How did RAdm Tanaka's destroyers aka "Rat Transportation" transported its troops?

Hi,

After reading several books about the Guadalcanal campaign and
Rear Admiral Raizo Tanaka's troop transport destroyer squadron aka "Rat Transportation" / "Tokyo Express"
that sent reinforcement and resupply shipments to Imperial Army troops at Guadalcanal.

My question is, how did these ships landed their troops?

RAdm Tanaka's destroyer squadron consisted of
one light cruiser (Sendai-class or Nagara-class or Tenryu-class) and
6 or up to 12 destroyers from 2 to 4 different destroyer divisions.
Is possible that each light cruiser could carry up to 80 or 100 fully equipped Imperial Army troops
with the maximum of four mountain guns.
Each destroyer could carry up to 60 fully equipped Imperial Army troops.

Normally, all ships carried on board the utility boats and
maybe the "Rat Transportation" cruisers and destroyers carried
some type of special landing boats for the troops and supply.

The number of utility boats for each class cruisers and destroyers
that participated in the "Rat Transportation":
The Sendai-class light cruisers boarded:
one x 15-meter Motor Launch (each carried approx. 24 naval officers)
two x 11-meter Motor Launch (each carried approx. 12 naval officers)
three x 9-meter Cutter (each non-motor boats carried approx. 25 sailors)

The Nagara-class light cruisers boarded:
two x 11-meter Motor Launch (each carried approx. 12 naval officers)
two x 9-meter Cutter (each non-motor boats carried approx. 25 sailors)
two x 12-meter Motor Launch (each carried approx. 60 sailors)

The Tenryu-class light cruisers boarded:
two x 11-meter Motor Launch (each carried approx. 12 naval officers)
two x 9-meter Cutter (each non-motor boats carried approx. 25 sailors)

The destroyers such as the Yugumo-class, Kagero-class, and Shiratsuyu-class boarded:
two x 7.5-meter Motor Launch (each carried approx. 20 sailors)
two x 7-meter Cutter (each non-motor boats carried approx. 20 sailors)

The Imperial Japanese Army possessed three types of landing crafts during the Guadalcanal campaign
such as:
the 10-meter Shohatsu-class that carried approx. 30 troops
the 14-meter Daihatsu-class that carried approx. 90 troops
the 17-meter Toku Daihatsu-class that carried approx. 190 troops

These landing crafts were usually transported by Imperial Army Troop Transports.
Is possible that the Imperial Navy light cruisers could carry on board
two additional 10-meter Shohatsu-class.

Also, the Imperial Japanese Navy did have their own landing crafts
Such as:
the 13-meter Chuhatsu-class that carried approx. 80 sailors

Please share any information regarding the Japanese transportation of troops to Guadalcanal.
Thanks in advance.

 

Hi.

In general IJA used so called "anchorage" units to organise unloading sea transports from land (or sea if it´s an innitial landing). These "anchorages" commanded "sea duty" units using landing craft to unload the transports at sea and to unload personell and cargo on the chosen landing beach. There "land duty" units organised and executed the transport of the supplies from the beach to depots. The ship-own boats would speed up the process but the operation did not only depends on them.

There were also special engineer units for sea transport or river crossings which were equipped with Daihatsus and Moku-Daihatsus used to unload soldiers and supply but mainly at innitial or opposed landings.

I don´t have the detailed OOBs of Guadalcanal so it´s hard to say if there were such sea and land duty units around.

Edit:
IJA 17th Army had a total of three sea duty companies and two land duty companies available after 20.10.1942. No idea if one or more were on Guadalcanal but as this was the main battlezone for this army at this time I would assume that.

- 31st Sea Duty Company
- 35th Sea Duty Company
- 49th Sea Duty Company

- 69th Land Duty Company
- 96th Land Duty Company

Yours

tom

 

Thanks Tom for your reply.

I found several websites in Japanese that describes the transportation of The Ichiki Corps and The Kawaguchi Corps in August 1942:

A paragraph taken from
http://minoworld2.web.fc2.com/guadal02.html
旭智輝・斎藤清たち第一梯団の生き残り兵は、第二梯団の到着を待ちわびた。
そして8月28日から連日、川口支隊を含め計約4千名の将兵が上陸してきた。
斎藤清は、駆逐艦が来ると折りたたみ式舟艇を海に出し、到着した兵士を迎えに向かった。
方川新一たち一木支隊第二梯団（1100名）は、実に三度も上陸を前に途中で引き返している。
上陸は夜間でなければ、アメリカ軍機の餌食になってしまう。
8月22日、米軍機の襲来にあい第二梯団は最初の反転をし、上陸は24日に延期された。
The surviving soldiers of Chiaki Asahi and Kiyoshi Saito, the first ladder, waited for the arrival of the second ladder.
From August 28, approximately 4,000 soldiers including Kawaguchi Corps landed every day.
Saito Kiyoshi launched a foldable boat into the sea when the destroyer arrived and headed for the soldiers who arrived.
Shinichi Hokawa and Ichiki Corps 2nd ladder (1100 people) are turning back halfway before landing.
If landing is not at night, it will be a prey for American military aircraft.
On August 22, the second ladder made its first reversal during the attack of the US military aircraft, and the landing was postponed on the 24th.

These folding boats were used to transport the Imperial Army troops from a Japanese destroyer to Guadalcanal.
イル川渡河戦 - Wikipedia
一木支隊の戦闘序列は、
歩兵第二十八聯隊、
工兵第七聯隊第一中隊および独立速射砲第八中隊、
人員約2,000名であった。
ミッドウェー作戦においてミッドウェー島攻略を目的に編制された一木支隊は約40隻の折り畳み舟艇を持っており、
ガ島では駆逐艦の内火艇と組み合わせて上陸することになった。
The Ichiki Corps had a rank of about 2,000 people,
consisting of
the Infantry 28th Regiment,
the 1st Company of the Engineer 7th Regiment, and
the Independent Rapid Fire Gun 8th Company.
The Ichiki Corps, organized for the Midway strategy in order to capture Midway,
had about 40 folding boats, and landed in Ga Island in combination with destroyer internal fire boats.

The Ichiki Corps attached engineer unit according to this website:
ガダルカナルの死闘
「一木支隊の全滅」
Guadalcanal's death battle
"Ichiki annihilation"
９５歳ブログ「紫蘭の部屋」
８月１８日、一木支隊の先遣隊（歩兵一個大隊と工兵一個中隊）
は６隻の駆逐艦に分乗してルンガ飛行場の東４０キロのタイボ岬に上陸した。
On August 18, the Ichiki Corps advance (one infantry battalion and one engineer company)
split into six destroyers and landed at Cape Taivo, 40 km east of Lunga Airfield.

The Japanese engineer regiments developed collapsible assault boats.
According to this website:
Handbook of Japanese Military Forces
Section V: Engineer Equipment
Section V: Engineer Equipment | Chapter X: Equipment | TM-E 30-480: Handbook on Japanese Military Forces, Technical Manual, U.S. War Department, October 1, 1944 (Lone Sentry)
"The boat will hold 20 men, and it is estimated that 9 such boats could be loaded flat on a 2 ton truck. Light outboard motors have been used to propel this boat."

Another paragraph taken from
ガダルカナルの死闘
川口支隊上陸
Gadarukanaru no shitō
Kawaguchi shitai jōriku
Guadalcanal's death battle
Kawaguchi Corps landing
９５歳ブログ「紫蘭の部屋」
駆逐艦の輸送力は兵員１５０人、軍需品１００トンが限度で、
大発（大発動艇・上陸用舟艇）は人員２００名ほどしか運べないので、戦車や大砲などの重火器の輸送は不可能だった
Kuchiku-kan no yusō-ryoku wa heiin 150-ri, gunju-hin 100-ton ga gendo de,
Daihatsu (daihatsudōtei jōriku-yō shūtei) wa jin'in 200-mei hodo shika hakobenainode, sensha ya taihō nado no jūkaki no yusō wa fukanōdatta
The destroyer ’s transport capacity is limited to 150 troops and 100 tons of munitions.
Large firepower (large motor boats / landing boats) can only carry about 200 people, so it was impossible to transport heavy weapons such as tanks and cannons.

 

Hi.

Type 95 Collapsibe Boats were not really suitable for oceanic transport. It must have been a hard ride if they really used these....





And regarding the transport capacity of the Daihatsus:
It was indeed impossible to load a Type 97 Medium Tank but a small gun like a Type 94 or Type Meiji 41 Mountain Gun was no problem. I´m not shure if a Type 95 Light Tank was impossible, too. The only thing was to load this equipment inside the landing craft. You need a crane with the necessary capacity and I doubt a destroyer had such a crane. A light Cruiser had one for his aircraft. These should be able to unload at least the guns.

For tanks like the Type 97 Medium Tank Chi-Ha the Toku Daihatsu class was developed.



Yours

tom!

 

Thanks for sharing.

Type 95 Collapsible Boat
Type 95 Collapsible Boats



From Rikugun Vol.2

 

Here other ways the Japanese landed troops.

These boats appear like the 9-meter fire boats used on naval ships
写真の船は大発か中発ですか。折りたたみ舟艇じゃないでしょ！？


工校−大発

九五式折畳舟 - Wikipedia

ミッドウェー作戦では、一木支隊のミッドウェー上陸の際に使用する計画で、40隻が用意されていた。より大型の上陸用舟艇である大発動艇から、上陸点手前の環礁で乗り換える予定であった。これは、折畳舟より喫水の深い大発では環礁突破や機雷原通過が困難な一方、環礁内部は水深が100mにも及び渡渉も不可能だったため、考案された方式であった。しかし、海軍が海戦で敗れたため、上陸は実施されなかった。
In Operation Midway, there were 40 ships planned to be used when the Ichiki corps landed on Midway . It was planned to transfer from a large launch boat , a larger landing craft , to the atoll before landing . This was a method that was devised because it was difficult to break through the atoll and pass through the minefield at a large draft that was deeper than the folding boat, while the depth of the water at the inside of the atoll was 100m and it was impossible to cross. However, the landing was not carried out because the Navy was defeated in the naval battle.

H•ºŠwZ‚̉‰K



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