Re: WI: Yamamoto has a further realization

You have to start with the Japanese submarine. Unlike the Germans the
Japanese had never engaged in war using submarines and had no feel for
either ASW or the capabilities of submarine detection. Their subs were
fast and heavily armed on the surface, below they were slow and
shallow, making them easy prey for experienced ASW.

The oil sources were ports like Richmond, Avila,  Long Beach and San
Diego. Richmond is inside San Francisco Bay. Avila is on the Central
Coast of California and the by-play between ASW and sailings and the
IJN subs is illustrated in the sinking of the SS Montebello on
December 23, 1941. (see score sheet below for other sinkings)

"The next day, while running at periscope depth, the I-21's periscope
is spotted by what Matsumura identifies as a small "Coast Guard patrol
boat". In a well-executed attack with only two depth-charges the
patrol boat knocks out the I-21's vertical rudder and all her lights.
Commander Matsumura gives the order to surface and battle it out, but
at the last minute the emergency lighting is restored and the
engineers manage to repair the steering."

http://www.militarymuseum.org/Montebello.html

As it was the IJN lost 127 of their 160 large submarines during WWII,
the long trek across the Pacific and the subsequent need to cover oil
ports would have great increased the early loss of submarines. U.S.
Navy and Coast Guard would have loved having live targets so near at
hand and so nice and slow and shallow.

There is a high probability that the IJN sub skippers would find the
coastal deployment a form of capital punishment, the previous loss of
other submarines and the long trek across the Pacific would make for
some personal introspection about death, honor and the ability to
achieve the goal.

score sheet

Dec 7, 1941. On its way to the US west coast, I-26 tracks a US
freighter. Precisely at 8:00 a.m., Dec 7, Pearl Harbor time, she
surfaces and sinks Cynthia Olson with gunfire. Dec 15, 1941. Japanese
submarine shelled Kahului, Maui, Hawaii.

Dec 20. Unarmed US tanker sunk by Japanese submarine I-17 off Cape
Mendocino, California. 31 survivors rescued by Coast Guard from
Blunt's Reef Lightship.

Dec 20. Unarmed US tanker shelled by Japanese submarine I-23 of the
coast of California

Dec 22. Unarmed U.S. tanker sunk by Japanese submarine I-21 about four
miles south of Piedras Blancas light, California, I-21 machine-guns
the lifeboats, but inflicts no casualties. I-21 later shells unarmed
U.S. tanker Idaho near the same location.

Dec 23. Japanese submarine I-17 shells unarmed tanker southwest of
Cape Mendocino, California.

Dec 27. Unarmed US tanker shelled by Japanese submarine I-23 10 miles
from mouth of Columbia River.

Dec 30, 1941. Submarine I-1 shells, Hilo, Hawaii.

Dec 31, 1941. Submarines shell Kauai, Maui, and Hawaii.

Feb 23, 1942. I-17, shelled Ellwood oil refinery at Geleta on the
Californian coast. The skipper had fueled there many times before the
war.

June 20, 1942, the radio station on Estevan Point, Vancouver Island
was fired on by a Japanese submarine I-26.

June 21. I-25 shells Fort Stevens, Oregon.

Sept 9 . Phosphorus bombs were dropped on Mt. Emily, ten miles
northeast of Brookings, Oregon, to start forest fires. A Yokosuka
E14Y1 "Glen" reconnaissance seaplane piloted by Lt. Nubuo Fujita was
been catapulted from submarine I-25.

Sep 29. Phosphorus bombings were repeated on the southern coast of
Oregon.

http://www.ww2pacific.com/attacks.html

Reference material the below is a link to an academic paper published
in the US Air Force Journal of Logistics, entitled "Oil Logistics in
the Pacific War" by Lt. Col. P.H. Donovan USAF in volume XXVIII number
1 of that journal

http://www.aflma.hq.af.mil/lgj/Vol%2028%20No%201%20www.pdf

In this work among many other things  Donovan points out the real bind
the US Navy would have been put into if during the attack on Pearl
Harbor the Japanese had ignored warships and attacked oil tanks, and
fleet oil tankers only.  Nimitz is quoted by him as stating that "Had
the Japanese destroyed the oil (at Pearl Harbor), it would have
prolonged the war another two years."

In this paper it is also well documented that the Pearl Harbor attack
was Yamamoto's idea and he had to threaten to resign   as CIC of the
IJN to push the plan through, as it went strongly against Japanese
Naval doctrine to that time.

Suppose he has a further epiphany, caused in part perhaps by the
logistical necessities that were pushing Japan to war?  He realizes
the critical nature of the ability of Pearl Harbor to stockpile ~ 4.5
million BBL of oil at any given time, and that wrecking of the
facilities at Pearl would drastically reduce the capability of  the US
Navy to operate in the western Pacific, further that setting his
submarines on duty to specifically attack all US oil tankers, would
further cripple the ability of the US Navy to retaliate against Japan,
or otherwise meddle with Japanese plans.

In the paper Donovan documents how a specific fleet oil tanker that
had been sitting at anchor at Pearl Harbor, was not attacked, and had
been critical to the US Navy logistics at the Battle of Guadalcanal.

Further the US Navy oil tankers in the Pacific Fleet in late 1941 had
a combined total capacity of 760,000 BBL of oil, and within  9 days of
the attack at Pearl Harbor the US Pacific Fleet had burned 750,000
BBL.  This goes to show the deep dependence of the US Pacific fleet on
the tank farms at Pearl, which were quite vulnerable to attack.

So, WI Yamamoto realizes this, and  has the attack at Pearl Harbor
focus on the real vulnerability of the US Pacific Fleet, the tank
farms, and after that has all Japanese long range subs tasked to sink
US tankers sailing off the US coast or from Panama.  This may result
in a very different Pacific war.  In the end I am sure Japan loses due
to the atomic bomb, but still, the differences will be huge.

Comments?