SUBMERGE BACKING DOWN

In September 1955 I rode SEA LEOPARD (SS 483) for a week of type training in the Virginia Capes Operating Areas-the underway part of my submarine qualification examination. Monday I was snapped in on SEA LEOPARD’s procedures, got the boat underway, was OOD out the channel, compensated and made the trim dive; routine functions with no drills thrown in. Next morning, Tuesday, I stood by on the bridge awaiting the real tests with some apprehension.

The skipper, Commander Robert L.J. Long, joined me on the bridge and asked if I’d ever submerged backing down. Surprised that he would even ask, I said, “Yes, sir; many times.”

“I didn’t say, ‘Backed down submerged,’ “he said patiently, “he said, ‘Submerged backing down’.”

I did a double-take, saw that be wasn’t joking, and said, “No, sir.”

The captain said, “Neither have I. Let’s try it.”

Thoughts of what to do filled my head, but he hadn’t finished:

“After we get Steinway I’ll drop down to the conning tower; when I order the dive I’ll see that the helmsman holds the rudder amidships and rings up all back full rather than ahead full. Think about the boat’s attitude: negative tank is going to give you an immediate bow-down angle; you’ll have to deal with that. I’ll order 80 feet; that should give you some leeway in leveling off. Ready? Back her down.”

The sea was lovely with no waves, just one of those long gentle swells so often seen in the summer off the Virginia Capes. At about six knots sternway the captain called up the hatch, “Submerge.”

I yelled, “BLOW NEGATIVE”, as I held the upper hatch shut; even so when I hit the diving stand I could feel the bow-down attitude. With full dive on both planes, backing full, and negative at the mark SEA LEOPARD still clung stubbornly, interminably, to the surface. Finally, the angle shifted aft. I called for a two-thirds backing bell. Suddenly the angle, sluggish for so long, began running. And once started, how it ran!

The inclinometer bubbles quickly vanished; the pendulum inclinometer was swinging at an alarming rate.

“All stop; all ahead full. Blow the after group.”

There was a rush of 600 pound air. The air manifold operator reported, “Blowing the after group.”

The chief of the watch on the hydraulic manifold, urgently intense, was saying, “sir! The main vents are open!”

“secure the blow.” I was straining to retain the professional sang froid of the crew around me. What a boat! Everyone in the control room was silent except as their jobs required, holding onto whatever was available to keep their feet. The only disturbance was a crash of dishes in the crew’s mess and the duty cook’s hastily subdued cussing. I was balanced with my right foot on the deck and my left on the bulkhead behind the conning tower ladder. The depth gauges were rotating fast. I saw the pendulum inclinometer hit 43 degrees by the stem as we passed 200 feet.

A quiet voice from above said, “Everything all right, Lefty?”

Executive Officer Lieutenant Commander Lionel (Lefty) Goulet, similarly balanced behind me (he hadn’t uttered a word to that moment), answered in the same calm manner, “OK here, Captain.”

And indeed everything was all right. The angle was easing, the planesmen were getting control.

“All stop; all back two-thirds.” So, in reverse, we planed placidly up to where I was able to report, “Eight zero feet, conn.”

I was astonished when the captain called down, “well done.”

Later, in the wardroom, Lefty reviewed the morning exercises. When he addressed the backing down dive, he said, “There were several good lessons in the dive. In particular, when we lost the bubble, the diving officer used his bead and blew the after group with the vents open. That put enough air in the tanks to help check the angle, but almost immediately vented off. As unstable as the boat was with sternway we probably would have broached had venting been delayed.”

If my face was red it wasn’t from modesty. Here’s the background on what had happened:

In 1955 the submarine procedures manual was being updated and standardized in SUBLANT. In COBBLER (SS 344), the boat I was trained in, the chief of the watch automatically shut the main vents when passing 4-0 feet on a dive; SEA LEOPARD’s chief of the watch, except at the diving alarm, only shut or opened the main vents on order from the diving officer. Blowing main ballast with the vents open hadn’t been a matter of being smart; in the excitement I’d forgotten the (to me) unfamiliar SEA LEOPARD procedure, then compounded the error by not checking the Christmas tree before ordering the blow.

I’ve always suspected that Lefty knew rd forgotten those damn vents. It’s too late to ask, but it would have been in that gentleman’s character to give a young squirt the benefit of the doubt knowing that the lessons were perhaps even more effective when swallowed with a dose of guilt.