Kawasaki Ki-45 Toryu IN The Solomons

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Mark McShane
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Kawasaki Ki-45 Toryu IN The Solomons

#1

Post by Mark McShane » 31 Aug 2022, 20:22

Can anyone provide info if the Ki-45 was used in the Solomon's campaign, particularly in the anti-shipping role?

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fontessa
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Re: Kawasaki Ki-45 Toryu IN The Solomons

#2

Post by fontessa » 08 Sep 2022, 03:22

Mark McShane wrote:
31 Aug 2022, 20:22
Can anyone provide info if the Ki-45 was used in the Solomon's campaign, particularly in the anti-shipping role?
Ki45 Kai was used to escort Japanese convoys, but not to attack enemy ships.


Ki-45 → Ki-45 Kai
The IJAAF ordered the prototype of Ki-45 twin-engine fighter to Kawasaki Heavy Industry in 1937. The prototype was completed in January 1939. But it was a complete failure due to the problem of engine malfunction and *nacelle stall problem. However, the IJAAF did not give up and ordered the improvement of KI-45 in October 1940. Kawasaki entrusted this work to 土井武夫 Doi Takeo. He was one of Japan's top class designers, and were chief designers of Ki-48 (Lily), Ki-45 Kai (Toryu, Nick), Ki-61 (Hien, Tony), Ki-100 (Tony II) and Ki-102 (Randy). With the engine upgrade and his resolve of the nacelle stall problem, the Ki-45 was revived and adopted as the Type2 Two-seat Fighter Ki-45 Kai in February 1942.
* Nacelle stall: If the engine nacelle was improperly shaped, turbulence in the airflow could cause the aircraft to stall due to loss of lift.

Armament Enhancements for B-17 Interception
The armament of Ki-45 Kai A was:
- Ho-103 12.7mm Cannon x 2 (Nose)
- Ho-3 20mm Cannon x 1 (Under Nose Fuselage)
- Type98 7.92mm Swivel Machine Gun (Rear Seat)
The IJAAF upper management had insufficient awareness of the B-17 threat, and countermeasures against it were haphazard. After testing captured B-17s with fuel tanks, they realized that 20mm cannons could not reliably penetrate them, so their countermeasure was to install a 37mm tank gun. The IJAAF had lagged behind in the development of large-caliber cannons, and had no choice but to equip a type94 37mm tank gun which was used in type95 light tank. It was decided that Ki-45 KaiA and Type 100 Headquarters Reconnaissance Aircraft Ki-46II. The problem was that manual reloading was needed because the tank gun didn’t have an automatic loading mechanism. As for Ki-45 Kai A, a Ho-3 20mm Cannon was replaced with a type94 37mm tank gun. And it could be reloaded by the rear seat crew. The Ki-45 KaiA with the tank gun was renamed to Ki-45 KaiB. This was still acceptable. But the situation was not so easy for Ki-46. The tank gun was placed in the nose and its breech protruded above the pilot's knee. The pilot had to load the tank gun with one hand while holding the steering wheel with another hand. It took 30 seconds to load the gun - damn it.
Of course, the tank gun was a "stopper" until the 37mm cannon was put into practical use.
Ki-45 Kai with Ho-203 30mm Cannon was named Kai-C. At the first, Naval Air Depot conducted the mounting of HO-203. The final type was Ki-45 Kai-D added “Oblique” Ho-5 20mm Cannons.

Dispatch of Tryu and Dina to the South
洋11703部隊 Yo11703 Unit
Temporally organized with 6 Ki-45 KaiBs and 6 Ki-46IIs with tank guns. One Ki-46II was lost during the movement to Rabaul. They came under the command of the 12th Air Brigade Commander in the middle of February 1943. In addition to intercepting B-17s at Rabaul, she advanced to eastern New Guinea in April to support the 6th Air Division. Unfortunately, the unit did not achieve remarkable results during this period. It's not clear what happened to Ki46s. The surviving Ki45s were absorbed by the next dispatched the 13th Air Regiment.
飛行第13戦隊 The 13th Air Regiment
The movement of the 13th Air Regiment began in April. And there were 34 Ki45s (31 operational) of the 13th Air Regiment, which gathered in Rabaul at the end of June absorbing the survivors of Yo11703 Unit. In July, 2 companies advanced to Wewak, but most of the combat occurred during daytime, so the poorly maneuvered Ki45 Kais were rapidly depleted, and by October there were no operational aircraft.

The Ki45 Kais were largely unremarkable in the Solomons. It was in the homeland air defense that they demonstrated their ability.

屠龍 甲乙.jpg

屠龍 丙.jpg

屠龍 丁.jpg
屠龍 丁.jpg (78.33 KiB) Viewed 4100 times

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Re: Kawasaki Ki-45 Toryu IN The Solomons

#3

Post by ShindenKai » 08 Sep 2022, 05:33

Fontessa,

Did the Ki-45 Kai-C & Kai-D still have the 20mm in the ventral tunnel as well?

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Re: Kawasaki Ki-45 Toryu IN The Solomons

#4

Post by fontessa » 08 Sep 2022, 06:41

ShindenKai wrote:
08 Sep 2022, 05:33
Fontessa,

Did the Ki-45 Kai-C & Kai-D still have the 20mm in the ventral tunnel as well?
Ki45 Kai-C: Yes. (See the 2nd picture.)
Ki45 Kai-D: No. (Only “Oblique” cannons.)
I have a question.
What are these "Oblique" canons called in America?

fontessa

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Re: Kawasaki Ki-45 Toryu IN The Solomons

#5

Post by ShindenKai » 11 Sep 2022, 09:23

fontessa wrote:
08 Sep 2022, 06:41
ShindenKai wrote:
08 Sep 2022, 05:33
Fontessa,

Did the Ki-45 Kai-C & Kai-D still have the 20mm in the ventral tunnel as well?
Ki45 Kai-C: Yes. (See the 2nd picture.)
Ki45 Kai-D: No. (Only “Oblique” cannons.)
I have a question.
What are these "Oblique" canons called in America?

fontessa
Thanks Fontessa, I've never heard of the oblique cannons being called by any other name.

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Re: Kawasaki Ki-45 Toryu IN The Solomons

#6

Post by Takao » 11 Sep 2022, 12:26

Only ever seen them referenced as Schräge Musik or oblique cannon in the West.

AFAIK, neither the Americans or British used anything comprable.

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Re: Kawasaki Ki-45 Toryu IN The Solomons

#7

Post by fontessa » 11 Sep 2022, 13:47

ShindenKai wrote:
11 Sep 2022, 09:23
I've never heard of the oblique cannons being called by any other name.
Takao wrote:
11 Sep 2022, 12:26
Only ever seen them referenced as Schräge Musik or oblique cannon in the West.
Thanks to the both for the answering.

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Re: Kawasaki Ki-45 Toryu IN The Solomons

#8

Post by ShindenKai » 11 Sep 2022, 18:10

Fontessa, I've seen a drawing and maybe a pic or two showing a secondary aim sight (Type 4?) for aircraft with the oblique guns, but not always. What sightings systems were used for these guns?

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Re: Kawasaki Ki-45 Toryu IN The Solomons

#9

Post by fontessa » 11 Sep 2022, 21:04

ShindenKai wrote:
11 Sep 2022, 18:10
I've seen a drawing and maybe a pic or two showing a secondary aim sight (Type 4?) for aircraft with the oblique guns, but not always. What sightings systems were used for these guns?
At first, cannons IJN called 斜銃 “Oblique gun” were called in IJA 上向き銃 “Upward gun”. JIN and IJA ridiculously didn't like to use the same name. Well, I didn't find any good documentation about Toryu's upward gun sighting system. But I found one for the Ki-46. The upward ray of the sight for the Ho-103 37mm cannon was reflected by 2 mirrors so that it could be seen through the reticle by the pilot. Toryu had probably the same system. The 1st picture shows it. The 2nd picture shows the CG image with another firing sight.

屠龍 照準システム.jpg



Additional info about IJN Irving Model11 upward / downward gun sighting system
月光_照準.jpg

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Re: Kawasaki Ki-45 Toryu IN The Solomons

#10

Post by ShindenKai » 12 Sep 2022, 09:04

I have not seen this Type 3 HUD sight before, very interesting. I like the idea of using the same sight to aim both sets of guns. I'm a bit confused as to where the pilot would be looking to aim the 37mm. Is one of the mirrors a prism? Is there another book I can find more info about this? Any info about the sighting systems for the following aircraft with oblique cannons? -Its interesting that only the 37mm in the Ki-46 seemed to be mounted at 70* angle, while all the 20mm & 30mm seemed to be between 30*-60* angles. Great info of the Gekko sight set-up as well.

A6M5-S 1x 20mm (S was US designation for Zeke night-fighter)
P1Y Ginga 2+x 20mm OR 1x 30mm
D4Y Suisei 1x 20mm
C6N Saiun 1x 30mm
Ki-109 2x 37mm

Thank you again Fontessa
Last edited by ShindenKai on 12 Sep 2022, 18:55, edited 2 times in total.

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Re: Kawasaki Ki-45 Toryu IN The Solomons

#11

Post by ShindenKai » 12 Sep 2022, 10:39

Just came across a couple images showing a P1Y Ginga w/oblique 30mm cannon, seems only one Type 5 is mounted but the angles of both don't show right side... "Meat Balls and Dead Birds" by J.P. Gallagher

-No sighting devices are visible but this is after the end of the war and they may have been carried off by souvenir hunters...
Attachments
P1Y_Ginga_30mmOblq2.jpg
P1Y_Ginga_30mmOblq.jpg

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Re: Kawasaki Ki-45 Toryu IN The Solomons

#12

Post by Takao » 12 Sep 2022, 14:49

ShindenKai wrote:
12 Sep 2022, 09:04
I have not seen this Type 3 HUD sight before, very interesting. I like the idea of using the same sight to aim both sets of guns. I'm a bit confused as to where the pilot would be looking to aim the 37mm. Is one of the mirrors a prism? Is there another book I can find more info about this? Any info about the sighting systems for the following aircraft with oblique cannons? -Its interesting that only the 37mm in the Ki-46 seemed to be mounted at 70* angle, while all the 20mm seemed to be between 30*-60* angles. Great info of the Gekko sight set-up as well.

A6M5-S 1x 20mm (S was US designation for Zeke night-fighter)
P1Y Ginga 2+x 20mm
D4Y Suisei 1x 20mm
C6N Saiun 1x 30mm
Ki-109 2x 37mm

Thank you again Fontessa
The setup was confusing at first, likely due to the direct translation of "mirror."

After looking at the setup for awhile...I can only conclude that the "1st mirror is a typical mirror. However, I am of the opinion that the "2nd mirror" is not a "mirror" at all(in the normal sense like the "1st mirror"). Instead, it is another reflective glass piece like that used on the reflector(reflex) gunsight. This allows the gunsight(crosshair or pipper) to be projected on it, while still allowing the pilot to see, and aim at, his target above him.

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Re: Kawasaki Ki-45 Toryu IN The Solomons

#13

Post by fontessa » 12 Sep 2022, 15:56

Takao wrote:
12 Sep 2022, 14:49
The setup was confusing at first, likely due to the direct translation of "mirror."

After looking at the setup for awhile...I can only conclude that the "1st mirror is a typical mirror. However, I am of the opinion that the "2nd mirror" is not a "mirror" at all(in the normal sense like the "1st mirror"). Instead, it is another reflective glass piece like that used on the reflector(reflex) gunsight. This allows the gunsight(crosshair or pipper) to be projected on it, while still allowing the pilot to see, and aim at, his target above him.
In the Japanese book I referred to, the Kanjis 反射鏡 were used for both 1st and 2nd. So I mechanically translated them as mirrors. But I think that what you say makes sense. Thanks for the accurate comment.

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Re: Kawasaki Ki-45 Toryu IN The Solomons

#14

Post by fontessa » 12 Sep 2022, 16:07

ShindenKai wrote:
12 Sep 2022, 10:39
Just came across a couple images showing a P1Y Ginga w/oblique 30mm cannon, seems only one Type 5 is mounted but the angles of both don't show right side... "Meat Balls and Dead Birds" by J.P. Gallagher
The standard armament of P1Y1 was 2 x 20mm cannons + 1 20mm cannon later 2 20mm canons + 1 13mm MG. ヨD 181 in the 2nd photo was P1Y1 of which the oblique gun was changed from 2 20mm cannons to a 30mm cannon at 302nd Naval Air Group. 
(ヨ was / is a Japanese Katakana YO. And ヨD was the unit code letter of 302nd Naval Air Group.)

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Re: Kawasaki Ki-45 Toryu IN The Solomons

#15

Post by fontessa » 13 Sep 2022, 05:35

ShindenKai wrote:
12 Sep 2022, 09:04
A6M5-S 1x 20mm (S was US designation for Zeke night-fighter)
P1Y Ginga 2+x 20mm OR 1x 30mm
D4Y Suisei 1x 20mm
C6N Saiun 1x 30mm
Ki-109 2x 37mm
The below plus Gingaga and Zero Night Fighter is the all of what I know.
The 1st picture show Suisei and Saiun Night Fighters belonged to the 302nd Naval Air Group. The 2nd picture shows Raiden Night Fighter Prototype with a 20mm oblece gun mounted on the left side.Note the unit letters code on vertical tail were ヨD. And the 2nd picture also shows Raiden with 2 30mm cannons. Tree of them were seen in the 302nd Naval Air Group.
The 302nd Naval Air Group stayed at Atsygi was the most powerful air defense force in eastern Japan, comparable to the 343rd Naval Air Group stayed at Matsuyama which was the strongest in western Japan.
The composition of it was;
- 1st Battalion: 2 Raiden Squadrons and 1 Zero Squadron
- 2nd Battalion: 2 Gekko Squadrons and 1 Ginga Squadron
- 3rd Battalion: 2 Suisei Night Fighter Squadrons and 1 Saiun Night Fighter
Capt Kozono Yasuna 小園安名 who had invented the oblique gun system during the Rabaul era was the commanding officer of it. Against the end of the war, he staged a rebellion on August 15, but was soon crushed. (Atsugi Incident) Capt Genda Minoru 源田実 the commanding Officer of the 343rd Naval Air Group. CFR genda Muniru had been appointed the Air “A” Staff Officer of the 1st Air Fleet when at Pearl Harbor Attack. Now he gathered skilled Shiden Kai pilots and had a good fight with the fighters of the US aircraft carrier task force.

The 3rd picture shows Ki-46 III Otsu + Hei. It had 2 Ho-5 20mm cannons on nose and 1 37mm on the center of the fuselage.
The 4th picture shows Ki-102 variations. It was the Ki-45Kai advanced model designed by Doi Takeo 土井武夫 who was the chief designer of Ki-45 Kai.
The 5th picture shows the 2nd prototype of Ki-109 Special Air Defense Airplane which was the modified version of Ki-67 Hiryu. The war ended when two prototypes were built.

302空 夜戦.jpg

夜戦 雷電.jpg

防空 Ki-46.jpg

防空 Ki-102.jpg

防空 Ki-109.jpg

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