US sub warfare myth

[Laffertytig]

ive constantly read that as the war in the pacific progressed, unlike the atlantic theatre the war got easier for the US subs as technology and tactics improved.

but after some research it shows that sub losses increased every year up to 1944.

was this due to better japanese ASW tactics or the fact that there was simply more US sibs on aggressive patrols?

[Armistead]

Probably many factors. No telling how many subs were lost due to the failure of the M14 up to mid 43. Even after that some subs were lost due to circle runners and other misc failure.

Add to that JP shipping became harder to get at requiring more risk. The JP's did revert to a convoy system, although it failed in many ways.

[Torplexed]

I'd chalk it up to increased submarine production coupled with more aggressive skippers. 1944 was also the year Japan finally started producing proper escorts in some numbers. 1942 was pretty much a lost year since it took so long to weed out the timid skippers, the defective torpedoes and the indifferent leadership. Not to mention bases and facilities being lost and relocated.

[razark]

There was a congressman or senator, don't remember the name, that revealed in a press conference that the Japanese were setting their depth charges too shallow, so the US subs were simply able to go deep and avoid them. Shortly after, the Japanese started setting their charges to deeper depths.

Edit:
Andrew May
http://en.wikipedia.org/wiki/Depth_c...acific_theater
http://en.wikipedia.org/wiki/Andrew_...e_May_Incident

[Torplexed]

Originally Posted by razark

There was a congressman or senator, don't remember the name, that revealed in a press conference that the Japanese were setting their depth charges too shallow, so the US subs were simply able to go deep and avoid them. Shortly after, the Japanese started setting their charges to deeper depths.

Kentucky Representative Andrew J. May. Also found guilty of war profiteering. It's still unclear as to whether the Japanese ever latched on to his comment.

http://en.wikipedia.org/wiki/Andrew_J._May

[I'm goin' down]

two damn good reasons for coming to this site.

As noted there were a number of factors affecting USN submarine operations in the Pacific so if you are constantly reading that things got "easier" for Fleet Boat captain's it might be because your sources are flawed, superficial or leave something to be desired.

1. Japanese ASW started off relatively primitive but did improve as the war went on. Their hydrophones and active sonar never achieved the sophistication of the RN or USN but did get better with time. Japanese convoy and escort techniques improved even if they suffered from major institutional and doctrinal flaws rooted in cultural factors like Bushido mythology.

2. The Japanese deployed airborne Magnetic Anomaly Detectors (MAD) before anybody else. There is some debate over whether MAD actually resulted in any kills since Japanese air-dropped ASW weapons often left much to be desired but there is no doubt that submerged boats were attacked without warning having been detected by MAD overflights.

3. Targets became scarcer in the late war forcing commanders to operate take greater risks and conduct inshore operations where ASW assets were strongest and the large Fleet Boat was at a disadvantage. The lack of sizable targets and reduction in kills per day at sea meant was coupled with greater relative losses. There was a similar trend in U-Boat operations but the loss/success curves in the Atlantic were far more extreme.

4. The American submarine service continued to grow but later boats would have suffered from an excess of relatively inexperienced crew members as the talent pool was diluted by continual expansion. Looking at the book The Last Patrol, which details the loss of every US submarine in WW2, the narratives of the sinking often allude to the levels of training, particularly late in the war. The more difficult conditions that came about from the issues identified above (and others) also meant that more late war boats were lost on their first or second patrol.

Defensive weapons and tactics paint only a small part of the picture. The relative increase in sinking's as the war progressed makes perfect sense even if they never reached the catastrophic scale experienced by the U-Boot Waffe.

[WernherVonTrapp]

Originally Posted by Torplexed

Kentucky Representative Andrew J. May. Also found guilty of war profiteering. It's still unclear as to whether the Japanese ever latched on to his comment.

The "May Incident" of 1943 probably had more to do with U.S. sub losses than any other single factor. The Japanese caught on right away since his words were published in newspapers all across the country. It's hard to say whether the IJN ever would've caught-on to the U.S. sub capabilities, or caught-on in enough time to make much of a difference. Later in the war, especially after the attrition battles during the Solomon's campaign, the IJN was always short of destroyers.

Originally Posted by Randomizer

2. The Japanese deployed airborne Magnetic Anomaly Detectors (MAD) before anybody else. There is some debate over whether MAD actually resulted in any kills since Japanese air-dropped ASW weapons often left much to be desired but there is no doubt that submerged boats were attacked without warning having been detected by MAD overflights.

This is not true. According to the "The Tenth Fleet", the USN had deployed MAD aboard blimps and other specialized aircraft in the Atlantic as early as 1942. According to "Japanese Radar And Related Weapons Of WWII" (pg. 72), Japanese MAD (model 03) wasn't deployed until April 1944 around the Philippines and Formosa. Fifteen subs were detected by IJN MAD, five were sunk as a result of MAD.

The fact that, later in the war, US subs were forced to move closer to the Japanese mainland probably facilitated the escort-to-fleetboat ratio since the number of subs was more concentrated instead of spread out across the vast Pacific. Like Armistead says, there was a number of combining factors. I think May did the most damage.