Sort of an AAR re: Japanese ASW

[spence]

Just finishing a PBEM Rising Sun Scenario (last turn made but no final tally or whatever yet). Game played with v1.77. Allied sub doctrine was OFF. Don't remember what the IJN setting was but my observations relate principly to Japanese ASW.

During the course of the game I (Allied) pretty much tried to move my subs every turn. I also endeavored to operate them at least 2-3 hexes from any medium/large Japanese airbase or port and to keep them in deep water (though as the scenario progressed this became increasingly difficult). I used some Political Points during the game to get rid of skippers that were real duds replacing them with skippers with higher naval ratings. When choosing replacement skippers I tried to get ones with middling aggressiveness and specifically chose not very aggressive ones for the USN fleet boats. The Allied subs didn't accomplish much of note.

By about mid-game about half of the Allied subs had suffered systems damage of more than 20 and were essentially incapable of launching attacks. Most of the rest had 5 or more sys damage through a combo of attacks and just plain sea time. The principal agents of the carnage were my opponent's ASW groups of PGs, PCs, MSWs. These groups always detected a sub when ending their move in a sub occupied hex and never (I can't remember any at least) suffered a torpedo attack before hand. Enemy DDs performed equally well but to tell the truth I wasn't nearly impressed with the performance of IJN DDs in terms of how much damage they inflicted. Not really sure of how many Allied subs got sunk by these ASW groups (suppose the tally sheet at the end will tell) but they pretty much put the subs out of business.

I glanced at the experience ratings of these sub-killers and at least initially they seem to fall into the same kind of night/day experience range as their Allied counterparts.

Historically the IJN didn't think about ASW much pre-war. It also tended to foist off the lesser capable officers to ASW duties. As I understand it sonar was not universal equipage for ships assigned as escorts/ASW duties. The historical record shows only like 3 USN subs sunk by IJN action in the period of the game though I think they got a Dutch sub or two as well.

For the time frame, IJN ASW seems a bit over the top. Not really sure what factors impact on ASW detection and attack. Don't know if additional changes in v1.795 effect IJN ASW but I've got a game going using that version as well and things seem different.

I'm not complaining or excusing - figure I lost fair and square - but with 50 odd subs to begin with, having 25 of them put out of action by IJN the second-string in a month and a half just seems like it ought to be the farthest reach of possibilities. Got another game in v1.77 going and those PCs/PGs/MSWs are doing pretty well again (though not so well against PT Boats[:D]).

[Mike Dixon]

I was Spence's Japanese opponent. Without giving away too many state secrets (we have a First Year Scenario ongoing), I basically put the PC's/PG's and MSW's into ASW TF's ranging in sizes from 5 to 10 ships. They sailed to wherever a sub was spotted, so nothing too fancy there. The hits on the Allied subs were very much reduced over a 2x2 game I've got going with v1.6, in which in my view subs are next to useless.

In Rising Sun, Spences subs were very effective early on in the game, damaging or sinking many transports and also nearly sending the Haruna to the bottom, after moderate damage in the Battle of Kuching. Later on they were less effective, perhaps because the Japanese had more room to manouver. I am hoping to emulate Spences early success in our current First Year game, where my brave mariners are laying seige to PH. Alreadly one U.S. carrier has had a lucky escape.....

[Ron Saueracker]

I suspect the real culprit is the ease with which the air units spot subs in the game. Two things...1) each time it is spotted, the Detection Level of the sub goes up. Multiple sightings of a sub means that the DL goes up directly in relation to how often the sub is sighted so even in just one turn, a sub can be spotted an ungodly amount of times with the current model and basically becomes a target, incapable of launching an attack and vulnerable to 2) surface ASW. A spotted sub is easy prey for a PBEM guided ASW TF, and the subs with the current air search model may as well have their torpedo tubes, ballast tanks and periscopes removed because they are sitting ducks for surface ASW TFs with a DL as high as it gets currently. Coupled with the fact that every sub in range of an airbase is getting spotted each turn, the player must move his subs every effing turn to lower the DL. Mistakes, frustration, boredom, whatever, takes its toll and the player forgets to move a sub and bang...gone.

[Mike Dixon]

Japanese submarine I-68 on patrol at the Hawaii Islands

[Mike Dixon]

The Akatsukai on ASW patrol near Saigon

[fairplay]

The U.S. lost 52 boats during WW2 (http://www.maritime.org/subslost.htm). I didn't check but I think most of them were sunk in the Pacific Theater. But if your opponent shows unhistorical behaviour and is sending hunter-killer groups then this will of course lead to unhistorical results.[:(] As every player of course is trying to 'outperform' history you will see a lot of strange results.

[Mike Dixon]

I must admit I do also try to move my subs every turn.

Not sure what unhistorical behaviour I'm doing - I cant let the little bleeders sail around unchallenged can I?