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In the 1990s I was able to get some data from the Japanese Diet Library (Library of Congress) - which uses retired military officers for military matters - and from Mitsubishi - re AFV research and production. From that I build some spreadsheets describing about 100,000 vehicles in the Japanese empire at the time the decision to mobilize was made (early July, 1941) - including vast numbers of motorcycles (including passenger and cargo models - called Sanrinsha) - ox carts - wierd cargo bycicles - and some very amazing AFVs - including the first true APCs ever - one of them fully submersable. I came to understand there were armored formations larger than battalion size - but I am still coming to terms with these.

Nomanhan lists - in July 1942 - a mechanized army (meaning corps) with two armored divisions. Now it is usually denied Japan EVER had a mechanized corps - although it is known Yamashita proposed one. The same book does NOT list this organization in August Storm (1945) - but rather lists "independent tank brigades."

Separately, Tsuji (Chief of Operations for Yamashita, the head of the planning group for Malaya, and author of Japan's Greatest Victory, Britain's Greatest Defeat) says the Japanese armor in Malaya was the "Third Tank Brigade." Now I find a reputable scholar saying that at the same time (that is, in 1941!!!!) there were two "Tank Brigades" in Kwangtun Army - numbered 1 and 2 - which sort of makes a number 3 make a lot more sense.

Still seperately, I have a new OB for the Japanese "Tank Division" (which in Japanese is actually "Tank Group") -

unlike the more usual version, this one has two tank brigades - each with two tank regiments (battalions) - vice the one tank brigade - with three tank regiments I always saw before.

A separate datum: the Type 89 tank was issued in two forms - A (gasoline engine) and B (diesel engine). It was deliberately expended at the start of the war - sent to the Philippines - so it could be used while it was still of value - against enemies not outfitted to fight tanks. Two tank regiments were sent - and they operated together - landing side by side on the Eastern Shore of Linguyan Gulf - near Buang and Agoo - that is south of San Fernando and north of Linguyan. Flashback to the new organization table above - it says a "tank brigade" was just two tank regiments plus an 11 man HQ element. OK - these same Type 89 tanks - with a larger number of Type 97s - were made part of the Second Tank Group when it went to Luzon in 1944.

I suspect the Tank Groups (small divisions) were in fact not wholly separate organizations. Mitsubishi tank production would not allow for the tank regiments, these divisions, the independent companies, and tank attachments (companies and battalions) of Class A divisions. I think the Tank Groups just took over management of the former tank regiments and, now, also the tank brigades - which I didn't understand existed early. [The US Army Handbook on Japanese Forces, dated October 1944, says there is no "perminant" higher tank organization. That may imply they knew about the brigades, but felt they were temporary - but I always thought it meant there were no brigades at all.] Now we know the tank groups themselves formed in 1942 - and that they had tank brigades inside them. I think those first two tank groups took over the first and second tank brigades already in Kwangtung Army. I think the third tank brigade (from Malaya) probably went into one of the tank groups as well - but I am not sure which one? And I now wonder if there might not have been a fourth tank brigade on Luzon - which became an element of the second tank group when it went there in 1944?

IF we assume this new data is correct - that a tank brigade has only two tank regiments as components - and nothing else but a HQ - then the force on Luzon is a defacto tank brigade - wether or not it really was called one. We could then - in game terms:

start the war with 8 of the tank regiments in the form of 4 tank brigades. Since a brigade breaks into 2 parts, you could still operate them as 8 units if you wanted to.

Later we add motorized infantry regiments and a tank group H&S element (call it an artillery unit - it is mostly motorized artillery, AAA and support). This way the players get the de facto tank groups - pre divided as it were - and there is no duplication (tanks in regiments separately duplicated by the tank groups which actually absorbed them). And the maneuver elements can be either independent tank regiments, tank brigades which are dual tank regiments, or half brigades which are de facto tank regiments. The motorized infantry regiment is a but unusual - it has a motorized infantry regiment, a mechanized infantry battalion and an ATG battalion - so it is big enough to treat as a brigade in its own right - and it too could divide. This is the ONLY significant motorized infantry in the empire - other stuff is just penny packets inside non-motorized formations. It is very unusual to see this stuff available for simulation games.

Other issues which are confusing me is the reason so many units (most) in WITP list Type 89 tanks - when few were made - many were no longer servicable by 1941 - and they could not possibly have been in so many units. Also, there is a "Type 2 CS Tank" which makes no sense - it has 45mm of armor - a value on NO Japanese AVF at all - and a 120 mm gun (based on its penetration - reverse calculated) - a value very rare - found on a 1944 Ko Ni Gun Tank (with only 8 mm of armor) and on a NAVY vehicle with an AA gun - also in 1944 - yet this type 2 is available in 1941! What might it be?

ORIGINAL: el cid again

Separately, Tsuji (Chief of Operations for Yamashita, the head of the planning group for Malaya, and author of Japan's Greatest Victory, Britain's Greatest Defeat) says the Japanese armor in Malaya was the "Third Tank Brigade." Now I find a reputable scholar saying that at the same time (that is, in 1941!!!!) there were two "Tank Brigades" in Kwangtun Army - numbered 1 and 2 - which sort of makes a number 3 make a lot more sense.

These "brigades" actually were 1st Tank Group (formed 1st March 1938 with 3rd, 5th, and 9th Tank Rgt), 2nd Tank Groups (formed 1st August 1940 with 4th, 10th, and 11th Tank Rgt), and 3rd Tank Group (formed 1st September 1941 with 1st, 2nd, 6th, and 14th Tank Rgt).

ORIGINAL: el cid again
Still seperately, I have a new OB for the Japanese "Tank Division" (which in Japanese is actually "Tank Group") -

unlike the more usual version, this one has two tank brigades - each with two tank regiments (battalions) - vice the one tank brigade - with three tank regiments I always saw before.

All Tank Groups were converted to Tank Divisions (different word in Japanese) in June 1942 and added support elements (artillery, motorized infantry, and recce regiments; probably not newly raised but by redesignation of existing formations). 1st and 2nd Tank Divisions (created from the Tank Groups) received one additional tank regiment each and formed two brigade staffs each (one brigade staff for two tank regiments). 3rd Tank Division already had four tank regiments and only needed to form the brigade staffs. 4th Tank Division, formed at about the same time with newly raised tank regiments, had only three tank regiments and no brigade staff. Later (in late 1944/early 1945) the "brigades" of the tank divisions formed Independent Tank Brigades but their tank divisions were not disbanded.

K

Other issues which are confusing me is the reason so many units (most) in WITP list Type 89 tanks - when few were made - many were no longer servicable by 1941 - and they could not possibly have been in so many units. Also, there is a "Type 2 CS Tank" which makes no sense - it has 45mm of armor -

Sid...I believe if others need verification of this, there is a Q&A section at the bottom of Takis' site in which he discusses this very issue.
For some reason, Japanese OOB's fail to mention this, almost uniformly, as if "looking over each others' shoulders".

These "brigades" actually were 1st Tank Group (formed 1st March 1938 with 3rd, 5th, and 9th Tank Rgt), 2nd Tank Groups (formed 1st August 1940 with 4th, 10th, and 11th Tank Rgt), and 3rd Tank Group (formed 1st September 1941 with 1st, 2nd, 6th, and 14th Tank Rgt).

OK - where did you find that? This is very early - and contradicts the US Army manual - and almost everyone else - but it seems to fit the data picture I am building from various reliable sources. I need to know where you found it though. The 3rd actually had three regiments - a fourth went to Malaya it is true - but then went to Burma - and either was not part of the unit or was only briefly so.

All Tank Groups were converted to Tank Divisions (different word in Japanese) in June 1942 and added support elements (artillery, motorized infantry, and recce regiments; probably not newly raised but by redesignation of existing formations). 1st and 2nd Tank Divisions (created from the Tank Groups) received one additional tank regiment each and formed two brigade staffs each (one brigade staff for two tank regiments). 3rd Tank Division already had four tank regiments and only needed to form the brigade staffs. 4th Tank Division, formed at about the same time with newly raised tank regiments, had only three tank regiments and no brigade staff. Later (in late 1944/early 1945) the "brigades" of the tank divisions formed Independent Tank Brigades but their tank divisions were not disbanded.

Wow. Again, quite different than in most materials, but also quite consistent with bits and pieces I have been putting together. Also it implies my proposal - start with tank units and add other components of the tank divisions - might be best - since it means we do not create entire divisions duplicating existing tank units. One major change is the idea four divisions all formed in 1942 - and it means the US intel was wrong about no higher organizations in 1944. I am sure the motorized elements were newly raised - or newly issued vehicles - and I suspect the other division support elements were either new or wholly reequipped - but the basic artillery "unit" seems to be a standard mixed battalion - so it might have existed - and the AT unit is also standard organization. The mech bn and SPG company were probably new or re-equipped. I still want to know where you found this - I don't care in what language.

What is Takis site?

On further review and integration, it now appears:

Japan has three Tank Brigades in 1941. These are generally triangular - and if Third Brigade had a fourth regiment - since it saw detached service in Burma - and died there in 1944 - it can be a separate element in any case. The two regiments in the Philippines are not part of a Tank Brigade.
In June 1942 a brigade of motorized infantry with attachments is added to form the First and Second Tank Groups up in Manchukuo. Not very long after (in 1942) a third and fourth Tank group are similarly formed - but the tanks for the fourth are a "newly raised" bunch for a new Tank Brigade. The non-tank elements of a Tank Group can be well represented by a single Infantry Brigade. A tank group thus will have only two elements - a tank brigade and an infantry brigade (motorized).
Other tank regiments will remain separate elements - and both the brigades in a tank group can subdivide.

I remain confused about tank battalions in Class A divisions - and about the number of independent tank companies - which seem to be only light tank companies? Also, I just found data on a US Marine tank battalion - its C company had Shermans - very unusual - since almost all tanks in the Pacific were light.

ORIGINAL: el cid again

What is Takis site?

http://www3.plala.or.jp/takihome/

I must conclude a "Type 2 CS-Tank" means a Ho Ni II Gun Tank -

as it had only 8mm armor - that needs fixing -

as it had only a 75mm gun - the penetration is incorrect (short range penetration for high velocity weapons is 1.75 times caliber)

and the anti-soft value is slightly too high

I conclude the Type 4 is the Ho Ni IV - which did have a 12 cm gun so its penetration is correct - and it also had 25 mm armor - so that is right - but the anti-soft value should be 7 in my system - and I will use it to repalce the Ho Ni II

Since these don't begin in tank brigades, they will show up in the everything else brigade of the tank group

Sid, the Taki site will also give details on Japanese HEAT rounds for each gun............

I am familiar with the HEAT rounds. They came from Germany and were something of a "secret weapon." Japan had an effective one for the 70mm battalion gun, and we didn't realize it at all, during the war. We have adopted HEAT as standard option, post war.

Experimenting with my proposed organization, I find it practical and economical of slots (8 for 4 "divisions" - and we get rid of a similar number of regiment slots). But there is still one duplication/history issue:

4th Tank Regiment goes to the Philippines (apparently detached from 2nd Tank Brigade). Later 2nd Tank Brigade actually goes to the Philippines (players won't have to send it there but they still have it). THat means 2 Brigade is 1/3 duplicated. Much better than the existing situation - at least 6 regiments are duplicated and it should be 9 - if we had not omitted 3. IF we sent 2nd Brigade to the Philippines we could then kill the 4th Regiment - and delay appearance of 7th Regiment - but that would still give players 1/3 too many tanks in the Philippines early. Ideas are requested. As someone wrote (Andrew or Joe - or both) - OB work ALWAYS means compromises!

Taki, is very helpfull, you can E mail him and perhpas ask directly some of these interesting questions, he may be able to shed some light on them, BTW I just orderd his book, should be interesting[:)]

ORIGINAL: el cid again

I am familiar with the HEAT rounds. They came from Germany and were something of a "secret weapon." Japan had an effective one for the 70mm battalion gun, and we didn't realize it at all, during the war. We have adopted HEAT as standard option, post war.

Actually, we deployed the first effective HEAT weapon in 1942..., the Bazooka. Problem with HEAT warheads is that higher delivery velocity denegrated the effects of the round, as did spin stabilazation.
Made it impractical for delivery with a standard artillery weapon, and lead to such wonderful creations as the PIAT and the "Lunge Mine".

Actually, we deployed the first effective HEAT weapon in 1942..., the Bazooka. Problem with HEAT warheads is that higher delivery velocity denegrated the effects of the round, as did spin stabilazation.
Made it impractical for delivery with a standard artillery weapon, and lead to such wonderful creations as the PIAT and the "Lunge Mine".

Note, however, that the 70 mm battalion gun is LOW VELOCITY. So is the 57mm tank gun. These weapons had EFFECTIVE HEAT rounds. And they were not understood to be such at the time. The 75mm field guns were effective with kenetic energy rounds, but the low velocity rounds were better using HEAT. Also note no one has programmed these rounds into WITP.

If memory serves, the Germans invented HEAT. As with many war era devices, the principles of physics are the same, and so there were parallel programs in other countries. But the Japanese got theirs from Germany before the war began (from our point of view). [When did WWII really begin? I say it began in China in 1935 when disputes between Japan and China got out of control. There are many other answers to this question, but from that day onward, until August 1945, there was war.]

My latest compromise is this:

we separate the 4th Tank Regiment from the 2nd Tank Brigade - permitting each to be in the right location (Manchukuo and Formosa).
We make the 2nd be 2/3 strength, representing the absence of the 4th.
We then could theoretically leave the 4th weaker - but not giving it a formation means it will not tend to rebuild properly. Or we can allow it to rebuild to full strength - and then not deliver some later tank regiment as a reinforcement to compensate. I favor this latter option.

EDIT: The missing unit is the 12th - not listed anyway - but surely a unit. Japan might skip a high number - but never an 11 or 12.

I am still not getting any data about which Class A divisions had a tank unit of battalion size - was it all?

Japanese Tank Division 1944 Organization

13,000 men
141 Lt Tanks
175 medium Tanks
103 Hvy Trucks
1582 Light Vehicles

Arm Recce Company (Armd Cars?)
Mot. Engineer Rgt
Tank Bde - 3 Tank Rgts @ 4 Tank Companies
Mot Inf Rgt - 3 Mot Inf Bns & Mot Art Battery
Mot AT Bn
Mot Art Rgt - 3 Mot Art Bns
Mot AA Rgt - 3 Mot AA Bns

My article says the doctrine was to form 3 echelons , each with a Tank Rgt as the core and supporting troops added.

In 1944, 3rd Tank Div was in 12 Army/North China Area Army and had 12, 13 & 17 Tank Rgts. In July 44, the Div was broken up with 13 & 17 Rgts forming 6th Tank Bde (11th Army/China Expeditionary Army) and 13th Rgt becoming independent.

Burma Area Army had 14th Tank Rgt.

ORIGINAL: el cid again

If memory serves, the Germans invented HEAT. As with many war era devices, the principles of physics are the same, and so there were parallel programs in other countries. But the Japanese got theirs from Germany before the war began (from our point of view). [When did WWII really begin? I say it began in China in 1935 when disputes between Japan and China got out of control. There are many other answers to this question, but from that day onward, until August 1945, there was war.]

Actually, I think it was a couple of Swiss fellows who figured out how tho make the "Monroe effect" into a usefull armor-peircing weapon..., and tried to sell it to the British as a new super-powerful explosive. Brits took a look at their "sample" said thanks but no thanks, and invented the hollow-charge principle themselves. The two Swiss later got jobs in American work in the same field. The Germans seem to have picked it up from captured Allied Weapons---and faced with Soviet tank production they grabbed on with both hands and churned out all sorts of weapons making effective use of it. The real oddity of the whole situation was that the Americans, who had been in the lead in the field with their 60mm Bazooka in 1942 never fielded anything better. Even though the original designers of it had gone back to work and turned out a 90mm version with much better performance within three months or the original design. This 3.5" super-bazooka model sat on the shelf until the Korean War. Proving that the Americans could be just as stupid as anybody else at times.

ORIGINAL: el cid again
Note, however, that the 70 mm battalion gun is LOW VELOCITY. So is the 57mm tank gun. These weapons had EFFECTIVE HEAT rounds. And they were not understood to be such at the time. The 75mm field guns were effective with kenetic energy rounds, but the low velocity rounds were better using HEAT. Also note no one has programmed these rounds into WITP.

But it was still spin stabilized. Which spreads the effect of the "armor-piercing jet" over a wider area and diffuses the result. As you say, "Japan had an effective one for the 70mm battalion gun, and we didn't realize it at all, during the war". The fact that we DIDN'T NOTICE IT AT ALL during the war would argue against it being very effective. Panzerschrecks and 88's WERE effective against against armor, and we certainly noticed THEM. I would doubt that the game requires much if any adjustment to account for 70mm HEAT rounds.

Arm Recce Company (Armd Cars?)

Light tanks.

Unit HQ
3 Light Tank Companies - 10 Light Tanks each
1 Gun Tank Company - 10 gun tanks
1 Infantry Company
1 Maintenance Company