[WIP] Prolonged DC Evasion

Peto · 11-27-07, 01:34 AM

Purpose: To create a more intense, slow and methodical escort pursuit and submarine evasion.

Why? I like to sweat.

Before the how and what I'm doing, I think a little background can help. From information I have gleaned from dozens of books and interviews with WWII Submarine Veterans and a couple Soundmen from Destroyer Escorts, I have come to the realization that what I really want in a subsim is not only the intensity of attacking. In fact, what I really want is an atmosphere that is even more intense while I'm trying to escape. And it doesn't feel right to me if an escorts attack (and my evasion) feels rushed.

Japanese Sonar in WWII had serious limitations--the most serious being the loss of contact with a submerged target during the attack run. This was because during the run, a deep target would would pass beneath the escorts sonar cone, creating a time when the sonar was blind. A submarine at 300 feet would typically pass beneath this cone at a range of approximately 500-600 yards (in real life). That gave the submarine time to evade.

Sonar Range was not the issue. The Japanese Type 93-1 Active Sonar could detect a submarine at 2500 yards if sonar conditions were good. This range remained basically unchanged throughout the war. The main upgrade the Japanese had in Active Sonar technology came from the Germans who gave them their S-Gerat sonar in late 44.

What I have done/learned: I've increased the sonar range to 2400 meters. I changed the sonar cone elevations (up and down angle) to 92-102 degrees. I then decreased the sensitivity of the sonar to 0.03--and I'm now tweaking it by smaller amounts. It is the sensitivity that is so important to creating a good balance.

What happens: I've now been testing this for over 20 hours. The scenario is simple: Gato Class vs Subchaser (Elite) in 0 wind/clear conditions. The sonar cone seems to be about right--ie the SC loses me on the way in while about 500 meters away. Now--you may be thinking that this will make evading easy--just go flank and turn. But it isn't easy. He still has time to pick up my noise passively and if he has the angle, leads me very well. Sometimes I am pinged for about a minute and he doesn't contact me. It is possible to crawl away and think you've made it only to picked up 20 minutes after he'd last had a firm contact. And I think the little guy learns though I won't say more about that for now.

The Downside: It can take 3-4 hours to get away. You can get sunk.

The Upside (to my way of thinking): it can take 3-4 hours to get away. It's all about "Angles and Dangles", when to pour on the coal and when to cut speed to 1 knot.

What I'm looking for (and why I'm posting this now): I want to run a couple more tests to tune this a bit more. But by this weekend, I should have a decent test set up with a couple small scenarios. One of them will probably be the one I'm using now. I'd like about 4 people who are interested to run this test and provide feedback. I would prefer old-timers who've been playing subsims since Aces of the Deep--because this feels a lot like I remember evasion felt in that sim. I would also prefer that this test is done with external view disabled.

Well--this is a long post. If I've bored you to tears send me a bill and I'll mail you a box of kleenex

. My closing thought is:

This is the most fun/challenge I've had evading escorts in any subsim I've played. But the proof will be in the pudding.

Cheers!!!

Peto

Questions Welcome.

panthercules · 11-27-07, 01:58 AM

Count me in. I haven't been challenged by the escorts in this sim yet, and I miss the nail-biting times from SH3. One question - will I be able to test this using my current NSM/ROW/RFB/RSRD install, or will I need to skinny down to stock or something else to give this a test? As easy as JSGME has made it to deactivate all the mods and get them back in again, it probably doesn't matter, but if I'm gonna be spending a few hours getting dogged by destroyers I'd just as soon have my nice, tricked out boat to spend that time in if I have a choice

BTW - when you say below that "The sonar cone seems to be about right--ie the SC loses me on the way in while about 500 meters away.", I'm curious how you know that they have lost you (I've never really spent any time analyzing the escort behavior in SH4 - always playing with external view off (except when I'm testing the weather or something else like that), so the only way I can tell they've really lost me is when I eventually get away

)

Peto · 11-27-07, 02:09 AM

Well--for testing I ned external view on so I can check ranges. It feels like cheating

. I know he loses me on active because his pinging fades and stops while he's running in.

As far as mods (Great question)--you should be OK. I'm using TM and others. The only files that will be changing are Sensor_AI and a couple sound files. The sound files are to make your sub more quiet so you can hear the escort's approach better--Very Important!!! I'll have it set for JSGME. NSM won't matter when you're trying to get away :hmm:.

Thanks Panther! I'll be looking forward to your remarks--and if you don't like it, that's what I want you to tell me. Just tell me why. I don't expect it to be everybody's cup o' tea.

Bill Nichols · 11-27-07, 08:56 AM

I'm totally in favor of this

I've reached March, '45 in my current career and I'm frankly disgusted with the escorts. True, they've forced me to break off an attack a couple of times, but evading them has been a cut-and-dry process of going deep, slow and ultra-quiet. They've yet to cause me to break out in a sweat, and they give up too easily.

Peto · 11-27-07, 09:01 AM

Quote:

Originally Posted by Bill Nichols

I'm totally in favor of this

I've reached March, '45 in my current career and I'm frankly disgusted with the escorts. True, they've forced me to break off an attack a couple of times, but evading them has been a cut-and-dry process of going deep, slow and ultra-quiet. They've yet to cause me to break out in a sweat, and they give up too easily.

Bill: Thanks for the Post! Can I ask what mods (if any) you're using? My experience was much like yours but TriggerMaru definitely raised the bar of escort ferocity

!

tater · 11-27-07, 09:08 AM

Very interesting.

Gets me thinking... What about an active sonar with a HUGE range, but low sensitivity. I'm talking 20km type ranges.

Would that work? IJN escorts were known to drive around banging away with the sonar pinging. You could make a "bungo pete" clone of a few escorts, and the only change is a super range sonar... If the sensitivity is low enough it just might work.

AVGWarhawk · 11-27-07, 09:11 AM

Peto!!!!!!!!! This little ditty is long over due!!!! Often when I'm detected and attacked I will go silent and deep. As I wait it out (about 15 minutes before the DD leave) I leave the computer to do other things. If I have to go silent for 4 hours I can enjoy the realistic counter attack and go do other things around the house. This opens up other aspects of the counter attack that can become a concern....battery life, CO2 levels. These two aspects just do not matter at the present moment. 15 minutes and they are gone, I surface and start the chase. Nice work

Bill Nichols · 11-27-07, 10:12 AM

Quote:

Originally Posted by Peto

Bill: Thanks for the Post! Can I ask what mods (if any) you're using? My experience was much like yours but TriggerMaru definitely raised the bar of escort ferocity

!

I'm a big fan of RFB, that's what I always use.

Ditto for AVGWarhawk's comment, my experience has been identical to his.

11-27-07, 01:34 AM	#1
Peto Ace of the Deep Join Date: Jul 2007 Location: The details of my life are quite inconsequential Posts: 1,049 Downloads: 4 Uploads: 0	[WIP] Prolonged DC Evasion Purpose: To create a more intense, slow and methodical escort pursuit and submarine evasion. Why? I like to sweat. Before the how and what I'm doing, I think a little background can help. From information I have gleaned from dozens of books and interviews with WWII Submarine Veterans and a couple Soundmen from Destroyer Escorts, I have come to the realization that what I really want in a subsim is not only the intensity of attacking. In fact, what I really want is an atmosphere that is even more intense while I'm trying to escape. And it doesn't feel right to me if an escorts attack (and my evasion) feels rushed. Japanese Sonar in WWII had serious limitations--the most serious being the loss of contact with a submerged target during the attack run. This was because during the run, a deep target would would pass beneath the escorts sonar cone, creating a time when the sonar was blind. A submarine at 300 feet would typically pass beneath this cone at a range of approximately 500-600 yards (in real life). That gave the submarine time to evade. Sonar Range was not the issue. The Japanese Type 93-1 Active Sonar could detect a submarine at 2500 yards if sonar conditions were good. This range remained basically unchanged throughout the war. The main upgrade the Japanese had in Active Sonar technology came from the Germans who gave them their S-Gerat sonar in late 44. What I have done/learned: I've increased the sonar range to 2400 meters. I changed the sonar cone elevations (up and down angle) to 92-102 degrees. I then decreased the sensitivity of the sonar to 0.03--and I'm now tweaking it by smaller amounts. It is the sensitivity that is so important to creating a good balance. What happens: I've now been testing this for over 20 hours. The scenario is simple: Gato Class vs Subchaser (Elite) in 0 wind/clear conditions. The sonar cone seems to be about right--ie the SC loses me on the way in while about 500 meters away. Now--you may be thinking that this will make evading easy--just go flank and turn. But it isn't easy. He still has time to pick up my noise passively and if he has the angle, leads me very well. Sometimes I am pinged for about a minute and he doesn't contact me. It is possible to crawl away and think you've made it only to picked up 20 minutes after he'd last had a firm contact. And I think the little guy learns though I won't say more about that for now. The Downside: It can take 3-4 hours to get away. You can get sunk. The Upside (to my way of thinking): it can take 3-4 hours to get away. It's all about "Angles and Dangles", when to pour on the coal and when to cut speed to 1 knot. What I'm looking for (and why I'm posting this now): I want to run a couple more tests to tune this a bit more. But by this weekend, I should have a decent test set up with a couple small scenarios. One of them will probably be the one I'm using now. I'd like about 4 people who are interested to run this test and provide feedback. I would prefer old-timers who've been playing subsims since Aces of the Deep--because this feels a lot like I remember evasion felt in that sim. I would also prefer that this test is done with external view disabled. Well--this is a long post. If I've bored you to tears send me a bill and I'll mail you a box of kleenex . My closing thought is: This is the most fun/challenge I've had evading escorts in any subsim I've played. But the proof will be in the pudding. Cheers!!! Peto Questions Welcome. __________________ If your target has a 30 degree AOB, the range from his base course line equals the current range divided by 2. Last edited by Peto; 11-27-07 at 01:47 AM.

11-27-07, 01:58 AM	#2
panthercules The Old Man Join Date: Apr 2005 Posts: 1,336 Downloads: 6 Uploads: 0	Count me in. I haven't been challenged by the escorts in this sim yet, and I miss the nail-biting times from SH3. One question - will I be able to test this using my current NSM/ROW/RFB/RSRD install, or will I need to skinny down to stock or something else to give this a test? As easy as JSGME has made it to deactivate all the mods and get them back in again, it probably doesn't matter, but if I'm gonna be spending a few hours getting dogged by destroyers I'd just as soon have my nice, tricked out boat to spend that time in if I have a choice BTW - when you say below that "The sonar cone seems to be about right--ie the SC loses me on the way in while about 500 meters away.", I'm curious how you know that they have lost you (I've never really spent any time analyzing the escort behavior in SH4 - always playing with external view off (except when I'm testing the weather or something else like that), so the only way I can tell they've really lost me is when I eventually get away ) __________________

11-27-07, 02:09 AM	#3
Peto Ace of the Deep Join Date: Jul 2007 Location: The details of my life are quite inconsequential Posts: 1,049 Downloads: 4 Uploads: 0	Well--for testing I ned external view on so I can check ranges. It feels like cheating . I know he loses me on active because his pinging fades and stops while he's running in. As far as mods (Great question)--you should be OK. I'm using TM and others. The only files that will be changing are Sensor_AI and a couple sound files. The sound files are to make your sub more quiet so you can hear the escort's approach better--Very Important!!! I'll have it set for JSGME. NSM won't matter when you're trying to get away :hmm:. Thanks Panther! I'll be looking forward to your remarks--and if you don't like it, that's what I want you to tell me. Just tell me why. I don't expect it to be everybody's cup o' tea. __________________ If your target has a 30 degree AOB, the range from his base course line equals the current range divided by 2.

11-27-07, 08:56 AM	#4
Bill Nichols Master of Defense Join Date: Mar 2000 Posts: 1,502 Downloads: 125 Uploads: 0	I'm totally in favor of this I've reached March, '45 in my current career and I'm frankly disgusted with the escorts. True, they've forced me to break off an attack a couple of times, but evading them has been a cut-and-dry process of going deep, slow and ultra-quiet. They've yet to cause me to break out in a sweat, and they give up too easily. __________________ My Dangerous Waters website:

11-27-07, 09:11 AM	#7
AVGWarhawk Lucky Jack Join Date: Jun 2005 Location: In a 1954 Buick. Posts: 28,277 Downloads: 90 Uploads: 0	Peto!!!!!!!!! This little ditty is long over due!!!! Often when I'm detected and attacked I will go silent and deep. As I wait it out (about 15 minutes before the DD leave) I leave the computer to do other things. If I have to go silent for 4 hours I can enjoy the realistic counter attack and go do other things around the house. This opens up other aspects of the counter attack that can become a concern....battery life, CO2 levels. These two aspects just do not matter at the present moment. 15 minutes and they are gone, I surface and start the chase. Nice work __________________ “You're painfully alive in a drugged and dying culture.” ― Richard Yates, Revolutionary Road

11-27-07, 09:08 AM	#6
tater Navy Seal Join Date: Mar 2007 Location: New Mexico, USA Posts: 9,023 Downloads: 8 Uploads: 2	Very interesting. Gets me thinking... What about an active sonar with a HUGE range, but low sensitivity. I'm talking 20km type ranges. Would that work? IJN escorts were known to drive around banging away with the sonar pinging. You could make a "bungo pete" clone of a few escorts, and the only change is a super range sonar... If the sensitivity is low enough it just might work.