A sub v sub scenario from the High Tide boxed set.

 

This is my second AAR based on sub verse sub. I know a bit more about the rules so more stuff might come into play. I’m also plotting movement on graph paper for the first time, rather than just having two subs approach each other and measuring closing distance.

 

LA class submarine is up against an Oscar sub and tensions are high with sea state 4, so neither has deployed their towed array sonar in case they need to suddenly manoeuvre. The LA is very quiet while the Oscar (quiet) has a better hull mounted sonar … actually, checking the stats and I found my first mistake. I used the LA’s hull mounted sonar with a range of 3.8nm but when I used the Oscar hull mount I used its ACTIVE range of 5.1 instead of its passive rand of 2.6. Oh well.

 

Random die rolls seen the LA class heading south at 15kts at a depth of intermediate II while the Oscar was heading East at a speed of 10kts at a depth of intermediate I. So they are approaching a common point from 90 degree different aspects. At the time this meant the Oscar had a slight advantage (moving slower) because it had a better chance of detecting the LA class. Even so, I thought this would be a good encounter and see how the soviet sub would fare.

 

Initial distance between contacts was just over 6.0nm. The Oscar had two chances to pick up the LA sub but failed to do so. In the 3rd tactical (3 minute) turn both subs had a chance to detect each other, with the Oscar having a 50% chance to the LA’s 25% chance. The Oscar detected the LA sub this turn, and at the start of the next turn reduced speed to 5kts to make itself harder to be detected. This worked, because the range of detection shrank to under 2.0nm for the LA due to Oscars reduced speed.

 

Before being able to fire, the subs had to classify the target before engaging. Having detected “something” out there I had the Soviet Oscar try and classify, but found it was unable to do so due if it was using its hull mounted sonar. So at the start of the next tactical turn, the Oscar began the process of deploying its towed array which would take 21 minutes. This mean the Oscar would have to shadow the contact for 7 tactical turns. Would it be able to maintain contact for that length of time, would the LA pick up the Oscar?

 

Distance between the two subs got as close as 2.5nm but neither sub would know that, since passive detection only gives a direction and not distance. Regardless, the LA sub had its only chance of 25% to detect the Oscar at the 9 minute mark of the encounter but failed, and since then has not been within detection opportunity range.

 

For 6 of the 7 turns it took to deploy its towed array, the Oscar was able to maintain contact. In reality, the chance to maintain the contact was 90% so it was no surprise contact was able to be maintained.

 

Once deployed, the sonar maintained contact for another turn and then classification was able to be done … but the roll failed (miserably, a 98 giving no information at all).

 

Next turn contact was lost (at the 45 minute mark by now) but was regained at 48 minutes but classification was still not able to turn anything up. At 51 minutes range was 5.0nm and Oscar maintained contact and was able to classify the contact as a sub, but that’s all she was able to deduce.

 

54 minutes into the scenario, contact maintained and classification showed the contact to be a USA sub. So the Oscar was not able to fire. Range by now was 5.5nm and two torpedoes were fired.

 

At this point I’d used up a bit over an hour of real time. I knew the range from the Oscar to the LA was 5.5nm and it got me thinking again about how would the sub commander know when to make his torps go active????? Still, that’s another thread. ….

I’ll finish up the AAR later. I'm away for the next 2 weeks.

At this point I’d used up a bit over an hour of real time. I knew the range from the Oscar to the LA was 5.5nm and it got me thinking again about how would the sub commander know when to make his torps go active????? Still, that’s another thread. …

 

KC

 

Does this help at all?

Hmmm, bad link i think.

 

The other thread i was referring to was one that was discussed around here a few weeks ago. I was just saying the whole when do torps go active thing is a discussion i wasnt going to have in this AAR.