Testing & Validating Subsea Cable Specifications

Discover how to turn theory into proven performance under pressure. We've also designed this blog post for an optimum user experience: first, read this blog post in less than 5 minutes, then decide if you want to download the ebook (30-minute-read).

Introduction

In subsea engineering, design alone doesn’t prove reliability. Testing does. Defining, testing, and validating specifications early ensures your subsea cable will survive real-world forces. From crushing depths to relentless handling cycles. At DeRegt, we’ve built a process that turns requirements into hard data and data into confidence. Here’s how we make sure a cable does what it’s designed to do. Every time.

1. Define and Prove Your Specifications

Every project starts with a question: What exactly must this cable do, and under what conditions? That clarity determines everything: design choices, materials, test scope, and eventually, the project’s success. A well-defined specification is your benchmark for testing. It’s what allows you to prove, not just assume, compliance.

2. The Five-Phase Design & Validation Process

Our engineers follow a five-step process that keeps every requirement traceable and testable from day one:

• Preliminary Design – Define the cable’s function, explore concepts, and establish how each requirement will be verified.
• Critical Design – Finalize drawings, review as a team, and “freeze” the design for prototype production.
• Prototype Phase – Build and test. Develop custom test setups that simulate real-life handling, pressure, and performance.
• Production Phase – Manufacture the first article and run the Factory Acceptance Test (FAT) — including electrical, optical, and pressure tests — on every product.
• Continuous Optimization – Use field data to make minor refinements, never major redesigns. Real consistency starts with discipline.

This structure gives engineers complete control — not just over the cable, but over the proof that it works.

3. Why Testing Matters More Than Analysis

Modeling and simulation can predict performance — but the ocean always finds what your model missed.

Cables are complex, multi-material helices where friction, temperature, and motion interact in unpredictable ways. That’s why physical testing remains non-negotiable. It’s the only way to guarantee your design survives under real forces.

Testing isn’t just a cost; it’s risk prevention — and the fastest route to true reliability.

4. Two Essential Tests for Every Subsea Cable

System Integration Testing

Do all interfaces work together — mechanically, electrically, and optically?

We replicate the full system connection with counter-connectors to confirm continuity and alignment.

It’s how we eliminate surprises before deployment, especially with precision fiber optics.

Fatigue Testing

How long will the cable last under tension, bending, and repeated use?
We model dynamic loads using sea-state and towing data, then validate with bend-cycle and tension-tension tests.

Steel-armored cables can often be predicted analytically; aramid fibers demand deeper testing. Either way, we prove the lifespan, not just estimate it.

5. From Documentation to Proof

Testing without documentation is just experimentation.

Our process ensures every step — from design to FAT — is recorded, reviewed, and repeatable. This isn’t paperwork; it’s traceability.

It’s how you show clients and certifiers that your system meets every operational requirement.

Conclusion

Every subsea project faces the same challenge: proving that what’s been engineered will actually perform — under pressure, fatigue, and time. A clear specification process, disciplined testing, and thorough validation are what transform a cable design into mission-ready hardware. At DeRegt, we call that engineering with evidence.

Download the full e-book