Resin-Bonded Cable Hang-Off Assembly for Tape Armour Loads
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Solution Overview
Problem
Existing hang-off devices are not suitable for power cables with armours made of helically wound tapes, as they lack sufficient tensile strength and mechanical resistance, and applying the assembly directly to the cable core can cause undue stress.
Innovation Solution
A hang-off assembly using a frusto-conical tube with self-curing resin adhering to the cable core, which provides mechanical support by compressive force after curing, and an annular flange for attachment to offshore structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional hang-off devices clamp armour wires to sustain cable weight, then mechanical support is provided, but they are not suitable for cables with helically wound tape armours due to insufficient tensile strength
Solution Approach 1:
The patent introduces self-curing resin as an intermediary material between the frusto-conical tube and the cable core. This resin mediator enables the hang-off assembly to adhere to cables with helically wound tape armours by bonding to the cable core surface, providing the necessary tensile strength (up to 200kN) without requiring mechanical clamping of the armour wires. The resin acts as a bonding interface that transfers and distributes the cable weight effectively.
Solution Approach 2:
The patent changes the physical and chemical parameters of the resin material to achieve optimal performance. The self-curing resin has a Shore D hardness of 40 and a density of 1.05 g/cm³, with specific adhesion strength to the cable core. By controlling these material parameters, the invention achieves both high tensile strength and compatibility with different cable constructions, including those with helically wound tape armours.
2Adaptability or versatility
If the hang-off assembly is applied directly to the cable core, then compatibility with helically wound tape armours is achieved, but undue stress may be applied to the conductor
Solution Approach 1:
The patent applies preliminary protective actions by first exposing a controlled length of the cable core by removing protecting layers, then carefully applying the self-curing resin to bond the frusto-conical tube to the cable core. The resin is allowed to self-cure and achieve optimal adhesion before the cable is subjected to full tensile load. This preliminary bonding action ensures that the conductor is protected from undue stress during the hanging operation.
Solution Approach 2:
The patent controls the parameters of resin application, including the exposed length of cable core (controlled by removing protecting layers), the Shore D hardness of the cured resin (40), and the density (1.05 g/cm³). These parameter controls ensure that the resin provides sufficient bonding strength to support the cable weight without concentrating excessive stress on the conductor, achieving both compatibility and protection.
3Strength
If a frusto-conical tube with self-curing resin is used, then high tensile strength and mechanical congruence are achieved, but the device complexity increases
Solution Approach 1:
The patent segments the hang-off assembly into distinct functional components: a frusto-conical tube made of two coupled half-shells, self-curing resin material, and an annular flange. This segmentation allows each component to be optimized for its specific function while simplifying manufacturing and assembly. The half-shells can be separately manufactured and then coupled, and the resin can be independently prepared and applied, reducing overall device complexity despite the high performance requirements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The assembly effectively sustains the power cable under tensile strain, reducing the risk of slippage and detachment, with a tensile strength of up to 200kN when the resin has a Shore D hardness of 40, ensuring mechanical congruence among cable layers.
Implementation Method 1
a self-curing resin to be poured and cured between the frusto-conical tube and the at least one cable core of the power cable, said self-curing resin being adapted to adhere to the at least one cable core
Data Source
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AI summary
Hang-off assembly (200) for power cable (100) comprising at least one cable core (110) and at least one protecting layer (120, 160) radially external to the at least one cable core (110), the hang-off system (200) comprising: - a frusto-conical tube (210) configured to be arranged around a length of the power cable where the at least one cores are exposed, the frusto-conical tube (210) being made of two half-shells (211, 212) coupled to each other and defining a first opening (213) and a second opening (214) opposite to the each other wherein the first opening (213) is circumferentially smaller than the second opening (214); - a self-curing resin to be poured and cured between the frusto-conical tube (210) and the at least one cable core (110) of the power cable (100), adapted to adhere to the at least one cable core (110).