What if the US Pacific Fleet stayed based in San Diego, while the US kept all other relations with Japan as OTL. Instead of an attack on Pearl Harbour to open the war, could Japan have pulled some kind of submarine attack on the Fleet at anchor on the West Coast? Some combination of mass Kō-hyōteki midget sub attack with more mother ship subs, and/or full size subs infiltrating the harbour like Gunther Prien.
Submarine only Pearl Harbour in San Diego?
- Thread starter YYJ
- Start date
-
- Tags
- 1941 pearl harbor
Japan had some pretty long ranged submarines. And they could be refueled at sea for the final dash. I-26 torpedoed 2 freighters and shelled a lighthouse on the Canadian West Coast. I-17 shelled Santa Barbera. But the longer ranged they were, the larger they were. So at more of a disadvantage maneuvering in a confined harbour. U-47 (Gunther Prien's boat that infiltrated Scapa Flow) Range 8700 NM surfaced, length 218'. I-65 Range 10,000 NM surface, length 320'. I also think that since they wold have to do most of their travelling on the surface they would be prone to accidental detection travelling all that way.
RamscoopRaider
Donor
It would be harder than Scapa, Scapa has multiple entrances and the widest is almost twice as wide as the single entrance to San Diego Bay. It's not as narrow as the entrance to Pearl, and they did try that, but it's still not easy. The real problem is they only have 5 subs fitted for carrying midget subs, so 5 subs with 10 torpedoes. Even the Japanese were not optimistic enough to think 10 torpedoes would do significant damage on their own. They'd have to build a bunch of specialist subs just for this job, or convert type A or B subs to type C, and the issue is they intended Type A as command ships and B as general purpose vessels while Type C were more specialized. Given this I find it unlikely they would try, too much risk of getting spotted and giving the game away for too little damage
I'd favor a multitiered operation. Send the five mini subs into PH. Have two of the long range subs rigged to lay mines. Have all the participating I types run standard patrols off the San Diego coast & stalk capitol ships for a few weeks. Probable result: one or two capitol ship torpedoed inside the harbor, one or two more outside the harbor. The mines will be indiscriminate & odds are they will detonate on something less important before being swept. At the end of the operation the USN has three capitol ships laid up for hull repairs, and maybe one sunk. A similar number of smaller ships may be damaged or sunk.
If the japanese want to get really squirlly they can turn a less valuable sub into a bomb. A reduced crew takes it across the pacific, and after a at sea transfer a reduced crew takes into the harbor. When a capitol ship passes overhead in the channel its detonated.
If the japanese want to get really squirlly they can turn a less valuable sub into a bomb. A reduced crew takes it across the pacific, and after a at sea transfer a reduced crew takes into the harbor. When a capitol ship passes overhead in the channel its detonated.
six aircraft carrying either a torpedo or two 500 or 1 1800 pd bomb are not going to much
Rather than submarines they'd probably do better with a merchantman flying false colours and carrying frogmen. They'd have more chance of surviving long enough to attack their targets than a sub trying to penetrate the port.
Yeah, I think so too. I was sort of imagining a dozen midget subs and a dozen fleet subs letting loose with everything inside the anchorage. But this would likely mean all kinds of fratricide and groundings. The Japanese war machine was not yet as suicidal as it got in 1945. The Pearl Harbour Kō-hyōteki midget subs had self destruct charges that were used on at least one instance. But I can't imagine Yamamoto sending 12 fleet subs on a suicide mission to start the war.
Mines didn't occur to me, that would add some destruction, until the Americans figured it out. If the few successful attacks were all on aircraft carriers that would count for a lot. But even so, like Pearl Harbour, unless a ship capsizes or suffers a magazine explosion it is only really damaged if you sink it in port, because the ship only sinks 10 feet. I can't see any way that this mission could provide the kind of fleet killing weight of fire that the OTL Pearl Harbour attack did.