Response and cable tension characteristics of variable-length towed marine systems

A towed system consisting of cable and vehicle, undergoes deployment, maneuvering, and retrieval during operations. Understanding its dynamic responses throughout these phases is essential. However, most studies focus on isolated phases or components, offering partial insights. This study employs a modified lumped mass method to analyze the full-process dynamic response of towed system. The model's accuracy and effectiveness are validated using data from both literature and sea trials. Comparing cable deployment and retrieval speeds, a relationship is established between cable speed and dynamic tension. Results show a tension peak when deployment speed falls below a critical threshold, an instantaneous tension surge occurs at the start of retrieval. The mother ship’s speed oscillation effects during straight-line towing are examined. Y-direction velocity oscillations mainly propagate along the cable’s Y and Z axes, displaying periodic behavior correlated with the ship’s speed. These findings detail the towed system’s dynamic performance across all operational stages.