Structure and Process Optimization of Small-Sized Lightweight Multi-Layer Transverse Watertight Branch Cables

Aiming to address the drawbacks of existing branched cables for underwater and dynamic applications, including excessive bulk, high weight, inadequate waterproofing performance, and inconvenient installation of the branch structure, a small-sized lightweight multi-layer transverse watertight branch cable along with its corresponding manufacturing method, was presented in the paper. By leveraging high-strength silver-plated copper alloy conductors maturely applied in aerospace industry, a polytetrafluoroethylene (PTFE) wrapping insulation process was innovatively adopted by the proposed cable to achieve extreme miniaturization and weight reduction. Furthermore, a unique multi-layer transversely arranged branch configuration and an elliptical cylindrical vulcanization sealing structure were specially designed. Experimental results indicated that zero water leakage was maintained by the proposed cable under a transverse water pressure of 1.5 MPa, and outstanding mechanical performance was delivered: more than 10000 cyclic bending tests and more than 10000 cyclic flexion tests were withstood, while tensile strength requirements of ≥200 N for the main cable and ≥50 N for the branch cables were met. The service requirements under repeated bending, flexing and tensile loads induced by high-frequency motion in underwater environments were satisfied by the cable due to these properties. A high-performance and high-reliability cable solution for underwater equipment, marine vessels, and offshore engineering applications was provided by the developed technology.