Underwater Cable Considerations

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March 27th, 2018 - As temperatures rise in the Midwest, the snow melts, and the lakes begin to thaw, we start to think about key factors for designing cables for underwater or wet environments. If your end application operates in these types of conditions, be sure to consider these critical-to-quality design factors:

  1. Application. For example, underwater vision systems may require a fundamentally different type of cable than underwater lighting or monitoring and research applications.
  2. Compliance. It will help your Cable Designer to know ahead of time if any ratings, agency listings, government certifications and/or environmental standards will need to be met such as: UL, ANSI, CSA, CE, IEEE, ABS, RoHS2, REACH, and 1,000 hour weatherometer requirement.
  3. Time of exposure. Will the cable be submerged for the life of the application, will it simply be exposed intermittently or to spray?
  4. Water Type. Different options exist for salt, fresh, brackish, chemical-treated, waste, and potable water. For example, cable in contact with potable water may need to be made of FDA-approved, food-grade materials.
  5. Cable Depth. Cable systems at greater depths require heavy-duty materials and pressure resistance. Northwire’s underwater cable capabilities extend to a depth of 30 meters (98.43 feet).
  6. Flex. Cold bend, torsional, rolling, variable, bend, and continuous flex options exist for cables whose applications require regular motion.
  7. Environment. Knowing whether a cable must function in an industrial pipe, ocean, or rocky riverbed determines many design factors.
  8. Temperatures. From Arctic to elevated temperature, cable systems are designed for a specific range of conditions. Water can get extremely cold and an insulating layer might be necessary for your cable. In which case, a filler-like foamed polypropylene might be necessary. This filler adds insulation without adding much weight.
  9. Buoyancy. Special considerations must be taken when a cable is required to have a negative, neutral, or positive buoyancy.
Underwater Cable

For cable systems, a choice of water-blocking conductors, tapes, and fillers work to not only prevent leaks, but to create a barrier in case of cut, abrasion, or severe damage. Unlike many cable assemblies, which use a jelly filler as a barrier for the first few inches of the cable, Northwire implements a dry component throughout the entire length of the cable that only activates when wet. Highly effective in preventing and mitigating leaks, this unique alternative also allows for a much more convenient and cleaner process when installing and handling the cable.

Interested in learning more? Download our Underwater White Paper. If you have any questions about protecting your cable or want to talk with an expert give us a call at