US3739591A

US3739591A - Method and apparatus for evaluating offshore pipeline laying operations

Info

Publication number: US3739591A
Application number: US00147834A
Authority: US
Inventors: Raymond Edward Jones
Original assignee: Brown and Root Inc
Current assignee: Brown and Root Inc
Priority date: 1971-05-28
Filing date: 1971-05-28
Publication date: 1973-06-19
Anticipated expiration: 1990-06-19
Also published as: DE2220489B2; CA950691A; NO137057B; DK135184C; GB1320885A; NL172185B; NO137057C; DE2220489A1; NL172185C; NL7205551A; DK135184B

Abstract

Methods and apparatus for conducting evaluations of offshore pipe-line laying operations and characterized by the performance of inspection operations, in relation to submerged pipeline means, prior to the termination of a pipeline laying operation. The inspection operation is performed while a floating vessel means, effecting the pipeline laying operation, remains operable to lay and/or retrieve pipeline increment means containing a defect detected during the inspection operation.

Description

United States Patent Jones June 19, 1973 [54] METHOD AND APPARATUS FOR 2,459,499 1/1949 Caste] 73/151 X EVALUATING OFFSHORE PIPELINE 3,562,916 2/1971 Duckworth 73/151 LAYING OPERATIONS Primary Examiner-Jacob Shapiro Attorney-Burns, Doane, Swecker & Mathis [57] ABSTRACT Methods and apparatus for conducting evaluations of offshore pipe-line laying operations and characterized by the performance of inspection operations, in relation to submerged pipeline means, prior to the termination of a pipeline laying operation. The inspection operation is performed while a floating vessel means, effecting the pipeline laying operation, remains operable to lay and/or retrieve pipeline increment means containing a defect detected during the inspection operation.

22 Claims, 16 Drawing Figures [75] Inventor: Raymond E. Jones, Houston, Tex.

[73] Assignee: Brown & Root, Inc., Houston, Tex.

[22] Filed: May 28, 1971 211 App]. No.: 147,834

[52] US. Cl. 61/723, 73/151 [51] Int. Cl. F161 1/00 [58] Field of Search 61/723, 72.1, 72.4;

[56] References Cited UNITED STATES PATENTS 3,438,213 4/1969 Broussard et a1.

1,805,343 5/1931 Robbins 73/151 X PAIENIEL 3.739.591

SHEET 1 0i 6 INVENTOR 4. 1 a U I RAYMOND E. JONES ,1? BY e zw 54,014, m

ATTORNEYS PAIENTEDJUNISIHH 739,5391

SHEET 2 0f 6 FIG. 20

PATENTED JUN 1 sum SHEEY 3 0F 6 PAIENIED JUN 1 9 ms SHEET '& 0f 6 rU I PATENIED JUN 1 91915 SHEU S [If 6 PAIENTEU JUN v 9 ma SHEET 6 0F 6 METHOD AND APPARATUS FOR EVALUATING OFFSHORE PIPELINE LAYING OPERATIONS Offshore pipeline laying operations are complex and costly in nature.

Contributing to the cost and complications entailed in offshore pipelaying operations are the inspections which must necessarily be performed to ensure that a pipeline, when laid, is in structurally sound, safe, useable form.

Such inspection operations are concerned with detecting adverse conditions which would impair the safety or operating efficiency of the laid pipeline, or confirming a satisfactory condition.

One common fault sought to be detected involves a buckle condition which might inadvertently result from stresses imposed upon a pipeline during a laying operation. Such stresses would be imposed on the pipeline as it was being manipulated from a pipelaying barge, or other floating vessel means, downwardly through a body of water into a position supported on a submerged surface.

Traditionally, such inspection operations have been performed after the pipeline laying operation has been completed. Where a buckle condition has been detected utilizing this conventional inspection technique, it has generally been necessary to resort to expensive means for raising the buckled pipeline portion to the surface and effect repairs.

At times, when it has not been feasible to raise a pipeline portion containing a buckle, it has been necessary to go to the extreme measure of either cutting out a buckled portion and effecting underwater repairs or raising to the surface the entire portion of the pipeline extending from the buckle area to a free end or terminus of the pipeline.

Such repair operations can be extremely costly and entail several hundred thousand dollars in costs. In addition, such repair operations significantly delay the placing of a pipeline in operating condition.

Bearing such contingencies in mind, it is a principal object of the present invention to provide a pipeline inspection or condition detecting operation which enables abnormalities to be detected prior to the termination of a pipeline laying operation.

It is a particular object of the invention to provide such techniques by means of which inspection or condition detecting operations may be performed generally throughout the pipeline laying operation so as to provide prompt indications of undesirable or abnormal prior conditions, or confirm a satisfactory condition.

It is a further object of the invention to provide such techniques which enable abnormalities or defects to be detected before underwater currents or tides have induced partial or complete burying of pipelines, which burying might significantly impair repair operations.

It is likewise an object of the invention to provide such techniques which enable inspection or condition detection operations to be performed while a pipeline laying barge, or other floating vessel means effecting pipe-laying, remains operable to retrieve previously laid pipeline increment means containing a detected adverse condition.

In relation to a preferred embodiment of the invention, it is an object to provide a pipeline condition detecting arrangement which enables a detecting means to be propelled to a location within a submerged pipeline section, and then be disconnected from an extraneous power source which effected the propelling operation. This disconnecting simplifies the subsequent detecting operation and enables it to be performed without reliance upon power sources carried by the detecting unit.

A still further object of the invention, in relation to I the preferred embodiment, is to enable scanning ma- However, it has been found that the objectives heretofore set forth may be implemented, at least in part, by practicing the following method aspects of the invention.

One such method aspect involves the performing of inspection or pipeline condition detecting operations, in relation to a submerged pipeline portion, while a portion of the pipeline remains supported on floating vessel means such that the submerged pipeline portion being inspected may be readily retrieved using laying apparatus and techniques.

Another independent aspect of the invention relates to a method of detecting a submerged pipeline condition where a pipeline is supported at an offshore location with a first portion supported on a submerged surface. In this technique, a second portion is supported on floating vessel means and a third portion extends through a body of water between the first and second pipeline portions.

In this second method aspect, a pipeline condition detecting means is positioned within the interior of a submerged portion of the pipeline. Utilizing this detecting means, a condition of the submerged pipeline portion is detected while the pipeline remains supported by the floating vessel means. In addition, the floating vessel means remains operable to retrieve the submerged pipeline portion by exerting a retrieving force on the second pipeline portion.

This technique is particularly advantageously em ployed in a third, independently significant method aspect of the invention. In this third method aspect of the invention the detecting means is caused to undergo relative movement in relation to relatively newly laid increment means of submerged pipeline means resting on a submerged surface so as to indicate dimensional irregularities such as buckles, etc.

In afourth, independently significant, aspect of the invention the pipeline indicating means is propelled from the floating vessel means to its detecting location within the first pipeline portion. In this fourth method aspect ofthe invention, scanning movement of the pipeline condition detecting means is effected by connecting the pipeline condition detecting means with conventional pipeline section alignment means (i.e. a line up clamp) on the floating vessel means. With this arrangement, normal repositioning of the pipeline section alignment means as it is moved into alignment with a new pipeline joint will induce relative movement of the pipeline condition detecting means and relatively recently laid additional increment means of the pipeline laying on a submerged surface. This movement will cause the detecting means to scan the newly laid increment means for irregularities.

A fifth facet of the invention, significant itself, relates to a propulsion technique for operating the detecting means. This propulsion technique entails the utilization of pressurized air to concurrently (l) latch the detecting means in coupled engagement with a source of pressurized air, (2) extend drive means into engagement with the interior of a pipeline, and (3) actuate the drive means for propulsion purposes. Reduction of the pressure of the pressurized gas will serve to concurrently (l) uncouple the source of pressurized air from the detecting means, (2) retract or permit retraction of the drive means from effective driving engagement with the pipeline interior, and (3) dea'ctuate the drive means itself.

A sixth independently significant aspect of the invention entails the retrieval of a pipeline increment, con-- taining an irregularity, by operation of pipeline tensioning means used for normal laying operations. This retrieval operation may serve to concurrently retrieve the detecting means itself so as to enable it to be rendered operational for subsequent detecting operations after the impaired section has been replaced or reconditioned.

A seventh independently significant method aspect of the invention entails the actual retrieval of a pipeline increment containing a buckle condition or other irregularity, by merely reversing the normal technique employed in the laying operation and retrieving this increment on board the floating vessel used for pipeline laying operations.

In conjunction with these independently significant method aspects of the invention, which are mutually compatible so as to provide cumulative benefits, the invention also contemplates various combinations of apparatus elements which uniquely interact to provide the advantageous functions heretofore described.

In describing the invention, reference will be made to preferred embodiments by way of example. However, it will be recognized that the preferred example is not limiting with respect to the scope of the invention insofar as detecting apparatus is concerned, pipelaying or retrieving apparatus is concerned, or the condition being detected is concerned.

Bearing this in mind, the invention will now be described with reference to certain illustrations.

DRAWINGS 1 Preferred embodiments of the invention are set forth in the appended drawings.

In the drawings:

FIG. 1a schematically depicts an offshore pipeline laying operation at the point in time where laying has been initiated and a pipeline condition detecting means is positioned on the laying vessel. This detecting means is disposed for subsequent propulsion to a location disposed within a submerged pipeline portion resting-on a submerged surface;

FIG. 1b schematically illustrates the FIG. 1a assembly with the pipeline condition detecting means disposed within the interior of an increment of a submerged portion of a pipeline which is generally resting on or located adjacent a submerged surface;

FIG. llc schematically depicts the FIG. Ia assembly with the pipeline condition detecting means disposed, as described in connection with FIG. 1b, and operable to scan the interior of the submerged pipeline increment in order to detect pipeline irregularities. An upper portion of the pipeline supported on the floating vessel means so as to permit retrieval of the submerged pipeline increment being scanned. FIG. 1c also schematically illustrates the interconnection of the pipeline detecting means with a conventional line up clamp or pipeline alignment means which is used to longitudinally align a new pipeline joint with the body of the pipeline for welding or interconnecting purposes;

FIGS. 2a-2d provide enlarged, schematic views of operational facilities located on the floating vessel means shown in FIGS. la-lc, it being understood that for purposes of ease and clarity of illustration, not all of the components shown in FIGS. 2a-2d are depicted in the schematic views of FIGS. la-lc;

FIG. 2a illustrates components as they would be arranged during an initial welding operation, with the line up clamp or pipeline alignment means securing a recently added pipeline section or joint in longitudinal alignment with previously welded or assembled joints for welding purposes. FIG. 2a further schematically depicts the manner in which the previously welded pipeline body is engaged by pipeline tensioning means which may be employed for pipeline laying or retrieving purposes, as in the manner generally described in Lawrence U.S. Pat. No. 3,390,532 and Lawrence U.S. Pat. No. 3,487,648. In FIG. 2a the pipeline section alignment means is disposed in connected relation with a flexible draft device such as a cable, rope, or chain, which extends from the pipeline section alignment means through the pipeline interior to the pipeline condition detecting means described in connection with FIGS. la-lc;

FIG. 2b schematically depicts the FIG. 2a components after the welding of the new joint (which may comprise the welding of an initial bead string or other partial or even complete welding), with the new section having been advanced relative to the pipeline vessel toward the submerged surface (normally effected by movement of the pipeline vessel away from the previously laid pipeline portion);

FIG. 2c depicts the FIG. 2b components with a second new pipeline joint disposed in position to be longitudinally welded or otherwise coupled to the remaining pipeline;

FIG. 2d illustrates the second additional pipeline increment or joint disposed in longitudinal, contiguous alignment with the previously welded pipeline body, with the line up clamp or pipeline section alignment means being moved away from the previously laid pipeline so as to bring it into alignment securing cooperation with the junction between the second additional joint and the previously welded joint. FIG. 2d further illustrates the movement of the pipeline section alignment means which induces scanning or condition detecting movement of the pipeline condition detecting means described in connection with FIGS. la-lc;

FIG. 3 provides an enlarged, longitudinally extending, sectional view of the submerged portion of the pipeline shown in FIG. 10 containing the aforesaid pipeline condition detecting means, this pipeline condition detecting means being shown in side elevation within the interior of the longitudinally sectioned pipeline;

FIG. 4 provides a transverse sectional view of the FIG. 3 assembly, and presents an end elevationalview of a pressurized air operated latching mechanism which serves to detachably secure a source of pressurized air, i.e. a flexible air hose, to a power train assembly of the pipeline condition detecting means, FIG. 4 being viewed along section line 44 as shown in FIG. 3;

FIG. 5 provides a transverse sectional view of the FIG. 3 assembly, as viewed along section line 55 of FIG. 3, and illustrates resiliently biased centering wheels incorporated at the left end of the pipeline condition detecting means, as shown in FIG. 3, and further illustrates pneumatic connections extending to the latching mechanism shown in FIG. 4;

FIG. 6 provides a transverse sectional view of the FIG. 3 assembly, viewing the interior of the right end of the pipeline detecting means as shown by reference to section line 6-6 of FIG. 3, and depicts structural aspects of propelling components including pneumatic motor actuated drive wheels and mechanisms for selectively extending or retracting these drive wheels (i.e. for exerting or releasing radially outwardly directed biasing force exerted upon the biasing means);

FIG. 7 provides a transverse sectional view of the FIG. 3 assembly, as viewed along section line 77 of FIG. 3, and illustrates in end elevation, pneumatically biased centering wheels disposed at the right end of the pipeline condition detecting means shown in FIG. 3;

FIG. 8 provides an enlarged, transverse sectional view of one of three drive wheel components shown in FIG. 6, as viewed along section line 8-8 of FIG. 6;

FIG. 9 provides an enlarged, transverse sectional view of a motor support and reaction surface portion of one of the three drive assemblies shown in FIG. 6, as viewed along section'line 9-9 of FIG. 6;

FIG. 10 provides a partially sectioned and enlarged view of the previously noted latching mechanism, with components generally disposed as shown in FIG.'3; and

FIG. 11 provides an enlarged, partially sectioned, side elevational view of one representative centering wheel shown in elevation in each of FIGS. 5 and 7.

DESCRIPTION OF PREFERRED EMBODIMENT Overall Context of Invention Pipe Laying Vessel FIGS. 1a and 2a illustrate the overall context within which the preferred embodiment of the invention is practiced.

As shown in these Figures, a pipeline laying installation 1 includes a floating vessel means 2. Floating vessel means 2 may comprise a pipe-laying barge of the type now used in major offshore pipeline laying operations, or for that matter any vessel operable to effect pipelaying operations.

Laying barge 2 may be provided with a pipeline tensioning means 3 of the wheel or caterpillar type and generally corresponding in mode of operation to the arrangement featured in Lawrence U.S. Pat. No. 3,390,532.

Floating vessel means 2 may also include a buoyant ramp or "stinger" 4 pivotally supported at connection joint 5 to one barge end.

Connecting joint 5 may correspond to the hitch structure featured in Lawrence U.S. Pat. No.

3,390,532. The buoyant ramp or stinger 4 may correspond generally to structures of the type featured in Lawrence U.S. Pat. No. 3,390,532, Hauber U.S. Pat. No. 3,280,571, and/or Rochelle et al. U.S. Pat. No. 3,507,126. A series of pipe cradling, roller assemblies 6 may be provided on the barge 2 as well as on the stinger 4, in the manner generally described in Lawrence U.S. Pat. No. 3,390,532, so as to provide longitudinal support underlying pipeline portions.

Such roller or cradle assemblies 6 serve to slidably support a pipeline 7 being laid by the barge 2. While a series of such roller assemblies 6 may be provided to provide a plurality of pipeline supports spaced longitudinally along the pipeline, only one such support 6 is schematically shown in FIG. la.

Welding In many instances, it is contemplated that the invention may be practiced in the context of a conventional welding-type, pipe joining operation. In such an operation, one, or a series, of welding stations, may be disposed longitudinally along the pipeline portion supported on the barge 2. At each such welding station, when the pipeline is substantially immobilized (except possibly for wave action induced movement) relative to the barge 2, welding is effected at a pipeline joint located at the station. Where multiple stations are in volved, each joint junction will be partially welded at each of several welding stations, with the total welding provided by the several weld stations producing a completed weld joint.

One such representative weld station 8 is shown in FIG. 2a. Weld station 8 may comprise an automatic welding unit or a conventional station operated by manual welders.

Solely by way of example, the welding station 8 shown in FIG. 2a is shown as the first welding station which would provide the initial or bead" weld between a new joint and the previously welded pipeline body, in the event that a multiple welding station system was being employed. It is also possible-that station 8 could comprise an automatic welding station where complete welding of the joint would be completed.

Where multiple stations would be employed, several additional stations 8 ordinarily would be interposed between the station 8, shown in FIG. 2a, and the tensioning unit 3.

As shown in FIG. 2a, initial installation of a new pipeline joint or increment 9 may be facilitated by a line up clamp or pipeline alignment means 10. Such a pipeline alignment means 10 would serve to secure the joint 9 in longitudinal and generally contiguous alignment with the previously welded pipeline body 7.

Conventionally, pipeline alignment means 10, now well known in the art, may comprise a body 11 supporting radially movable extendable and contractible pipeline alignment clamps. Such alignment clamps may be selectively motivated by pressurized air conveyed to them by an air pipe (i.e. conduit or hose) [2. Air pipe 12, as shown in FIG. 2a, will extend longitudinally of line up clamp 10. When disposed in alignment position, alignment means 10 will be disposed at the junction 13 between pipeline body 7 and new pipeline joint 9 and air pipe 12 will extend through the new joint 9. A flexible branch air line 14 may be detachably connected with air pipe 12 and serve to supply air to pipe 12 for transmittal to mechanism 10 under the manually controlled influence of valve located in pipe 12.

In operation of this mechanism, with the clamp positioned generally as shown in FIG. 2a, pressurized air would be supplied to pipe 12 so as to activate and radially extend the line up clamps of mechanism 10. This extension of line up clamp elements would serve to interlock or secure joint 9 in longitudinally aligned and contiguous relation with pipeline body 7. The aligning and securing operation of the clamps may be maintained by continuing to supply air to mechanism 10 with valve 15 open or by closing the valve 15 so as to provide an entrapped body of clamp-actuating pressurized air in the pipe 12 and mechanism 10.

When the securing operation at station 8 has been completed, the air pressure in pipe 12 may be reduced or vented so as to allow radially inwardly directed retraction of the line up clamp elements and thus permit relocation of the mechanism 10 for welding operations relating to a second new joint.

During each securing operation, the tensioning means 3 will tend to maintain the pipeline 7 generally stabilized in relation to the pipeline laying vessel 2, while accommodating limited movement induced by wave action as in the manner contemplated in Lawrence U.S. Pat. No. 3,390,532 and Lawrence U.S. Pat. No. 3,487,648.

When welding has been completed, the pipeline vessel 2 will be moved to the left, as shown in FIG. la so as, in essence, to cause the new. joint 9 to move relative to vessel 2 toward the previously laid pipeline portion.

This stop and go operation will be continued until pipeline laying is completed.

PIPELINE PROFILE As shown in FIG. la, the pipeline laying operation there depicted entails the laying of the pipeline 7 in a body of water 15. Conventional techniques may be employed to both initiate and terminate the pipeline laying operations depicted in FIGS. 1a through 1c.

The pipeline 7 comprises a first portion 7a lying on a submerged surface 16. Portion 7a, in general, will be substantially completely supported by the submerged surface 16 such that it is no longer subject to buckle inducing tendencies engendered during the pipeline laying operation.

A second pipeline portion 7b will be supported by the tensioning means 3 and roller assemblies 6 of the floating vessel means 2.

A third pipeline portion 70 extends through water body 15 between the second pipeline portion 7b and the first pipeline portion 7a.

In general, pipeline portion 7c may be viewed as the portion extending from the water surface 17 down to the general location of a tangency" point 18 where the pipeline moves into substantially full supported enoperation, as water depths vary and as the elevation or configuration of the submerged surface 16 varies, the

pipeline zone 7c may undergo changes in shape, profile and/or dimension. In addition, as pipeline laying progresses, the length of portion 7a will continuously increase, with the configuration of portion 7a depending upon the pipelaying route and the configuration of the submerged surface 16 upon which it is resting.

By way of reference, this general mode of pipelaying is described in Lawrence U.S. Pat. No. 3,390,532.

However, as will be appreciated, in view of the preceding and subsequent discussions relating to the inventive contribution herein presented, the invention may be practiced in the context of a variety of pipeline laying techniques including those described in Lawrence U.S. Pat. No. 3,487,648, Rochelle et al. U.S. Pat. No. 3,507,126, Lawrence U.S. Pat. No. 3,472,034, and other patents and publications.

The general setting of the invention having been discussed, it now becomes appropriate to consider structural details of a pipeline condition detecting means which may be employed in the practice of the invention.

Pipeline Condition Detecting Means FIG. 10 schematically illustrates a pipeline condition detecting means 19 disposed within the interior of pipeline portion 7a.

Pipeline condition detecting means 19 is connected with a flexible draft device 20 such as a rope, cable, or

chain which extends from the detecting device 19 upwardly through the interior of the pipeline body 7.

The manner in which draft device 20 is manipulated to induce relative movement of detecting device 19 in relation to relatively newly added or additional increments of pipeline portion will be subsequently described.

Suffice it to say, for the time being, that this relative movement will permit scanning of such additional increments of pipeline portion 7a very shortly after such increments have been laid on the submerged surface 16. This will permit an operator to determine at the earliest possible moment, or at least prior to the termination of the pipeline laying operation, the condition of the pipeline as it comes to rest on the submerged surface 16.

The condition being detected may be any of several conditions normally considered during pipeline laying operations.

Desirably, of course, the condition detected will involve a status devoid of unacceptable imperfections.

However, the detecting operation will be designed to locate unacceptable conditions such as pipeline buckles. Such buckle conditions would involve a distortion in pipeline cross section dimensions, resulting from a conduit buckling which would occur as pipeline joints move from the barge 2 through zone 7c to the submerged surface 16.

Although the present discussion will be confined to the detection of a buckle condition, it will be recognized that other adverse conditions may be detected including cracks, faulty joints, etc.

While a mechanical type of detecting unit will be subsequently described, other detecting devices might be employed, including those of an optical or television nature, and including those which rely upon radiological, x-ray, sonic, or other radiated energy type testing operations.

While it thus is apparent that the pipeline condition detecting operation embraces a wide range of conditions and detection apparatus, it will be appreciated that the invention is primarily concerned with the location of a condition which is detectable prior to the termination of the laying of the pipeline but which will remain in the laid pipeline after the termination of the laying operation unless detected and corrected.

Thus, the invention is to be distinguished from operations relating to determinationsof transient conditions which persist only during the laying of the pipeline such as tension in the pipeline, orientation of the profile of the pipeline portion 7c, etc.

Bearing the general scope of the detecting operation in mind, structural details of a detecting mechanism operable to detect a buckle condition will now be discussed.

Specific Structure of Buckle Detector Structural details of buckle detector 19 are illustrated in FIGS. 3-11.

Referring now to FIG. 3, it will be seen that buckle detector 19 comprises a pair of mutually spaced,

circular discs

21 and 22.

Discs

21 and 22 are interconnected by longitudinally extending and circumferentially spaced framing members 23. Detector 19 is connected with draft means 20 by wayof a yoke 20a as shown in FIG. 3.

At least the foreward disc 21 will have a diameter such as to enable it to move freely through an unbuckled pipeline interior but be prevented from moving through the interior of a pipeline which has been subjected to excessive buckling or cross-sectional distortion. Thus, at least disc 21 will function as a buckle detecting device.

Detector unit 19 includes, among its basic components, an air conduit or manifold 24 and an air operated latching mechanism 25 which serves to detachably connect the air conduit 24 to a flexible air hose 26.

Flexible air hose 26, when utilized, will extend from the mechanism 19 through the interior of pipeline 7. As shown in FIGS. 1a and 1c, hose 26 may extend to a reel or hose assembly 27, which-reel or hose assembly is provided with means for connecting hose 26, in a conventional manner, with a compressor or other source of pressurized air. As will be recognized, the term pressurized air is herein used in a generic sense to include any pressurized gas or fluid.

Mechanism 19 is also provided with a plurality of centering wheels 28.

As shown in FIG. 5, three such centering wheels 28 are carried in a symmetrical, radially oriented pattern by buckle detecting plate 21. Similarly, three other centering wheel assemblies 28 are carried in a symmetrical and radially oriented arrangement by disc 22 in the manner generally depicted in FIG. 7.

In order to optimize the centering action of the wheel assemblies 28, the wheel patterns may be circumferentially displaced 180 in the manner generally depicted in FIGS. and'7.

A compressed air operated, propulsion system 29 included in buckle detector 19 may comprise a series of three radially oriented and symmetrically arranged drive wheel assemblies 30, each arranged for radially gage a flange face 32 carried by flexible air conduit 26.

The propelling mechanism 29 serves to propel the detector 19 from the vessel 2 to the pipeline portion 7a. After this propulsion is effected, subsequent scanning movement of the detector 19 relative to the pipeline is effected by the draft means 20.

Prior to considering the manner in which detector 19 is propelled into operative position and utilized to detect a pipeline condition, it will be appropriate to consider specific structural and operational characteristics of the latching mechanism 25, the drive wheel assemblies 30 and the centering wheels 28.

LATCI-IING MECHANISM Structural details of the latching mechanism 25 are shown in FIGS. 3, 4, and 10.

As there shown, air conduit 24 of detector 19 is provided with a flange face 31. Flange face 31 is operable to matingly and generally sealingly and abuttingly en- The latch mechanism 25 which serves to secure the flange faces 31 and 32 in generally mutually abutting and sealed cooperation during the propulsion of detector 19, comprises a plurality of pivoted latch means 33.

As shown in FIGS. 3 and 4, two such latch means are provided each comprising a body 34 connected to plate 21 by a pivot mount 35. A pneumatically operated piston and cylinder-type actuator 36 is also connected to plate 21 in association with each latch body 34. Air for actuating the piston component 37 of each assembly 36 is derived from a branch conduit 38 extending from the primary air tube or conduit 24 of the detector 19. As

outwardly directed biasing extension and radially inshown in FIGS. 3 and 4, the piston portion 37 includes a rod disposed in biasing cooperation with an edge of the latching plate body 35.

Thus, when the flanges 31 and 32 are manually brought into abutting cooperation, and pressurized air.

is supplied byconduit 26 to conduit or manifold 24, this air will be transmitted through conduit means 38 to piston and cylinder assemblies 36. This air will actuate the assemblies 36 so as to cause the piston rod components to bias plates 34 to the positions shown in FIGS. 3 and 10. In these positions, the plate bodies 34 serve to press the flange 32 axially against the flange 31 and thus detachably interlock the air source 26 with the detector 19.

When the pressure of air in conduit 26 is released, biasing influence of assembly means 36 is obviated. With this biasing influence thus obviated, the conduit means 26 may be pulled free of the assembly 19.

If desired, the latch body elements 34 may be biased to a limited extent into the latching position shown in FIG. 3 by torsion springs or other spring means. However, while such spring means would facilitate the initial connecting of the conduit means 26 with the detector 19, this biasing would not be sufficient in and of itself to prevent the detachment of air hose 26 from the detector 19 in response to the exertion of a pulling force on conduit means 26.

Whatever arrangement is employed, it is contemplated that when the air in conduit 26 is reduced in pressure, as by venting to the atmosphere, or by otherwise eflecting a substantial pressure reduction, the conduit 26 will be retrievable to the deck of vessel 2 by the exertion of a pulling force on the conduit 26. However, this pulling force will not induce any significant longitudinal displacement of the detector 19 relative to the pipeline interior.

llll

As will also be recognized, the actuating assemblies 36 may also be of the type which are spring biased to a retracted condition such that when air pressure is reduced within these assemblies the pistons will automatically retract so as to automatically cause the plates or latches 34 to pivot outwardly and automatically free the flange 32 for uncoupling purposes.

DRIVE WHEEL ASSEMBLIES Structural details of the drive wheel means are generally depicted in FIGS. 3, 6, 8 and 9.

As shown in these Figures, each such drive wheel assembly 30 comprises a base plate 39 mounted for radially outwardly or inwardly directed movement by means of rail means 40 and 41 which are secured to disc 22. A drive wheel 42 is journalled in bracket means 43 and 44 by bearing assemblies 45 and 46 as generally depicted in FIG. 8. Bracket means 43 and 44 are connected with base plate 39, as shown in FIG. 8.

Each drive wheel 42 is connected with a drive shaft 47 which in turn is connected, by a worm gear type transmission 48, with a pneumatically actuated drive motor 49. Each drive motor 49, as shown in FIG. 6, is supported by bracket means 50, which bracket means is carried by base plate 39. As shown in FIG. 9, motor 49 provides a drive shaft 51 which serves to motivate or rotate the worm gear element 52 in the transmission mechanism 48.

Each pneumatic drive motor 49, which is of a rotary character, is motivated by and connected with a source of pressurized air. This source of pressurized air as shown in FIGS. 3 and 6, may comprise a flexible branch conduit 53 extending from main air conduit or manifold 24.

With slide 39 biased radially outwardly, its associated drive wheel 42 will be disposed in frictional engagement with the interior of a pipeline, in the manner generally shown in FIG. 3. This will permit rotation of the drive wheel 42, as induced by operation of the motor 49, to induce longitudinal movement or propulsion of the detector assembly 19 relative to the pipeline 29 so as to cause the detector 19 to be propelled sequentially through the

pipeline segments

7b and 70 to an operable location within the interior of pipeline portion 7a, or other portion.

When the outwardly directing biasing force is removed from plate 39, sufficient inward movement of plate 39 will occur as to permit the wheel 42 to be effectively disengaged from driving cooperation with the interior of the pipeline. Such disengagement may entail physical separation of the wheel from the pipeline interior or merely sufficient movement to remove excessive frictional interaction between the drive wheel 42 and the pipeline interior.

Radially directed extension or contraction of the plate 39, operable to manipulate the drive wheel 42 into and out of driving cooperation with the pipeline interior, may be effected by a plate-movement controlling motor means such as a reciprocable piston and cylinder assembly 54 associated with each unit 30.

Each such assembly 54 may comprise a pneumatically actuated piston and cylinder assembly 54, the operation of which is effected by pressurized air supplied by a branch conduit 55. As shown in FIG. 6, each such branch conduit 55 may be connected with and extend from the manifold or main air conduit 24 of the detector 19.

A piston rod portion 56 of each assembly 54 is disposed for radially directed reciprocation and is arranged in abutable or engaged cooperation with the bracket 50.

Thus, when piston rod 56 is extended radially outwardly, the rod 56 will abuttingly engage the bracket 50 and cause the plate 39 to move outwardly so as to bias the wheel 42 into driving cooperation with the pipeline interior.

When the air pressure in mechanism 54 is reduced or vented to atmosphere through the reduction of pressure in conduit 26, the biasing influence of piston rod 56 will be removed.

With the outwardly directed biasing influence of piston rod 56 removed, the plate 39 will be free to retract radially inwardly so as to obviate the formerly present radially outwardly directed biasing force acting on its associated wheel 42 which served to maintain wheel 42 in driving cooperation with the pipeline interior.

As will be recognized, motor or positioning means 54 may be of the automatic self-retracting type which would serve, when air pressure was reduced in its interior, to automatically retract plate 39. Where such automatic retraction was to be effected, the piston rod 56 would be connected with the bracket 50 or some other element associated with plate 39 or possibly plate 39 itself.

As will be recognized, each of the drive wheel assemblies 30 will function in the manner heretofore described, with the three assemblies being simultaneously extendable in response to the supplying of pressurized air to manifold 34.

As will also be appreciated, the drive wheels 42 in the three assemblies 30 depicted in FIG. 6 will be generally concurrently actuated or rotated for propelling purposes in response to the supplying of pressurized air to manifold 24.

Thus, the supplying of pressurized air to manifold 24 by pressurized air source 26 will serve to concurrently actuate the previously noted operating components of the unit 19 and:

I. operate latch means 25 so as to secure source 26 with detector 19;

2. bias drive means, i.e. wheels 42, radially outwardly into frictionally interacting and driving cooperation with the pipeline interior; and

3. actuate or operate wheel means 42 so as to induce propelling of the detector 19 through the pipeline intenot.

As will also be appreciated, the reduction of pressure in conduit 26, for example, which may be effected by venting the conduit on vessel 2 to the atmosphere, will concurrently serve to:

l. deactivate latch means 25 so as to pennit or effect the separation of conduit means 26 and detector 19;

2. remove the radially outwardly directing biasing force acting on wheel means 42 (which may be considered as retraction of the wheel means); and

3. deactivate the drive motors 54 associated with wheel means 42.

CENTERING WHEELS With the mode of operation of the propulsion system having been reviewed, it now becomes appropriate to consider structural aspects of the centering wheel assemblies 28.

A representative wheel assembly 28 is shown in FIG. 1 1

As there shown, each assembly 28 includes a body 57 which is connected to its associated disc by a bracket means 58. A telescoping inner component 59 is reciprocably mounted within the body 52.

As shown in FIGS. 5 and 7, each body 57 is generally radially oriented so as to permit generally radially oriented movement of the component 59.

A coil spring 60 contained within body 52 may exert a radially outwardly directed biasing force on each element 59, when the element 59 has been moved radially inwardly of body 52 in response to insertion of unit 19 into the interior of pipeline 7.

If desired, a retaining pin or rod 61 may be connected with component 59. Such a rod would be telescopable through an inner end wall of housing 57 and have a headed end 61a to limit outward movement of component 59.

As shown in FIG. 11, each component 59 carries at its outer end a centering wheel 62.

The yieldably biased nature of the wheel 62, as provided by the action of spring means 60, will serve to ensure that the wheels 62 of the various assemblies 28 are concurrently brought into centering cooperation with the pipeline interior.

The cooperative interaction of the various wheel means 62 will thus serve to maintain an appropriate, limited clearance between peripheries of

discs

21 and 22 and the pipeline interior, at least where an unbuckled pipeline interior is involved.

PIPELINE CONDITION DETECTING OPERATION The structural and operating characteristics of detector 19 having been reviewed, it now becomes possible to consider the overall manner in which the invention is practiced so as to enable the detector 19 to perform a pipeline scanning function during the pipeline laying operation itself.

As will be appreciated from the foregoing discussion, this operation will be conducted while tensioning means 3 remains engaged with pipeline portion 7b. This engagement of the tensioning means 3 with pipeline portion 7b will be such as to enable the tensioning means 3 to operate to retrieve the pipeline in the event that a buckle condition is detected.

This mode of retrieval is described, for example, in Lawrence U.S. Pat. No. 3,390,532.

Such retrieval could be effected, for example, when the detector 19, in moving through an increment of the submerged pipeline portion (ordinarily a newly added increment of portion 7a), would detect a buckle condition in such an increment. When the buckle was detected, the tensioning means would be operated so as to exert a sufficient tensioning force on the pipeline portion 7b as to retrieve enough of the previously laid pipeline so as to bring the increment containing the buckle on board the vessel 2. This retrieval of the pipeline increment containing the buckle would also entail the concurrent retrieval of the detector 19 itself.

When the tensioned or buckled increment was on board vessel 2, it would be repaired or replaced, and pipeline laying reinitiated. The detector would be relocated and scanning resumed, employing the operational techniques now to be described.

CONDITION DETECTING This invention pertains to the detecting of an irregular or adverse condition, or an acceptable condition, in a portion of a submerged pipeline and may commence with an installation as shown in FIG. 111.

With system elements disposed as shown in FIG. la, the initially laid first portion 7a of a pipeline is supported on a submergedsurface 16 while a second portion 7b is supported by the tensioning means 3 on the vessel 2. The tensioning means 3 is concurrently operable to implement laying of the pipeline under tension or effect retrieval of the previously laid pipeline for repair purposes.

A third pipeline portion 7c extends through the body of water 15 between the first pipeline portion 7a and the second pipeline portion 7b.

As shown in FIG. 1a, when detecting is to be initiated, the detecting means 19 may be positioned within the interior of the extremity of the pipeline portion 7b on lay barge 2, with the draft means 20 connected with means 19 and extending possibly from a coil or pneumatic winch mechanism, schematically depicted by the reference numeral 63. Operators on board the vessel 2 would position the flange 32 of the air hose 26 adjacent the flange 31 of the detecting means 19. By supplying pressurized air through the hose 26, the latch means 25 would be actuated so as to detachably interconnect the source 26 of pressurized air with the detecting means 19 and activate propulsion wheels 42. This actuation would include (1) substantially concurrent actuation of the various drive wheel extending motor means 54 so as to bias the wheels 42 outwardly into driving engagement with the pipeline interior and (2) substantially concurrent actuation of the motor means 49 so as to induce propelling rotation of the wheel means 42.

By appropriately paying out" the air hose 26 and draft means 20, the detecting means-will propel itself through the interior of the pipeline 7 until an operator determines, based on known profile characteristics of the pipeline, that the detecting means 19 has come to a rest either within the first pipeline portion 7a or possibly within another submerged pipeline portion. For example, the detecting means might be initially positioned in the vicinity of the junction 18 between pipe-- line portions 7a and 70, or even within the pipeline portion 70, depending upon the condition being detected.

After the appropriate position of the detecting means 19 within the pipeline interior has been effected, possibly as generally shown in FIG. lb, the pressure of air within air hose 26 would be reduced so as to permit the decoupling of hose 26 and detecting means 19 in the manner previously described. FIG. lb depicts the flange terminus 32 of the air hose 26 within pipeline portion 7:: during the retrieving or recoiling operation of this air hose, possibly as implemented by winch means 63.

A portion of the flexible draft means 20 would then be disconnected from coil means 63 and be connected with a pipeline alignment means or line up clamp 10 as schematically shown in FIG. 10.

The line up clamp would then be positioned within the interior of the pipeline, possibly generally as shown in FIG. 2c. r

A first additional pipeline segment or increment (i.e. joint) would then be manipulated into position in axial alignment with the pipeline terminus and the alignment clamp 10 might then be drawn back into the position shown schematically in FIG. 2a where it would be aligned with the junction 13 between pipeline body 7 and new joint 9.

This manipulation could be facilitated by a cable or rope connected with the air pipe 12, with the cable or hose being threaded through the new joint 9 to permit alignment means 11 to be drawn into the FIG. 2a position.

With the components disposed as shown in FIG. 2a, the detecting means 19 is connected by flexible draft means to the pipeline alignment means 10. Concurrently, this pipeline alignment means is interconnecting the pipeline portion 7b in longitudinal alignment with the additional pipeline increment 9.

With the components disposed as shown in FIG. 2a, air would be supplied through branch conduit 14 to air pipe 12, as permitted by valve 15, so as to actuate the alignment means 10 and maintain its clamps in aligning cooperation with the joint 9 and pipeline body 7.

During this operation, a flexible cable or rope 64 extending from coil or winch means 63 may be detachably connected with the air pipe 12.

After the welding operation at station 8 has been completed, the laying barge 2 would move ahead, i.e. away from the previously laid pipeline segments, so as, in essence, to displace the increment 9 into the first pipeline portion 7a as shown schematically in FIG. 2b.

During this movement, the line up clamp 10 may remain in its expanded or actuated condition by virtue of a closed condition of valve 15 serving to entrap pressurized air within pipe 12 and line up clamp or alignment means 10. Alternatively, valve 15 may be open and pipe 12 disconnected from air source 14. Under these circumstances, the clamps of mechanism 10 would be retracted and mechanism 10 would be frictionally immobilized within pipeline portion 7b.

During this movement, which constitutes a part of the laying operation, the tensioning means 3 would maintain appropriate control tension on the pipeline.

During the movement operation depicted in FIG. 2b, not only may the air conduit 14 be uncoupled from the pipe 12, but the rope or cable 64 may be disengaged from the air pipe.

With the components disposed as shown in FIG. 2b, conventional techniques may be employed to bring a second additional pipeline increment 65 into position in longitudinal alignment with the first additional increment. This first increment, being at least partially welded or secured to the pipeline body, now comprises a terminus of the second pipeline portion 7b.

Throughout this operation, pipeline portion 7b, as well as second increment 65, would be appropriately supported by roller or cradle means 6, most of which are not shown.

With the components disposed as shown in FIG. 2c, a section of cable or rope 66 may be threaded through the interior of joint 65 and connected with line 64 and the end of air pipe 12. The valve 15, if closed, may be opened so as to effect retraction of the clamps in mechanism 10. Prior to retracting the clamp means 10, the winch means 63 may be operated so as to take the slack out of the interconnected draft means 64 and 66.

The winch means 63 may then be operated to move the alignment means 10 generally toward the new joint 65 and into position in aligning cooperation with the juncture 67 between the joint 9 and the joint 65.

Thus, this movement of the alignment means 10, schematically depicted in FIG. 2d, will thus serve to cause the detecting means 19 to move, or attempt to move, generally toward an additional increment of the pipeline portion 7a which has moved into the pipeline zone 7a as a result of the advancing movement of the barge 2 described in connection with FIG. 2b. The movement of the barge described in connection with FIG. 2b, of course, served to cause an additional increment of the pipeline to come to rest on the submerged surface 16 so as to, in essence, extend the length of pipeline portion 7a, i.e. cause an additional increment to move into the zone designated 70.

In other words, during the retracting movement of the line up clamp or alignment means 10, the draft means 20 would have exerted a retracting or pulling force on the detecting means 19. This pulling force would have caused the detecting means 19 to move, or attempt to move, within the interior of the submerged pipeline, generally toward the vessel 2 and second pipeline portion 7b and through a recently or newly added increment of portion 7a. This movement would have permitted the detector to thus scan the interior of such an increment of the pipeline portion 7a, with a view to detecting irregularities such as a buckle condition.

In the event that a buckle condition is detected (due to an inability to move unit 19 because of engagement of disc 21 with a buckle), the tensioning means 3 may be operated to retrieve the increment containing'the buckle condition and the detector means 19 so that appropriate repairs may be initiated and pipelaying and condition detecting resumed.

In the event that no irregularity is detected by the de-' tecting means '19, the alignment means 10 will be positioned at joint juncture 67, as shown in FIG. 2d, so as to permit the additional segment 65 to be disposed in generally abutting and longitudinally aligned relation with the joint 9 so that interconnection or welding of

joints

9 and 65 may be effected. When the welding at illustrated station 8, between aligned

sections

9 and 65, is terminated, the sequence of operations heretofore described may be resumed.

As will be appreciated, prior to effecting the welding of

joints

9 and 65, the air hose 14 would be reconnected with the air pipe 12 and the valve 15 opened to effect the actuation of the line up clamp elements in the mechanism 10.

While in many operations the welding at station 8 would involve the formation of an initial bead so as to weldingly and at least partially interconnect the

joints

9 and 65, under certain circumstances, automated welding equipment may effect substantial or complete welding of the

joints

9 and 65 at the single welding station shown in FIGS. 2a and 2d.

Optimum benefits of the invention are realized where the scanning device or detecting means 19 is disposed in pipeline portion 7a reasonably near the tangency point 18. This disposition of the detecting means 19 will ensure that the scanning movement of the detecting means 19 will take place through the most recently added increment or increments of the pipeline which have come to rest on the submerged surface 16. Following this technique, scanning of pipeline increments which have passed through the zone 7b and 7c, where buckling might occur, will be effected at the earliest moment so that repairs may be made as expeditiously as possible.

Depending upon operating conditions, the detecting means 19 may effect scanning of additional increments added to pipeline portion 7a somewhat after or before the point in time that such increments have come to rest on the submerged surface 16.

ALTERNATIVE SCANNING TECHNIQUE The scanning technique heretofore described is effected between incrementsv of lay barge movement which serve to cause pipeline laying on surface 16.

In other words, as the lay barge 2 is moved ahead so as to displace the joint 9 from the FIG. 2a to the FIG. 2b positions, an additional increment of pipeline will be added to the pipeline portion 7a, i.e. the submerged and suspended profile of the pipeline will translate along the laying route so as to cause an additional increment of the pipeline to come to rest on the submerged surface 16 within the zone designated as first pipeline portion 7a.

Those skilled in the pipelaying art and familiar with the disclosure will recognize that the invention might also be practiced by securing the detecting means 19, as for example by connecting it with astationary or immobilizeddrum of winch means 63, during the pipelaying or advancing movement of the lay barge.

Under these circumstances, the advancing movement of the lay barge would exert a pulling force on unit 19,

through the draft means 20, so as to cause scanning means I9 to move relative to the pipeline during the actual advancing or laying movement of the lay barge itself.

In any event, regardless of which scanningtechnique is employed, the present invention contemplates that scanning or detecting operations will be performed during the laying operation, that is to say, between the termination and initiation of the laying of the complete pipeline 7 and while the retrieving means 3 of the lay barge 2 remains continuously operable to effect retrieval of a defective'pipeline section.

SUMMARY OF MAJOR ADVANTAGES AND OVERALL SCOPE OF INVENTION A principal advantage of the invention resides in the provision of a technique which enables defects in submerged pipelines to be detected during the laying operation.

Defects may be determined almost as soon as a defective section has come to rest on the submerged surface so as to enable repairs to be made as expeditiously as possible.

Significantly, condition detecting is effected while the lay barge or floating vessel means remains continuously operable to retrieve a defective section for repair operations. Where the retrieval is effected by the tensioning means, i.e. utilizing the pipelaying equipment itself, proper and effective control over pipeline stress may be maintained so as to minimize the chance of causing pipeline tension during the repairing operation.

The necessity of resorting to underwater repairs or costly repairs initiated after pipeline laying has been completed may be avoided.

The technique described heretofore enables an operator to ensure a customer at the completion of the laying operation, without further delay, that the pipeline has been scanned for certain abnormalities and is in an acceptable condition. In this manner, delays involving subsequent inspection operations are avoided and the pipeline may be placed in operating condition more quickly. Such savings in time are particularly significant where weather conditions or other factors limit the time available to complete pipeline laying operations and place pipelines in operating condition.

In performing these detecting or scanning operations concurrently with the pipelaying operation itself, a substantial savings in time and money is effected.

The propulsion mechanism described in connection with the detecting mechanism of the present invention is uniquely advantageous in that it permits a propulsion power source to be effectively deactivated and removed from the pipeline interior once the detecting means has been appropriately located.

A variety of modified aspects of the invention have been heretofore set forth. In summary, it will be recognized that the invention may be practiced by:

l. employing substantial variations in pipeline laying techniques and equipment;

2. detecting a wide variety of pipeline conditions;

3. performing detecting operations with a wide variety of detecting apparatus; and

- 4. conducting the detecting operation itself either in between increments of lay barge movement or concurrent with lay barge movement, or possibly in both ways.

Such variations are indicative of the scope of the invention and it will be apparent to those skilled in the pipelaying art and familiar with this disclosure that such variations and other additions, deletions, substitutions, and modifications may be made within the scope of the invention as set forth in the appended claims.

What is claimed is: 1. A method of detecting a submerged pipeline condition, said method comprising: I supporting a pipeline at anoffshore location with a first portion supported on a submerged surface, a second portion supported on floating vessel means, and a third portion extending through a body of water between said first and second pipeline portions; positioning pipeline condition detecting means within the interior of a submerged portion of said pipeline; increasing the length of said pipeline from said floating vessel means so as to provide an additional submerged pipeline increment, and while the pipeline of increased length remains supportedby said floating vessel means and while said pipeline condition detecting means remains within the interior of a submerged portion of the pipeline of increased length, inducing relative movement between the additional submerged pipeline increment and said pipeline condition detecting means, and detecting a condition of said additional submerged pipeline increment with said detecting means; said floating vessel means being operable to retrieve said additional submerged pipeline increment by exerting a retrieving force on said second pipeline portion. 2. A method of detecting a submerged pipeline condition, said method comprising:

supporting a pipeline at an offshore location with a first portion supported on a submerged surface, a second portion supported on floating vessel means, and

a third portion extending through a body of water between said first and second pipeline portions; engaging said second pipeline portion by pipeline tensioning means on said floating vessel means; supporting said third pipeline portion, at least in part, by at least partially submerged buoyant ramp means extending from and connected with said floating vessel means; positioning pipeline condition detecting means within the interior of a submerged portion of said pipeline; inducing relative movement between said first pipeline portion and said pipeline detecting means by flexible draft means extending from said pipeline detecting means through the interior of said third pipeline portion, over said buoyant ramp means, and through the interior of said second pipeline portion engaged by said pipeline tensioning means on said floating vessel means; and detecting a condition of said submerged pipeline portion with said detecting means while the pipeline remains supported by said floating vessel means;

said pipeline tensioning means on said floating vessel means being continuously operable to retrieve said first pipeline portion on board said floating vessel means by exerting a retrieving force on said second pipeline portion so as to displace an increment of said first pipeline portion into said second pipeline portion through movement of said increment upwardly through said body of water, over said buoyant ramp means, and onto said floating vessel means.

3. A method as described in claim 1, wherein:

the step of inducing relative movement between said pipeline condition detecting means and said additional submerged pipeline increment responsively causes detection by said detecting means of a buckle condition in said increment of said pipeline; and wherein a retrieving force is exerted on said second pipeline portion to retrieve said increment of said pipeline containing said detected buckle condition on board said floating vessel means.

4. A method of detecting a dimensional irregularity in an internal cross section of a submerged pipeline portion, said method comprising:

supporting a pipeline at an offshore location with a first pipeline portion supported on a submerged surface,

a second pipeline portion supported on floating vessel means, and

a third pipeline portion extending through a body of water between said first and second pipeline portions;

propelling pipeline detecting means from said floating vessel means sequentially through said second and third pipeline portions to position said pipeline detecting means within the interior of said first pipeline portion;

said pipeline detecting means, when disposed within the interior of said first pipeline portion, being operable to detect an irregularity in dimension in the cross section of said pipeline in response to relative movement between said pipeline detecting means and said first pipeline portion;

Ell

increasing the length of said pipeline from said floating vessel means so as to provide an additional pipeline increment in said first pipeline portion;

from said floating means, inducing relative movement between said pipeline detecting means and said additional increment of said first pipeline portion, with said relative movement being operable to permit said pipeline detecting means to detect a dimensional irregularity in the cross section of said additional increment of said first pipeline portion; and

providing pipeline retrieving means on said floating means operable to retrieve said additional increment of said first pipeline portion in the event that said pipeline detecting means should detect a dimensional irregularity in the cross section of said additional increment of said first pipeline portion.

5. A method as described in claim 4:

wherein said second pipeline portion is engaged by pipeline tensioning means on said floating vessel means;

wherein said third pipeline portion is supported, at

least in part, by at least partially submerged buoyant ramp means extending from and connected with said floating vessel means; and

wherein said method additionally comprises inducing relative movement between said first pipeline portion and said pipeline detecting means by flexible draft means extending from said pipeline detecting means through the interior of said third pipeline portion, over said buoyant ramp means, and through the interior of said second pipeline portion engaged by said pipeline tensioning means on said floating vessel means;

said pipeline tensioning means being continuously operable to retrieve said first pipeline portion on board said floating vessel means by exerting a retrieving force on said second pipeline portion so as to displace an increment of said first pipeline portion into said second pipeline portion through movement of said increment upwardly through said body of water, over said buoyant ramp means, and onto said floating vessel means.

6. A method as described in claim 5, wherein:

the step of inducing relative movement between said pipeline detecting means and said additional increment of said first pipeline portion responsively causes detection by said detecting means of a buckle condition in said additional increment; and wherein a retrieving force is exerted on said second pipeline portion by said pipeline tensioning means to retrieve said additional increment of first pipeline portion containing said detected buckle condition on board said floating vessel means.

7. A method of detecting a dimensional irregularity in an internal cross section of a submerged pipeline portion, said method comprising:

a second pipeline portion supported on floating vessel means, and

, said pipeline detecting means, when disposed within the interior of said first pipeline portion, being operable to detect an irregularity in dimension in the cross section of said pipeline in response to relative movement between said pipeline detecting means and said first pipeline portion; connecting said pipeline detecting means with pipeline section alignment means; on said floating vessel means operating said pipeline section alignment means to generally secure in longitudinal alignment a first additional pipeline section with a terminus of said second pipeline portion; weldingly, and at least partially, interconnecting said first additional pipeline section and said second pipeline portion terminus, with said pipeline section alignment means securing said first additional pipeline section and said second pipeline portion terminus in longitudinal alignment, and remaining connected with said pipeline detecting means; advancing said first additional pipeline section on said floating vessel means toward said body of water, with said pipeline detecting means remaining connected with said pipeline section alignment means, and said pipeline section alignment means interconnecting and aligning said first additional pipeline section and said second pipeline portion terminus; said advancing of said additional pipeline section on said floating vessel means being operable to increase the length of said first pipeline portion and provide an additional pipeline increment in said first pipeline portion; positioning a second, additional pipeline section in general longitudinal alignment with said first additional pipeline section; moving said pipeline section alignment means toward said second additional pipeline section, away from said first additional pipeline section: said movement of said pipeline section alignment means away from said first additional pipeline section causing said pipeline detecting means to move generally toward said additional increment of said first pipeline portion, with this movement being operable to permit said pipeline detecting means to detect a dimensional irregularity in the cross section of said first pipeline portion; said movement of said pipeline section alignment means away from said first additional pipeline section being operable to position said pipeline section alignment means in position to secure, in mutual longitudinal alignment, a terminus of said first additional pipeline section and a terminus of said second additional pipeline section; and providing pipeline retrieving means on said floating means operable to retrieve an increment of said first pipeline portion in the event that said pipeline detecting means should detect a dimensional irregularity in the cross section of said first pipeline portion.

8. A method as described in claim 7:

wherein said third pipeline portion is supported, at

wherein said method additionally comprises inducing relative movement between said first pipeline portion and said pipeline detecting means by flexible draft means connected with said pipeline section alignment means and extending from said pipeline detecting means through the interior of said third pipeline portion, over said buoyant ramp means, and through the interior of said second pipeline portion engaged by said pipeline tensioning means on said floating vessel means;

said pipeline tensioning means being continuously operable to retrieve said first pipeline portion on board said floating vessel means by exerting a retrieving force on said second pipeline portion so as to displace an increment of said first pipeline portion into said second pipeline portion through movement of said increment upwardly through said body of water, over said-buoyant ramp means, and onto said floating vessel means.

9. A method as described in claim 8, wherein said pipeline detecting means is propelled from said floating vessel means to said first pipeline portion by:

pneumatically operating latch means to interconnect a source of pressurized air with said pipeline detecting means;

in response to said interconnection of said source of pressurized air with said pipeline detecting means, i extending drive means carried by said pipeline detecting means into driving engagement with the interior of said pipeline, and operating said drive means so as to exert a propelling force on the interior of said pipeline tending to propel said pipeline detecting means toward said first pipeline portion; in response to operation of said drive means, propelling said pipeline detecting means from said floating vessel means sequentially through said second and third pipeline portion to said first pipeline portion; reducing the pressure of said pressurized air and in response to said reduction of pressure disconnecting said source of pressurized air from said pipeline detecting means, retracting said drive means out of driving engagement with the interior of said pipeline means, and discontinuing operation of said drive means; and retrieving said source of pressurized air from said pipeline detecting means sequentially through said second and third pipeline portions to said floating vessel means.

10. A method as described in claim 9, wherein:

11. Apparatus for detecting a submerged pipeline condition, said apparatus comprising:

floating vessel means operable to support, at least in part, a pipeline at an offshore location with a first portion supported on a submerged surface, a second portion supported on floating vessel means, and a third portion extending through a body of water between said first and second pipeline portions; pipeline condition detecting means positioned within the interior of a submerged portion of said pipeline; said floating vessel means being operable to increase the length of said pipeline so as to provide an additional submerged pipeline increment;

means for inducing relative movement between the additional submerged pipeline increment and said detecting means, while said detecting means remains within the interior of a submerged portion of pipeline and while said pipeline remains supported, at least in part, by said floating vessel means;

said pipeline detecting means being operable to detect a condition of said additional submerged pipeline increment while said pipeline remains supported at least in part, by said floating vessel means;

said floating vessel means being operable to retrieve said additional submerged pipeline increment by exerting a retrieving force on said second pipeline portion. I

12. Apparatus for detecting a submerged pipeline condition, said apparatus comprising:

floating vessel means operable to support, at least in part, a pipeline at an offshore location with a first portion supported on a submerged surface, a second portion supported on floating vessel means, and a third portion extending through a body of water between said first and second pipeline portions; pipeline condition detecting means positioned within the interior of a submerged portion of said pipeline; said pipeline detecting means being operable to detect a condition of said submerged pipeline portion while said pipeline remains supported at least in part, by said floating vessel means;

pipeline tensioning means on said floating vessel means operable to engage said second pipeline portion; I

at least partially submerged buoyant ramp means extending from and connected with said floating vessel means and supporting, at least in part, said third pipeline portion; and

flexible draft means extending from said pipeline detecting means through the interior of said third pipeline portion, over said buoyant ramp means, and through the interior of said second pipeline portion engaged by said pipeline tensioning means on said floating vessel means, said flexible draft means being operable to induce relative movement between said first pipeline portion and said pipeline detecting means; and

13. Apparatus as described in claim 11, wherein:

said pipeline condition detecting means comprises means operable, in response to relative movement between said pipeline detecting means and said pipeline, to detect a buckle condition in said pipeline.

14. Apparatus for detecting a dimensional irregularity in an internal cross section of a submerged pipeline portion, said apparatus comprising:

floating vessel means operable to support, at least in part, a pipeline at an offshore location with a first pipeline portion supported on a submerged surface,

a second pipeline portion supported on floating vessel means, and

pipeline detecting means;

means for propelling said pipeline detecting means from said floating vessel means sequentially through said second and third pipeline portions to position said pipeline detecting means within the interior of said first pipeline portion;

means for increasing the length of said pipeline from said floating vessel means so as to provide an additional pipeline increment in said first pipeline portion; means operable from said floating means to induce relative movement between said pipeline detecting means and said additional increment of said first pipeline portion, with said relative movement being operable to permit said pipeline detecting means to detect a dimensional irregularity in the cross section of said additional increment of said first pipeline portion; and

pipeline retrieving means on said floating means operable to retrieve said additional increment of said first pipeline portion in the event that said pipeline detecting means should detect a dimensional irregularity in the cross section of said additional increment of said first pipeline portion.

15. A method as described in claim 14 including:

pipeline tensioning means on said floating vessel means operable to engage said second pipeline portion;

at least partially submerged buoyant ramp means extending from and connected with said floating vessel means and supporting, at least in part, said third pipeline portion;

flexible draft means extending from said pipeline detecting means through the interior of said third pipeline portion, over said buoyant ramp means,

and through the interior of said second pipeline portion engaged by said pipeline tensioning means on said floating vessel means;

said flexible draft means being operable to induce relative movement between said first pipeline portion and said pipeline detecting means; and

16. Apparatus as described in claim 15, wherein:

said pipeline detecting means comprises means operable, in response to relative movement between said pipeline detecting means and said additional increment of said first pipeline portion, to detect a buckle condition in said additional increment.

17. Apparatus for detecting a dimensional irregularity in an internal cross section of a submerged pipeline portion, said apparatus comprising:

floating vessel means operable to support, at least in part, a pipeline at an offshore location with a first pipeline portion supported on a submerged portion, a second pipeline portion supported on floating vessel means, and a third pipeline portion extending through a body of water between said first and second pipeline portions; pipeline detecting means; propelling means for propelling said pipeline detecting means from said floating vessel means sequentially through said second and third pipeline portions to position said pipeline detecting means within the interior of said first pipeline portion;

said pipeline detecting means, when disposed within the interior of said first pipeline portion, being operable to detect an irregularity in dimension in the cross section of said pipeline in response to relative movement between said pipeline detecting means and said first pipeline portion; pipeline section alignment means; means operable to connect said pipeline detecting means with pipeline section alignment means;

said pipeline section alignment means being operable to generally secure in longitudinal alignment a first additional pipeline section with a terminus of said second pipeline portion;

welding means operable to at least partially interconnect said first additional pipeline section and said second pipeline portion terminus, with said pipeline section alignment means securing said first additional pipeline section and said second pipeline portion terminus in longitudinal alignment, and

remaining connected with said pipeline detecting means;

means for advancing said first additional pipeline section on said floating vessel means toward said body of water, with saidpipelinc detecting means remaining connected with said pipeline section alignment means, and

said pipeline section alignment means interconnecting and aligning said first additional pipeline section and said second pipeline portion terminus; said advancing of said additional pipeline section on said floating vessel means being operable to increase the length of said first pipeline portion and provide an additional pipeline increment in said first pipeline portion; means for positioning a second, additional pipeline section in general longitudinal alignment with said first additional pipeline section; means for moving said pipeline section alignment means toward said second additional pipeline section, away from said first additional pipeline section; said movement of said pipeline section alignment means away from said first additional pipeline section causing said pipeline detecting means to move generally toward said additional increment of said first pipeline portion, with this movement being operable to permit said pipeline detecting means to detect a dimensional irregularity in the cross section of said first pipeline portion; said movement of said pipeline section alignment means away from said first additional pipeline section being operable to position said pipeline section alignment means in position to secure, in mutual longitudinal alignment, a terminus of said first additional pipeline section and a terminus of said second additional pipeline section; and pipeline retrieving means on said floating means operable to retrieve an increment of said first pipeline portion in the event that said pipeline detecting means should detect a dimensional irregularity in the cross section of said first pipeline portion. 18. Apparatus as described in claim 17: pipeline tensioning means included in said floating vessel means operable to engage said second pipeline portion; at least partially submerged buoyant ramp means extending from and connected with said floating vessel means and supporting, at least in part, said third pipeline portion; flexible draft means connected with said pipeline section alignment means and extending from said pipeline detecting means through the interior of said third pipeline portion, over said buoyant ramp means, and through the interior of said second pipeline portion engaged by said pipeline tensioning means on said floating vessel means, said flexible draft means being operable to induce relative movement between said first pipeline portion and said pipeline detecting means; and said pipeline tensioning means being continuously operable to retrieve said first pipeline portion on board said floating vessel means by exerting a retrieving force on said second pipeline portion so as to displace an increment of said first pipeline portion into said second pipeline portion through movement of said increment upwardly through said body of water, over said buoyant ramp means, and onto said floating vessel means. 19. Apparatus as described in claim 18, wherein said propelling means comprises:

a source of pressurized air;

Claims

1. A method of detecting a submerged pipeline condition, said method comprising: supporting a pipeline at an offshore location with a first portion supported on a submerged surface, a second portion supported on floating vessel means, and a third portion extending through a body of water between saId first and second pipeline portions; positioning pipeline condition detecting means within the interior of a submerged portion of said pipeline; increasing the length of said pipeline from said floating vessel means so as to provide an additional submerged pipeline increment, and while the pipeline of increased length remains supported by said floating vessel means and while said pipeline condition detecting means remains within the interior of a submerged portion of the pipeline of increased length, inducing relative movement between the additional submerged pipeline increment and said pipeline condition detecting means, and detecting a condition of said additional submerged pipeline increment with said detecting means; said floating vessel means being operable to retrieve said additional submerged pipeline increment by exerting a retrieving force on said second pipeline portion.

2. A method of detecting a submerged pipeline condition, said method comprising: supporting a pipeline at an offshore location with a first portion supported on a submerged surface, a second portion supported on floating vessel means, and a third portion extending through a body of water between said first and second pipeline portions; engaging said second pipeline portion by pipeline tensioning means on said floating vessel means; supporting said third pipeline portion, at least in part, by at least partially submerged buoyant ramp means extending from and connected with said floating vessel means; positioning pipeline condition detecting means within the interior of a submerged portion of said pipeline; inducing relative movement between said first pipeline portion and said pipeline detecting means by flexible draft means extending from said pipeline detecting means through the interior of said third pipeline portion, over said buoyant ramp means, and through the interior of said second pipeline portion engaged by said pipeline tensioning means on said floating vessel means; and detecting a condition of said submerged pipeline portion with said detecting means while the pipeline remains supported by said floating vessel means; said pipeline tensioning means on said floating vessel means being continuously operable to retrieve said first pipeline portion on board said floating vessel means by exerting a retrieving force on said second pipeline portion so as to displace an increment of said first pipeline portion into said second pipeline portion through movement of said increment upwardly through said body of water, over said buoyant ramp means, and onto said floating vessel means.

3. A method as described in claim 1, wherein: the step of inducing relative movement between said pipeline condition detecting means and said additional submerged pipeline increment responsively causes detection by said detecting means of a buckle condition in said increment of said pipeline; and wherein a retrieving force is exerted on said second pipeline portion to retrieve said increment of said pipeline containing said detected buckle condition on board said floating vessel means.

4. A method of detecting a dimensional irregularity in an internal cross section of a submerged pipeline portion, said method comprising: supporting a pipeline at an offshore location with a first pipeline portion supported on a submerged surface, a second pipeline portion supported on floating vessel means, and a third pipeline portion extending through a body of water between said first and second pipeline portions; propelling pipeline detecting means from said floating vessel means sequentially through said second and third pipeline portions to position said pipeline detecting means within the interior of said first pipeline portion; said pipeline detecting means, when disposed within the interior of said first pipeline portion, being operable to detect an irregularity in dimension in the cross section of said pipeliNe in response to relative movement between said pipeline detecting means and said first pipeline portion; increasing the length of said pipeline from said floating vessel means so as to provide an additional pipeline increment in said first pipeline portion; from said floating means, inducing relative movement between said pipeline detecting means and said additional increment of said first pipeline portion, with said relative movement being operable to permit said pipeline detecting means to detect a dimensional irregularity in the cross section of said additional increment of said first pipeline portion; and providing pipeline retrieving means on said floating means operable to retrieve said additional increment of said first pipeline portion in the event that said pipeline detecting means should detect a dimensional irregularity in the cross section of said additional increment of said first pipeline portion.

5. A method as described in claim 4: wherein said second pipeline portion is engaged by pipeline tensioning means on said floating vessel means; wherein said third pipeline portion is supported, at least in part, by at least partially submerged buoyant ramp means extending from and connected with said floating vessel means; and wherein said method additionally comprises inducing relative movement between said first pipeline portion and said pipeline detecting means by flexible draft means extending from said pipeline detecting means through the interior of said third pipeline portion, over said buoyant ramp means, and through the interior of said second pipeline portion engaged by said pipeline tensioning means on said floating vessel means; said pipeline tensioning means being continuously operable to retrieve said first pipeline portion on board said floating vessel means by exerting a retrieving force on said second pipeline portion so as to displace an increment of said first pipeline portion into said second pipeline portion through movement of said increment upwardly through said body of water, over said buoyant ramp means, and onto said floating vessel means.

6. A method as described in claim 5, wherein: the step of inducing relative movement between said pipeline detecting means and said additional increment of said first pipeline portion responsively causes detection by said detecting means of a buckle condition in said additional increment; and wherein a retrieving force is exerted on said second pipeline portion by said pipeline tensioning means to retrieve said additional increment of first pipeline portion containing said detected buckle condition on board said floating vessel means.

7. A method of detecting a dimensional irregularity in an internal cross section of a submerged pipeline portion, said method comprising: supporting a pipeline at an offshore location with a first pipeline portion supported on a submerged surface, a second pipeline portion supported on floating vessel means, and a third pipeline portion extending through a body of water between said first and second pipeline portions; propelling pipeline detecting means from said floating vessel means sequentially through said second and third pipeline portions to position said pipeline detecting means within the interior of said first pipeline portion; said pipeline detecting means, when disposed within the interior of said first pipeline portion, being operable to detect an irregularity in dimension in the cross section of said pipeline in response to relative movement between said pipeline detecting means and said first pipeline portion; connecting said pipeline detecting means with pipeline section alignment means; on said floating vessel means operating said pipeline section alignment means to generally secure in longitudinal alignment a first additional pipeline section with a terminus of said second pipeline portion; weldingly, and at least partially, interconnecting said First additional pipeline section and said second pipeline portion terminus, with said pipeline section alignment means securing said first additional pipeline section and said second pipeline portion terminus in longitudinal alignment, and remaining connected with said pipeline detecting means; advancing said first additional pipeline section on said floating vessel means toward said body of water, with said pipeline detecting means remaining connected with said pipeline section alignment means, and said pipeline section alignment means interconnecting and aligning said first additional pipeline section and said second pipeline portion terminus; said advancing of said additional pipeline section on said floating vessel means being operable to increase the length of said first pipeline portion and provide an additional pipeline increment in said first pipeline portion; positioning a second, additional pipeline section in general longitudinal alignment with said first additional pipeline section; moving said pipeline section alignment means toward said second additional pipeline section, away from said first additional pipeline section: said movement of said pipeline section alignment means away from said first additional pipeline section causing said pipeline detecting means to move generally toward said additional increment of said first pipeline portion, with this movement being operable to permit said pipeline detecting means to detect a dimensional irregularity in the cross section of said first pipeline portion; said movement of said pipeline section alignment means away from said first additional pipeline section being operable to position said pipeline section alignment means in position to secure, in mutual longitudinal alignment, a terminus of said first additional pipeline section and a terminus of said second additional pipeline section; and providing pipeline retrieving means on said floating means operable to retrieve an increment of said first pipeline portion in the event that said pipeline detecting means should detect a dimensional irregularity in the cross section of said first pipeline portion.

8. A method as described in claim 7: wherein said second pipeline portion is engaged by pipeline tensioning means on said floating vessel means; wherein said third pipeline portion is supported, at least in part, by at least partially submerged buoyant ramp means extending from and connected with said floating vessel means; and wherein said method additionally comprises inducing relative movement between said first pipeline portion and said pipeline detecting means by flexible draft means connected with said pipeline section alignment means and extending from said pipeline detecting means through the interior of said third pipeline portion, over said buoyant ramp means, and through the interior of said second pipeline portion engaged by said pipeline tensioning means on said floating vessel means; said pipeline tensioning means being continuously operable to retrieve said first pipeline portion on board said floating vessel means by exerting a retrieving force on said second pipeline portion so as to displace an increment of said first pipeline portion into said second pipeline portion through movement of said increment upwardly through said body of water, over said buoyant ramp means, and onto said floating vessel means.

9. A method as described in claim 8, wherein said pipeline detecting means is propelled from said floating vessel means to said first pipeline portion by: pneumatically operating latch means to interconnect a source of pressurized air with said pipeline detecting means; in response to said interconnection of said source of pressurized air with said pipeline detecting means, extending drive means carried by said pipeline detecting means into driving engagement with the interior of said pipeline, and operating said drive means so as to exert a propellIng force on the interior of said pipeline tending to propel said pipeline detecting means toward said first pipeline portion; in response to operation of said drive means, propelling said pipeline detecting means from said floating vessel means sequentially through said second and third pipeline portion to said first pipeline portion; reducing the pressure of said pressurized air and in response to said reduction of pressure disconnecting said source of pressurized air from said pipeline detecting means, retracting said drive means out of driving engagement with the interior of said pipeline means, and discontinuing operation of said drive means; and retrieving said source of pressurized air from said pipeline detecting means sequentially through said second and third pipeline portions to said floating vessel means.

10. A method as described in claim 9, wherein: the step of inducing relative movement between said pipeline detecting means and said additional increment of said first pipeline portion responsively causes detection by said detecting means of a buckle condition in said additional increment; and wherein a retrieving force is exerted on said second pipeline portion by said pipeline tensioning means to retrieve said additional increment of first pipeline portion containing said detected buckle condition on board said floating vessel means.

11. Apparatus for detecting a submerged pipeline condition, said apparatus comprising: floating vessel means operable to support, at least in part, a pipeline at an offshore location with a first portion supported on a submerged surface, a second portion supported on floating vessel means, and a third portion extending through a body of water between said first and second pipeline portions; pipeline condition detecting means positioned within the interior of a submerged portion of said pipeline; said floating vessel means being operable to increase the length of said pipeline so as to provide an additional submerged pipeline increment; means for inducing relative movement between the additional submerged pipeline increment and said detecting means, while said detecting means remains within the interior of a submerged portion of pipeline and while said pipeline remains supported, at least in part, by said floating vessel means; said pipeline detecting means being operable to detect a condition of said additional submerged pipeline increment while said pipeline remains supported at least in part, by said floating vessel means; said floating vessel means being operable to retrieve said additional submerged pipeline increment by exerting a retrieving force on said second pipeline portion.

12. Apparatus for detecting a submerged pipeline condition, said apparatus comprising: floating vessel means operable to support, at least in part, a pipeline at an offshore location with a first portion supported on a submerged surface, a second portion supported on floating vessel means, and a third portion extending through a body of water between said first and second pipeline portions; pipeline condition detecting means positioned within the interior of a submerged portion of said pipeline; said pipeline detecting means being operable to detect a condition of said submerged pipeline portion while said pipeline remains supported at least in part, by said floating vessel means; pipeline tensioning means on said floating vessel means operable to engage said second pipeline portion; at least partially submerged buoyant ramp means extending from and connected with said floating vessel means and supporting, at least in part, said third pipeline portion; and flexible draft means extending from said pipeline detecting means through the interior of said third pipeline portion, over said buoyant ramp means, and through the interior of said second pipeline portion engaged by said pipeline tensioning means On said floating vessel means, said flexible draft means being operable to induce relative movement between said first pipeline portion and said pipeline detecting means; and said pipeline tensioning means on said floating vessel means being continuously operable to retrieve said first pipeline portion on board said floating vessel means by exerting a retrieving force on said second pipeline portion so as to displace an increment of said first pipeline portion into said second pipeline portion through movement of said increment upwardly through said body of water, over said buoyant ramp means, and onto said floating vessel means.

13. Apparatus as described in claim 11, wherein: said pipeline condition detecting means comprises means operable, in response to relative movement between said pipeline detecting means and said pipeline, to detect a buckle condition in said pipeline.

14. Apparatus for detecting a dimensional irregularity in an internal cross section of a submerged pipeline portion, said apparatus comprising: floating vessel means operable to support, at least in part, a pipeline at an offshore location with a first pipeline portion supported on a submerged surface, a second pipeline portion supported on floating vessel means, and a third pipeline portion extending through a body of water between said first and second pipeline portions; pipeline detecting means; means for propelling said pipeline detecting means from said floating vessel means sequentially through said second and third pipeline portions to position said pipeline detecting means within the interior of said first pipeline portion; said pipeline detecting means, when disposed within the interior of said first pipeline portion, being operable to detect an irregularity in dimension in the cross section of said pipeline in response to relative movement between said pipeline detecting means and said first pipeline portion; means for increasing the length of said pipeline from said floating vessel means so as to provide an additional pipeline increment in said first pipeline portion; means operable from said floating means to induce relative movement between said pipeline detecting means and said additional increment of said first pipeline portion, with said relative movement being operable to permit said pipeline detecting means to detect a dimensional irregularity in the cross section of said additional increment of said first pipeline portion; and pipeline retrieving means on said floating means operable to retrieve said additional increment of said first pipeline portion in the event that said pipeline detecting means should detect a dimensional irregularity in the cross section of said additional increment of said first pipeline portion.

15. A method as described in claim 14 including: pipeline tensioning means on said floating vessel means operable to engage said second pipeline portion; at least partially submerged buoyant ramp means extending from and connected with said floating vessel means and supporting, at least in part, said third pipeline portion; flexible draft means extending from said pipeline detecting means through the interior of said third pipeline portion, over said buoyant ramp means, and through the interior of said second pipeline portion engaged by said pipeline tensioning means on said floating vessel means; said flexible draft means being operable to induce relative movement between said first pipeline portion and said pipeline detecting means; and said pipeline tensioning means being continuously operable to retrieve said first pipeline portion on board said floating vessel means by exerting a retrieving force on said second pipeline portion so as to displace an increment of said first pipeline portion into said second pipeline portion through movement of said increment upwardly through said body of water, over said buoyant ramp means, and onto said floating vessel means.

16. Apparatus as described in claim 15, wherein: said pipeline detecting means comprises means operable, in response to relative movement between said pipeline detecting means and said additional increment of said first pipeline portion, to detect a buckle condition in said additional increment.

17. Apparatus for detecting a dimensional irregularity in an internal cross section of a submerged pipeline portion, said apparatus comprising: floating vessel means operable to support, at least in part, a pipeline at an offshore location with a first pipeline portion supported on a submerged portion, a second pipeline portion supported on floating vessel means, and a third pipeline portion extending through a body of water between said first and second pipeline portions; pipeline detecting means; propelling means for propelling said pipeline detecting means from said floating vessel means sequentially through said second and third pipeline portions to position said pipeline detecting means within the interior of said first pipeline portion; said pipeline detecting means, when disposed within the interior of said first pipeline portion, being operable to detect an irregularity in dimension in the cross section of said pipeline in response to relative movement between said pipeline detecting means and said first pipeline portion; pipeline section alignment means; means operable to connect said pipeline detecting means with pipeline section alignment means; said pipeline section alignment means being operable to generally secure in longitudinal alignment a first additional pipeline section with a terminus of said second pipeline portion; welding means operable to at least partially interconnect said first additional pipeline section and said second pipeline portion terminus, with said pipeline section alignment means securing said first additional pipeline section and said second pipeline portion terminus in longitudinal alignment, and remaining connected with said pipeline detecting means; means for advancing said first additional pipeline section on said floating vessel means toward said body of water, with said pipeline detecting means remaining connected with said pipeline section alignment means, and said pipeline section alignment means interconnecting and aligning said first additional pipeline section and said second pipeline portion terminus; said advancing of said additional pipeline section on said floating vessel means being operable to increase the length of said first pipeline portion and provide an additional pipeline increment in said first pipeline portion; means for positioning a second, additional pipeline section in general longitudinal alignment with said first additional pipeline section; means for moving said pipeline section alignment means toward said second additional pipeline section, away from said first additional pipeline section; said movement of said pipeline section alignment means away from said first additional pipeline section causing said pipeline detecting means to move generally toward said additional increment of said first pipeline portion, with this movement being operable to permit said pipeline detecting means to detect a dimensional irregularity in the cross section of said first pipeline portion; said movement of said pipeline section alignment means away from said first additional pipeline section being operable to position said pipeline section alignment means in position to secure, in mutual longitudinal alignment, a terminus of said first additional pipeline section and a terminus of said second additional pipeline section; and pipeline retrieving means on said floating means operable to retrieve an increment of said first pipeline portion in the event that said pipeline detecting means should detect a dimensional irregularity in the cross section of said first pipeline portion.

18. Apparatus as descrIbed in claim 17: pipeline tensioning means included in said floating vessel means operable to engage said second pipeline portion; at least partially submerged buoyant ramp means extending from and connected with said floating vessel means and supporting, at least in part, said third pipeline portion; flexible draft means connected with said pipeline section alignment means and extending from said pipeline detecting means through the interior of said third pipeline portion, over said buoyant ramp means, and through the interior of said second pipeline portion engaged by said pipeline tensioning means on said floating vessel means, said flexible draft means being operable to induce relative movement between said first pipeline portion and said pipeline detecting means; and said pipeline tensioning means being continuously operable to retrieve said first pipeline portion on board said floating vessel means by exerting a retrieving force on said second pipeline portion so as to displace an increment of said first pipeline portion into said second pipeline portion through movement of said increment upwardly through said body of water, over said buoyant ramp means, and onto said floating vessel means.

19. Apparatus as described in claim 18, wherein said propelling means comprises: a source of pressurized air; pneumatically operated latch means operable to interconnect a source of pressurized air with said pipeline detecting means; drive means carried by said pipeline detecting means; positioning means operable to extend and retract said drive means; operating means operable in response to said interconnection of said source of pressurized air with said pipeline detecting means, to actuate said positioning means and extend said drive means carried by said pipeline detecting means into driving engagement with the interior of said pipeline, and actuate said drive means so as to exert a propelling force on the interior of said pipeline tending to propel said pipeline detecting means toward said first pipeline portion; said drive means being operable to propel said pipeline detecting means from said floating vessel means sequentially through said second and third pipeline portion to said first pipeline portion; means for reducing the pressure of said pressurized air and causing, in response to said reduction of pressure, the disconnecting of said source of pressurized air from said pipeline detecting means, the actuation of said positioning means to retract said drive means out of driving engagement with the interior of said pipeline means, and the discontinuing of actuation of said drive means; and means for retrieving said source of pressurized air from said pipeline detecting means sequentially through said second and third pipeline portions to said floating vessel means.

20. Apparatus as described in claim 19, wherein: said pipeline detecting means comprises means operable, in response to relative movement between said pipeline detecting means and said additional increment of said first pipeline portion, to detect a buckle condition in said additional increment.

21. A method of eveluating an offshore pipeline laying operation, said method comprising: conducting an offshore pipeline laying operation; during said offshore pipeline laying operation, supporting a portion of said pipeline on floating vessel means, with the floating vessel means being operable to effect retrieval of previously laid pipeline increment means; and prior to the termination of said offshore pipeline laying operation, and while a portion of said pipeline is supported on said floating vessel means and while said floating vessel means remains operable to effect retrieval of previously laid pipeline increment means, detecting a condition of a submerged portion of said pipeline; the step of detecting being performed by scanning a submerged portion of the pipeline with pipeline condition dEtecting means operable to detect a pipeline condition which is detectable prior to the termination of the laying of said pipeline and is operable to remain in said submerged portion of the pipeline after the termination of the pipeline laying operation.

22. A method according to claim 21 wherein: the steps of conducting the offshore pipeline laying operation and supporting a portion of the pipeline on floating vessel means comprise laying the pipeline from the floating vessel means and onto a submerged surface with the pipeline profile including a downwardly concave pipeline portion extending to a pipeline portion on the submerged surface; and wherein the step of detecting comprises detecting a pipeline condition at a pipeline location beyond the downwardly concave pipeline portion.