In the April issue of THE SUBMARINE REVIEW, Rear Admiral Holland offered some very useful ideas about uncertainty in submarine fire control solutions, and by extension-in the new age of information warfare. He mentions the seemingly overwhelming “need” for “one more leg” by the fire control party before they are ready to shoot. I had occasion to observe this first hand as Commander Submarine Division Forty One in Charleston during the period 1971-1972.
There were eight submarines and one submarine rescue vessel in the division at the time. Five of the boats were Guppy IIIs, equipped with the AN/BQG-4 sonar-Puffs. Despite the Puffs installation, it wasn’t apparent from the review of the torpedo firing reports that the Guppy Ills were doing much better at torpedo shooting than their non-Puffs equipped contemporaries in the division. That puzzled me. I had been Executive Officer in USS PICKEREL (SS-524) in 1962-1963, when we went through the Guppy m conversion, and Puffs was installed. We had learned how to use the new passive ranging sensor and found that it gave us many advantages in submarine vs. submarine combat. Asking around, I found that none of the Guppy III COs had any doctrinal publications on the use of Puffs in the passive sonar approach and attack. I contacted the Operational Test and Evaluation Command up in Norfolk, and was able to obtain a copy of the OPEV AL report on Puffs and refresh my knowledge of the recommended tactics.
One of my first opportunities to observe the use, or rather the non-use, of Puffs information, came while embarked in REMORA while she and TIRU were returning in company from the Bahamas. The two boats alternated serving as ASW target and attacker as we transited back. I watched the REMORA CO, sonarmen, and fire control party detect the TIRU as she commenced snorkeling, determine initial true bearing, and take an approach course. So far so good. Then we commenced to jink and maneuver, as the fire control party strived to determine range to the target. It seemed that we were changing course every 3-5 minutes. We wound up twisting and turning, and on the fire control plot looking like the legendary bird, the Australian Side Hill Merrill, which according to the old story-when startled goes faster and faster, in circles of ever decreasing radius with ever increasing speed until it vanishes in a puff of smoke. The fire control party was never able to obtain useful range information from the Puffs sonar. We wound up simulating shooting at short range with a dubious solution.
After a quick critique of the approach by the CO while we served as a target for TIRU, I asked the CO if I could have the next run. He was somewhat surprised, and I quickly assured him I did not want the conn-merely wanted to dictate REMORA’s maneuvers to him during his next run as attacker. He agreed, as any CO is wont to do when the DIVCOM suggests some thing that doesn’t have the potential to sink the boat, but you could see the uncertainty.
The next run started out much the same as the REMORA’s previous turn as attacker. Detection, followed by determination of direction of target motion. I then told the CO to take a 70 degree lead angle, make turns for 2/3 speed and, and-not do anything. You could see the palpable desire to maneuver flitting across the COs face and it was reflected in the faces of the fire control party as the leg proceeded. Sonar was having no trouble tracking the snorkeling target. Finally the Puffs sonar provided a range, then another, and another. Initially the ranges were bouncing around and it wasn’t easy to determine target course and speed from the plot because you had no idea which ranges were good. The fire control party, and the CO, looked appropriately suspicious of my tactics, although not a word was said. Then, something strange happened as we continued on a steady course and speed. The ranges started to smooth out, and before long the fire control plot looked like a good ST radar approach when you didn’t have to worry about the target detecting your periscope radar. We had target range, course and speed cold. We could have fired Mk 14-5 torpedoes for a hit, let alone using the Mk 37 acoustic torpedoes
which we carried for attacking submerged targets.
Afterwards, as we reviewed the run, I pointed out something that I considered absolutely key. We didn’t need to determine target course and speed before firing. We didn’t need a fire control solution. We only really needed to know that the target was inside 10,000 yards and closing. The Mk 37 torpedo would take care of the fire control solution all by itself. The important thing was to get a shot off early-before the target could shut down-just as soon as the attacker had good ranges, and the range didn’t exceed the torpedo’s reach. The key to getting the good ranges was to maintain a steady course and speed while maintaining a broad aspect and allow the Puffs computer time to integrate the information it was receiving.
When we returned to Charleston, I put out the information on recommended Puffs approach tactics to all the Guppy III COs. I also did something else, slightly underhanded. The torpedo shop in Orion used to issue exercise Mk 37 torpedoes with either six minute or ten minute batteries. As you might imagine, there were far more six minute batteries available than ten minute batteries. This exercise battery limitation worked to further constrain the COs to focus on short range solutions, since they knew that they could only fire at short ranges during exercise firings if they were to get a hit. In order to eliminate that bias, I told the Weapons Officer in Orion that I didn’t care how he did it. but that from now on SUBDIV 41 boats would only take exercise Mk 37 torpedoes equipped with ten minute batteries to sea to shoot. With these two measures, the Guppy Ills of the division were able to increase the firing ranges of their Mk 37 exercise torpedoes by 100 percent, and to increase their hit percentages significantly