Thread: naval units of the Imperial Japanese Army

Hi.

During the innitial stages of an amphibious assault the landing craft are very vulnerable to enemy defence fire. So in 1924 IJA started the development of an armoured gunboat armed with machine guns and small infantry guns. In 1927 the first gunboats were delivered and named „Army-type armoured gunboat“ or „AB-Tei“ (not sure about the correct meaning, „Tei“ = boat):



length: 17,10 m
width: 3,50 m
displacement: 30 t
engine: 1 X gasoline, later 1 x diesel at 350 hp
maximum speed: 13 kts
armament: 1-2 X british 57 mm tank gun, later 1-2 X type 90 or type 97 57 mm tank gun; 1-2 X type Taisho 3 7,7 mm double-mount heavy machine gun, later type 92 double-mount 7,7 mm heavy machine gun



At bow a turret with a gun was placed. The early gunboats had a second turret placed elevated behind the first turret with a MG or gun. A third turret with a gun or MG was placed on the superstructure at stern. Later the second turret was placed above an enlarged bridge. Due to weight limitations this turret was armed with MG only.

These boats were transported to the landing zones aboard landing craft motherships or transport vessels. During the innitial stage of the landing they provide direct fire support for the landing forces. After a successful landing they were used to cover the operation at the flanks.



A lot of gunboats were also used as river gunboats in the occupied countries

The total production number is unknown


A special thanks to Taki, who gives at least basic informations on these types of equipment on his website.

Yours

tom!

it is interesting to see,. on how those two branches of Japanese forces, Army and Navy, are totally self providing their own necessity without having to much depend on the other branch for assistance. However sadly for them, they also seems having each self goal in how and where to wage the war.

Hi.

In 1922 JN bought a few british Thornycroft 55 ft coastal motor boats and tested them. After the tests IJA decided to build similar speedboats especially for scouting and communication purposes.

The scout boat was named "Kosokutai Ko" (speedboat version A):



length: 14,42 m
width: 2,74 m
displacement: 5,3 t
engine: 1 X gasoline, 400 hp
maximum speed: 37 kts
armament: none

Main purpose of this vehicle was high-speed reconnaissance just before the landings began to gather an actual view on surviving enemy equipment. Another pupose was fast transport of personell.
Total production number is unknown.


The smaller communication boat was named "Kosokutai Otsu" (speedboat model B)



length: 11 m
width: 2,43 m
displacement: 4,5 t
engine: 1 X diesel, 100 hp
maximum speed: 13 kts
armament: 1 X type 92 7,7 mm mg, 1 lmg

These boats were not real speedboats due to the limited maximum speed. Main purpose was building up communication lines by serving as central communication platform on company level during the early stages on a landing.
The boats were equipped with several wireless communication devices including optical (flags, morse lights, special optical communication devices).
A hmg could be mounted above the bridge and a lmg was also aboard.

Both speedboat types were introduced around 1930.


A special thanks to Taki, who gives at least basic informations on these types of equipment on his website.

Yours

tom!

Hi.

After the outbreak ot the 2. sino-japanese war 1937 IJA was able to exercise their amphibious landing tactics at war. The concepts were found successful but there were also improvements necessary.

One problem was that neither IJA nor IJN was able to provide the necessary patrol capacities to secure habours and rivers. So IJA decides to develop patrol boats, too.

There were several concepts based on IJN developments. All were armed with heavy automatic weapons or even tank guns.



In 1942 one of these developments was officially introduced as type 2 patrol boat, armed with a type 98 20 mm aa-gun, later type 4 twin-mount 20 mm aa-gun at stern and a type 94 tank gun in a pivot mount in front of the bridge. Additionally a rack with two depth charges could ne mounted on each side at stern.





Infos on these boats are rare, so no further infos, sorry

Yours

tom!

Hi.

I was ill the last week so no new data last week, sorry.

Some additions to Army SB.101 landing ships:

Tanks, vehicles, soldiers and supply was transported in the transport deck between bridge and bow. Additionally tanks and equipment could be transported on the deck above the transport deck. After landing the bow ramp was lowered and vehicles and equipment were unloaded. After the transport deck was empty an internal ramp could be lowered to allow unloading the upper deck, too.




The SB.101-class also carried a 9 m standard navy issue motorboat and a Shohatsu.

In 1945 the naval T.101 and T.103-classes were fitted with a standard type 22 air and surface radar. I´m not sure if the army SB.101 were fitted with this radar, too.





Yours

tom!

This is a very interesting history, unfortunately I am unable to open the photos is there any way I can view them.
Regards Alex.