That would be because the Japanese truly sucked at ASW.

They lost 50% of their Merchants to Subs, their ASW doctrine, training and equipment were all poor and they had a cultural bias against it.

Its covered in all the references.

A much less than 20% kill rate (most USN subs made multiple sorties during the war making the 'kill per cruise' rate much lower) is not something to boast about.

For a navy that only had around 130 operational DDs,40 kills with what they had to work with was damn good.

Under estimating IJN ASW is going to get you killed...and often.

IT gave one US sub as absolute thrashing, The aircraft got a fix a droped depth charges on the sub, which caused a lot of damage, the escorts of the convoy the sub was attacking joined in, causing more damage and keeping the sub under attack for over a day and a half. The hull of sub was buckled in from the force of the deth charging. When it did surface almost two days after last seeing the sun, it was a floating wreck, it managed to limp home, but it was never repaired.

130 operational DD's?

well, this means shooting a DD in campaign would really be worth something. :roll:


About that comparison to u-boats:

US subs couldn't co as deep as a U-boat, this is primarily caused by their construction:
In technics, you calculate the thickness of the material e.g. the pressure hull by dividing the maximum pressure a material can handle by a safety value. For example: if you want 2 times the safety against destruction, you play as if the material you are using is only half as durable as it is and therefore use double the material.

.....this safety value was 1,8 for US subs and 2,5 for the u-boats, so a u-boat could take more pressure and dive deeper.

However, US-Subs weren't required to dive deeper, because this was mostly impossible in their areas of operation. And well, if you have seen what shallow water can do to you in GWX, you will notice that this can make SH4 really dangerous.

40 kills over 4 years. or roughly 1 a month, for 130 DDs (plus subchasers, a/c, q ships, IJN subs, mines etc) that is frankly pathetic - it is a less than 1% a month (per DD) success rate, and they can't even claim the defensive victory of keeping the USN subs away from the merchants - 50% of their merchants were sunk by USN subs.

WOW!...I never knew that.

The Japanese had a HELL of a lot more area to cover than the Allies did in the Atlantic. Those 130 DDs et al were strung all over half the Pacific, from New Guinea to the northern islands near Siberia.

Did the Japanese have a cultural bias just about ASW or submarines and everything to do them? Why did they have this bias?
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AddictiveLara cam

The Japanese actually made some pretty decent subs, but the problem they had with using them and in their ASW efforts was the whole ersatz-Bushido thing that they were brought up with when the country was militarized starting in the late 19th century. How that impacted their sub/ASW efforts was that the submarine captains felt that they would only get honor by attacking warships and not merchants, while on the flip side being an ASW specialist was not seen as a true calling for a warrior.

That's the greatly simplified version but the fact remains that the Japanese never used either their submarines or their ASW assets in a very effective manner for winning a war. Their subs sometimes did pull off some stunning attacks against warships, the Indianapolis immediately comes to mind, but those sort of things would not, and could not stop the Allied advance in the Pacific. For a nation that was so completely relient on the sea, not only for their major resource imports like oil and metals which caused them to start the war, but also since many of their domestically produced products moved via sea from point to point in Japan itself the lack of ASW planning is mindboggling actually. I suppose they were still reading their Mayhan and thought we'd use our subs the way they did theirs, but after we started sending many, many of their merchants down you would have thought they would have adapted better to the threat.

They were biased against the defence and ASW was seen as being defensive, so doctrine, training, resources were all utterly neglected. The best DDs were assigned to combined fleet where attack was emphasised rather than ASW.

That left the merchants very poorly protected.

Rather than quote parts, I would suggest that you get hold of 'The Japanese Merchant Marine in World War II' by Mark P Parillo - it is shocking just how ineffective the Japanese were.

Yes but none of that is relavent to the discussion at hand, i.e. IJN ASW. The Japanese felt that ASW work was beneath the best officers, and in many respects was a waste of time, remember they were planning on a war that was to be very short and followed by a peace settlement. They felt that efforts directed towards ASW could be better expended on offensive efforts which could bring the war to a swifter conclusion.

HB

Actually, since the Japanese used shipping lanes, the area they had to cover was not so different as that in the Atlantic (and the amount of available bases along the way should have allowed plenty of ASW a/c and refueling stops for shorter ranged vessels), its not as if the Japs had to do ASW out in the middle of the Pacific, they just had to protect their shipping and provide local ASW to their task forces.

The Japs were just incompetent at maritime organisation/protection.

They barely protected their merchants and then wasted vast amounts of potential shipping by lack of organisation, poor routing and an unwillingness to share resources between the IJA and the IJN.

SH-4
 

I think "game wise" The Japanese Sonar is going to be better ! These people were & still are producing great Electronics ! Remember those signs in American factories Produce more & better quality as your military depends on it! My mother in law worked in one of those" Rosie the riveter factorys in WW 2 ! Well the Japanese Had their own sign, "suykio kitsine" which translated said "No Play with your D**K" MAKE A RADIO"

Actually, the vaunted Japanese electronics revolution didn't begin until the postwar era of the 1950s. Japanese electronics pre-war were abysmal. Radar itself was not provided for escorts until the end of 1944, and then barely reached the standard of the earliest Allied sets, plus there were constant problems with the componets. A US technical mission after the war concluded that in the field of radio, radar and sonar, Japan had been a victim of her isolated sense of power and superiority. Specifically, success in the pre-Pacific war operations in China had convinced them of the superiority of their equipment. It was only after their drive south into the tropics that reports had begun to indicate the need for specialized component design, tropicalization, and better performance overall.

In reality Japanese ASW capabilities were rather poor and US subs were mostly sunk in shallow water (like USS Wahoo). In shallow waters you don't need cutting edge technology but a lot of DCs.
In SH4 however Japanese ASW capabilities will be far more better I guess because otherwise the game would really be too arcadish. If it's too easy it's not fun, at least for me.;)