Design and Certification of Submerged Systems Handling Equipment

ABSTRACT This paper presents the basic design criteria and procedures for certification of submerged systems handling equipment. The authors discuss the total design evolution from establishment of design parameters to certification documentation. The philosophy and the need for certification are also discussed. Examples of design and certification of submerged systems for the U.S. Navy are highlighted. The intent of this paper is to present a useful guideline to be used by engineers designing handling equipment for submerged systems. BACKGROUND In 1966, the United States Navy formally began certifying non-combatant submersibles. Certification is basically the process of conducting a system adequacy review of the submersible. Its purpose is to insure that all submersibles owned or operated by the Navy will perform satisfactorily for the specified mission, are safe, and will be maintained in a safe operating condition. Certifying submersibles is a detailed process which involves a general design review of the system, verification of calculations and minimum factors of safety, review of test reports, checks on operational and maintenance procedures, and on-site verification of the as-built condition of the submersible. To assist the certifying agency in conducting the certification, the Navy has two basic applicable documents; ‘Material’ Certification Procedures and Criteria Manual for l-fanned Non-Combatant Submersibles" (Certification Manual), and the Preliminary Survey Outline Booklet (PSOB). The Bertification Manual gives both general guide lines and specific design criteria for the certification process. The PSOB is a document that categorically lists the submersible systems and components that are within the scope of certification and specifies what aspects of the system must be verified for system adequacy. Until 1971, however, there was no formal certification of the submersible's handling equipment. At that time, it was recognized that since handling equipment ''ti'fects the safe operation of the submersible it ought to be considered part of the certification procedure. Several accidents in the past, such as the loss of the submersible Alvin in 1968, had pointed out the consequences of failure of, a submersible's handling equipment. Although no lives were lost as a result of the accident with Alvin, a costly salvage operation which required almost a year's effort was necessitated. A discussion of Alvin's loss, as well as several other accidents involving handling equipment, is given in Reference 1. To effect the certification of handling equipment the scope of the'PSOB was broadened to include handling equipment. However, definite guidelines for the certification of handling equipment were not specified, until recently when the Navy's Certification Manual was revised. The scope of the manual will include all deep submerged systems, and a separate appendix dedicated to handling equipment will be added. Deep submerged systems are defined as non-combatant submersibles, in or on-bottom habitats, hyperbaric facilities, diving systems, diver equipment, and attendant handling equipment.