JPH0352399B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to a structural vessel, an apparatus for its construction, and a method for its construction. More particularly, it relates to a double-walled vessel that is helically wound and has a stiffening spacer helically wound between the walls.

Long cylindrical vessels with large diameters are already known as bases for offshore drilling operations;
Typically, single-walled or double-walled vessels are constructed with multiple cylindrical plate sections welded along continuous or overlapping edges between each section. Not only circular reinforcements but also longitudinal reinforcements are required, and in some cases support walls are also required at intervals to ensure structural integrity. The construction of such particularly large and heavy Vessels, however, requires extremely long lead times and costs due to the numerous labor-intensive steps involved in welding and weld inspection operations.

On the other hand, cylindrical pipes, conduits, or conduits may be constructed more quickly and with less effort by using spirally wound sheet material to seal the successive ends of successive turns to each other. . Generally, however, such helical seam tubing is primarily designed for use in single-walled fluid (pressurized or non-pressurized) fluid conduits, conduit systems, etc., and supplementary It has a relatively small diameter and has sufficient shell strength without using reinforcement.

SUMMARY OF THE INVENTION Accordingly, one object of the present invention is to provide a double-walled, spirally wound structural vessel, which is reinforced with an auxiliary material between the walls along the spiral windings, and has continuous end portions. It is an object of the present invention to provide a betsu cell in which seam welding is performed. Such vessels are relatively easy to construct at substantially less cost and with less effort than previously known structures, and yet have superior strength, allowing the use of relatively thin shells.

Another object of the present invention is to provide a double-walled, auxiliary-reinforced, spirally wound construction vessel, the structural beams of which are secured to both walls by forming seams along the aforementioned continuous edges. The object of the present invention is to provide a vessel constructed to be used as a stiffener, and a method and apparatus that allow its construction to be carried out simply and economically.

Yet another object of the invention is to provide a stiffening material (which may be a honeycomb shaped material) cracked longitudinally at the tip of the inner wall before the inner wall is spirally wound.
is applied so that the overlapping ends of successive pairs of turns are seamed, the other split end of the filler is welded to the first turn filler, and the outer wall is placed over it. To provide a structural vessel which is spirally wound and welded and whose overlapping ends are also welded.

Yet another object of the invention is to use a water-floating housing for construction in carrying out the construction method according to the invention, in which the Bethels are constructed in the housing and closed at the ends so that they are gradually completed. The vessel extends out of the housing through a sealed opening, the housing being weighted with ballast such that the vessel floats therein. Ballast adjustment of the housing is provided to adjust the inclination of the housing for variations in the inclination of the construction vessel extending outwardly of the housing.

A further object of the present invention is to provide a vessel of double-walled construction with a spacer or stiffener wound in a helical pattern between spaced spirally wound strips. It is an object of the present invention to provide a simplified construction method that allows a design different from the above-mentioned structure by making it possible to construct a large diameter Vessel with excellent density and structural integrity.

Yet another object of the present invention is a double-walled vessel in which the liner and shell are shifted relative to each other such that the shell end is moved out of alignment with the backing edge, and which includes spacer means. It is an object of the present invention to provide a vessel having means for securing to the strip and securing overlapping liner ends and overlapping shell ends.

Yet another object of the invention is a double-walled vessel, the spacer means comprising a profile section having a flange extending along the liner end and the shell end, and the spacer means comprising a profile section having a flange extending along the liner end and the shell end; The object of the present invention is to provide a vessel which is similarly fixed to opposite sides of the strip between the two.

Yet another object of the invention is a double-walled vessel in which one of the profile portions is secured to one end of one end of the strip before winding the strip to form the backing. , the other of the overlapping ends of successive turns of the liner is fixed to said one end and the profile section, and the other of the profile sections is connected to said other strip end before the other strip is wound to form a shell. the other of the overlapping ends of successive ends of the shell being fixed to said other strip end and the other of the profile parts, the ends of the profile parts opposite the flanges
It is an object of the present invention to provide a vessel which is fixed to opposite sides of a strip.

Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description of the invention in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION Upon examining the relevant drawings, similar reference characteristics are shown in similar corresponding parts throughout several figures, a complete helical seam structure Betsu cell is shown in FIG. may be fixed in place in some way to close each end of the opposing faces of the formed vessel. For example, as commonly shown at 20 as having multiple caps with conical ends. Although this vessel can vary in diameter without departing from the invention and can be towed in water density by means of a tow line 22 hooked as seen at 23, The bethel is hollow, preferably cylindrical.

Reference is now made to FIG. 7, which illustrates the essential features used in manufacturing a helical seam structure vessel in accordance with one embodiment of the present invention.

An internal strip 24 of material, such as steel, is wound helically from a supply (not shown) around a series of forming rolls 25 to form the internal tubular liner. Suitable tube-forming means are utilized to form spiral turns from continuous or side-seamed strips.

Configuration I-beam (or double T-beam) 2
The first longitudinal half 26a of the rib stiffener produced from 6 (FIG. 3) is welded along the leading edge of the internal strip.

The first and second halves 26a and 26b are shaped by separating each web of the beams along wavy or trapezoidal lines to form separate beam sections 26a and 26b . , produced in a well-known manner, the protruding section is a well-known honeycomb beam of the type shown in FIG.
To produce the sections, they are placed opposite each other in the manner described below and then welded together.

Prior to helically winding the inner strip 24, the beam section 26a is clamped along the leading edge of the strip as shown to one side of the flange half of the section 26a extending outwardly of the leading edge. , 28 and/or 28 a (FIG. 8). This extended flange section is superimposed on the trailing edge 31 of the next adjacent molded helical turn (FIG. 9) as seen in the station 32 and, via beam section 26 a , is brought into contact with the turn. A fillet weld is made on the station to connect the leading and trailing edges. The beam sections 26b , on the other hand, are connected to the web sections 26a such that the projecting web sections are arranged oppositely to form a honeycomb beam structure of the type shown in FIG.
wrapped around the top. These protruding web sections are used to complete the weld joint between the leading and trailing edges and to fill the gap between them at 34 of the station 37 (Fig.
and 10) are then welded together. An automated ultrasonic inspection station for the welds of the main portion of the internal strip is positioned as shown in FIG.

An external strip 38 of material, such as sheet steel, overlaps the flange of this section to form an external tubular shell, extending from the trailing edge 3.
9 (Fig. 10) together with beam section 26 b
The upper part of the tube is wound up in a helical manner, after which a fillet weld 41 is made to the station 42.

The leading edge 43 of the external strip is connected to the station 4
Via the beam section 26b of 5 is welded to the contact edge of the next adjacent turn as seen in 44 (Fig. 11), the main part weld 40 completes the welded seam and the station At 46, the gap between the outer edges of the outer strip turns is filled. An automatic ultrasonic inspection station 30a for the welding of the main part of the external strip is arranged as in FIG.

The sandblasting room 47 is a painting and drying room 48
It is equipped to carry out the external finishing work of the molded Bethel.

A plurality of support roller assemblies 49 (FIGS. 5 and 7) are each provided on the underside opposite the formed vessel and are attached to the workpiece housing 51.
Molding the cradle support inside (Fig. 2),
These roller assemblies are mounted on a plurality of cross-feed box beams 52, or the like, and support on a partition floor 53 (FIG. 15) is provided inside the workpiece housing. Each support roller assembly 49, shown in more detail in FIGS. 12 and 13, includes therewith a hub 56 and a hydraulic drive motor 57 on the top of the wheel to which it is attached for rotation. a pair of pneumatic wheels each containing an internal hydraulic drive motor unit 55, or
Includes tires 54. This motor is a stationary type.
In turn, a plurality of hydraulic lines 58 are connected such that their output drives a hub 56 that rotates a wheel 54.
Supplied via. These drive motors are
To establish a periodic speed between the drive rolls,
Relief valves are provided and properly controlled for fluctuations and reversals as required.

The support brackets 59 for the wheel pairs to which the wheel arm supports 60 are attached are directed in the direction of the axis of rotation of the molded vessel and in order to adjust for variations in the diameter of any of the plurality of wheels. , an underlying bracket 6 with a plurality of fasteners extending away from the axis of rotation and through a plurality of slots extending into one of each flange for adjusting a plurality of wheels.
the plurality of flanges that engage with the plurality of flanges of the first one.

A plurality of spaced holes 62 along each box beam are used to adjust the diameters of different sized vessels.
The assembly is made adjustable. Each pair of support wheels in each assembly is typically positioned along the seamed edges of the external helical winding (Figure 7) to drive during manufacturing, in the direction of the arrow in its main section. Selected.

The above-mentioned support and drive part of this Betu cell draws the strings from multiple ribs reinforced with chrysanthemum-shaped grooved beams, as well as to transfer loads from each expected direction without being subjected to external shell distortion. Allow for some expected slight irregularities, such as keeping weld sides in roundness. Motors 63 for synchronous steering then hold and support the drive wheels 54 along reinforcing ribs of the structure with precise forward feed for well gap control. Provision may be made for steering each wheel along each external seam in order to do so.

The housing 51 of the workpieces has internal and external strips and a plurality of reinforcing ribs introduced from their respective stock supplies for the manufacture of structural vessels (FIG. 2) according to the invention on their side walls. It has an opening 64 for entering and exiting.

The end wall 65 of the housing has an opening 66 through which the assembled end of the Bethel extends.
(Figs. 14 to 16).

A water lock in the form of a pneumatic seal is provided at least along the edge of the bottom half of this opening to seal against water ingress into the interior of the housing. Said seal may be in the form of a closed-ended arcuate tube 67 of elastomeric material supplied with pressurized air from an air supply 68, since the air creates not only an anti-friction bearing but also a pneumatic seal. , along the inner wall surface of it from which the air is released.
Has multiple air openings. A plurality of support and drive roller assemblies 49 similar in construction and operation to those described with respect to FIG. 12 are provided along the upper half of the edge of opening 66.

an outer surface of the housing holding the vessel downwardly against the housing seal to compensate for nose-up or nose-down loads generated during assembly, depending on the extent of the vessel;
The function of these rollers should be ballasted out from synchronizing the housing and the vessel.

The workpiece housing floats on top of the density of water (Figure 2), which may be the same as floating vessels that are shaped to extend from the housing. And as the shaped vessel extends outwardly from the plurality of end walls 65 in a progressive manner, the housing tends to slope slightly downwardly at its ends. To avoid any damage to the pneumatic seal surrounding the opening in the end wall and/or the multiple assemblies, the housing must be compressed properly through valve movement to specifically adjust the inclination of the housing according to the inclination of the vessel. Multiple ballast tanks 71 connected to air (Fig. 15, 1
By installing 6), water ballast is controlled. A plurality of openings 70 in the bottom of each tank facilitate ballast control in a known manner.

It should be pointed out that the opening 66 can be varied to accommodate the assembly of vessels of different diameters by providing a plurality of seam plates in the opening in which the pneumatic seals and rollers 49 are attached. be.

In accordance with another embodiment of the invention, a spirally seamed, double-walled vessel is generally shown in the process of being assembled with a portion thereof shown on the left side of the figure being completed.

It may be of varying diameter and may be provided with a plurality of conical end caps to facilitate easy towing at water densities, also in connection with FIG. As can be seen, the structural vessel according to this other embodiment of the invention also secures together the edges of the contacting liner, via means of securing together the edges of the contacting shell. , a beth cell comprising a spirally wound inner shell surrounded in spaced relation by a spirally wound outer shell with a spirally wound spacer between the liner and the shell. This is similar to one of the previous examples. The above-mentioned spacer means, which are continuous and also function as stiffeners, may e.g.
Individual beams with multiple chrysanthemum-shaped grooved webs to facilitate bending while being spirally wound.
By shaping sections 81 and 82, they may be produced in known manner from structural I-beams, double T-beams, groove beams, or Z-beams.

Otherwise, continuous bars of rectangular cross section that are bent when helically wound can be utilized without departing from the invention.

In the process of assembling the vessel, a continuous internal strip 83 of material, such as sheet steel, is spirally wound around a series of forming rolls to form the internal tubular liner (see FIG. 7). (not shown). Suitable tube-forming means are utilized to form helical turns from connected strips, either continuously or laterally. Before winding the beam section 81,
For example, a fillet weld is made along the leading edge of the internal strip with about one half of its flange 81a extending outwardly from this edge. This extended flange portion is superimposed on top of the trailing edge of the next adjacent shaped helical turn, and the butt weld 86 is routed through beam section 81 to the contacting leading edge of each internal turn. Applied to communicate with the trailing edge.

The beam section 82 has a trailing edge 88 of an external strip of material, such as sheet steel, with a flange 82a on approximately one half of the section 82 extending outwardly from this edge as shown.
7 may be fillet welded. 19 and 20 so that the edges of the outer strip can be taken out of alignment with the edges of the inner strip as shown in FIGS. 19 and 20. are maintained axially shifted relative to each other such that the plurality of web tapes of beam section 81 face the interior surface of strip 88 and remain axially shifted relative to each other.
The multiple web tapes of section 82 are
Facing the outer surface of the strip 83. Multiple webs of multiple beam sections can be created using the method described above.
The tapes are each disposed between opposing edges of the plurality of strips facing them. The leading edge 89 of the outer strip 88 then overlaps the exposed portion of the flange 82a with the already wrapped outer strip, and the seam of these edges passes through the beam section 82 as seen at 91. Butt welded together. Each web tape of both beam sections is then fillet welded or fusion welded to the respective surface of the wound strip that it faces.

A plurality of support roller assemblies are provided on opposing undersides of the molded vessel to similarly mold cradle supports within the workpiece housing, as described with reference to FIG. All of the above cradle supports, during the assembly process as described with reference to FIG. , located inside the water-floating workpiece housing.

Additionally, the external strips are wound in place and, for structural purposes, concrete may be pumped into the spaces between the strips. It is prepared for.

The internal liner may then be lined with a thin concrete lining during the erection process to protect the steel vessel from corrosion, for example when used as an aqueduct.

From the above, double-walled web-cured structural vessels can be produced in accordance with the invention in a simple, uniform manner in virtually any predetermined size. For example, Bethel 20 is shown in FIG.
18 by simply slitting a double wall longitudinally from its cylindrical shape along a line 72 parallel to the central axis of the vessel, designated 20' or 20'' in FIG. Can be easily modified.

The plurality of free ends 73 and 74 may be thus formed and then moved a predetermined distance apart, such as by jacking, so that the spanning ends 73 and 74 of the flat deck 75 normally The structure of the bulkhead and/or may be fixed to a submersible or partially submersible vehicle hull for conversion to a beamed submersible without the need for much of an internal support.

The width of the beam can be varied meaningfully between the hulls 20' and 20'' without substantially reducing the overall depth of the hull. During the modification process, the opposite end 7
3 and 74 are spread apart, while in some conventional manner a substantially helical profile for hulls utilized as cargo ships, ore carriers, superbarges, liquid tankers, pressurized ocean vessels, etc. is maintained.

The structural vessel according to the invention may then be utilized as a storage tank, grain elevator, tunnel, transport unit, offshore drilling platform, etc. A plurality of continuous edges of the inner and outer strips form beams or ribs 2.
May be seamed together via 6
Position welding (directed in the downward direction) for seaming both internal and external strips is even more reliable and less time consuming. As the beth cell advances during assembly, its dead weight is supported by the density of water outside the floating housing, which does not require any external mechanical support, thereby allowing the floating work housing to Reduces assembly costs and the need for replacement of external friction bearings and supports.

Vessel 80 can also have its hull modified in a manner similar to that described above. Additionally, the Bethel 80 is designed to have multiple web tapes during the assembly process in accordance with the present invention, since these web tapes are now welded along and facing the respective surfaces of the inner and outer strips. The narrow webs of the spacer ribs need not be traced as in the first embodiment of the current design. During the wrapping of the ribs, the web tapes of the inner section fan out slightly and the web tapes of the outer section contract slightly, so that the chrysanthemum grooved web tapes are compressed during the assembly process. During this process, care must be taken in properly cutting the beam web along the wavy lines to match as closely as possible.

The present invention avoids these possible difficulties since multiple web tapes between beam sections do not have to face or match.

Inherent in the assembly type of the Vessel of the present invention is sufficient overall buckling force to eliminate the need for direct bulkheads or deep frames. The ability to use thinner plates also provides superior physical and mechanical properties and is less restrictive in assembly performance. The assembly process is unique in that it provides for continuous, automatic, and integrated operation. Labor costs are reduced and skills required are minimal. layout, cutting,
Shaping, welding and weld testing, blasting and painting of the metallization process can be carried out sequentially.
Economy in capital costs such as welding fixtures, slipways, and scaffolding, bending rolls and precision cutting operations, bevelling equipment, overhead cranes, etc. is minimal or non-existent. Vessel's internal bulkhead installation operations and end capping are enhanced by Vessel's rolling capabilities for either installation or welding locations. Production facilities, along with the use of water density to support the completed portion of Bethel, are made portable and
It is relatively inexpensive, which saves money on tunnel project support, etc.

Unsinkable monolithic hulls can be produced due to their high buoyancy, low water absorption, stiffness, and filling the spaces between the interior and exterior walls with urethane foam.

As each helical segment of the Bethel is completed, the components of the form system are
are metered, mixed and dispensed as liquid streams into the cavity, where they are
It reacts and expands to fill the void.

During inflation, a permanent internal pressure is created which additionally strengthens the vessel as in a pneumatic tire.

Synthetic Betucell not only has reliable buoyancy, but also the foam's insulation efficiency is
Further increases the use of current beth cells for storage or operation in extremely hot climates. Super-compressive and/or rigid concrete products can be injected into the spaces between walls using similar techniques.

Additionally, by varying the density of the concrete mix, the weight/displacement ratio can be adjusted in a floating arrangement to meet design requirements. Moreover, conventional hulls can be produced by splitting the bethel axially and moving each side of it a distance apart to exceed 60 percent of its original diameter.

In this way, lightweight hulls can be assembled quickly and at minimal cost.

The closed vessel 20 of the present invention is also generally designed for dual-purpose transportation and/or storage of liquids and gases by providing a longitudinally flexible diaphragm separating the same as disclosed in U.S. Pat. No. 4,000,700. may be used for.

Obviously, many other modifications and variations of the present invention are possible in light of the teachings above. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

[Brief explanation of drawings]

FIG. 1 is a side view of a helically formed structural vessel according to the invention; FIG. 2 is a perspective view of the structural vessel at the stage of construction in a flotation work housing; FIGS. 3 and 4 are honeycomb structures. FIG. 5 is a side view of a structural vest cell according to an embodiment of the invention during construction; FIG. 2 along line 5--5; FIG. 6 is a cross-sectional view of an internally reinforced double-walled vest cell according to the invention along line 6--6 in FIG. 5; FIG. Figures 8, 9, 10 and 11 are lines 8-8, 9-9, 10-10 and 11-11 of Figure 7, respectively;
A cross-sectional view showing each process adopted in the construction of the Bethel in Figure 5 along the lines; Figure 12 is an enlarged detailed view of a pair of supporting drive rolls provided in the Bethel during construction;
Figure 3 is an enlarged detail of one of several drive support rolls provided for rotating the structural vessel during construction; Figure 14 is a working example that allows the openings through which the structural vessel to be constructed to pass to be liquid-tight. A partially enlarged view of the housing; Figures 15 and 16 are a side view and a plan view, respectively, of the Bethel under construction, with the working housing shown in cross-section; Figure 17 is an end view of the completed Bethel. FIG. 18 is a diagram illustrating the modification of the shape of the vessel of FIG. 17 to form a hull with different widths; FIG. 19 is a diagram of a structure adopted to construct a structural vessel according to another embodiment of the invention; A perspective view illustrating the technique; FIG. 20 is a cross-sectional view of the constructed Bethel along line 20-20 in FIG. 19; FIG. 21 is a cross-sectional view along line 21-2 in FIG.
A cross-sectional view of the structure in which the spacer portion is attached to the inner liner along line 1; and FIG. 22 is a cross-sectional view along line 2 of FIG.
2-22 is a cross-sectional view of the structure with the spacer portion attached to the outer shell; FIG. Numbers 20 and 80 in the diagram are Bethel, 26a and 2
6b is a profile portion, 24 is a strip of material forming the inner liner, 38 is a strip of material forming the outer shell, 51 is a working housing, 52 is a profile,
66 is an opening.

Claims (1)

Claims: 1. A structural vessel comprising an inner tubular liner and an outer tubular shell surrounding and spaced from the liner, wherein the liner and shell are arranged in a helical manner. a curved strip of material and a continuous, helically curved spacer means between said liner and shell, said spacer means straddling both at successive turns of said liner. and an overlapping end that spans both successive turns of the shell, and further includes stitching means for stitching and welding the liner end and the shell end. A structural vessel according to claim 1, wherein said spacer means is secured to said strip by said stitching means. 2. A vessel according to claim 1, wherein said spacer means comprises a profile section having a flange extending along said liner end and said shell end. 3. A vessel according to claim 2, wherein said strips are arranged one on top of the other such that said shell ends are aligned with said liner ends. 4. Vessel according to claim 3, characterized in that the profile parts are interconnected. 5. Vessel according to claim 3, in which the profile section has toothed webs defining interlocking projections at their distal ends. 6 A method for constructing a structural Beth cell, which includes the following steps:
a strip of material is spirally wound to form an inner tubular liner; another strip of material is spirally wound around and spaced apart from the liner to form an outer tubular shell; between the liner and the shell; arranging another continuous and spirally curved spacer means;
the spacer means has an end that overlaps both successive turns of the liner and an end that overlaps both successive turns of the shell; and securing the shell ends to each other and to the spacer means. 7. The method of claim 6, wherein said winding step includes aligning said shell end with said liner end. 8. The method of claim 7, wherein said spacer means includes said profile section having a flange extending along said liner end and said shell end and joining the profile sections. 9. said spacer means comprising a profile section having a flange, one of said sections being first secured to one of said strip ends before said one strip is wound to form said liner; and fixing the other of the overlapping ends of successive turns of the liner to the section, then fixing the other of the sections to the section, and then fixing the shell ends to each other and to the other section. 7. A method as claimed in claim 6, characterized in that a fixing step is carried out. 10 Furthermore, in order to construct a circular vessel, the one strip and the other strip are held at a constant curvature during the winding process, and the vessel is cut along a single line parallel to its central axis. 7. The method according to claim 6, comprising the steps of: separating opposing portions of the vessel formed after cutting, and joining the separated portions. 11. The method of claim 10, further comprising the step of forming the portions into opposing helical shapes during the separating step. 12. A method as claimed in claim 10, including the step of interconnecting the separated parts with a flat deck material for forming a hull structure from the vessel. 13. A method of constructing a structural vessel, comprising the steps of: floating a water-floating housing in water; providing a sealed aperture in the side wall of the housing at approximately the water level; spiraling at least one strip of material into the housing; A method comprising the steps of: winding to form a long tubular vessel; extending the wound vessel into the closed aperture during the winding process; and supporting the wound vessel by levitation in water. . 14. The method according to claim 13, further comprising adjusting the inclination of the housing relative to the inclination of the wound vessel outside the housing, the inclination adjusting step being carried out by ballast control of the housing. 15 The tubular vessel defines an inner tubular liner, and the outer tubular vessel is formed by: spirally winding another strip of material within the housing and spaced apart from and surrounding the liner; forming a shell; disposing another continuous, helically curved spacer means between said liner and said shell;
the spacer means has an end that overlaps both successive turns of the liner and an end that overlaps both successive turns of the shell; 14. The method of claim 13, comprising the steps of: securing the shell ends to each other and to the spacer means; and securing the shell ends to each other and to the spacer means. 16 Apparatus for constructing a structural vessel, comprising: a closed, water-floating housing containing a portion of a helically wound strip of material to form a long tubular vessel; the remainder of said vessel being extended during the helical winding; a side wall of said housing having an aperture therein; a sealing means along the end of said aperture for closing the ingress of water into said housing during winding of said strip; 17. said sealing means comprising: a trachea having an air hole extending from said end; means for supplying pressurized air to said tube to form an air cushion through said air hole between said tube and said end; 17. The apparatus of claim 16, wherein said air cushion serves as an anti-friction bearing for the seal and the wound vessel. 18. The apparatus of claim 16, wherein ballast control means are provided in the housing to adjust the inclination of the housing to the inclination of the wound vessel through the aperture. 19. A structural vessel comprising an inner tubular liner and an outer tubular shell spaced apart from and surrounding the liner, the liner and shell having a helically curved strip of material and a continuation therebetween. and spirally curved spacer means, said spacer means having overlapping ends spanning both successive turns of said liner and spanning both successive turns of said shell. overlapping ends, said liner and said shell being shifted relative to each other to cause said shell ends to be discontinuous with said liner ends, and said spacer means relative to said strip and said liner. Vessel having means for securing the ends to each other and said shell ends to each other. 20. The vessel of claim 19, wherein said spacer means comprises a profile section having a base extending along said liner end and said shell end. 21. A vessel according to claim 19, wherein said spacer means are secured to opposite sides of said strip between their mutually opposite ends. 22 Both ends of the section facing the bottom are:
21. A vessel according to claim 20, wherein the vessel is fixed to opposite sides of the strip between its ends. 23. Vessel according to claim 22, wherein the profile section has toothed webs at its ends. 24. A method of constructing a structural vessel comprising the steps of: spirally wrapping a strip of material to form an inner tubular liner; forming an outer tubular shell by spirally wrapping another strip of material around and spaced apart from said liner. forming another continuous, helically curved spacer means between said liner and said shell;
said spacer means has an end that overlaps across successive turns of said liner and an end that overlaps across both successive turns of said shell; during said winding step; , shifting the liner and shell relative to each other such that the shell end is out of alignment with the liner end; securing the spacer means and the strip to each other, in which case the liner end and the shell A method comprising the step of causing said liner end and said shell end to be respectively secured such that the ends are secured to each other by said spacer means. 25. said spacer means comprising a profile section having a bottom extending along said liner end and said shell end, the ends of the profile section opposite said bottom being connected to a strip surface facing these ends; 25. The method of claim 24, including the step of combining. 26. Said spacer means consists of a profile section having a bottom, for securing one of the profile sections at one end of the strip before winding the strip to form said liner, and for securing one of the profile sections at one end of the strip in successive turns of the liner. fixing one of the overlapping ends to said end and the profile part, and fixing the other of said profile part at that end before winding another strip to form a shell;
Claims comprising the step of fixing one of the overlapping ends of successive turns of the shell to said end and the profile section, and fixing the end of the profile section opposite the bottom to the facing surface of the strip. The method according to item 24.