RHS IJA Division Nomenclature (New)

[el cid again]

Future updates will include information besides the division number in the unit name:

Generally they will contain an indication if it is an A or B division

Generally they will contain an indication of the nature of the transport: motorized, draft or pack (motorized means semi-motorized)

In general, an A unit has heavier ATG than a B unit does. An A draft unit always has motorized recon, a tank unit, or even a tank regiment. An A pack unit always has cavalry recon.

In general, a pack unit has mountain artillery and three times the support train (which is 1/3 labor squads - eating another 1/3 - leaving only 1/3 for real support). This unit is light on artillery power but heavy on logistic cost to feed and lift. It probably sustains combat better, though - due to high squad counts. A large number of divisions are pack.

In genaral, a draft unit has field artillery and normal support. A large number of divisions are draft. They can be Type A or B, they can have cavalry or motorized recon, and in EOS there can even be an attached tank regiment.

In general, a "motorized" unit has about half its support as motorized support. There are both A and B motorized units - but there is only one division of each in CVO and BBO families, and it isn't clear if there will be more even in EEO? Production is approaching its limits.

In general, a "light" unit has mountain artillery and motorized recon. The normal draft or pack unit has cavalry recon. "Cavalry" means 2/3 horse and 1/3 motorized cavalry. There are few light divisions. So far only three.

In general, a "garrison" division has no artillery as such in CVO or BBO - and very little in EOS family. [Artillery support comes from 81mm mortars] It is composed of two brigades each of four independent infantry battalions - and it is not normally a line combat formation intended to engage other divisions. A large number of divisions are garrison - many late in the war.

When tank regiments are attached to divisions (in EOS) they are named. But the Type A2 division has an organic tank regiment which is not named - there may only be one or two of these - because it is not attached - it is organic.

In general, a "amphib" division is a pack division stripped of 2/3 of its train.

There is apparently (it may be an intel error) a case of B draft units with no recon element. This is doctrinally impossible - but might have occurred in the sense no dedicated recon battalion or company of any sort is organic. In which case a peculiar Japanese practice would form on from organic assets - a "special unit" or "ad hoc unit" - perhaps an infantry company - would be assigned the mission. It might not always be the same element. On the principle of "respect your sources" we will have some of these - but they are just listed as (Draft) "B" units - just as several other configurations are. They will not have recon devices (cavalry, motorized infantry, tankettes, light tanks, medium tanks, or mechanized) - as most other divisions do.

The term (+Tank Unit) will be used with a Class A division which has a small tank recon element. This appears to be a very exceptional case - possibly only one in CVO and BBO families.

[el cid again]

The RHS system is based on giving players more information to work with. I decided that just "Div" with a number is not much information. So we will include more information in the name as a player aide. To the extent a division is named to the enemy - it will be both players who benefit.

[Kereguelen]

ORIGINAL: el cid again
When tank regiments are attached to divisions (in EOS) they are named. But the Type A2 division has an organic tank regiment which is not named - there may only be one or two of these - because it is not attached - it is organic.

There were no organic tank regiments in Japanese infantry divisions. It was planned for the A-Type divisions but never implemented [no surprise, considering that no divisions were converted to the A-Type].

ORIGINAL: el cid again
The term (+Tank Unit) will be used with a Class A division which has a small tank recon element. This appears to be a very exceptional case - possibly only one in CVO and BBO families.

Tank 'units' were quite common as part of divisional infantry groups (originally 17 Tankettes per group, later upgraded to T95 Light Tanks). But the recon element of Japanese divisions (if present in a given division) was either a motorized recce regiment (which contained seven armoured cars or tankettes) or a cavalry regiment (without any armoured vehicles. Both variants were battalion-sized units.

[el cid again]

It is official - working with a Japanese military historian (retired) at the National Diet Library - I have learned that a Type A division not only was formed - but formed before the war began - and it operated outside the Kwangtung army - where most other of the Type A divisions formed up. That unit was the 5th Division - and it was apparently the only Type A Motorized (I prefer Semi-Motorized as half the transport remains draft, and the infantry is bicycle type) formed. However, there were other types - and once again that is official. Aside from that, I already knew it was the case from firearms history: the divisions fitted with the 7.7 mm rifles and LMGs were Type A. There were never enough of these even to outfit all the Type A divisions formed - and that tells us that the number was indeed significant - as these weapons were produced in great numbers (although not for as many years as the 6.5 mm).

As far as organic tank regiments - this is a different story. Here you may be confused by terminology (as may we all - Japanese ordnance and military terminology is inherantly confusing - even more than the general case of all things Japanese usually is). There were cases where tanks were organic to divisions - both light and medium - but these were not really tank regiments in the classical Japanese sense. They were either recon units that upgraded from tankettes (which themselves upgraded from trucks and jeeps - meaning "black model" - and motorcycles - or even horses) - or they were in Tank Units. A "unit" can be anything - and in general for a large formation - it is binary. But while it is more or less SOP for a Japanese division to rate a recon battalion - and a three company battalion at that - cases exist where it was two or one - or even zero - companies (although in the latter instance a company sized organic unit would still do the job). The above discussion is general - covering all cases: so it includes the cases where there was a company sized tank unit - which might come from upgrading a tankette company - or by attaching a light tank company to a unit that had no recon element previously. It also includes cases where the historical planning was implemented - meaning EOS family scenarios mainly. There is also one other case in EOS family: I have paired certain tank regiments with certain divisions: these may "divide" only insofar as a division may split. It is a technical trick - because the same two units in a hex do not produce the same combat outcome - and it is meant to represent a kind of doctrinal shift which did not happen IRL but might have had Yamashita's proposals been fully adopted.

RHS adopted a CHS revision by historian Joe Wilkerson (also a mathmetician and programmer for Matrix - but this was pre Matrix work) for IJA. It listed explicitly A1, A2, and A with mountain artillery type divisions - as well as a motorized division I now know was A type. We have been talking about this work this week - out of sight of the board - and he says it is all a matter or interpretation - almost an art form. I also strongly depend on sources like Nomanhan - the National Diet Library - and US Army monographs (The Levenworth Papers - two in particular). There are clear differences between organizations - and I classify them based on (a) weapons; (b) transport and (c) organization. Thus we have a normal case of a triangular division, the special case of a "six battalion division" (two of two regiments of three battalions, one of three regiments of two battalions), and the alternate case of a garrison division with de facto eight independent battalions (whose two brigade command structure should not be confused with brigades of an operational sort). We also have what I call motorized, draft and pack organizations. And we have units fitted with 37 mm ATG or 47 mm ATG; 7.7 mm rifles or 6.5 mm rifles, etc. What do YOU call a unit with 7.7 mm rifles and 47 mm ATG????

In real life each division was probably almost unique. Not at birth - but over time it might evolve. At birth Japanese divisions either were square (if old enoough) or triangular; the square ones converted to triangular just as in the US Army. Except the security or garrison divisions: these were formed in what might be called binary form - but initially these were really independent infantry brigades unified into a divison. [It may be later in the war security divisions were also born in this form] We need to simplify - and I use traditional terminology for flavor - and try to give it meaning for player understanding from a cryptic name what sort of formation this one or that one may be?

Note that while the cavalry recce units were not originally armored, they were 1/3 (i.e. one company) motorized. The Kurogane company made a kind of micro jeep - normally it held three people - and Japan licence produced the "Harey" (Harley) motorcycle. These were used for recon work, supported by 4 x 6 trucks that you would say were 1.5 ton trucks. Eventually a number of these recce units lost their horses - and some not only gained armored vehicles - but grew to become tank units or tank regiments. Others retained their horses - but apparently never were they entirely horsed - although historically it must have been they were all horsed at one time.

[el cid again]

I have disestablished the Imperial Guards Division as a Type A division. It never was. It did not have a motorized recce element either - it was the Guards Cavalry - and it used horses in perade. This unit was not experienced when the war began - it had been on cerimonial duty for a very long time. It also didn't do well - and indeed the division commander was dressed down in front of his assembled division by Gen Yamashita - because of misconduct in Singapore (which misconduct was witnessed by Tsuji - who wanted the men shot - but didn't get his way: Yamashita held the division commander responsible for discipline in his formation). This led to the splitting of the division - that is why there is a second Imperial Guards division evenutally - to keep the bad apples apart (not that I see how that helps - it was the idea anyway). I classify the IG division as Type B - normal Draft - with moderate experience - robbing it of its super high experience and morale ratings. In EEO - where there are years to work on it - it is presented as an Amphib division - meaning it gets some extra assault engineers (and IRL was stripped of some things you don't need in the assault).

[el cid again]

When WWII begins - but not in any version of WITP I am aware of - 5th division is square: it has four regiments.
In addition, its "recon regiment" is hexigonal:

2 x Motorized infantry companies
1 x motorized "HMG" (MMG) company
1 x motorized ATG company
2 x tankette companies (later tank companies)

The latter are the "tank unit, 5th division" - and show that some divisions indeed had proper tank units - with two companies.

Technically we should show 8 square divisions in IJA: 3rd, 5th, 18th, 19th, 20th, 110th and 116th.

It also appears that the 18th division was motorized to exactly the same extent as 5th division (500 trucks).

And that 19th division had two artillery regiments.

[Kereguelen]

ORIGINAL: el cid again
I have disestablished the Imperial Guards Division as a Type A division. It never was.

Correct!

ORIGINAL: el cid again
It did not have a motorized recce element either - it was the Guards Cavalry - and it used horses in perade.

The Imperial Guards Division (from 1943: 2nd Guards Division) had its own recce regiment. The Guards Cavalry Regiment was part of the Guards Mixed Brigade (which eventually formed the 1st Guards Division in 1943) in Dec 1941.

ORIGINAL: el cid again
This unit was not experienced when the war began - it had been on cerimonial duty for a very long time.

Basically correct, as it had been the Guards Mixed Brigade which had been in China before while the regiments that were eventually assigned to the Imperial Guards Division had stayed behind. The division had been formed in 1891 but only the 1st Guards Infantry Brigade had been in China. And this unit became the Guards Mixed Brigade while the 2nd Guards Brigade 'became' the Imperial Guards Division (the 5th Guards Infantry Regiment was formed in Nov 1940 and the division became triangular then).

ORIGINAL: el cid again
It also didn't do well - and indeed the division commander was dressed down in front of his assembled division by Gen Yamashita - because of misconduct in Singapore (which misconduct was witnessed by Tsuji - who wanted the men shot - but didn't get his way: Yamashita held the division commander responsible for discipline in his formation). This led to the splitting of the division - that is why there is a second Imperial Guards division evenutally - to keep the bad apples apart (not that I see how that helps - it was the idea anyway). I classify the IG division as Type B - normal Draft - with moderate experience - robbing it of its super high experience and morale ratings. In EEO - where there are years to work on it - it is presented as an Amphib division - meaning it gets some extra assault engineers (and IRL was stripped of some things you don't need in the assault).

No, the 'splitting' had occurred earlier and for different reasons (see above) - but the performance of the division in Malaya had indeed not been really convincing.

[Kereguelen]

ORIGINAL: el cid again
And that 19th division had two artillery regiments.

No, this is an error (or rather incorrectness) on the Niehorster site. 15th Hvy FA Regt (or 'Medium FA', Japanese term translates to both) was attached to the division in Dec 1941 because it was planned to form a divisional artillery group. But the 15th Hvy FA Regt had only 8x 150mm howitzers then and eventually stayed behind when the division left Korea.

[el cid again]

Although told - and there are many scholarly sources saying so - there were only two motorized divisions in IJA - when the war BEGAN there were no less than four. Two of these were square - as mentioned above - one was the 48th - and UNLIKE what I said above - so was the IG division - although apparently it ALSO had true cavalry elements - probably for its ceremonial duties. Wierd.

I now see why Joe put in "square" divisions - there are six more or less normal ones and two motorized ones.

Also - First Division BEGINS the war as a Class A division WITH a true Tank Unit. Yet another case where we have Class A - and have it when the war begins. This from N - I cannot spell his name in spite of familiarity with German - under "Infantry Division (triangular)" detail listings. In fact, all of this material is following N.

I think you are correct about the 18th Division and the 150s. N correctly lists there are only 8. Further - it is SOP for "heavy" artillery "regiments" to have 2 battalions of 2 batteries of 4 guns. But in keeping with Japanese love of complexity, some "heavy" artillery regiments have 2 of 2 of 2, and others 2 of 2 of 8. Then there is the case of 2 of 2 of 1. Not to permit any sort of consistency, there are also two independent "companies" - each with multiple batteries. One has a single rail gun - but supporting batteries, while the other is very heavy artillery with 150s in support.

[Dili]

One decision i have made for WITM40 is that 2 Regiment Divisions (most of Italian Army) are classified as Brigades to split in two instead of splitting in three.

[el cid again]

Joe (Wilkerson) and I decided to do that with the Japanese two regiment divisions over a year ago. In RHS these are called "Division" Brigades so player will know. A similar case is a six battalion division with three regiments - it is called a "brigade" Division (65th - a famous unit so green its commander expected little which covered itself in glory: at one point it had two corps bottled up on Bataan with less than 2000 men in the line - not the way we usually tell the story of the Siege of Bataan) - and will split into three parts - because it could. But it points at the same formation - and will have the same squad count (basically - it starts with an attachment that will be lost as it attrits).

[el cid again]

I have made the Japanese infantry guns range limited just as Allied ones are. These weapons may have more range, but they are not used with fire direction centers manned by artillerymen, nor with forward observers. So they are used only in the direct fire mode. The Allied ones have a range limit of 3 - the same as the better tanks - and that is about right - 3000 yards - so now so will the Japanese.

The problem with this device change is that it requires some time to implement - many units are affected - as we had combined two simialar weapons into one device (type 38 and type 95) and now they are separated by function (and range).