On January 16, 1982, near midnight, the “mini-sub,” a Navy Seal delivery vehicle (SDV) involved in a classified mission off the coast of the Philippines, returned to its host submarine USS Grayback (LPSS-574). After stowing the SDV, USS Grayback’s support divers and the SDV crew (six team members total) remained within the flooded wet side starboard hangar preparing to shut the outer hangar door and drain and vent the hangar prior to re-entering the submarine.
Soon the wet-side divers felt dizzy and short of breath. One operator checked vent valve position but couldn’t open the valve any farther. Later, someone keyed the wet-side communication microphone but didn’t speak. Five of the six divers passed out and fell into the water. One diver managed to hook his arm over a pipe to avoid falling before he also passed out. The dry-side operators attempted microphone and tap signal communications. After several more minutes of communications attempts, the diver whom had hooked his arm on a pipe began to revive and reported that he needed help. Dry-side operators then entered the hangar and found that five of the six divers had died.
Charles Wayne Bloomer, Rodney Lee Fitz, William C. Robinson, Leslie C. Shelton, and Richard D. Bond lost their lives that night.
A formal investigation revealed several design flaws as well as personnel training, maintenance and operation issues in the USS Grayback diver transfer system. It was concluded that a wet-side operator had opened the vent valve only partway, causing a vacuum to form.
Contributing factors included:
•Neither the vent valve, nor its operating linkage, had been lubricated properly
•Those who claimed to have done greasing maintenance didn’t know a fitting existed for greasing the vent valve
•Other grease fittings in the hangar were painted over or rusted shut
•17 gauges were overdue for calibration and another one was missing
•Hangar drain procedures had not been submitted to NAVSEA for approval; mandated changes to other procedures had not been made.
•Two senior watches were often combined, in violation of procedures
•Diver personnel had received less than 1-1/2 hours of diving training in the previous six months
•Not all participating divers had attended the pre-dive brief
Each one of these factors wasn’t catastrophic by itself, but when combined led to a tragedy.
Tragic events in January 1982 resulted in the creation of the Deep Submergence Systems (DSS) Certification Program (commonly referred to as DSS-SOC). The Navy now requires that all diving systems be designed to prevent or minimize the possibility of unintentionally causing a vacuum, and hazard and safety analyses are required during design. Additional work and material requirements are required during new construction and maintenance on DSS-SOC systems and components.
Thirty-eight years later, we as shipbuilders commemorate the anniversary of this tragedy by continuing to apply lessons learned and share the story of the men that lost their lives aboard the USS Grayback.
Today, the DSS certification process provides maximum reasonable assurance that a material or procedural failure that could imperil the operators or occupants will not occur, and that DSS personnel may be recovered without injury if there is an accident. The most current requirements are contained in the System Certification Procedures and Criteria Manual for Deep Submergence Systems, NAVSEA SS800-AG-MAN-010/P-9290 available on the DSS-SOC Program website.
As members of the EB Team, our challenge and responsibility is to maintain the high level of the standards established by the DSS Certification Program during design, new construction and maintenance work. Compliance with procedures is critical. Attention to detail, regardless of the task, should be the mindset we have with anything we do associated with diver safety. A questioning attitude is critical—am I using the correct lubricant? Did I maintain cleanliness of the breathing systems? Is my work task in the DSS-SOC boundary? Did I only use DSS-approved materials? Would I trust my life to this work?