Underwater electrical cable and connector seals: Some in-house design options, commercial options, and performance/failure analyses

Very limited information is currently available on the options available to engineers who need to select or design an appropriate connector or cable seal for long-term underwater use. To help solve this problem, the Applied Physics Laboratory has compiled a Reference Manual on Interference Seals and Connectors for Undersea Electrical Applications that (1) presents factors in the theory and design of underwater cable and connector seals, (2) provides information on manufacturers and commercially available products, (3) gives bibliographies on pertinent military specifications and technical publications, and (4) discusses procedures for initiating quality assurance programs based on performance/failure analysis and consequent connector and seal redesign. This paper is a brief summary of much of that information. Considerable space is devoted to a number of approaches currently utilized for long-term cable terminations, with emphasis on the Morrison, or interference, seal. Recommended proportions are given for housings and packings for simple and complex interference seals that can be constructed in-house. The paper also identifies most current underwater connector manufacturers. It presents the results of a number of performance/failure analyses and makes recommendations on redesign and quality control.