DE2545545A1 - SYSTEM FOR INSTALLING A PIPELINE - Google Patents

Description

Patent attorneys Dipl.-Ing. H. Weickmann, Dipl.-Phys. Dr. K. Fincke

Dipl.-Ing. F. A. Weickmann, Dipl.-Chem. B. Huber

g MUNICH 86, DEN

PO Box 860 820

MÖHLSTRASSE 22, CALL NUMBER 983921/22

Harry William Harrison, Box 99, Route 1, Dripping Springs,

Texas, 78620, V.St.A.

System for enabling a pipeline

The invention relates to a system for enabling a pipeline. Such systems are used on a pipelayer ship or the like. used to move a part of the pipeline that extends from the pipelayer into the water in a controlled manner.

Pipelayers, such as barges, are used for laying a pipeline at the bottom of a sea or other body of water. Such pipelayers generally include a or several welding stations in order to successively connect pipe lengths to weld the already existing part of the pipeline. Every time new pipe lengths are welded to the existing pipeline it is necessary to move the pipelayer out from under the new pipe section so that it is on the pipelayer Space is created for the attachment of further pipe lengths. This is generally done with the help of an anchor towing system, which is mounted on the bow of the ship in order to pull the ship away relative to the already formed pipeline part and To create space for aligning and welding new pipe lengths to the pipeline that has already been formed. About this relative movement It is to be carried out between the pipeline section that has already been built and the pipelayer barge or other ship necessary that a pipe control mechanism special on the ship Kind is attached to continuously detect the pipeline part and a relative movement of the pipeline part to

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Admit ship, especially if the ship or the like as a result of the anchor towing system. exercised at the bow of the ship Pulling forces forward moving / egt. Such devices are known as pipeline tensioners. But this is a bit of a misleading one Name because the pipeline tensioner is actually gripping devices which allow the pipeline portion to be carried away from the ship as the ship advances; the The actual voltage applied to the pipeline is the result of the tensile forces exerted by the anchor towing system on the Ship to be exercised.

In general, pipe lengths that form underwater pipelines are covered with concrete or the like. complained. It is therefore necessary to have gripping mechanisms for gripping the pipeline and for Provide control of their movement relative to the ship that does not destroy this concrete pavement. Another difficulty involves placing a concrete pavement at the joint after the pipe lengths are welded together; In order to be able to weld the pipe lengths together on the ship, the ends of the pipe lengths are not covered with a coating weighted down so that the bare metal is exposed for welding. The bare connection area must then be weighted down with a coating after the pipe lengths are welded together but before the pipe lengths enter the water as part of the pipeline be sunk. Generally, after welding, an annular jacket is placed over the exposed joint area attached and concrete is poured into the mantle. A pipeline clamping or gripping device must be able to to hold the pipeline part under enormous forces without the annular jacket made of aluminum or the like. can be, and Damage the freshly formed concrete layer in it. In addition, these pipeline tensioning and G-hooping devices must be capable be to hold the already formed part of the pipeline running away from the ship in its position, even if the diameter changes the pipe lengths attached to the pipeline changes.

An already known pipeline clamping device uses several

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rere sets of grippers on endless conveyor chains, which are arranged in such a way that the already formed pipeline part between the grippers is received movably relative to the barge or other Sohiff. The use of such However, gripping devices of the endless conveyor type do not solve all of the above-mentioned problems. So it is e.g. necessary) that the pipeline gripping devices grasp the already formed part of the pipeline with extremely high gripping forces and hold tight; The reason for this is the enormous tensile forces exerted on the ship by the anchor towing system, and that great weight of the pipeline already formed. The use of such grippers of the endless conveyor type causes some Localization of the load and thereby increases the risk of destruction or damage to a part of the concrete pavement the pipeline. In addition, the concentration of the loads in certain areas by the endless chain conveyor also makes damage to the annular casings that support the freshly poured concrete is more likely.

The invention relates to a new, improved system for mounting on a pipe-laying ship or the like. That for attitude control a pipeline section running to the bottom of a sea or other body of water is used, the pipeline section passing through Attaching pipe lengths one after the other shaped on the ship will. The system according to the invention for the controlled movement of a pipeline part comprises a first and a second pipeline station on the ship, which alternately cover the part of the pipeline running from the ship to the seabed and let go. The first and second pipeline stations are arranged on the ship at a distance from each other and operate in such a way that they alternately capture the pipeline part and allow relative movement between the base and the pipeline part, around the ship below that already formed To move pipeline part

Included in a preferred embodiment of the invention

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the first pipeline station has a first gripping device for gripping of the pipeline part and a first position control device to a relative movement between the gripped pipeline part and to enable the ship as the ship advances relative to the pipeline portion already formed. The first pipeline station also has a first release device in order to release the grip on the pipeline part. The second Pipeline station has a second gripping device for holding of the already formed pipeline part before it is released by the first release device of the first pipeline station on. The second pipeline station also includes a second position control device that controls a relative movement between the gripped part of the pipeline and the ship, if the ship continues to move forward, and a second Release device for releasing the second pipeline part after the first gripping device of the first pipeline station has captured the pipeline part again.

In the preferred exemplary embodiment, the two pipeline stations of the invention each have a main frame that can be mounted on the pipelayer, and one opposite the main frame movable carriage. A gripping device is mounted on the sledge, which moves with the sledge in order to alternately pick the one from the ship into the water Capture and release part of the pipeline; furthermore, a drive device is functional with the carriage and the main frame connected to move the carriage along the main frame and thereby remove the already formed pipeline part from the Pipelayer ship and at the welding stations to create space on the ship for the attachment of further raw lengths

The gripping devices for the two pipeline stations include each is a helically interwoven braid of strands that form a collapsible cuff to exert a holding force practically evenly distributed over the circumference on a piece of pipeline held therein.

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The contractible cuff is from an expanded state to a constricted state and vice versa transferable by moving their supported ends in the longitudinal direction relative to one another. Further details of the invention result from the following description of an exemplary embodiment with reference to the accompanying drawings. In this demonstrate:

Pig.1 a pipelayer for laying an underwater pipeline j

Pig.2 is a side view of a pipeline station in one embodiment the invention;

Pig. 3 a view of the pipeline station in multiple sections of Fig.2j

Pig.4 is a sectional view along line 4-4 of Pig.5;

Pig. 5-8 schematic representations showing the successive, illustrate coordinated movement of the two adjacent pipeline stations according to the invention.

As particularly Pig.1 shows, the system according to the invention is S for bringing a pipeline into position on a pipelayer Y attached to lay a pipeline P under V / ater. The ship V may be a pipe-laying barge or other such Be ship that has one or more welding stations 10, which are used to one or more lengths of pipe to weld the already formed pipeline part P, which is held by the system S according to the invention in its position. The pipe-laying ship V can be of any type. The ship

V of Pig.1 has a slowly sloping guide track 11 and a pipeline stinger 12 which, in cooperation with the system S support the pipeline part P, which extends from the ship

V extends to the bottom 13 of a body of water, the surface of which is indicated by a dashed line 14. One or more winches 15 are of conventional design on the ship mounted, which are used to wind up traction ropes, such as 15a, which are anchored to the bottom 13 of the sea or other body of water.

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The ship V is used, for example, as follows. Of the Pipeline part P, which is already finished, is tightened with the aid of the system S according to the invention or known pipeline tensioners held in place. At the welding station, e.g. 10, new pipe lengths are added to the existing pipeline part P. welded on. The winches are used for welding, for example 15 »actuated and pull the ship V forward in the direction of the arrow 16 in order for a pipe handling system 17, which is mounted on the ship to create space for this system to have further pipe lengths in the correct position for welding can bring to the already existing pipeline part P. So that the winch 15 the ship V in the direction of the arrow 16 moved forward, the winch must have extraordinarily high pulling forces on the order of hundreds or thousands of kilograms raise. The system S for enabling the pipeline must also hold the pipeline part P and allow a controlled relative movement between this and the ship Y.

The system S comprises reciprocating pipeline stations S1 and S2, which on the ship V at a distance from each other are appropriate. The system S also includes a third pipeline station S3, which is arranged in a stationary manner and is used as a Safety precaution serves. The two movable stations S1 and S2 are essentially the same except for each other their workflow} therefore, the same reference numerals and letters are used to describe the same elements of these stations used.

The pipeline station S1 is shown in detail in FIGS. 2-4. It has a main frame 20 which is attached to the cover 21 of the ship V ". The main frame 20 has lateral Rails 22a and 22b in which a carriage 23 runs. A gripping device is mounted on the carriage 23, which is designated as a whole with 24. It detects the pipeline part P and alternately releases it again, so that it is relatively can be moved to ship V. It should be noted that

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the pipeline section P is weighted down with a concrete coating 25 » except for the ends 25a of the pipeline part, which are used for welding are exposed. After welding, an annular jacket made of aluminum or another can be attached to these ends 25a Appropriate material must be placed in the concrete to be poured on the entire pipeline part P before laying to provide a continuous concrete pavement on the bottom 13 of the water.

The main frame 20 has a support structure at the front end. tion 20a and a support structure 20b at the rear end. The front support structure 20a is in the same direction oriented like the bow of the ship V and the aft support structure 20b has the same direction as the stern of the ship V. The forward girder structure 20a comprises double-T cross girders or the like. 26a and 26b resting on vertical supports 27a, 27b and 27c. The beams and supports bind together connected in a known manner, for example welded. The rear support structure 20b is essentially the front support structure 20a and therefore need not be described in detail. Both support structures 20a and 20b collectively support and hold the side rails 22a and 22b. The side rail 22a is formed by an upper and a lower double T-beam 28a and 28b, which are attached to the vertical supports, for example 27a, of the front or rear support structure 20a or 20b are welded or otherwise suitably supported. In appropriate Way, the side rail 22b is made up of I-beams 29a and 29b or other suitable beams connected to the front and rear beam structures 20a and 20b, respectively are.

The carriage 23 is on the main frame 20 in the side rails 22a and 22b between the front and rear Support structure 20a and 20b can be moved to and fro. It has a front plate 30, which by means of I-irons 31a and 31b with a back plate 31 is connected; the I-irons are on the

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Plates 30 and 31 in a suitable manner, such as by welding, attached. The front plate 30 carries rollers 30a which run in the side rails 22a and 22b. The is accordingly Back plate 31 is provided with rollers 31c which run in the side rails 22a and 22b. As can be seen in particular from Figure 3, the roller 31c is mounted by means of bearings in a downward-facing wheel mount 31e of the back plate 31. The position of the roller 31c can be adjusted by inserting the roller in other openings, for example 31f. To this Way can be the total height of the back plate 31 above the Alter deck 21 of the ship. The rollers 30a on the face plate 30 are similarly supported. The sled is thus movable to and fro along the side rails 22a and 22b of the main frame by means of the rollers 30a and 31c. By having both an upper and a lower double T-beam 28a and 28b is used for the side rails, for example 22a, the carriage 23 is displaceable held, while at the same time it is at least partially secured against forces that strive to the solite from Pulling up deck 21 of the Sohiff.

With the front support structure 20a and the back plate 31 of the carriage 23 is a position control device 32 for connected to the carriage which controls the movement of the carriage 23 along the side rails 22a and 22b. The attitude control device 32 comprises hydraulic cylinder units 32a and 32b mounted one behind the other. The hydraulic Cylinder unit 32a has a hydraulic cylinder 33a which is mounted on the front support structure 20a by means of a bolt bearing at 33b. A piston with a piston rod 33c is received in a known manner in the cylinder 33a and also on the downward-facing wheel mount 31e of the back plate 31 hinged. The pivot connection between the piston with piston rod 33c and the wheel mount 31e is through a combination of a bolt 33d with eyes 33e formed. The hydraulic cylinder unit 32b is shown in FIG

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Mounted in the same way on the front support structure 20a and the rear plate 31 of the carriage 23. Suitable hydraulic Controllers are provided to control the pressure in the hydraulic cylinder units 32a and 32b and thereby to move the carriage 23 back and forth in the side rails 22a and 22b. The hydraulic controls are not shown because such hydraulic controls are known in the art.

In the front plate 30 an opening 30b is provided through which the pipeline part P enters. The back plate 31 also has a corresponding opening that corresponds to the opening 30b of the front plate is aligned and the pipeline part P receives. On the back plate 31 there is a rearwardly protruding bar 31g is provided, which is attached to the downward-facing wheel mount 31 β. The bar 31g has the shape of a platform, which carries a V-shaped roller 34 in suitable pillow blocks 34a «The V-shaped roller 34 has the same profile as a roller 351 in suitable bearings 35a on the front support structure 20a is attached. The roller 35 is so fixed to the ship V, while the roller 34 with the Slide 23 moves with it. The rollers 34 and 35 jointly support the pipeline part P also during the to-and-fro movement of the Slide 23 off. In addition, a roller assembly 50 is attached to the front support structure 20a around the pipeline part P against any moment forces that strive to move the pipeline part P away from the ship deck 21 upwards draw. The roller structure 50 serving as a hold-down device has a roller 51 which is formed by an upright frame part 52 Above the pipeline part P is brought into position. The upright frame portion 52 has vertical posts or rails, about 52a, which are mounted on the front support structure 20a and stand up from this. More vertical Posts or rails 52b protrude from the ship deck 21 and are connected to the posts 52a by roller holders 52c, which hold the roller 51 in a suitable bearing similar to the bearing 35a.

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Between the two end plates 30 and 31 of the carriage 23, a movable plate 36 is attached as an actuating member, which is movable relative to the end plates 30 and 31. A guide track 37, consisting of three cylindrical slide tubes 37a, 37b and 37o, is on the end plates 30 and 31 appropriately attached and extends horizontally between these panels. The plate 36 is provided with holes 36a, which are aligned with the sliding tubes and accommodate them. A suitable bushing, such as 36b, is fastened in each hole, which receives the corresponding slide tube 37a-c, so that the plate 36 is displaceable on the slide tubes 37a-c. The plate 36 also has an opening which is connected to the openings, about 30b, is aligned in the fixed end plates 30 and 31 and through which the pipeline part P passes. At the Plate 31 and on the plate 36 an actuator, denoted as a whole by 38, is fastened, which is used to push the plate 36 to move with respect to the end plates 30 and 31. The actuator 38 has two hydraulic cylinder units 38a and 38b which are identical to one another, but are attached to different sides of the plate 36. The hydraulic cylinder units 38a and 38b each have a hydraulic cylinder 38c which is attached to the sliding plate 36 and protrudes from this in a lateral direction. In the hydraulic cylinder 38c there is a combination of piston and piston rod 38c, which extends to a pivot connection 38e with the end plate 31. The hydraulic one Cylinder 38c is a double-acting cylinder that is known in the Manner receives fluid in each end so that it slides plate 36 in either direction along slide tubes 37a-37c can·

The gripping device 24 according to the illustrated embodiment of the invention is on the plate 30 of the carriage and on the movable plate 36 attached to the pipeline part P to capture its entire circumference, so that it is relative to the ship V can be moved so that space can be created for the addition of new pipe lengths at the welding stations 10. the

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Gripping device 24 has a sleeve 40 which is attached to the plates 30 and 36 in refugee with the openings, for example 30b, in the plates 30, 31 and 36 is detachably attached. The removable cuff 40 has a contractible one Strand braid 40a attached to retaining rings 40b and 40c, retaining ring 40b being removably attached to plate 30 and the other retaining ring 40c is removably attached to the sliding plate 36.

The strand braid 40a becomes helical from a row formed interwoven strands 40d, which are fastened to the retaining rings, such as 40c, in a suitable manner. Of the Angle of inclination 41 of the strands to a line 41a which runs parallel to the main axis of the pipeline part P accommodated therein, can be changed in accordance with the desired contraction and expansion of the entire strand mesh 40a.

The retaining rings 40b and 40c, which carry the strand braid 40a, are circumferentially spaced on plates 30 and 36 by means of Clamps 42 releasably attached. As shown in Figures 3 and 4, the clamps 42 are spaced around the moveable Plate 36 attached. Each clip 42 has a portion 42 which has an Ir-shaped indentation 42b in which the retaining ring 40c is recordable. A countersunk screw 43, which extends through the sliding plate 36, is fitted in the part 42a and is secured by a nut 42c. So if the cuff 40 is to be replaced, only need the circumferentially spaced clamps 42 are removed from the plates 30 and 36, whereupon the retaining rings 40b and 40c can be taken away. If a different size cuff 40 has different size retaining rings 40b and 40c on the plates 30 and 36 is to be attached, the position of the clamps 42 must be changed. Such an adjustment lies in the context of professional action.

The strand braid 40a forms a cylindrical sleeve which is between an open, expanded state, which is shown in FIG

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Fig.2 is shown, and an elongated, contracted State can be changed with a reduced diameter. In the latter, the strands 40d capture the pipeline part P and hold him tight. The movement of the strand braid 40a between the open release position and the closed gripping position takes place by moving the plate 36 with the aid of the hydraulic cylinder units 37a and 37b. The helical interwoven strands collectively capture the pipeline part P over its entire circumference, thereby damaging the concrete coating 25 is largely avoided. To the strand mesh 40a in the closed gripping position with reduced To transfer diameter, the retaining ring 40c, which is retained on the sliding plate 36, is held by the ring 40b, attached to the end plate 30 is moved away. If, on the other hand, the displaceable plate 36 approaches the stationary end plate 30 is, the diameter of the strand braid 40a expands to the open position in which the diameter of the Strand braid is larger than the outer diameter of the pipeline part P including the concrete coating 25..

In operation, stations 81 and S2 become so sequentially actuated that they alternately grasp the pipeline part P, transport it on and release it again. In Fig.5 and 8 the stations S1 and S2 are shown schematically. In Figure 5, the strand mesh 40a of station S1 is in ■ closed position and the carriage 23 assumes its front position. The hydraulic cylinders 32a and 32b are actuated, around the carriage 23 from its front starting position shown in Figure 5 into the rear position shown in Figure 6 to convict.

Then, as Figure 7 shows, the sleeve 40 for the movable Station S2 actuated by the hydraulic cylinder units 38a and 38b to the sliding plate 36 for the To bring station S2 into an effective position in which the strand mesh 40a encompasses the pipeline part P. The plate 36

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for station S1 then becomes the stationary endplate moved towards, whereby the strand mesh 40a of the station S1 expands to the open position.

As FIG. 8 shows, station S2, which is now the Has control over the pipeline part P, from the front starting position 7 transferred to the second, rear position of FIG. 8, the pipeline part P in the direction of the arrow

50 is transported away from the ship V. Simultaneously with the onward transport through station S2, the hydraulic Cylinders 32a and 32b of station S1 are activated in such a way that they move the carriage 23 of station S1 into its front starting position bring back. The final step of the work cycle is to pull together the strand braid 40a of the station

51 and the subsequent opening of the strand braid 40a of Station S2, so that now the station S1 has control of the pipeline section P again. This cycle is repeated continuously, in order to require the pipeline part P away from the ship V so that There is space for adding new pipe lengths.

The station S3 is practically the same as the stations S1 and S2 with the exception that the carriage 23 is in a stationary position Location is held. The station S3 serves as a safety measure to hold the pipeline part P in place in an emergency. aside from that station S3 can be used in conjunction with station S1 or S2 be used to detect the pipeline part P in a coordinated sequence with one of the moving stations and release.

The cuff 40 for the stations St, S2 or S3 can if necessary removed and exchanged for sleeves with other open and closed diameters. So For example, it may be necessary to gradually increase the diameter of the pipes used in a pipeline to be laid to reduce when the pipeline approaches a shallower body of water, such as a bay or the like. In such Cases, cuffs with a smaller contraction

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diameter attached to the plates 30 and 36. When the cuff 40 is replaced, it may be necessary to change the vertical position of the plates 30 and 31 to dae To keep the lower end of the inserted tube with a different diameter at the same height as the lower end of the previous one run through pipe. To do this, it may be necessary to determine the position of all rollers handling the pipe, e.g. 35 at station S1, or any other pipeline pulley or handling equipment that supports the pipe from below. This change can be made by making other holes, for example 31f, to attach the rollers, for example 31c can be used.

Compared to the described embodiment, changes in size and shape and in the scope of the invention. Materials and details of the construction shown are possible. For example, the system S according to the invention can do this can be used to move the pipeline part P in other cases than for transporting it away from the ship in a controlled manner. To the For example, the system S can be used to move the ship V under the pipeline part P. In rough seas you can the slide 23 serve to create a relative movement between the ship V and the pipeline part P to compensate for the wave movement to enable. .

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Claims (21)

Expectations System for bringing a pipeline in a position to a part of a pipeline reaching from a pipelayer ship into a body of water to move in a controlled manner, characterized in that the system comprises several pipeline stations (S1, S2, S3), which are mountable on the ship (V), and that each pipeline station has a main frame mountable on the ship (V) (20), as well as a slide (23) »which is guided on the main frame to be movable relative to this, one on the pipe gripping device (40, 38, 36) held on the slide, which can alternately grip and release the pipeline part (P) reaching from the ship into the water, and so on is designed to catch the pipeline part (P) uniformly over the entire circumference of a length, further a position controller (32) connected to the carriage (23) and the main frame (20) so that they the carriage can move along the main frame between a first and a second position to thereby the To move the pipeline part (P) relative to the ship in such a way that that further pipe lengths are added or removed can, wherein such an arrangement is made that the pipe gripping device with the carriage between the first and second positions and has a releasable retaining element (40), which the pipeline part holds when moving the carriage in one direction and for moving the carriage in the other Releases direction. 2. System according to claim 1, characterized in that the retaining element (40) of the pipe gripping device the pipeline part (P) detected on a substantial peripheral portion thereof. 3. System according to claim 1 or 2, characterized in that the pipe gripping device as a retaining element has annular collar (40), and that fastening 609817/0894 elements (42) are provided, which the sleeve can be removed attach to the slide (23). 4. System according to one of the preceding claims, characterized in that that the plague holding element (40) of the pipe gripping device is a cylindrically shaped strand mesh (40a) for detecting the pipeline part, which is fastened to retaining rings (40b, 40c) which can be moved relative to one another, wherein the diameter of the cylindrical braid decreases when one retaining ring is removed from the other, and increases when the one retaining ring is approached to the other, and that an actuating device for the pipe gripping device (38) belongs to remove one retaining ring from the other and thereby the diameter of the strand braid to reduce so far that the strand mesh holds the pipeline part. 5. System according to claim 4, characterized in that the Strand braid (40a) is formed from helically interwoven strands (40d) and between a widened Position in which the pipeline part can be pushed through the strand mesh, and a contracted position, in which the strand mesh holds the pipeline part in place and is movable » 6. System according to claim 4 and 5, characterized in that the actuating device (38) of the strand braid expanded into the contracted position and vice versa 7 »System according to one of claims 5 or 6, characterized in that that on the strand mesh (40a) a first end part (30) is attached, which is stationary on the carriage (32) is fixed and moves with it, as well as a second end part (36) which is attached to the carriage by means of guides (37a-c) relative to the first end part (30) and to the slide S09817 / 0894 th is displaceable and through this its relative movement the strand mesh from the expanded to the contracted Position and vice versa 8. System according to one of claims 4 to 7, characterized in that that the actuating device (38) is connected to the ends of the strand braid in such a way that it causes a relative movement in the longitudinal direction between the ends in order to change the diameter of the strand braid 9 system according to one of claims 5 to 8, characterized in that 4ass the helically interwoven Strands (40d) of the strand mesh (40a) an expandable sleeve (40) for gripping and releasing the pipeline part (P) form. 10. System according to one of the preceding claims, characterized in that that the main frame (20) has at least one running rail (22a, 22b) in which the slide (23) runs, and that the load control device is a drive device (32) which moves the carriage in the running rail. 11. System according to claim 10, characterized in that the Drive device (32) consists of double-acting hydraulic cylinder devices (32a, 32b), which with the Main frame and the slide are connected to move the slide. 12. System according to one of the preceding claims, characterized gekennzeiohnet, that the pipe gripping device holds the pipeline part (P) while the drive device (32) a movement of the carriage (23) and the pipeline part connected to it to the stern of the ship (V) allows, and that the pipe gripping device then releases the pipeline part 609817/0894 there and the drive device moves the slide towards the bow of the ship to bring the slide into its starting position to get back. 13. System according to one of the preceding claims, in which the pipeline part is made by successively adding lengths of pipe is formed on the ship, characterized by a first pipeline station (S1) with a pipe gripping device for capturing, transporting and releasing the part of the pipeline extending from the ship to the seabed, and a second pipeline station (S2) which is arranged at a distance from the first pipeline station (S1) and in a coordinated manner Sequence with the first pipeline station operating to alternate the location of the pipeline section running from the ship to the seabed to steer as the ship moves forward to add more lengths of pipe. 14. System according to claim 13 »characterized in that the first pipeline station (S1) a first pipe gripping device (36, 39 »40) for detecting the pipeline part (P), furthermore a first position control device (32) which controls a relative movement between the detected part of the pipeline and the ship (V) when the ship is moving forward, and a first release device which releases the grip on the pipeline part. 15 · System according to claim 14, characterized in that the second pipeline station (S2) has a second pipe gripping device which detects the pipeline part before it has been released by the first release device, and a second release device which releases the grip on the pipeline part after the first pipe gripping device has captured the pipeline part. 16. System according to claim 15 »characterized in that the 609817/0894 second pipeline station (S2) also nooh a position control device includes, which allows a relative movement between the detected pipeline part and the ship when the Ship moving forward. 17. System according to claim 15 or 16, characterized in that a third pipeline station (S3) is provided which cooperates with the first and second station (S1, S2) in such a way that it detects the pipeline part (P) before this has been released by the first and second station. 18. System according to any one of the preceding claims, characterized in that the carriage (23) has a first and a second end support (30, 31) and parts (31a, 31b) which rigidly connect the two end supports to one another, as well as a Actuating member (36) in the form of a support, which between the end supports (30, 31) for a relative movement is supported on these and together with one (30) of the end supports the retaining element (40) on the slide (23) holds. 19 · System according to claim 18, characterized by a drive device (38), which moves the actuating member (36) relative to this one end support (30), whereby by this movement the pipeline part is alternately detected and released. 20. Device for alternately detecting and releasing a Tube or other cylindrical object, characterized by ring-shaped holding elements (40b, 40c) which can be fastened to a device (23) which provide a relative movement between the annular holding elements can, and through a cylindrical strand braid (40a), which is attached to the annular holding elements (40b, 40c) is attached and its diameter due to the movement 609817/0894 of the one holding element can be reduced away from the other and can be enlarged by the movement of the one holding element towards the other. 21. The device according to claim 20, characterized in that the cylindrical strand braid (40a) is several helically includes interwoven strands (4Od) that are intertwined to the general shape of a hollow cylinder and are attached to the annular holding elements (40b, 40c). f> 09817/0894