Numerical Strength of Japanese 15th Army during Operation U-Go?

[riverpass312]

Some historians have stated that the Battle of Imphal-Kohima was the largest defeat on land in the history of the IJA. So I'm trying to compare this battle numerically--in terms of the number of men involved--with other battles involving the IJA like Okinawa.

I've seen many numerical figures regarding the strength of Renya Mutaguchi's 15th Army during the disastrous U-Go offensive in Burma, from as low as 70,000 to as high as 115,000. The highest figure is more than 1.5 times larger than the lowest. Hemant Singh Katoch, writing for Osprey Publishing's "Imphal 1944" states that the 15th army started the offensive with 84,000 soldiers split into three divisions as well as army troops. These were backed by 4,000 reinforcements and 6,000 INA soldiers, giving a total of about 94,000.

Most OOBs for this engagement list 31st, 33rd, and 15th divisions as the main components, plus a tank regiment. Occasionally the Yamamoto force and 151st regiment included as separate formations. None of the OOBs I've seen mention any "army troops." Assuming that each Japanese division is approx. 15,000-20,000 men, the 70,000 figure seems realistic, but the higher figures from 90,000 to 115,000 seem exaggerated. Either the three divisions were heavily reinforced--Katoch states that they were in some ways actually understrength--or there were a ton of army troops not listed.

Does anyone here have any sources breaking down the strength and composition of the Japanese 15th Army in Burma during 1944?

[Akira Takizawa]

According to Senshi Sosho, the strengths of 15th Army are as follows.

15th Division - 16,000 men
31st Division - 16,600 men
33rd Division - 17,000 men
Army direct-controlled units - 36,000 men

Total - 85,600 men

Taki

[riverpass312]

According to Senshi Sosho, the strengths of 15th Army are as follows.

15th Division - 16,000 men
31st Division - 16,600 men
33rd Division - 17,000 men
Army direct-controlled units - 36,000 men

Total - 85,600 men

Taki

Senshi Sosho is a historian right? Does he have any books in English about U-Go?

Edit: Just realized that it's the official history, not a person lol. Is there an english translation?

[Akira Takizawa]

There is no English translation of the volumes of Senshi Sosho concerning operation U-Go.

Taki

[riverpass312]

Is it true that only 60,000 men crossed the chindwin though?

[Akira Takizawa]

Is it true that only 60,000 men crossed the chindwin though?

Senshi Sosho presumed so.

Taki

[Kelvin]

Hello, Taki, three Divisions of 15th Army totally had 51 x mountain guns, apart from this, any non-divisional artillery accompanied them in this Campaign ? Thank

[Carl Schwamberger]

There is no English translation of the volumes of Senshi Sosho concerning operation U-Go.

Taki

I've heard the Australians translated portions relating to their campaigns. The source did not indicate if this translation was published or only printed as a archival reference. The same source indicated US military historical sections had attempted no translation effort of any significance. Last the Soviet military obtained its own translation for understanding another PoV of fighting the US Army and Navy.

[BobTheBarbarian]

In my opinion, JM-134 is the best available source on this in English (http://ibiblio.org/hyperwar/Japan/Monos ... JM-134.pdf). It goes into the campaign in considerable detail, although certain topics like numbers of artillery pieces are not enumerated exactly but rather in approximate terms (regiments and battalions).

Edit: here are personnel statistics from page 164 of the above

[Akira Takizawa]

Hello, Taki, three Divisions of 15th Army totally had 51 x mountain guns, apart from this, any non-divisional artillery accompanied them in this Campaign ? Thank

Senshi Sosho presumed that 64 mountain guns were brought to Imphal. The details of Senshi Sosho's presumption are as follows.

　　　　　　　　　　　　　15D 31D 33D
Type 41 Mountain Gun　　　 10　 6　 6
Type 31 Mountain Gun　　　　6
Type 94 Mountain Gun 　　　　　18　18
Type 95 Field Gun　　　　　　3
Type 91 10cm Howitzer 　　　 4


Taki

[Kelvin]

Hello, Taki, thank a lot.

[Akira Takizawa]

I forgot to write non-divisional artillery.

12 Type 96 15cm Howitzers
16 Type 92 10cm Cannons

Taki

[Kelvin]

I forgot to write non-divisional artillery.

12 Type 96 15cm Howitzers
16 Type 92 10cm Cannons

Taki

Hi, Taki, thank again.