The  Steep  Dive
by  Crew  Members
28  Jan  2006
 I had a Sea Story ready to post when I received a similar story on the same incident from Ken DeKing. I begin to
think there must be others who also remember the time the Thornback unexpectedly took a steep down angle and
was headed for the bottom of the Atlantic Ocean. So, if you remember the incident and would like to tell us where
you were and what you were doing during that time, send me your comments. There's also a reference to the
incident in the newspaper article, "Thornback Heads Home", from the Charleston Evening Post by Ed Harrill. This
article, written in July 1959, is posted on the Newspaper section of this website.

DeKing remembers:
I wonder how many people remember the incident on our shakedown cruise after the Charleston Navy Yard
overhaul when we lost depth control.
We had an automatic depth control devise that had a bad habit of going to full dive when it was shut off. The yard
was supposed to have fixed this problem, and we were snorkeling at standard speed, testing the fix, when the
officer of the deck decided to shut it down to see if it really was fixed. It was not, the planes went to full dive. I was
on duty in the maneuvering room, as senior controllerman, and as soon as I felt us going at a steep angle, I shut
down the engines and told the junior controllerman to go to "All back full". The junior guy, I'm sorry I can't
remember his name but he was an EM3 with red hair, said "We didn't get a bell", and I said "I don't care, do it". We
got to a very steep angle before the boat was leveled. A few minutes later Captain Babbitt called on the 7MC,
"maneuvering, how long before you got the bell did you get to all back full"? We both felt a cold chill, but I said
something like "about 20 seconds, sir", the captain said "very well". As long as I served on the Thornback, I don't
think they ever used the automatic depth control again.

Gurr remembers:
The incident aboard the Thornback when the DKC (Depth Keeper Control) malfunctioned will always be with me. I
was the throttleman on the 2000-2400 watch in the after engine room at that time.  We were snorkeling from Key
West to Charleston with the DKC set for snorkel depth (I believe that was 56-57-58 feet) when we suddenly took a
steep nose-down attitude. The snorkel head valve closed as it went below the surface and the engines were
sucking air from inside the boat and exhausting it out the snorkel exhaust mast. The engines were supposed to
shut down automatically at 6 inches of vacuum and I had never seen that happen. Usually the worst case in rough
seas would only result in about 2.5 - 3 inches of vacuum before the snorkel head valve would pop out of the water
and open. The snorkel head valve had 3 electrodes on it, which caused the valve to shut when the electrodes
became wet. Once, I was asleep in my bunk during snorkeling and it must have been rough because when I awoke
my ear drums were very tender and it hurt when I swallowed. This was due to the interior of the boat switching back
and forth between vacuum and pressure over and over, and, me being asleep I wasn't swallowing to equalize the
atmosphere in the boat.
Anyway, as we nosed down I remember grabbing the overhead circulating sea-water valve to keep from falling
forward.  I was thinking we were not going to pull out of the dive in time to prevent the engine automatic shut-down
because of how fast we were going deeper, the steep down-angle, and the speed of the vacuum gauge needle.
The two men (I believe Kostiuk was the throttleman and Sears was the oiler) in the forward engine room were trying
to hold on and I remember seeing Sears slip down due to the steep angle and he was bumping along forward on
the engine room deck on his butt. Like me, Kostic was hanging on to an overhead valve handle.
Around 6 inches of vacuum the engine(s) shut down, we were still heading down and loose gear was falling over
and sliding forward along the deck. I can't remember if we were snorkeling on one or two engines. I was very
puzzled as to what was going on as we kept going down. Then I heard the air as the control room begin blowing the
bow tanks in an attempt to check the dive. But we kept going down.
I seem to remember the depth gauge in the engine room was passing 200 feet when I felt the boat begin to shake,
indicating the screws had been put in reverse. The down angle begin to lessen and we slowly begin to level out but
then the boat begin to take a stern-down angle. Shortly after this the boat returned to zero bubble.
I was later told the DKC had malfunctioned, suddenly put us in a steep dive and before the dive was checked the
forward torpedo room depth gauge was reading 400 feet. We had a reporter on board from the Charleston
newspaper riding with us to do a story for his newspaper.  
Was the Big Dive played down by the reporter or did he not understand we were close to losing control due to the
steep down angle? There had to be a degree of panic in the control room and he would have had to pick up on it. I
would estimate our down angle at between 35 and 45 degrees. There was no way you could have stood on the
deck or walked through a compartment. I was hanging on to the overhead valve handle, almost swinging from it
and I knew not to let go. And when I heard the tanks being blown and we still continued down I remember thinking
the angle was so great that the air could not raise the bow. Imagine what was happening in the control room when
the blowing of the tanks didn't correct the problem. (Remember one of the first things we did on orders to surface
was blow the bow tank to get an up angle.) Maybe the reporter was asked to make it sound routine and not to get
After reading DeKing's remembrance and learning how he reacted, one could speculate that he could have
possibly saved the boat and crew that night. Suppose DeKing had waited for the order to reverse the screws?
Suppose the other electrician had refused DeKing's order to go to reverse until he got the bell?