottom is disclosed. The unit comprises a base adapted to be positioned on the marine bottom and an insert member adapted to be connected to the lower end of the offshore structure. The base has a recess thereon adapted to receive the insert member. Releasable vertical latch means comprised of a plurality of tapered shear blocks are carried by the insert member and cooperate with tapered lugs in the recess to lock the insert member against vertical movement within the recess. Releasable horizontal latch means comprised of a plurality of wedge members are positioned on the base around the recess and cooperate with load surfaces on the insert member to center and lock the insert member against horizontal movement within the recess.

Abstract: A fail-safe guy line system for marine structures. In the event of cable failure near the water surface, a braking device, such as a cable clamp, can be wedged into a sheave or fairlead to prevent loss of the guy line.

Abstract: A multiple bore marine riser adapted to form a communication between equipment on a floating structure and pipelines on the sea bottom includes flexible reinforcement means to prevent the occurrence of high bending stresses in the flowlines of the riser when the latter is subjected to large bending forces.

Abstract: The invention relates to a pivotal connecting device of the kind forming a universal Cardan joint coupling in particular for a compliant or articulated column of a sea-bed working structure, said column being pivotally connected to a base member, wherein said universal Cardan joint coupling is associated with one or more rigid connecting ducts for conveying the flow of at least one fluid between said base member and said column.

Abstract: A stiff, straight spar is allowed to pivot about an anchor on the seafloor. he location of the bottom with respect to the top is then determined by measuring the tilt of the spar and computing the offset of the bottom relative to the top. The straight member uses its internal buoyancy to remain erect and stable while the weight of the anchor keeps it in place on the seafloor. The top of the spar is tracked by shore stations while the tilt and heading of the spar is monitored by an instrumentation system. Simultaneous readings of the shore instruments and the spar's tilt and heading indicators allow direct determination of the anchor location relative to the shore. An air ballast control enables the apparatus to be easily maneuvered on the ocean bottom by divers or on the surface and an internal plumb bob system allows calibration of the overall system.

Abstract: An offshore tower having a buoyant column; a yoke at the lower end of the column; a socket joined to the end of the yoke; a base, adapted to be anchored to a sea floor, having a ball which fits in the socket for rotational joined movement relative to each other; a fluid delivery passageway, extending through the base and ball, communicating with a fluid swivel above the ball; and a fluid conduit having a flexible portion, extending outwardly from the fluid swivel and into engagement with the column.