The USAAF didn't like the night... or it did?????

[Escuadrilla Azul]

The doctrine of the USAAF was daylight bombing.

The 8 AAF practiced it and also the different bombing commands in the MTO and the CBI but I have just finished reading the South Pacific Air War series and was surprised how many night bombings against Rabaul were made by the 5 AAF and previous commands due to fierce opposition by the japanese defenses.

How could the USAAF bomb by night in the SWPac because they faced strong defense and think that they could bomb Germany in daylight without fighter cover when they knowed that over Europe would be even fiercer and stronger?

I mean, the Fw 190 was more heavily armed than the A6M (and was known). The germans had radar since 1939 (and was also known).

I supose that the different AAFs won't talk to each other easily due to the means of communications of the day but nobody in an upper echelon connect the dots?

It was daylight bombing over Europe only for political causes? If so, why not in the SWPAC?

What I'm missing here?

 

[Tkdog]

I've always assumed it was because the Pacific objectives were so small. If you need to attack Rabaul… they know where you're going to be. The European command could range over a wide area day to day and disperse the defenses via uncertainty. But I'm not an expert by any means.

 

[EwenS]

Heavy bomber raids in the Pacific were on a much smaller scale than in Europe because far fewer units were deployed. In the early days often at squadron level.The B-24 groups were:-

5th AF
22nd BG - converted from B-25/B-26 to B-24 in Feb 1944 after Rabaul had been isolated.
43rd BG - arrived Australia in March 1942 and transitioned from B-17 between May & Sept 1943.
90th BG - arrived at Iron Range, Queensland Australia in Nov 1942
380th BG - arrived Fenton, NT, Australia May 1943.

13th AF
307th BG - Feb 1943 in Solomons then northwards, through New Guinea to Philippines
5th BG - arrived Espiritu Santo Nov 1942. Converted to B-24 Aug-Dec 1943. Then through Solomons, New Guinea to Philippines.

7th AF
5th BG - Feb-Nov 1942 in Hawaii with B-17. Then to 13th AF
307th BG - Nov 1942-Feb 1943 out of Hawaii. Then to 13th AF
11th BG - from 13th AF in April 1943 when it transitioned from B-17 to B-24. Supported ops across the Pacific island groups.
30th BG - arrived Hawaii Oct 1943. Then across Pacific island groups until March 1945.
494th BG - arrived Hawaii June 1944 then on through Pacific islands.

From early 1943 USN squadrons with PB4Y-1 Liberators began operating out of Guadalcanal up the Solomon Is to bomb Rabaul.

A Nov 1942 raid on Rabaul by 90th BG was planned with just 15 aircraft, but only 11 got off the ground due to an accident. 2 were lost on the mission.Takeoff was at 2300. Only 3 reached the target.

 

[Escuadrilla Azul]

Heavy bomber raids in the Pacific were on a much smaller scale than in Europe because far fewer units were deployed. In the early days often at squadron level.

Yes, I know that. But that is the reason for night bombings? The japanese fighters weren't numerous also and they had a bunch of places to cover: Rabaul, Gasmata, Kavieng, New Guinea at some different points, the Solomons from August 1942, the convoys plying the sealanes connecting the strongpoints.

Due to lack of radar and coastwachters they didn't had enough notice of a coming plane or raid and struggle to take off and climb to face the intruders at height and had to mount standing patrols, wearing planes and pilots.

 

[EwenS]

The Japanese did have radar in the SWPA and in particular around Rabaul. Reportedly capable of detecting larger formations out to 150 miles.

In Jan 1944 2 converted B-24 Liberator "Ferret" aircraft (Ferret VII & VIII) arrived in theatre under the administrative control of 63rd BS 43rd BG. They reported to Section 22 in Brisbane in charge of all allied ECM operations. These aircraft started their activities by mapping the Japanese radars around Rabaul.

"Section 22", Intelligence Organisation in SWPA during WW2

Japanese Radar Type Designation Systems

I've tried to collect the WW2 Japanese radar Type designation systems with data and if possible photos and drawings. Japanese radar were designated by Mark (Go), which indicated the intended use; Model (Kei/Kata/Gata); Modification (Kai); and Type (Shiki). Mark 1 was ground based search and...

www.secretprojects.co.uk

 

[33k in the air]

Yes, I know that. But that is the reason for night bombings?

The reason was that losses in daytime were too high, since the bombers could not be escorted by fighters due to the longer ranges of operations in the Pacific. And given the far fewer forces assigned to the theatre, heavy losses simply could not be afforded.

In Europe, as has been mentioned, bombing formations were considerably larger, and the belief that such large, dense formations could defend themselves held sway until the Schweinfurt raids proved the belief unfounded. There was then a push by the British to get the U.S. to switch to nighttime bombing, but the U.S. ultimately turned that down, citing the amount of retraining of crews in theatre that would be needed, and the complete reworking of the training establishment in the continental U.S. that would be required.

 

[Escuadrilla Azul]

The Japanese did have radar in the SWPA and in particular around Rabaul. Reportedly capable of detecting larger formations out to 150 miles.

Do you know when it was installed at Rabaul? So far I haven't found a source for that, only that the marines got one set in Guadalcanal in August 42 (not mention if it was in a working state).

The South Pacific Air War series don't said anything about that.

 

[Escuadrilla Azul]

The reason was that losses in daytime were too high, since the bombers could not be escorted by fighters due to the longer ranges of operations in the Pacific. And given the far fewer forces assigned to the theatre, heavy losses simply could not be afforded.

But A6Ms didn't had nuch success even in downing single recon B-17 (although sometimes they shot them up pretty much).

Of course the route for sending reinforcements and replacements from CONUS to theatre was much longer to SWPAC than to UK but the opposition was heavier also.

 

[Geoffrey Sinclair]

The 8th Air Force was working on an assumption of herd immunity, so many bombers that the Germans could not shoot down enough to stop the attacks, the everything that could fly mission of 24 December 1944 lost 35 bombers (only 12 MIA), or over half the 1943 deep penetration raids, but from 1,884 effective sorties or around 6 times as many aircraft, so in 1943 around 20% loss rate, in 1944 2%.

The Japanese defences were good enough to inflict unacceptable losses to allied bombers attacking Rabaul. Note the allied approaches to Rabaul in 1942/43 did fly over plenty of Japanese controlled territory. I have no date for radar deployment at Rabaul. As people have pointed out the number of allied bombers available meant they could not take losses comparable to those deployed in Europe.

Cavity Magnetron,

"Two Soviet engineers, N.F. Alekseev and D.D. Malairov, developed the technology in the late 1930s and actually published a description of it in a public technical journal in 1940. "

Abstract about Shigeru Nakajima who invented a 500W magnetron (as powerfull as Randall and Boot's) in 1939, and then developed the Type 22 naval radar.

http://www.ieee.org/web/aboutus/history_center/oral_history/abstracts/nakajimasab.html

The British seem to have come third, but put it into service first. The interesting thing is they told the Americans, sharing the idea, whereas the Japanese did not share.

Another quote,

"Okabe & Yagi at the Tohoku College of Engineering developed a split-anode magnetron in 1927 and by 1939 the Japan Radio Company had developed an 8-cavity, water-cooled magnetron at a wavelength of 10 cm with a continuous output power of 500W. However, this research (which stopped in 1941 due to material shortages) was not published until after WW2. Another design, the first successful multicavity magnetron design, was developed in Russia in 1936-37 by Aleksereff & Malearoff, with results first published in 1940 "

Hiryu had radar before its Indian Ocean deployment, the set had a blind spot due aft.

 

[pbehn]

The 8th Air Force was working on an assumption of herd immunity, so many bombers that the Germans could not shoot down enough to stop the attacks,

I think it is more correctly called the shoal effect. They were correct in the theory but not in the numbers. The LW probably did shoot down as many as they could on the Schweinfurt raids. A Thousand bomber raid would have suffered similar losses and may have shot down more LW planes. If a similar raid could be mounted two days after with 1000 bombers, and then again and again the LW would have been defeated, but the cost in men and machines would have been enormous. Far more than those who were advocates of defensive firepower predicted.

 

[Escuadrilla Azul]

Hiryu had radar before its Indian Ocean deployment, the set had a blind spot due aft.

Was that blind spot the cause why the US Navy planes weren't detected?

 

[EwenS]

Do you know when it was installed at Rabaul? So far I haven't found a source for that, only that the marines got one set in Guadalcanal in August 42 (not mention if it was in a working state).

The South Pacific Air War series don't said anything about that.

29 Feb 1944 2 PV-1 Ventura aircraft from 2 squadron RNZAF based at Munda were tasked with locating a suspected Japanese radar station at Adler Bay, to the south of Rabaul believed to be reporting Allied aircraft coming from the south to strike Rabaul. They found and bombed it. On 2nd March there was a follow up raid by by 12 SBD and 6 TBF and another raid on 3rd March to complete its destruction. Then on the 5th March a force of US destroyers was able to enter St George's Channel to bombard Simpson Harbour.

The Assault on Rabaul : Operations by the Royal New Zealand Air Force December 1943 — May 1944 | NZETC

This will give you a feel for the level of operations and the Japanese aircraft strength during the Rabaul air campaign.

HyperWar: The Army Air Forces in WWII: Vol. IV [Chapter ]

 

[Escuadrilla Azul]

This will give you a feel for the level of operations and the Japanese aircraft strength during the Rabaul air campaign.

HyperWar: The Army Air Forces in WWII: Vol. IV [Chapter ]

Quote from that link:

"The Southeastern Fleet had built up an extensive and efficient early warning radar system. Besides the sets at Rabaul with ninety-mile coverage, there were radar sets to the southwest on New Britain, at Kavieng and Cape St. George on New Ireland, and at Buka. These sets would pick up Allied strikes and would radio warning to Rabaul from thirty to sixty minutes ahead of the attack."

No date is mentioned so I suspect that in 1942 that radar coverage wasn't in place at all or not complete due to the need for standing patrols and scrambles when the allied planes over Rabaul.

Thanks for sharing.

 

[BlackSheep]

The Japanese did have radar in the SWPA and in particular around Rabaul. Reportedly capable of detecting larger formations out to 150 miles.

In Jan 1944 2 converted B-24 Liberator "Ferret" aircraft (Ferret VII & VIII) arrived in theatre under the administrative control of 63rd BS 43rd BG. They reported to Section 22 in Brisbane in charge of all allied ECM operations. These aircraft started their activities by mapping the Japanese radars around Rabaul.

"Section 22", Intelligence Organisation in SWPA during WW2

Japanese Radar Type Designation Systems

I've tried to collect the WW2 Japanese radar Type designation systems with data and if possible photos and drawings. Japanese radar were designated by Mark (Go), which indicated the intended use; Model (Kei/Kata/Gata); Modification (Kai); and Type (Shiki). Mark 1 was ground based search and...

www.secretprojects.co.uk

Here is an additional resource on Japanese radar types and their usages, as well as, the other players in WW2:

The Pacific War Online Encyclopedia: Radar

 

[Escuadrilla Azul]

Here is an additional resource on Japanese radar types and their usages, as well as, the other players in WW2:

The Pacific War Online Encyclopedia: Radar

The Pacific War Online Encyclopedia seems a very impresive source!

 

[pinehilljoe]

Gen LeMay reinvented night area bombing with the B-29 missions in the Pacific. (no offense to Bomber Command).

 

[33k in the air]

Gen LeMay reinvented night area bombing with the B-29 missions in the Pacific. (no offense to Bomber Command).

Well, he had to. Conventional high-altitude strategic bombing wasn't working, and the higher ups were getting impatient for results.

 

[EwenS]

This might be of interest on Japanese Navy radars. Official US report from 1945

Note the comments about the land based Type 11 of the type captured at Guadalcanal and the Aleutians with a range of 200km. Although "large and cumbersome" it "gave an excellent account of itself" but the Japanese found they needed something more portable.

https://apps.dtic.mil/sti/pdfs/AD0895893.pdf

Clearly another document somewhere on Japanese Army radars.

 

[EwenS]

Hiryu had radar before its Indian Ocean deployment, the set had a blind spot due aft.

Geoffrey
Do you have a source for that?

The reason I ask is that Parshall & Tully devoted Appendix 8 in "Shattered Sword" to the question of whether the Japanese had radar at Midway and followed up on the reports from a couple of Japanese officers interrogated at the end of the war that Hiryu had radar during Operation C in the IO. Those contradicted statements from other officers. Then John Prados in "Combined Fleet Decoded" made reference to Hiryu's post Op C action report that said she had some new form of detection gear that had a blind spot at the rear.

Parshall & Tully managed to trace a copy the action report filed by Hiryu after Operation C which only commented on the need for something better than the Mk.1 eyeball. Let me quote that part of the Report in "Shattered Sword" with my emphasis.

"With the search installations at present on the Hiryu class [i.e. referring to the standard spotting glasses atop the island, as well as gun director optics used for such searches - JP], it is very difficult to sight targets at an altitude over 5000 meters. At present ..... an enemy bomber unit that breaks into the center of the cruising disposition from the rear ... cannot be sighted. On the Akagi there have been many times when the first warning was the splash of bombs .... As a counter-measure, it is necessary to install AA search radar or sound equipment at once."

So it seems clear that Hiryu didn't have radar during Operation C. They also concluded that fitting the radar was a dockyard job and that Hiryu, Akagi & Soryu did not spend long enough in Japan from the end of 1941 to allow this to be done. While Kaga underwent repairs in Japan prior to Midway, it was noted that her island was too small to allow its fitment. So their conclusion was that none of their carriers had radar at Midway.

Further evidence comes from the note that the first prototype of the Type 21 radar, a mattress affair as the Japanese officers described in 1945, was only put aboard the battleship Ise in May 1942. At the same time the battleship Hyuga received a Type 22 surface warning set. Both those ships went as part of the covering group for the Aleutian force in June 1942. Sending those ships to the north actually makes some sense due to the weather likely to be encountered.

 

[pbehn]

In general finding targets at night was easier if they were by the coast, places like Raboul were. In Europe flying at night and finding a target needed a lot more training and RAF bomber command were already doing it, having two forces putting on 1000 bomber raids at night over Europe was inviting a disaster of historic proportions.

edit, I dont mean flying at night needed more training because it is more difficult, it is a different skill to the skill of forming up in bomber boxes by day.