soc.history.war.world-war-ii

"Duwop" wrote in message
news:00c7c1e6-1486-4334-b237-9f5db661f9c1@d4g2000prg.googlegroups.com...
> On Feb 18, 10:17 pm, mtfes...@netMAPSONscape.net wrote:

>> Note that this carried over to their field decisions as well; IJN
>> subs were known to let supply ships pass unmolested, saving their
>> torpedoes for more "worthy" targets, like carriers. Not sure their
>> IJA comrades on the beaches appreciated the finer points of that...

> Now it's widespread knowledge that Japan's submarine's did not have a
> good operational plan, but really how many times did this happen?
> Once?

It happened regularly enough, though to put a figure on it requires
the IJN logs to have noted the ships they could have attacked
but decided to ignore.

> We're getting into woulda/coulda territory here, though one that's
> easier to imagine than most: improved Japanese submarine assignments/
> tactics.

The IJN did run disguised commerce raiders in the Indian Ocean and
did do some submarine commerce warfare there and along the east
coast of Australia. There was also the initial blockade of Hawaii. The
Cynthia Olsen was actually attacked and sunk before the air raid on
Pearl Harbor began.

According to the RN of the 21,570,720 tons of merchant ships lost
in WWII the Pacific accounted for 1,347,510 tons. Of that 125,989
tons was before December 1941, 431,673 was in December 1941,
another 435,074 tons lost January to March 1942, leaving 354,774
GRT lost during the remainder of the war.

Merchant ship losses in the Indian Ocean is put at 1,789,870 tons,
246,440 tons before Japan entered the war, and another 306,682
tons in the period January to April 1945.

Shipping losses in the South Atlantic are put at 1,024,759 tons.

See also Axis submarine Successes 1939-1945 for more numbers,
the book has 193 pages devoted to sinkings in the Atlantic, 28
pages to the Arctic, 4 to the Baltic, 6 to the Black sea, 35 to the
Mediterranean, 22 to the Indian Ocean/South China Sea (where
U-boats operated starting in late 1942) and 14 pages to the Pacific.

Geoffrey Sinclair
Remove the nb for email.