Hydraulic and earth engineering – Subterranean or submarine pipe or cable laying – retrieving,... – With protection or indication of pipe or trench
Reexamination Certificate
1999-08-18
2001-08-14
Bagnell, David (Department: 3673)
Hydraulic and earth engineering
Subterranean or submarine pipe or cable laying, retrieving,...
With protection or indication of pipe or trench
C405S172000, C405S046000, C405S049000
Reexamination Certificate
active
06273641
ABSTRACT:
The present invention relates to a protective device made from a plate-shaped material, and relates in particular to a shell-shaped device adapted to cover a sub sea construction or parts of such a construction on the sea bed, which protective device is shaped as a downwards open and upwards closed convex shell, comprising a substantially plane roof plate with at least one mainly flat and preferably oblique directed side wall, which preferably ends in a transverse foot plate.
The device has extremely good mechanical qualities and low-weight and may accordingly be used for many different applications, such as tunnel linings, modules for buildings or building elements.
Previously there are known different protective devices adapted for covering of structures and equipment on the sea bed, to protect such structures against damages caused by over trawling, anchoring or other mechanical strain situations from ships and similar activities in the ocean, above the sub sea structures.
As examples of such protective devices it may be referred to Norwegian Patent No. 139.790 describing a device for protection of structures on the sea bed, where the protective device is a reinforced concrete element comprising two interconnected reinforcement nets. Further it is referred to Norwegian Patent No. 144.834 in which a similar protective device is built up as a covering, among other comprising flexible interconnected concrete elements, linked together both crosswise and lengthwise, and also UK-patent application No. GB 2178127A, which relates to a method for manufacturing of a protective mat for a flexible pipe, and where the mat elements are provided with pairs of holes designed to receive interlinking ropes or similar elements.
The above-mentioned solutions are all encumbered with different disadvantages, e.g. they are very heavy and compact, and accordingly large and also expensive vessels are required to produce/deploy/mount the earlier known protective devices, and the vessels also have to undertake many journeys before a long pipeline has been covered, causing large costs and risks during laying.
It is also previously known to make protective covers for sub sea use from plastics, and then in particular laminated, multi layer materials. The advantages are a low weight and less expensive materials, but these solutions have also led to problems, in particular as the material must be relatively thick to obtain sufficient stiffness and pressure resistance, but all the same large protective constructions built up of laminated artificial compositions, will easily be twisted so that the structures are unstable both during manufacturing, transportation and also during deployment on the site.
The object of the present invention is to provide a protective device in particular adapted for covering of a sub sea construction, such as a pipeline, a Christmas tree etc. in a much less expensive way and at least just as efficient as earlier solutions. Further it is an object of the present invention to provide a stable protective device which is not expensive, which is corrosion and pressure resistant, has a low weight causing that many or very large protective devices may be transported by a ship, which devices all the same are more stable than previously known lightweight constructions of similar design.
The object is also to provide a protective device for many applications both on land and in marine environments, which device is many cases may be used as a separate element and in other connections may be used as a module together with cooperating and similar, but not necessarily identical modules.
These objects are met by a protective device according to the below claims. The idea may primarily be said to stiffen the protective device as parts of it or the complete device is given a shallow wave form or a weakly corrugated shape which results in a rigid design without a corresponding weakening on the element.
It should be mentioned that corrugations also earlier have been used for different protective devices, but then as deep corrugations causing a very stiff material, e.g. in radial direction for corrugated tubes, but at the same time with increased flexibility or in other words increased weakening against bending stress, acting longitudinal to these deep corrugations. The measure of the present invention may accordingly be said to find an optimal value of shallow or weak corrugations so that increased stiffness is obtained across to the corrugations without a pronounced reduction of the rigidity longitudinal to the corrugations
If only one portion of the protective device, e.g. the roof plate of the same, is provided with shallow corrugations according to this invention, the interaction between these corrugations and the adjacent walls with a certain angle to the roof plate, causes a further stiffening of the device. This is in particular the case when the side walls are arranged across to the corrugations and is integrated with the roof plate in one single unit.
To give a clearer and more unambiguous understanding of the invention it is referred to the more detailed description below, and to the accompanying drawings in which:
FIG. 1
illustrates a protective device according to one embodiment of the present invention,
FIG. 2
illustrates the protective device according to
FIG. 1
, however in some more detail,
FIG. 3
shows an example of a preferred wave design, and
FIG. 4
shows a local protective device having a main structure similar to a bucket or box, turned upside down.
REFERENCES:
patent: 980442 (1911-01-01), Schlafly
patent: 3495410 (1970-02-01), Bailey et al.
patent: 4171174 (1979-10-01), Larsen
patent: 4242010 (1980-12-01), Gjerde et al.
patent: 4329084 (1982-05-01), Chapa
patent: 4523613 (1985-06-01), Fouss et al.
patent: 4563107 (1986-01-01), Peterson
patent: 4605338 (1986-08-01), Peterson
patent: 5052859 (1991-10-01), Miller
patent: 5160218 (1992-11-01), Hill
patent: 5385430 (1995-01-01), Connonrs
patent: 5556231 (1996-09-01), Sidaway et al.
ABB Off-Shore Technology AS
Bagnell David
Cohen & Pontani, Lieberman & Pavane
Lagman Frederick L.
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