Thread by @TrentTelenko

This thread is on Section 22's role in the Nov 3 1943 raid by Saratoga & Princeton on the IJN cruiser force assembled at Rabaul to stop the Bougainville invasion & radar threads leading else where.

It is at the 49 to 54 min. in this podcast. /1

the-bilgepumps.simplecast.com/episodes/bilge…

Adm. Halsey's raid was a strategic gamble because the pending Central Pacific landing at Tarawa had robbed him of his battleships and cruisers.

All he had were Saratoga and Princeton. /2

en.wikipedia.org/wiki/Bombing_o…

But while it was a strategic risk for Halsey.

It was a very...calculated...one, thanks in large part to GHQ SWPA Section 22's radar intelligence of Rabaul. /3

In October & early November 1943 Section 22 was working closely with 5th AF to get their planes under IJN radar coverage into Rabaul harbor. The strike photos and post strike BDA were used to spot & plot radars...including ones on IJN cruisers./4

Section 22 found a weakness in Rabaul's radar coverage to the North. There was a mountainous rise to the immediate north of Rabaul harbor on New Ireland and it was covered in heavy jungle.

The Japanese garrison knew of it. See the USSBS interview./5

The IJN garrison clued the cruiser force as to the weakness. The captain of the HIJMS Atago, in terms of radar, was the Adm "Ching" Lee of the IJN and his ship was the USS Washington. His ship's 10 CM Type 22 focused at this gap and gave a 10 min. warning to start moving/6

Atago, under a new captain, same radar crew and more radar, was the command cruiser for Adm. Kurita at the battle off Samar.

Her radar crew knew how to use their Type 22 to tell ship size.

She also had Kurita's Fleet Command plot./7

arstechnica.com/gadgets/2020/0…

Had Atago not been sunk by the USS Darter & Dace wolfpack. Her extensive radar fit and ace radar crew at the time would have been at the Battle off Samar.

She would have fed Kurita's fleet plot with accurate ship size and course data.

Taffy 3 would have been annihilated./8

Section 22's report on Atago is not the only radar thread missing from Pacific War standard narratives that reached back to Rabaul.

Another was RADM Ota Minoru./9

As commander of the 14th Base Force on New Ireland, RADM Ota owned the gap in Rabaul's radar coverage that Saratoga & Princeton's planes flew through and savaged the IJN cruiser force./10

RADM Ota had a powerful patron in the IJN. He was not left to rot at Rabaul.

The lessons in tactically operating and camouflaging the Cape St. George radar on New Ireland vs. 5th AF air power and Section 22's targeting followed Rear Admiral Ota Minoru, back to Japan./11

In March 1944 Ota was appointed to command Sasebo Kaiheidan and Sasebo Keibitai.

Kaiheidan's were a training/personnel pool org., but in emergency a Kaiheidan provided their men for local defense, a Keibitai's original duty.

These organizations had radars...and targets/12

On paper, Ota Minoru was the very model of a IJN Naval Infantry Admiral. He had commanded the naval infantry regiment meant to invade Midway.

Yet his time at New Ireland & Sasebo change him. He matured and learned the craft of being a operational level C3I warrior./13

And he learned to cooperate with the IJA and see the USA as the real enemy.

This made Ota...dangerous...in Japan.

So his IJN patron gifted Ota with a poisoned chalice that let Ota die honorably w/o hurting his patron.

He was given command of the Okinawa naval garrison./15

...and the Ryukyus.

These were the location of Imperial Japanese Navy Type E Look out (Radar) Stations under RADM Midoro Ota. All sites, save for Kume Jima, had RADAR units that could access US Mark III IFF beacons./16

Ota's knowledge of the need for radar at the Kume Jima "Bobitai" (Special Lookout Station type “E”) was such that Ota actively cooperated with General Ushijima's 32nd Army radar network for months, to the extent that Ota traded a navy radar crew for an Army radar./17

Ota's radar cooperation with Ushijima was not in any US Navy document.

This fact was buried in the post war US Army occupation report titled "Intelligence Report No. 30: Northern Ryukyus".

Also buried was the fact every Ryukyus radar, IJA or IJN, was under Ota's control./18

RADM Ota wanted a 4-meter band/72 Mhz IJA Tachi-6 for a very special reason. It operated on the USN's TCS radio primary frequencies.

The S. Okinawa Tachi-6 very carefully tuned it's transmission to be on top of USS El Dorado's - Adm Turner's command ship - TCS broadcast./19

The neat thing about a Tachi-6 was it was a true bi-static radar. The FEAF "Short Survey on Japanese Radar" found its receiving antenna's could be displaced up to 20km away from the transmitter and still provide early warning./20

However, when the very carefully tuned Tachi-6 transmitters were not operating...their receiving antenna's still did, listening to powerful 70 Mhz signals like on USS El Dorado.

We don't know if Ota's Tachi-6 were direction finding...but AGC were attacked like they were./21

And the extent of the Tachi-6 jamming was such that special Southern Okinawa photo missions were run to identify the transmitting antenna's for naval bombardment./22

The sad thing about Okinawa for the USN was Adm Halsey was not involved in it's planning. His experience with Rabaul's land based radars did not enter the planning for Operation Iceberg.

A comparison of where TF 58's CVBG operated compared TF 38 made that clear. /end

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