ASW depth charging successes in WitP (and UV) compared to historic results...

[Apollo11]

Hi all,

While reading book (I am still unable to play my UV PBEMs):


Martin Middlebrook

Convoy: The Greatest U-Boat Battle of the War

ISBN: 0-304-36578-5


I found wealth of interesting information.


This book deals with famous eastbound convoys SC.122 and HX.220 and resulting
battle in the north Atlantic in the March of 1943.

In that battle the convoy HX.229 lost 13 ships of 95,502 gross weight and the
convoy SC.122 lost 9 ships of 53,094 gross weight (for total of 22 ships and
146,596 tons gross weigh together with 161,000 tons of cargo lost).

Germans lost one U-boat during the battle (U.384) and had several others
damaged (but not sunk).

To get such results Germans fired 90 torpedoes (from around 30-40 submarines
involved).

The Allies, on other side, expended 378 depth charges (229 by HX.229 surface
escorts, 69 by SC.122 surface escorts and 80 by British Coastal Command
aircraft).

Therefore there were dozens and dozens of depth charge attacks and only one
sinking of enemy submarine.


So... how can we translate this huge battle in north Atlantic to our UV and
WitP?


Well... one thing is pretty clear... there were many many many unsuccessful
depth charge attacks (although if they didn't sink/damage submarine they did
stop it from attacking and thus were success in one way).


In our current UV v2.30 (and I presume WitP ALPHA) the depth charge attacks
once they happen are usually 100% deadly and result in submarine sinking.

This is especially true for Allied ASW effort where Japanese submarines almost
always pay the highest price once the surface ships start depth charging.


IMHO, the number of successful hits resulting from depth charge attacks in UV
(and WitP) should be greatly reduced but number of overall attacks (that miss
or sometimes damage submarine) should increase several times.

Historically submarines were subjected to depth charge attacks lots of times
(from all sides - Allies attacking German and Japanese submarines and Japanese
attacking US submarines) but only fraction of those attacks were fatal.


I think that it would be beneficial that similar results start happening in UV
and WitP...


Any ideas/comments/suggestions gentleman?



Leo "Apollo11"


P.S.
Please note that the north Atlantic convoy battle I mention above was one of
the largest battles ever fought there (certainly counting the overall number
of involved submarines) and that it was the last success of admiral Donitz
U-Boats. After March 1943 the "North Atlantic Air Gap" was closed and CVEs
started to come into convoy service together with many support escort TFs
which were able to help attacked convoys. In essence this battle was true
"swan's song" and peak of German U-Boat effort...

[Sonny]

The complaint I have with submarine warfare in UV is that you get a report that you sunk the sub. Like a lot of the intelligence in UV it is too much. Only occasionally should that message appear. The defender (submarine) will know by looking if he was sunk but the attacker should not always know of the success or failure - or even if the sub was hit. I am not totally sure but I don't remember a false sub sunk message as far as my subs are concerned.

EDIT: Also the hits are too deadly. Two hits and you are a gonner. Yes that should be enough to sink a sub. But a near miss (or near hit depending which side of the battle you are on) should do some damage. I have never seen anything like this that i can recall. It is either no hits or one hit with approx 50% damage or two hits and a sinking.

[mdiehl]

Leo -

In what year are the Allies seeing perfect success? 1942 would be too early (and in no year should the allies have a guaranteed kill). On the whole, however, Allied crews were far better trained at ASW and the Allies should be better at it, even when the only weapons deployed are pressure-triggered DCs.

Sonny -

Depends on the weapon. If the Allied escort is using mousetrap or hedgehog, a "boom" almost always indicates a hit. Not always enough to do for the sub, but usually enough to send her to the surface where she may be finished off.

I think the damage phenom that you are describing comes from the blob of hit points approach applied to subs. Maybe they could alter the dc routine however, so that fewer DC attacks are fatal but tend to inflict SYS damage. That way a good, serious, non-fatal DC pounding can send the sub home.

[Sonny]

...............

I think the damage phenom that you are describing comes from the blob of hit points approach applied to subs. Maybe they could alter the dc routine however, so that fewer DC attacks are fatal but tend to inflict SYS damage. That way a good, serious, non-fatal DC pounding can send the sub home.

Yeah, that is what I am talking about. Maybe some float damage to simulate a few leaks etc. but mostly system damage.

About enough damage forcing the sub to surface - yeah, I didn't think of that.

[gus]

To be fair you can't really compare WWII historical results, especially the battle cited, with UV sub & ASW behavior for a number of reasons,

First, sub & ASW doctirne as practiced in UV by most of my opponents and myself is completely ahistorical. Subs, especially Aliied S-boats, may be used far more aggressively than IRL and quite successfully I might add. Players also use them en masse and think nothing of moving them all over the map racing from one patrol zone to the next to take advantage of sighting rpeorts. On the flip side it can be argued quite effectively that ASW for both side is optimally executed via the use of large hunter killer groups instead of assigning these boats to normal convoy escort duties. Both of these behaviors combined effectively put subs and merchants in harms way so of course the 'effectivness of subs and ASW is grotequely skewed out of proportion. I believe the submarine system in PacWar while flawed in different ways was a much more accurate portrayal of this part of the war and the weapon suystems involved but I am probably a minority of one in that regard.

Also comparing WWII German sub doctrine and tactics in the Atlantic with the situation in the Pacific theater will only cloud the issue further as it is effectively comparing apples and oranges. The Germans were playing a completely different game than everyine else. The only nuggets of wisdom that one can coallesce from comparing these two theaters is that the Allies learned some very valuable lessons in both ASW and modern submarine doctrine from going toe to toe with the U-boat menace while the IJN did not, adapt or die as they say.

NB It can also be argued that most of the ahistorical behaviors in UV can be attributed to players taking advantage of the system and pushing units beyond their histroical capabilities. This certainly covers sub and ASW behavior as mentioned above but also can be applied to mine warfare, air combat and most of the other bug bears that UV players grouse about as well!

-g

[mogami]

Hi, I have seen many "I-16 sinks" reports and then next turn found the sub still alive. (sometimes damaged other times perfectly fine)

I've had my share of subs survive DC attack only to sink on way home.

I think the USN ASW is ok but was the Japanese ASW really so awful? The USN subs can move right through Japanese ASW and it is very rare to hit or sink them. (I'm happy when I can stop them from attacking) I'm still trying to get a sub to hit a mine in WITP. I've been able to hit both Allied and Japanese submarines with DC.

[gus]

Hi Mogami

I have seen many "I-16 sinks" reports and then next turn found the sub still alive. (sometimes damaged other times perfectly fine)

This hasn't been my experience but I will take your word for it. Whenever I get a sub sunk message for either side it has invariably been followed by the death rattle sound effect and at least with my subs has been an absolute indicator of death!

I've had my share of subs survive DC attack only to sink on way home.

This has been my experience too, as well as making it to a safe harbor and surviving.

I think the USN ASW is ok but was the Japanese ASW really so awful? The USN subs can move right through Japanese ASW and it is very rare to hit or sink them. (I'm happy when I can stop them from attacking)

I think most of us can live with the situation as we have learned how to deal with it I just wish it were implemented a bit better.

I'm still trying to get a sub to hit a mine in WITP. I've been able to hit both Allied and Japanese submarines with DC.

Agreed, I have no idea why subs are relatively immune to mine fields in UV especially in shallow water/port hexes, hope it is better in WitP.

-g

[mogami]

My all time favorite false report was "CV Lexington sinks" the next turn there she was without a scratch on her. The Japanese player had lowered most of his CAP and was limping back towards Shortlands. Lexington sank 2 IJN CV without a counter strike.

[gus]

My all time favorite false report was "CV Lexington sinks" the next turn there she was without a scratch on her. The Japanese player had lowered most of his CAP and was limping back towards Shortlands. Lexington sank 2 IJN CV without a counter strike.

Gotta love it when that happens!

[mogami]

Hi, It was a bug. The first two turns after changing versions (patches) could produce some strange results. I just remembered more about that game.
So it was a fluke (hiccup) while both players changed from older verison to new one. (Still it was funny at the time, but the Japanese player did not see the humour of it all)

[Brady]

From accounts I have read Japanese ASW was not as bad as what UV seams to make it to be, I have built ASW groups with up to 6PC and DD in them and sent them to know SUB hex's to have nothing happen repatedly and then to have a DD sunk by the sub with again no atack, in a scenario I am presently playing in UV after months of play I have sunk only one US sub, the victom of a very rare suxcessfull air atack, while I have lost several Japanese sub's.

[mogami]

Hi, The USN lost 52 subs total in WW2. in 46 months of war. so you shouldn't sink more then 1 a month too often. Still I think the subs are allowed to operate right under Japanese ASW too often and too freely.
The Navy did believe certain areas were too dangerous for sub patrols.

(It should be more dangerous for the sub to encounter enemy ASW. Japanese subs do find this out in UV by 1943. USN subs never seem to have to worry about improved IJN ASW. But in a current PBEM (The only one other then my test with TJ) I am Japan and sank 2 USN subs on same day in first week of scenario. I have not lost any yet.

[Apollo11]

Hi all,

Leo -

In what year are the Allies seeing perfect success? 1942 would be too early (and in no year should the allies have a guaranteed kill). On the whole, however, Allied crews were far better trained at ASW and the Allies should be better at it, even when the only weapons deployed are pressure-triggered DCs.

The 1942/1943 is way to early for almost 100% certain kill of Japanese
submarine when attacked with depth charges (and yet this is happening almost
all the time in UV 1942/1943).

In UV v2.30 (and I presume in WitP ALPHA) when Japanese submarine is attacked
by depth charges from escorts it would receive hits which would render it sunk
(2 hits) or fatally wounded (50% or more damage).


What I would like to see instead (and what is historically accurate) is:

#1
Many many more unsuccessful depth charge attack where submarine is not damaged
at all but such attack would force submarine to hide fore hours and thus not
attack.


#2
Many many more partially successful depth charge attack where submarine would
suffer all kind of damage from near misses (like leakage, system damage,
weapon damage, reduced speed from engine damage).


#3
Much much less direct hits where depth charge(s) would hit directly and cause
massive damage (like we have now: 50% for 1st hit and sunk from 2nd hit).


This is what I had in mind when I initially posted my first message...


Leo "Apollo11"

[gus]

Leo "Apollo11"[/QUOTE]

Hi Apollo11

When using large hunter killer groups in UV the vast majority of the ships in the TF do not detect let alone launch a successful ASW attack. If I have an 18+ ship Allied ASW TF assembled and it encounters an enemy sub I usually expect only one or two of the ships to engage the sub. Once engaged the sub is damaged about 50% of the time.

Using this as a rudimentary yardstick we can predict that only at best ~11% (2 out of 18) of all ships to subs encounters lead to a detection, of those about ~50% actually do damage to the sub. So on average you can expect to damage a sub about 5.5% of the time (per ASW ship) using these crude 'statistics'. These percentages will go up if the subs detection level is very high or it is in a shallow water hex.

I believe these numbers are in line with historical outcomes. The real problem is that ships and subs encounter each other far more frequently in UV and in higher concentrations than they did IRL so the rate of loss for ships and subs is greater than expected.

-g

[mdiehl]

52 US subs were indeed sunk during 46 months of war, but most of these were destroyed in 1943 and thereafter only AFTER Japan had substantially improved their ASW techniques by introducing more radar sets, better training in sonar operators, and multiple-ship coordination of attacks. Even so, they never came close to the abilities of the Allies in re detection and successful attack.

So 1 per month sounds about right. But really it should be lower than that for the first year and a half of the war and somewhat higher than that for the last 18 months. Most successful Japanese ASW efforts should occur inside the Marianas-Marcus-Philippines permiter. Depnding of course on other things like where the Japanese escorts are, where the merchant lanes are, and whether the US is in the merchant lanes and so forth.

[spence]

The US lost 52 subs during WWII. Japan lost somewhat over double that.

The cause of roughly 10% (5) of US subs given was mines. From the records available to me only 1 Japanese sub was almost surely sunk by a mine.

Quite a few Japanese submarines were sunk by US submarines, often with ULTRA info being used to set up an ambush for an IJN sub in transit between bases. In reviewing the various records I did not find many corresponding sinkings for the IJN sub fleet.

www.combinedfleet.com has a nice site with unit histories for many but not all Japanese subs. Having read extensively about the Battle of the Atlantic wherein the highest percentage of U-Boats were killed by aircraft I was struck by the frequency with which Japanese sub losses were attributed to attacks by surface ships and the relative infrequency with which the loss was attributed to an aircraft attack. Official Japanese records are not that good though with many sub losses listed officially as overdue or unreported since such and such a date. The losses have to some extent been correlated with attacks made by Allied units wherein oil/debris etc was reported subsequent to the attack.

Just for the record it appears that 35 Japanese and 19 American subs were sunk in the Pacific Theater during the time period covered by Uncommon Valor - again showing close to a 2-1 ratio between Allied ASW efforts and Japanese ASW efforts (I did not look to see the whereabouts of these losses though). That suggests a clear superiority for the Allies in that arena of naval warfare to me.

[Mike_B20]

The reliabilty of the "S" boats does seem a little overmodelled in UV after reading some of the boat histories at the following site:

http://thesaltysailor.com/s-boats/index.html

[Apollo11]

Hi all,

When using large hunter killer groups in UV the vast majority of the ships in the TF do not detect let alone launch a successful ASW attack. If I have an 18+ ship Allied ASW TF assembled and it encounters an enemy sub I usually expect only one or two of the ships to engage the sub. Once engaged the sub is damaged about 50% of the time.

Using this as a rudimentary yardstick we can predict that only at best ~11% (2 out of 18) of all ships to subs encounters lead to a detection, of those about ~50% actually do damage to the sub. So on average you can expect to damage a sub about 5.5% of the time (per ASW ship) using these crude 'statistics'. These percentages will go up if the subs detection level is very high or it is in a shallow water hex.

I believe these numbers are in line with historical outcomes. The real problem is that ships and subs encounter each other far more frequently in UV and in higher concentrations than they did IRL so the rate of loss for ships and subs is greater than expected.

-g

But is it historically accurate that such huge (you said 18+) ASW TF can
simultaneously engage one submarine?

In UV (and I presume WitP ALPHA) all those ships in such huge TF have chance
to attack submarine but I think that's unrealistic because that's simply too
many ships doing the same thing on small area.

I don't think that it's possible for more than, let's say, 4-5 ships to
coordinately attack single submarine...


Leo "Apollo11"

[Nomad]

One thing that I feel adds to all this is that sub crews( and by extension, all navel vessel crews) do not have a morale and fatigue rating. They would force the player to rest the sub/navel crews more which would bring the usage to a more historical/realistic level. How many times have players turned around subs the same day they come back to port for more torpedos and fuel? Time after time?

[Mike Scholl]

One thing that I feel adds to all this is that sub crews( and by extension, all navel vessel crews) do not have a morale and fatigue rating. They would force the player to rest the sub/navel crews more which would bring the usage to a more historical/realistic level. How many times have players turned around subs the same day they come back to port for more torpedos and fuel? Time after time?

Boy you got me there. Just as fast as I can get that sucker re-fueled and
re-armed---unless the damage levels are starting to add up. Your right, some
R & R might be a good thing to introduce into the game.