Turtledove.

Glenn got me thinking, (which he often does).

What the hell was Turtledove thinking?

This lead to an email exchange with a good friend, and military history expert ( MA, Kanasas State in Military History).

I was thinking about something that bothered me from Turledove's Pearl Harbor book. Why did Yamamoto destroy the fuel farms at Pearl Harbor, if they intended to capture the island? Why destroy 4.5 million barrels of fuel?
I was trying to google for the size of the fuel farm , and found this

It WAS all Roosevelt's fault.

-----------------------------------
That 4.5 million gals of fuel would have sustained IJN operations for quite some time had they captured it intact – however; looking at my previous post and Real Japanese war aims – Destroying the fuel farms would have virtually ensured Japanese short term war aims were achieved (i.e removal of the USN as a hindrence in Japan securing the NEI) just think what things had been like had Nagumo launched a third wave at the fuel dumps and the repair yards. US would have eventually pushed back into the Pacific, but would it have been worth it with the war in Europe ongoing? Realistically the US might have sued for peace temporarily until Hitler was done. After that though all bets were off. In retrospect – japan losing the war can be laid solely on Chuichi Nagumo – and the war was lost at 5pm 12/7/41. Remember when you look at the Tinfoil hat sites – Roosevelt wanted war with Hitler not the Japanese. How screwed would Roosevelt have been had Hitler had the brain of a gnat and not declared war on the US on 12/10/41. BTW an interesting Alt History book might be Hitler assassinated before Chrystallnacht and the Wehrmacht taking over. No war in Europe until Stalin thought he was ready in Mid ’43. Then basically Britain, US, Republican Germany and possibly Japan against USSR and China. Oooh the Possibilities.

(Where's France? :) )
--------------------------------------------
I've always thought the priorities should have been
carriers
fuel farms
rest of fleet.

That's what you get for having the wrong Admiral in charge.

Looks like the Pearl fuel farm was only 6 weeks of fuel for the IJN. Seems kinda low to me. 1 barrel = 159 liters= 715,500 kl of fuel. Of course, if you use the Oahu fuel just to support operations around the islands, it would last quite a bit longer.

-------------------------------------------------
Yup - Nagumo was a ditherer – Look at Midway. He may have been marginally better than some of the later Admirals the IJN had in command – like Kondo or Ozawa (think Leyte Gulf/Surigao Straits – Kondo’s main battlefleet ran from 6 jeep carriers and half a dozen DE’s). Given Japanese war aims – the carriers, fuel farms, repair yards, then the rest of the fleet would have been the best tasking order for the Pearl Harbor fleet. The third wave attack, which Yamamato planned as part of the attack was tasked against the repair yard and fuel farms, but Nagumo panicked when the carriers weren’t found and cancelled the third strike over the objections of both Genda and Fuchita. According to the latest Japanese accounts – Yamamato almost had a stroke when he found out.

It would be interesting to see figures for actual IJN POL usage between 12/41 and 1/45. See how the actual usage matched those projections. I’d be willing to bet that they far exceeded the forecast. There are accounts in several sources I saw when I was researching my thesis that showed throughout 1943 and 1944, the majority of the IJN Combined Fleet had to be stationed in Brunei or Palembang just to have access to fuel. They couldn’t even travel to Japan for repairs because of lack of fuel. We really put the Japanese in a no win situation with the embargos prior to Pearl Harbor. Looked at from their POV they had no option but to try to seize the NEI or their entire economy and Military operations in China would collapse. Forcing a country into a zero-sum situation like that was not the brightest foreign policy move Roosevelt made.

------------------------
So, back to the orignal intent. Why did Turtledove destroy the fuels farms, IF the Japanese were planning to invade and capture Oahu?

That's alot of fuel, when fuel was a very important consideration to the Japanese. With that kind of stockpile at Pearl, the Japanese would not have needed to send tankers over to supply Hawaii, until after they had established a very large air presence, and been able to maintain effective anti-sub patrols around the islands.

Following Turtledove's invasion, the US wold have had to base the PacFleet subs out of San Francisco, and later Seattle.

Gato/Tench class subs had a cruise range of 11800nm, 75 day endurance.
What's the distance from San Francisco to Tokyo? 4500nm, leaving 2800 nm of on station crusing time. Maybe 10 days. That would have a a huge impact on how effective the subs could be at attacking the Japanese merchant fleet operating in the GEACPS sea lanes.