Underwater Fiber Optic Cable Buoyancy Control via Jacket Density

Solution Overview

Problem

Existing underwater fiber optic cables face performance impairments due to drag and weight, which are not effectively addressed by current buoyancy control methods that alter the cable's diameter, requiring reengineering of components and increased spool sizes.

Innovation Solution

The use of a jacket with a polymer and nanoparticles of varying density distributed throughout, allowing for controlled buoyancy along the cable length without changing the outer diameter, achieved by varying the volume fraction of particles like titanium dioxide or zinc sulfide within the thermoplastic elastomeric polymer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If material is added to control buoyancy, then buoyancy control is improved, but cable diameter increases

Engineering Contradiction:

Improvebuoyancy controlVSAvoidcable diameter

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The patent changes the density parameter of the jacket material by incorporating particles with different densities (e.g., titanium dioxide, zinc sulfide, barium sulfate) into the polymer matrix. By varying the type and concentration of particles, the buoyancy is controlled without changing the cable diameter, as the particles are integrated within the existing jacket structure rather than adding external buoyancy elements.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The jacket is formulated as a composite material consisting of a polymer matrix (e.g., polyethylene, polypropylene) reinforced with inorganic particles of controlled density. This composite approach allows precise tuning of the jacket's overall density to achieve desired buoyancy characteristics while maintaining the same physical dimensions and outer diameter of the cable.

Inventive Principle:

Principle #40Composite materials

2Reliability

If cable diameter is increased for buoyancy control, then buoyancy control is improved, but spool size increases

Engineering Contradiction:

Improvebuoyancy controlVSAvoidspool size

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent achieves buoyancy control by modifying the density parameter of the jacket material through particle incorporation, rather than increasing the cable diameter. This allows the cable to maintain its original outer dimensions, ensuring that spool sizes remain unchanged while still achieving the desired buoyancy characteristics for underwater deployment.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If cable diameter is increased for buoyancy control, then buoyancy control is improved, but other cable components must be reengineered

Engineering Contradiction:

Improvebuoyancy controlVSAvoidcable component design

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The jacket is formulated as a composite material consisting of a polymer matrix (e.g., polyethylene, polypropylene) reinforced with inorganic particles of controlled density. This composite approach allows precise tuning of the jacket's overall density to achieve desired buoyancy characteristics while maintaining the same physical dimensions and outer diameter of the cable.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the density parameter of the jacket material by incorporating particles with different densities (e.g., titanium dioxide, zinc sulfide, barium sulfate) into the polymer matrix. By varying the type and concentration of particles, the buoyancy is controlled without changing the cable diameter, as the particles are integrated within the existing jacket structure rather than adding external buoyancy elements.

Inventive Principle:

Principle #35Parameter changes

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 solution enables independent buoyancy control of the fiber optic cable, reducing weight and drag while maintaining a constant diameter, thus conserving oxygen for underwater operations and allowing for flexible depth adjustments without altering spool sizes.

Implementation Method 1

a plurality of particles distributed throughout the polymer having a second density greater than the first density, and having a predetermined volume fraction to thereby provide the underwater cable with a predetermined buoyancy when underwater

Methodology Applied

Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentEP3399350B1Underwater fiber optic cable with a predetermined buoyancy and associated methods

Publication Date: 2020.06.03 HARRIS CORP

Figure 1
Figure 2
Figure 3~4

AI summary

An underwater fiber optic cable includes an optical fiber, and a jacket surrounding the optical fiber. The jacket includes a polymer having a first density, and particles distributed throughout the polymer having a second density greater than the first density. The particles have a predetermined volume fraction to thereby provide the underwater cable with a predetermined buoyancy when underwater.