Hovering an SSBN (maintaining the ship in a neutral state of buoy- ancy at a specified depth at very low speed) is a challenge for the div- ing and ship control operators. Early SSBNs were not provided with effective hovering systems. Later classes of SSBNs were equipped with systems that incorporated larger tank volumes (depth control tanks) and were designed with control systems to automatically adjust buoyancy as necessary during hovering. There were some learning curves, however, in the development of these systems. My experience with one of these earlier systems provided a lesson in the adaptability and expertise of our sailors.
USS Henry Clay (SSBN 625) was eBuipped with an early designed automatic system for hovering. To successfully hover, it was necessary to get the ship in a close to neutral buoyancy state by normal means-us- ing the trim system and then to put the hovering system in “automat- ic mode.” The system then should automatically maintain the ordered depth. As the Engineer Officer I was responsible for the hovering sys- tem. The system used pneumatic controls (low pressure air) and was unusually complex. It did not adequately compensate for changing pres- sure in the boat. Each sea trial period involved a test of the system, and the tests were usually unsatisfactory. This resulted in the Captain’s increasing frustrations and emphatic exertions to me to fix the system. This continued over several sea trial periods and patrols with the system not performing well. Continued extensive maintenance of the system was required. This maintenance was done by an experienced interior communications electrician first class petty officer (IC1). After several major attempts at correcting the system, we once again proceeded on sea trials and further testing. I was in the control room for this test and wit- nessed the most amazing performance. The system performed flawless- ly. The hovering control panel in the control room was in full automatic and the system was functioning without error. I could not believe what I was witnessing. I sensed something was totally different from our past experience and sensed that some major success had been achieved and I wanted to know the reason. So I went to the hovering system equipment
area, which was in the missile compartment, to see for myself. When I got there, I found my first class petty officer at the cage enclosure for the pneumatic controls. The cage assembly was removed and the petty of- ficer was manipulating the system by hand. He had conducted so much maintenance on the system that he knew all facets of its operation. He could control the system precisely by manipulating the various parts of the system by himself. I hesitated a moment. Should I tell the Captain? Or should I just ensure the petty officer was always at the cage area when we were attempting hovering operations?
