Light Fiber Tether Management for Underwater Vehicles

Background: Lightweight tethers are used on underwater vehicles to minimize drag and maintain mobility, but their range is limited due to the fragile physical communications link. To extend range, fiber optics are deployed in a free payout configuration from the vehicle. However, these fiber tethers can become lofted in the water column and carried by currents, leading to excessive payout. This results in high costs, marine debris, and potential entanglement risks for both the vehicle and future assets operating in the area.

Technology Overview: A self-retracting reel for fiber and light-tether payout management from underwater vehicles or host platforms. The designed reel holds a communication tether, and an active drive system designed to maintain minimal but sustained tension on the tether at all times. The reel speed and direction is dictated by fluctuations in the tether tension and will pay in or out to maintain low-tension conditions which reduces entanglement risks, runaway tether payout, and facilitates tether recovery after deployment. 

Benefits:

• Minimized tension ‑ aids in reducing risk of entanglements and operational disruptions
• Automized reel speed and direction ‑ prevents excessive payout that can occur with traditional systems
• Increased range ‑ enables longer operational ranges by ensuring stable tether management and reducing the limitations of fragile communication links
• Improved tether recovery ‑ self‑retracting features enables easier and more efficient tether recovery, saving time and reducing the risk of lost equipment

Applications:

• Marine research and oceanography
• Subsea infrastructure inspection and maintenance
• Military and defense
• Marine construction and salvage
• Telecommunications and seafloor data transfer