Marine propeller cables (also known as retractable spiral cables or drum cables) are highly flexible special cables specifically designed for frequently moving, reciprocating, or rotating equipment on ships. They are commonly found in winches, towing machines, A-frames, ROV (Remotely Owned Vehicle) deployment and retrieval systems, and helicopter platform lifting devices. Due to their spiral shape (similar to a spring), they possess excellent tensile resilience, torsional resistance, and bending fatigue resistance, earning them the reputation of being the “lifeline of dynamic connections on ships.”
- Typical Application Scenarios
| Application Equipment | Functional Requirements |
| ROV/Underwater Robot Umbilical Cable | Integrated power supply, signal, and fiber optic cable; deployed/retrieved with the ROV; withstands seawater pressure and repeated stretching. |
| Towed Sonar/Side-Scan Sonar System | Maintains stable signal during long-distance deployment and retrieval; resistant to seawater corrosion and mechanical wear. |
| Helicopter Platform Lift | Moves with the platform; requires high flexibility, flame retardancy, low smoke, and halogen-free properties. |
| Offshore Wind Power Maintenance Crane | Continuously supplies power amidst wave action; requires torsion resistance, oil resistance, and weather resistance. |
| Research Vessel A-Frame/Windlock | Withstands heavy tensile forces and high-frequency bending; cable must extend and retract synchronously with the reel. |
Note: Propeller cable ≠ Propeller motor cable!
The former refers to a highly flexible mobile cable with a helical structure, while the latter is a fixed power cable for driving the thruster. Their uses and structures are completely different.
II. Core Performance Requirements for TST Cable Marine Propeller Cables
Ultra-high flexibility and bending life
Minimum bending radius can reach 4–6 × D;
Passes ≥1 million dynamic bending tests (IEC 60227-7 or DIN VDE 0285-525).
Tensile strength and elasticity
The helical structure can be stretched to 1.5–3 times its original length and automatically returns to its original position after release;
Tensile elements (aramid/steel wire) prevent stress on the conductor.
Torsion resistance
Layered reverse stranding + central reinforcing core to prevent “knotting” or internal damage during use.
Environmental adaptability
Salt spray resistance: Passes 96h salt spray test (IEC 60068-2-11);
Oil/seawater resistance: Sheath material volume expansion rate < 10%;
Wide temperature range: -40℃ to +90℃ (special types can reach 125℃).
Safety and certification
Passenger ships/warships: Must be low smoke zero halogen (LSOH) + bundled flame retardant Class A;
Must comply with IEC 60092-359 (marine communication cables) or IEC 60502 (power section);
It is recommended to choose TST cable’s dedicated marine propeller cables, which have obtained certifications from multiple classification societies such as BV, ABS, DNV, LR, and CCS. III. Structural Design Features
Conductor: Ultra-fine tinned copper wire (Class 6 or higher) for enhanced flexibility;
Insulation: TPE (thermoplastic elastomer) or EPR, soft and resistant to bending;
Shielding (signal cable): Aluminum foil + tinned copper braid, coverage ≥85%, EMI resistant;
Reinforcement core: Central aramid fiber or stainless steel wire to bear tensile stress and protect the conductor;
Sheath:
General type: PUR (polyurethane) – wear-resistant, oil-resistant, and highly elastic;
Environmentally friendly type: TPE/LSOH – low smoke, halogen-free, for use in enclosed compartments;
Deep-sea type: Double-layer sheath + waterproof tape, for penetration resistance.
IV. Key Parameter List for Marine Propeller Cable Selection
| Parameters | Selection Recommendations: |
| Voltage Rating | 300/500V (Control/Signal), 0.6/1kV (Power) |
| Number of Cores and Cross-Section | Determine based on load current + signal type, with a 20% margin. |
| Stretch Ratio | Select 1.5x, 2x, or 3x based on equipment travel. |
| Sheath Material | Exposed deck → PUR; In-cabin → LSOH TPE |
| Whether Fiber Optic is Integrated | ROV/HD video transmission requires a composite optical unit. |
| Certification Requirements | Confirm the classification society (e.g., CCS for Chinese-flagged vessels). |
V. Key Points for Installation and Maintenance of Marine Propeller Cables
Avoid excessive stretching: Length used ≤ 80% of maximum elongation;
Guide wheel diameter ≥ 10 × cable diameter to reduce localized stress;
Do not knot or bend at sharp angles;
Regularly check for sheath cracks, spiral deformation, and loose joints;
Replacement cycle: For high-frequency use, mandatory replacement is recommended every 3–5 years.
On a deck tossed by waves,
propeller cables, with their “flexible bodies,” carry the flow of electricity and information.
Every extension and retraction is a silent test of reliability.
TST cable uses marine operating conditions as its laboratory, creating dynamic connection solutions that can withstand millions of bends and thousands of hours of salt spray corrosion—
because TST cable understands that on the high seas, no breakage means safety; no interruption means mission.
✅ TST cable engineers’ professional advice: Never use ordinary flexible cables instead of spiral cables! Static flexibility ≠ dynamic durability.
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