EP4148181A1

EP4148181A1 - Cut resistant jacket

Info

Publication number: EP4148181A1
Application number: EP21196955.5A
Authority: EP
Inventors: Jacinto Daniel VAZ TEIXEIRA; José Antonio CANEDO DUARTE ROCHA; Leandro Francisco HAACH
Original assignee: Lankhorst Euronete Portugal SA
Current assignee: Lankhorst Euronete Portugal SA
Priority date: 2021-09-14
Filing date: 2021-09-15
Publication date: 2023-03-15

Abstract

The invention is directed to a jacketed mooring rope (1) comprising a core rope (2) and a jacket (3) surrounding said core rope, wherein the jacket comprises a braided layer of jacket ropes (30) and wherein said jacket ropes each comprise a plurality of braided small ropes (40). In another aspect, the invention is directed to a rope (30) for use in the jacket (3) of the jacketed mooring rope (1), wherein said rope (30) comprises a plurality of braided small ropes (40) that each comprise a plurality of braided yarns (50) surrounding one or more core yarns (51), wherein the braided yarns and the core yarns comprise high performance fibers having a yarn count of at least 1400 den; a tenacity of at least 15 g/den; and/or a modulus of at least 1000 g/den.

Description

The invention is directed to mooring ropes. In particular, the invention is directed to jackets for mooring ropes to protect the mooring ropes.
Mooring ropes (e.g. tug ropes, hawsers, tethers and anchoring ropes) are commonly employed in deep-water long-term mooring systems. The ropes are conventionally manufactured with polyester in the cores and in the jacket, which is a consolidated technology around the world. The polyester cores fulfill the physical and mechanical requirements (tenacity, elongation, stiffness, and fatigue, for instance) and the function of the polyester cover is to join the sub-ropes and to protect them against abrasion during rope handling and installation. However, in terms of cut resistance, the conventional polyester jackets do not have a good performance. In various offshore experiences, after installment, the polyester mooring lines were easily cut by wire ropes.
In the art, various jackets are known that aim to protect mooring ropes against abrasion and the like. Examples include the jacket of Calora Mooring Systems AS, who developed a rope protection solution under the brand name Calorfloat^® technology of which the rope's core is basically covered by helically wound polymeric tapes that form the jacket. In EP3143196 and WO 2013/148711 , cut-resistant jackets based on metal are described. A drawback of using metal is its high density, its high weight to strength ratio and its tendency to corrode, in particular in off-shore applications.
Another jacket for mooring ropes is known from WO 03/054291 , wherein the OTS Protective Jacket^™ of Offshore & Trawl Supply (OTS) is described. A drawback of the OTS Protective Jacket^™ is that two braided layers are necessary to provide sufficiently protection, demanding two synchronized braiding machines working together or two consecutive braiding operations to cover the rope core.
It is an object of the present invention to provide a mooring rope that is cut resistant and that addresses at least one or more of the above-mentioned drawbacks.
The present inventors surprisingly found that this object can be met by a jacket that comprises a braided layer of jacket ropes which each comprise a braided plurality of small ropes.
Accordingly, the present invention is directed to a jacketed mooring rope comprising a core rope and a jacket surrounding said core rope, wherein the jacket comprises a braided layer of jacket ropes which each comprise a braided plurality of small ropes.

Figure 1A illustrates a preferred embodiment of the jacketed mooring rope according to the invention.
Figure 1B illustrates a preferred embodiment of the jacket rope according to the invention.
Figures 2A-2C illustrate preferred embodiments of the small rope according to the invention.
Figure 3A is a photographic image of a preferred jacket rope according to the invention.
Figure 3B is a photographic image of a preferred jacketed mooring rope according to the invention.
Figures 4A-4B are photographic images of a particular testing setup to quantitatively test the cut resistance of ropes.

In a preferred embodiment, the small ropes comprise a braided plurality of yarns (50) surrounding one or more core yarns (51). As such, and in particular by using one or more core yarns, a flat small rope can be obtained, which is preferred for the construction of the jacket rope, which is preferably also a flat rope. The small ropes may each comprise at least 3, preferably 4 to 12, more preferably 6 to 8 braided yarns surrounding one or more core yarns. And typically, the small ropes comprise two or more, preferably two core yarns.
The dimension of the small ropes are preferably such that they can be used to construct a small-dimensioned jacket, while not jeopardizing their main purpose: the protection of the core rope. As such, in preferred embodiments, the small ropes and preferably the braided yarns and the core yarns thereof, comprise high performance fibers having a yarn count of at least 1400 den, preferably at least 1600 den; a tenacity of at least 15 g/den, more preferably at least 20 g/den most preferably at least 30 g/den; and/or a modulus of at least 1000 g/den, preferably at least 1300 g/den. In a most preferred embodiment, the small ropes and preferably the braided yarns and the core yarns thereof consist essentially of the high performance fibers. High performance fibers are well known in the art and may for example be based on aramid, high-modulus polyethylene (HMPE), ultra-high-molecular-weight polyethylene (UHMWPE) or liquid crystal polymer (LCP). Fibers and yarns that are suitable for the present invention are for example those commercially available under the tradename Dyneema^™.
Particular good results were obtained with a jacket based on small ropes having a circular cross-section with a diameter of less than 5 mm, preferably between 1 and 4 mm, more preferably between 2 and 3 mm such as about 2.3 mm. In the embodiment wherein the small ropes are flat ropes, these ropes preferably have a smallest diameter of less than 3 mm, preferably between 1 and 2 mm such as about 1.7 mm. With smallest diameter is herein meant the diameter of the inscribed circle in the cross-section of the rope.
The small ropes are braided to form the individual jacket ropes, which in turn are braided to form the jacket. Typically, each jacket rope comprises between 3 and 64 braided small ropes. The number of small ropes can appropriately be selected based on the desired thickness of the jacket ropes and the jacket. Generally, the jacket ropes are hollow braid and do not comprise a core.
In a preferred embodiment, the jacket ropes are flat ropes comprising a thickness or smallest diameter of less than 15 mm, preferably between 4 and 10 mm, more preferably between 6 and 8 mm such as about 7 mm.
As the jacket ropes are based on the small ropes, it may be appreciated that also the jacket ropes preferably comprise the high performance fibers as described above. In preferred embodiments, the jacket ropes consist essentially of the small ropes and therefore, in a most preferred embodiment, the jacket ropes consist essentially of said high performance fibers. In particular, the jackets and thus the jacket ropes as well, are preferably free of metal wires or other forms of metal. Advantageously, the construction of the jacket according to the present invention provides good cut resistance without the necessity to use metal reinforcements. As such, the jacket and/or the jacketed mooring rope can have a density of less than 1 g/cm³, which allows it to float on water. This is particular beneficial for off-shore applications.
Moreover, the jacket can be provided by a single braided layer of the jacket ropes. Good cut resistance, as well as good abrasion resistance, can thus already be achieved with a single braided layer of the jacket ropes.
The core rope of the jacketed mooring rope is typically based on polyester. However, the jacket according to the present invention can in principle protect any type of rope and material. Exemplary core ropes can thus be based on polyester, polyethylene, high modulus polyethylene, polypropylene, aramids, liquid crystal polymers and/or polyamide. Given its particular suitability in mooring ropes, the core rope is preferably based on polyester. The core rope can for example be a 3-strand laid rope or a 12-strand or an 8-strand braided polyester rope.
A further aspect of the present invention is directed to the jacket ropes as such. These jacket ropes can be advantageously used for protection of mooring ropes, but also for other types of ropes such a hoisting ropes, mining ropes and other ropes that are exposed to abrasion and sharp environments.
The inventions can be described and illustrated by the following non-limiting figures.
In Figure 1A, a preferred embodiment of the jacketed mooring rope (1) comprising a core rope (2) and a jacket (3) is illustrated. The jacket surrounds the core rope by its braided construction of the jacket ropes (30). Each jacket rope comprises a braided plurality of small ropes (40), as is better visible in Figure 1B, which provides an isolated illustration of a part of a flat jacket rope.
Figures 2A-2C provide isolated illustrations of embodiments of a small rope. The small ropes illustrated herein comprise a braided layer of yarns (50). The small rope may be flat (Figure 2B) or its cross-section may be substantially circular (Figure 2A). In a preferred embodiment as illustrated in Figure 2C, the small rope comprises a braided plurality of yarns (50) surrounding two core yarns (51).
Photographic images of a jacket rope and a jacketed mooring rope according to preferred embodiments of the present invention are provided in Figures 3A and 3B, respectively.
As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "and/or" includes any and all combinations of one or more of the associated listed items. It will be understood that the terms "comprises" and/or "comprising" specify the presence of stated features but do not preclude the presence or addition of one or more other features.
For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.
The invention can further be illustrated by the following non-limiting examples.

Example 1

Rope construction

A jacketed rope as shown in Figure 3B was prepared. A polyester core rope was provided with a diameter of 114 mm. The jacket was based on jacket ropes as shown in Figure 3A, which were each based on small ropes made of a braided layer of Dyneema^™ 1600D yarns surrounding two core yarns of Dyneema^™ 1600D. The jacket flat ropes had an average thickness of 7 mm, the jacket had a thickness of about 14 mm and the final jacketed mooring rope had a diameter of 142.3.

Cut resistance testing

A cut resistance testing setup was designed to simulate and reproduce in a laboratory the effect of trawler wires coming into contact with synthetic fiber mooring ropes lines, quantifying the damage and assessing the ropes residual strength after the event. This allowed a comparative study between the state of the art cut resistant tape and ropes according to the present invention. The developed test rig is shown in Figures 4A and 4B. In the testing setup, a steel wire ropes (SWR, 5) is moved over a jacketed rope (1) under set test parameters. The test parameter were set as given in Table 1.

Table 1

Lankhorst test machine features
Diameter - SWR	mm	16
Tension - SWR (Tw)	kN	29
Linear velocity - SWR (U)	knots	0.3
Direction of movement - SWR		go and back
Displacement - SWR	m	9 per cycle

Results

The rope as described above (referred to as Lanko^®Shield) was tested and compared with a mooring rope comprising a double layered OTS Protective Jacket^™. The results are provided in Table 2.

Table 2

Jacket	Rope Ø (mm)	Jacket thickness (mm)	Number of cycles	Cut tapes/jacket ropes (%)	Cut core (%)
OTS Protective Jacket^™ (double layer)	141.7	13.2	100	11.4	4.8
Lanko^®Shield	142.3	14	100	14.5	2.85

Claims

Jacketed mooring rope (1) comprising a core rope (2) and a jacket (3) surrounding said core rope, wherein the jacket comprises a braided layer of jacket ropes (30) and wherein said jacket ropes each comprise a braided plurality of small ropes (40).
Jacketed mooring rope according to the previous claim, wherein the small ropes each comprise a braided plurality of yarns (50) surrounding one or more core yarns (51).
Jacketed mooring rope according to the previous claim, wherein the small ropes each comprise at least 3, preferably 4 to 12, more preferably 6 to 8 braided yarns surrounding one or more core yarns.
Jacketed mooring rope according to any claims 2-3, wherein the small ropes each comprise two or more, preferably two, core yarns.
Jacketed mooring rope according to any of the previous claims, wherein the small ropes have a diameter of less than 5 mm, preferably between 1 and 4 mm, more preferably between 2 and 3 mm such as about 2.3 mm.
Jacketed mooring rope according to any of the previous claims, wherein the small ropes are flat small ropes preferably having a smallest diameter of less than 3 mm, preferably between 1 and 2 mm such as about 1.7 mm.
Jacketed mooring rope according to any of the previous claims, wherein each jacket rope comprises 3 to 64 braided small ropes.
Jacketed mooring rope according to any of the previous claims, wherein the jacket ropes are flat ropes comprising a thickness of less than 15 mm, preferably between 4 and 10 mm, more preferably between 6 and 8 mm such as about 7 mm.
Jacketed mooring rope according to any of the previous claims, wherein the core rope comprises polyester strands that are braided together.
Jacketed mooring rope according to any of the previous claims, wherein the jacket ropes and preferably the small ropes comprise high performance fibers having a yarn count of at least 1400 den, preferably at least 1600 den; a tenacity of at least 15 g/den, more preferably at least 20 g/den most preferably at least 30 g/den; and/or a modulus of at least 1000 g/den, preferably at least 1300 g/den.
Jacketed mooring rope according to any of the previous claims, wherein the jacket is free of a metal wire, preferably essentially free of metal.
Jacketed mooring rope according to any of the previous claims, wherein the jacket is a single braided layer of the jacket ropes.
Jacketed mooring rope according to any of the previous claims, wherein the jacket and/or the jacketed mooring rope has a density of less than 1 g/cm³.
Rope (30) for use in a jacket (3) of a jacketed mooring rope (1) in accordance with any of the previous claims, wherein said rope (30) comprises a braided plurality of small ropes (40) that each comprise a braided plurality of yarns (50) surrounding one or more core yarns (51), preferably two core yarns and wherein the braided yarns and the core yarns comprise high performance fibers having a yarn count of at least 1400 den, preferably at least 1600 den; a tenacity of at least 15 g/den, more preferably at least 20 g/den most preferably at least 30 g/den; and/or a modulus of at least 1000 g/den, preferably at least 1300 g/den.
Use of a rope according to claim 14 in a jacket of a jacketed rope to provide cut-resistance to the jacketed rope.