Gamechanger 1956

[fitzpatv]

This is the second Silent Service scenario in date order. The USA has just commissioned the world's first nuclear-powered sub, the Nautilus, but is aware that the USSR isn't far behind in the technological race. As a training exercise, the Nautilus is ordered to carry-out a mock attack on the Iowa battlegroup as it sails from Norfolk, Virginia to Bermuda. (You also have the option to use the diesel-electric sub Razorback instead, the choice being made - hindered by an annoying bug - shortly after the scenario starts).

Starting W of Bermuda, Nautilus carries 16 Mk14 conventional and 14 Mk35 homing torpedoes. She has 4 forward and 2 rearward tubes, though I found that the numbers of 'fish' she can fire at once and in what direction is somewhat elastic and that reloads don't take long). As a nuclear sub, she can stay down indefinitely and has a flank speed of 23 knots, though she cavitates at 8.

To assist during the exercise, you have a squadron of Albatross flying boats on Bermuda. These have impressive endurance and make the job of finding the Iowa fairly easy.

Iowa is accompanied by the heavy cruiser Boston (which you are also ordered to 'sink') and escorted by six destroyers of Gearing, Forrest Sherman and Fletcher class (two of each). The escorts have sonar to just over 2nm and a selection of ASW torpedoes, depth charges and Hedgehog launchers. The task group is also accompanied by Neptune patrol planes, which rely on sonobuoys (with limited range and duration) for detection and ASW torpedoes for prosecution of contacts. Boston also has early Terrier SAMs with a range of 20nm to keep shadowing planes at bay. Terriers have a ceiling of 65,000', but are ineffective against sea-skimming targets below 1,000'.

The maths are very much against a successful attack. Iowa has 5,320 DP and Boston 2,250, whereas a Mk14 torpedo does 292 DP with 40% accuracy and a Mk35 150 (64%). Go figure. You're relying on critical hits and the rules on this aren't transparent. To the best of my knowledge, there were just three instances of a battleship being sunk by a sub in WW2 (the British Royal Oak at anchor at Scapa Flow and the Barham in the Med by U-Boats and the Japanese Kongo by USS Sealion II in the Pacific).

As expected, finding and tracking the task group wasn't difficult, using two Albatrosses with a third as backup. I was able to get in close for detailed info by skimming in at 800' with one while shadowing at a safe distance with another. This intel revealed that the two heavy ships were in the middle, with the Fletchers to the left of each close-in. The Gearings were positioned ahead left and right a couple of nm away, with the Forrest Shermans a little further away behind at similar angles.

Nautilus was able to carry-out a dummy attack on a tanker encountered en route to her rendezvous with the targets. This assured me that I could attack from just above the layer, but not below and that clear sonar readings required being about 2nm or less from the target at cruise speed.

As Nautilus approached the task group, it began to execute regular course changes to throw me off. This forced me to manoeuvre at Flank to keep up, but I was far enough away for this to be safe. With the Neptune absent at the key moment, I was able to drop to Creep, just above the layer for my attack run from just ahead, with the task group on my left.

Passing just behind the Gearing-class Basilone, I slipped through the screen undetected, closed and, since she was the nearer target, expended all of my ammo putting no less than 15 torpedoes into the Iowa. Ten penetrated her armour, doing heavy damage and leaving her dead in the water. This was enough for 500 VP and an Average result. Without being decidedly lucky, this was as much as I could reasonably have done.

The escorts didn't do a very energetic job of hunting me down, mostly dropping to Creep speed and searching in place. This left a nice big gap to the SW and I glided away at Creep until far enough to go to Cruise. The Neptune arrived too late to make a difference and sowed sonobuoys around the task group, but I was well away by then. The log showed that she'd used a ridiculous 742 buoys over the course of the game.

The Iowa refused to sink, so I ran down the clock for what on paper was a Draw. Had to be reasonably satisfied with that. Have to question, though, whether even a ship as big as the Iowa could really sustain 15 torpedo hits, with ten penetrating. Clearly, the successful attack run owed a lot to the shortcomings of 1950s sonar below shallow depth.