Modular Subsea Cable Tensile Test Rig for On-Site Bending Tests

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Solution Overview

Problem

Existing subsea cable testing rigs are large and fixed, requiring permanent installations onshore, which is inefficient and costly, and transporting cable samples poses challenges due to size and handling constraints.

Innovation Solution

A portable tensile test rig that can be disassembled into parts fitting within standard shipping containers, allowing on-site testing without fixed foundations, comprising a sheave module, load module, and elongate base that can be reversibly divided for transportation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed tensile bending test rig is used, then the test rig can apply large forces and perform accurate tensile bending tests, but the test rig requires permanent installation onshore with significant structural strength and substantial foundations

Engineering Contradiction:
Improvetesting accuracyVSAvoidinstallation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The test rig is divided into modular components including the sheave module, load module, and elongate base that can be disassembled and transported in standard shipping containers. This segmentation allows the rig to be relocated to different on-site locations while maintaining its testing capabilities through proper reassembly at the destination.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If cable samples are transported to fixed test facilities, then testing can be performed with established equipment, but transporting long cable samples poses challenges due to size constraints and handling requirements

Engineering Contradiction:
Improvetesting accessibilityVSAvoidcable sample length
Core Design Contradiction:
Ease of manufactureVSLength of moving object

Solution Approach 1:

Instead of transporting the cable sample to a fixed test facility, the test rig is brought to the cable sample location. This inversion of the traditional approach eliminates the need to transport long cable samples, allowing testing to be performed on-site where the cable is already installed or stored.

Inventive Principle:
Principle #13The other way round (Inversion)

3Adaptability or versatility

If a portable test rig is used, then the test rig can be transported in container(s) and assembled at different locations, but the test rig must be disassembled and reassembled which increases setup time

Engineering Contradiction:
Improvelocation flexibilityVSAvoidsetup time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The test rig components are pre-assembled into modular units (sheave module, load module, elongate base) that can be quickly connected together at the test location. This preliminary modular assembly reduces the time and complexity of setup compared to assembling individual components from scratch.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4556874B1Tensile test rig for subsea cable products
Publication Date: 2026.02.25 NEXANS SA
  • EP4556874B1 patent drawingFigure 1~2
  • EP4556874B1 patent drawingFigure 3
  • EP4556874B1 patent drawingFigure 4~5

AI summary

A test rig for a subsea cable product 1 comprises: a sheave module 22 including a sheave 10 for holding a subsea cable product 1 that is to be tested and a load module 30 for applying tension to the subsea cable product 1 on the sheave 10 in order to perform a tensile bending test. An elongate base 28 is provided for placement between the sheave module 22 and the load module 30, the elongate base 28 providing a horizontal beam that can hold a compressive load generated by tension in the subsea cable product 1 during the tensile bending test. The sheave 10 can be reversibly divided into parts for transportation in one or more container(s) of smaller cross-section than the diameter of the sheave 10. The elongate base 28 can be reversibly divided into parts for transportation in one or more container(s) of smaller length than the whole length of the elongate base 28. In this way the test rig is made portable, e.g. as a kit of parts, and may be used in methods involving transport to different locations along with assembly/disassembly of the test rig.