Mooring connector for connecting synthetic fibre ropes

The mooring connector has a hollow body or shell and a central core. The hollow body or shell is formed from an engineering polymer, e.g. polyamide, and is generally cylindrical and has two shell parts. The hollow body has an outer surface and an inner surface. The outer surface has a central groove portion or rope running surface and two outer groove portions or rope running surfaces. The two outer groove portions or rope running surfaces are tapered, such that the outer groove portions are not equally spaced from the central groove portion around the entire circumference of the hollow body or shell. The central core is a solid body that is formed from a metallic material, for example steel. The central core is generally cylindrical and has a shape that is configured to correspond to the shape of the recess of the hollow body or shell. The central core has a central portion and arms that extend from the central portion to outer flanges. The diameter of the central core at the outer flanges and the central portion is greater than the diameter of the central core at the arms. This is to ensure that the central core has the required strength in the areas of the mooring connector that supports a rope, in use.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. nationalization under 35 U.S.C. § 371 of International Application No. PCT/GB2019/050205, filed 24 Jan. 2019, which claims priority to United Kingdom Patent Application No. 1801168.4, filed 24 Jan. 2018. The disclosures set forth in the referenced applications are incorporated herein by reference in their entireties.

The present invention relates to a mooring connector, for example a marine mooring connector.

Mooring connectors are devices that are employed to connect components of offshore installations, for example, anchor chains or floating renewable energy devices, via mooring ropes.

Such mooring connectors are critical for the operation of offshore installations and so must be able to withstand the extreme, high energy, offshore environment.

Mooring ropes are held under tension against the surface of the connector and the connector and rope running through it move relative to each other due to the movement resulting from swell, the tides, wind and other phenomena.

Mooring ropes for large vessels such as tankers, gas carriers and container ships have typically been made from steel wire. However, these ropes are heavy which makes them difficult and time consuming to handle, placing an additional burden on crew and increasing time at berth. Also, as the wire ropes become worn, individual wires break away and they can cut the hands of rope handling personnel. Also, in the salt water environment steel ropes can be subject to corrosion.

Accordingly, synthetic fibre ropes have been offered as an alternative to steel. Generally these synthetic fibre ropes are made from a high modulus polyethylene fibre, aramid fibre or liquid crystal polyester fibre, all of which combine high strength with good resistance to stretch and make their performance largely equivalent to steel wire rope. The ropes are lighter and easier to handle. They tend not to present sharp fibres as they wear.

Also, steel ropes are prone to sparking as they drag along the deck and that risk, which is significant when it occurs on a tanker or gas carrier, is eliminated with the synthetic fibre rope.

One issue with the synthetic fibre ropes in relation to steel ropes is that they have a relatively poor wear resistance. Mooring connectors are generally made of steel. Whilst the steel surface does not present a wear problem for steel wire rope, the surface is rough enough to accelerate wear in synthetic fibre ropes. Steel mooring connectors are also heavy and prone to rust, which increases the abrasive qualities of the connector when the synthetic fibre rope is passing over it.

Some mooring connectors include exposed spools that are made from non-metallic materials, for example polymers. The steel components of these mooring connectors still causes wear to synthetic fibre ropes. One solution has been to coat the outer surface of synthetic fibre ropes with a polyurethane sheath; however, chaffing and wear of the polyurethane sheath and underlying synthetic fibre rope is still a challenge.

According to a first aspect of the present invention there is provided a mooring connector including a central core and a shell, wherein the shell includes a rope running surface.

The combination of a central core and a shell enables the provision of a high strength, yet lightweight, mooring connector.

The central core may include a first material and the shell may include a second material, wherein the first material is different to the second material. In this way, the material properties of the central core and the shell can be tailored to optimise the strength and weight of the mooring connector as well as the friction properties of the rope running surface. The central core may include a metallic material, for example steel, to ensure that the mooring connector has the required strength characteristics.

The shell may include a non-metallic material, for example an engineering polymer such as polyamide, to ensure that the weight of the mooring connector is controlled, that the rope running surface has desirable friction properties and the mooring connector has good corrosion resistance.

The shell may substantially surround the central core. In this way, the corrosion resistance of the mooring connector is further improved.

The shell may have an inner surface that is arranged to receive the central core. The mooring connector may, therefore, have an improved service life.

The shell may have an outer surface on which the rope running surface is formed. The shell may include a plurality of rope running surfaces.

At least one rope running surface of the plurality of rope running surfaces may be tapered. The reliability of the mooring connector may therefore be improved.

The shell may include a central groove in which a first rope running surface of the plurality of rope running surfaces is located.

The shell may include an outer groove in which a second rope running surface of the plurality of rope running surfaces is located.

The shell may include a first shell part and a second shell part. The first shell part and the second shell part may be fastened together to secure the central core within the shell.

The mooring connector may further include an outer casing that is configured to substantially surround the shell. In this way, the reliability and service life of the mooring connector may be increased.

The outer casing may include a recess that is configured to allow a rope to pass therethrough.

The outer casing may include a plurality of recesses that are configured to allow one or more ropes to pass therethrough.

The outer casing may include a first casing part and a second casing part. The first casing part may include at least one recess of the plurality of recesses that are configured to allow a rope to pass therethrough and the second casing part may include a further at least one recess of the plurality of recesses that are configured to allow a rope to pass therethrough.

Referring to the Figures, there is a mooring connector10. The mooring connector10has a hollow body or shell12and a central core14.

The hollow body or shell12is formed from an engineering polymer, e.g. polyamide, is generally cylindrical and has two shell parts16,18. The hollow body12has an outer surface20and an inner surface22.

The outer surface20has a central groove portion or rope running surface24and two outer groove portions or rope running surfaces26,28. The two outer groove portions or rope running surfaces26,28are tapered, as shown inFIG. 3a, such that the outer groove portions26,28are not equally spaced from the central groove portion24around the entire circumference of the hollow body or shell12.

With particular reference toFIG. 3a, the inner surface22has a recess that is defined by an outer wall32. The recess30is shaped such that the thickness of the outer wall32is increased in the portions of the hollow body12that are inward of the central and outer groove portions24,26,28, as shown inFIG. 3a. This is to ensure that the shell12has the required strength in the areas of the mooring connector10that supports a rope, in use.

With particular reference toFIG. 3a, the recess30has a central recess region34, an outer recess region36at a first end of the recess30, an outer recess region38at a second end of the recess30, a first intermediate recess region40between the outer recess region36and the central recess region34and a second intermediate recess region42between the outer recess region38and the central recess region34. The diameter of the recess30at the outer recess regions36,38and the central recess region34is greater than the diameter of the recess30at the intermediate recess regions40,42.

Referring now toFIG. 2, the central core14is a solid body that is formed from a metallic material, for example steel. The central core14is generally cylindrical and has a shape that is configured to correspond to the shape of the recess30of the hollow body or shell12. The central core14has a central portion44and arms46,48that extend from the central portion44to outer flanges50,52. The diameter of the central core14at the outer flanges50,52and the central portion44is greater than the diameter of the central core14at the arms46,48. This is to ensure that the central core14has the required strength in the areas of the mooring connector10that supports a rope, in use.

As shown inFIG. 4, the mooring connector10also has an outer casing or cover54. The outer casing or cover54is formed from a metallic material or a non-metallic material and has a first casing part or end cap56and a second casing part or end cap58.

The first casing part or end cap56has a circular outer face60, an outer wall62, an upper flange64and a lower flange66.

The outer wall62includes a pair of openings or recesses or cut outs68,70on one side and an opening or recess or cut out72on the opposite side. The upper flange64includes an aperture or hole74. Similarly, the lower flange66includes an aperture or a hole76.

In the same way, the second casing part or end cap58has a circular outer face80, an outer wall82, an upper flange84and a lower flange (not shown).

The outer wall82includes a pair of openings or recesses or cut outs88,90on one side and a further opening or recess or cut out (not shown) on the opposite side. The upper flange84includes an aperture or hole94. Similarly, the lower flange (not shown) includes an aperture or hole (not shown).

The outer casing54also includes connectors100,102.

The mooring connector is assembled as follows.

The metallic central core14is cast from a metallic material. The two shell parts16,18are formed from an engineering polymer, e.g. polyamide.

The central core14is fitted into the recess30of the shell part18such that the outer flange50fits within the outer recess region38, the arm46fits within the intermediate recess portion42, the central portion44fits within the central recess region34, the arm48fits within the intermediate recess region40and the outer flange52fits within the outer recess region36of the shell part18.

The shell part16is placed on top of the shell part18such that the outer wall32of the inner surface22of the shell part16abuts the outer wall32of the inner surface22of the shell part18.

As described above in relation to the shell part18, the central core14fits into the recess30of the shell part16such that the outer flange50of the central core14fits into the outer recess region38of the shell part16, the arm46fits into the intermediate recess region42, the central portion44fits into the central recess region34, the arm48fits into the intermediate recess region40and the outer flange52fits into the outer recess region36of the shell part16.

The shell parts16,18may then be bolted or fastened together by any known fastening means.

Once the mooring connector shell and core have been assembled, ropes104,106,108can be mounted on the outer surface20as shown inFIGS. 1 and 4. The rope104is positioned within the central groove24of the shell12, the rope106is positioned within the outer groove26of the shell12and the rope108is positioned within the outer groove28of the shell12.

The outer casing parts or end caps56,58are then positioned around either end of the mooring connector such that the ropes106,108extend through the openings68,70of the first casing part56and through the openings88,90of the second casing part58and the rope104extends through the opening70of the first casing part56and the opening (not shown) of the second casing part58.

To secure the two casing parts56,58, the connector100is threaded through the apertures74,94of the flanges64,84of the first casing part56and the second casing part58. In the same way, the connector102is threaded through the aperture76of the flange66of the first casing part56and the corresponding aperture (not shown) of the flange (not shown) of the second casing part58.

The ropes are arranged around the connector such that the unit is held in compression whilst in operation.

The outer casing of the connector is formed in two-parts to encase and enclose the rope “eyes”, thereby keeping the assembly together with the ropes opposed to each other.