Dual-Metal Undersea Cable Conductor for Lower Cost and Weight
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Solution Overview
Problem
Existing undersea optical communication cables face challenges with high material costs and increased weight due to the use of pure copper conductors, which limits their depth and handling capabilities.
Innovation Solution
The implementation of a dual metal conductor design, where an aluminum layer is wrapped around steel strength wires and a copper layer is wrapped around the aluminum, forming a hermetically sealed conductor with reduced electrical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If pure copper is used as the conductor material, then electrical resistance is reduced, but material cost and conductor weight increase
Solution Approach 1:
The patent applies composite materials by combining aluminum and copper in a layered conductor structure. The aluminum layer provides the primary conductive path with sufficient conductivity, while the copper cladding layer adds enhanced conductivity at the surface and provides hermetic protection. This composite structure achieves lower overall material cost compared to pure copper while maintaining acceptable electrical resistance levels for power delivery to undersea repeaters.
2Loss of energy
If pure copper is used as the conductor material, then electrical resistance is reduced, but conductor weight increases limiting depth capability
Solution Approach 1:
The dual-metal conductor uses aluminum as the core material which has approximately one-third the density of copper, significantly reducing conductor weight. The copper cladding layer is applied as a thin outer layer that provides sufficient electrical conductivity and hermetic protection without adding substantial weight. This composite approach achieves an optimal balance between weight reduction for deep-sea deployment and electrical performance for power delivery.
3Loss of energy
If thicker copper layers are used to reduce electrical resistance, then power delivery capability improves, but manufacturing rate decreases
Solution Approach 1:
The aluminum-copper composite conductor enables thinner overall conductor construction compared to pure copper designs achieving the same electrical resistance. The aluminum core provides bulk conductivity with minimal thickness, while the thin copper cladding adds surface conductivity and protection. This reduced thickness allows for faster cable assembly and manufacturing processes, increasing production rate while maintaining power delivery capability.
4Reliability
If pure copper conductor is used, then hermetic protection is achieved, but material cost increases
Solution Approach 1:
The conductor structure uses copper as an outer cladding layer that provides hermetic protection to the underlying optical fibers and strength members, preventing moisture and hydrogen ingress. The aluminum core layer provides the primary conductive function. This composite arrangement achieves the hermetic protection function with significantly reduced copper material usage compared to pure copper conductors, lowering material cost while maintaining reliability.
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
This dual metal conductor design achieves lower material costs, improved handling characteristics, enhanced manufacturability, and better protection against hydrogen aging, while maintaining low electrical resistance.
Implementation Method 1
Copper can be readily welded into a hermetic tube, protecting the underlying fibers and steel strength wires from moisture and hydrogen
Implementation Method 2
the conductor comprises a first metal layer surrounded by a second metal layer... sufficiently low electrical resistance to minimize resistive power dissipation
Data Source
AI summary
Disclosed is a cable with dual metal conductor structure. In some embodiments, an optical cable includes hollow buffer tube having a plurality of optical fibers therein, and a first plurality of layered strength members surrounding the hollow buffer tube. The optical cable may further include a conductor surrounding the first plurality of layered strength members, wherein the conductor includes a first metal layer surrounded by a second metal layer, and an outer insulating jacket surrounding the conductor.