Published on:2026-05-24 Click:17
ROV tether cable 3x4mm2 power + single-mode fiber, neutral buoyant. Foamed PUR for high-power work-class ROV requiring heavy power conductors and fiber optic data.
The 3x4mm² + single-mode fiber neutral buoyant ROV tether is a work-class ROV tether solution for vehicles requiring significant thruster power (3 x 4mm² conductors, ~32A per core) alongside a fiber optic high-bandwidth data link for 4K video, sonar data, and vehicle telemetry. The entire assembly is jacketed in foamed PUR to achieve neutral buoyancy at the ROV operating depth, ensuring the tether does not create a downward load on the vehicle during inspection missions. The foamed polyurethane (PUR) jacket uses a micro-cellular expanded jacket compound with a bulk density lower than seawater (~1.025 g/cm³), giving the cable near-zero or positive net buoyancy. This eliminates tether sag and reduces drag force on the ROV, improving vehicle manoeuvrability and reducing tether management workload during subsea operations.
| Parameter | Specification |
|---|---|
| Power Cores | 3 x 4 mm² stranded tinned copper |
| Current Rating | ~32A per core @ 40°C (derate for bundle) |
| Fiber | Single-mode OS2 9/125 μm (2--4 fibers, per spec) |
| Jacket | Foamed micro-cellular PUR |
| Buoyancy | Neutrally buoyant |
| Depth Rating | Up to 3,000 m |
| Strength Member | Kevlar optional |
| Colour | Yellow / black |
Request datasheet, custom length, or OEM pricing: sales@rovcable.com -- Shanghai Kabel Intelligence Technology Co., Ltd.
The jacket is manufactured from a micro-cellular expanded (foamed) polyurethane compound. During extrusion, a controlled foaming agent creates millions of tiny closed-cell air pockets within the jacket wall. These air cells reduce the bulk density of the jacket below that of seawater (~1.025 g/cm³), producing positive or neutral net buoyancy. The jacket retains all the abrasion resistance, oil resistance, and flexibility of standard PUR while achieving the buoyancy needed for ROV tether applications.
4mm² (approximately 12AWG) is rated for approximately 32A continuous in free air. In a ROV tether running 300m+ at 48V DC, larger conductor cross-section is essential to minimise resistive voltage drop. At 300m, 2 x 4mm² conductors carrying 10A lose only ~3.7V, keeping over 44V at the ROV. Thinner conductors (e.g., 1mm²) would drop ~15V under the same conditions, starving thrusters of power.
