My Maneuvering Watch station was on #4 line though I was an EN2(SS). The lead first class had the FER, my normal watch station for Maneuvering Watch and all of us grunts were distributed throughout the ship. Stations were manned and we were getting ready to shove off from the sub base in New London.
First clue that something was up was when somebody (maybe the Engineering Officer) told me, Get a truck and get twenty cans of hydraulic oil. I grabbed a 1150 chit book, got a sig from somebody and headed out with a striker. Checked the vehicles at the head of the pier until I found one with keys and helped myself. Whizzed over to supply and loaded up the hydraulic oil. Got back to the pier and the lines were already singled up. People appeared and the hydraulic oil went aboard as I returned the truck. As soon as I got my carcass aboard, the brow came right behind me.
Got underway pretty normally and settled into the regular underway watch. No big deals going on but did get a hint that there seemed to be a hydraulic leak somewhere and our oil was disappearing. There were many searches done in the superstructure and compartments. The oil that we had brought aboard was all sent to the FTR where a hose was rigged up into the escape trunk and some poor slob had to pour the oil into the funnel attached to the hose which went into the fill connection to the hydraulic storage tanks. There, for the benefit of those who might not know, the oil was pumped with a hand pump to the FER to the hydraulic supply tank. We were a Guppy IIA so the hydraulic system took up residence in the FER.
All was going fairly well with a trim dive and instruction over the squawk box to look for hydraulic leaks throughout the boat. We checked the lower flats in the FER over and over and found nothing. Apparently the skipper was determined to carry out whatever we were supposed to be doing, so we did it. Symptoms of the problem was really aggravated when a scope was lowered. Leak searches continued.
We were short of hydraulic oil again so began manufacturing it from our engine oil, 9250D, 2 parts, and diesel fuel, 1 part. This was mixed in the FER and carried through the boat all the way to the escape trunk in the FTR and poured in the funnel/hose rig to the storage tank and then pumped to the hydraulic supply tank which was about 2 feet from where we were making the stuff. Nobody figured out that we should find a way to get it in the tank directly.
We were steaming along at periscope depth and all of a sudden, one of the MBT vents opened magically all by itself!!! Apparently a scope had been raised and lowered and while it was going down, the vent opened itself. A bit more concern was raised about the hydraulic problem. The XO got the Engineer and was doing a compartment by compartment search. They got as far as the FER and just a freak chance of the boat rolling enough while someone was looking spotted the leak. Someone doing maintenance on the return line filters had left the vent open. The vent was piped up to the lowest part of the bilge so as it drained our hydraulic system, the oil just mixed with the other oil in the bilge and since the end of the vent line was below the surface, it couldnt be seen. That fixed the problem of losing the oil but the system was still messed up. Finally someone found the main hydraulic return stop valve shut, also left over from the filter job. The valve was opened and the problem solved, except for an apparent thought in someones mind that sabotage was afoot.
The XO was interviewing the people who stood watch in the FER. He sent for me and when I got to the compartment, he asked me if I knew where the valve was located. I told him, Sure, right over there, and pointed in the direction of the valve. He started jumping up and down and saying, He knows, he knows. I told him, I'm qualified and I'm supposed to know. That seemed to cool him a bit. I cant believe that I was the only watch stander in the FER that knew where that valve was located. I was allowed to return to my rack and continue my beauty rest. Never heard any more about the incident. The Engineer might have had notes made in his file or the A gang leader might have caught some well-deserved static.
This ends the saga of the hydraulic system screw ups except for the nagging 'what if'. What if we had been on the surface with the lookouts up and hatch open and the vent opened? One flooded ballast tank wouldnt have taken her down but it sure would have puckered some folks.