So what does it mean when you see several different “Type 92” vehicles that are older by many years than a “Type 4” tank?
The weapons the Imperial Japanese Army used during its wars in Asia and the Pacific were designated using a model system based on the reign of the Japanese Emperor they entered into service with. This can sometimes be confusing as the weapons available during those wars came from the reigns of three different emperors; Emperor Meiji (1867 to 1912), Emperor Taisho (1912 to 1926), and Emperor Hirohito (1926 to 1989). To confuse things further, during the reign of Emperor Hirohito the model system referred to the year in the Japanese calendar, which was 660 years ahead of the current western date, so 1939 was 2599 in Japan. Usually only the last two digits are used (minus the leading zero), although they are sometimes seen represented in all 4 digits in Western sources. The model is usually referred to as Type in English translations.
- For example the Type95 Ha-Go tank entered into service in year 2595 during the reign of Emperor Hirohito (1935)
- In the Japanese calendar year 2600, the famous “Zero” plane got its name from the final two zeroes in the calendar (drop the leading zero) as the Type0 Carrier Fighter. (1940)
- The old Type11 Light Machine Gun (also sometimes written as the Type11 Taishō Light Machine Gun) was named after the 11th year of the reign of Emperor Taishō, or 1922.
- The Type38 Arisaka Rifle was from the 38th year of the Meiji Emperor, or 1906 (!) This old bolt-action rifle was in service until the end of WW2.
- The Type2 Ke-To tank entered into service in the year 2602, during the reign of Emperor Hirohito.(1942)
All vehicles and weapons in the “90s” are from the 1930s. Keep that in mind when in War Thunder a “Type 95” tank from 1935 goes up against an American tank designed in the 1940s.
Type numbers do not always help as much as they might in determining the “newness” of a design. For example with the Ha-Go’s Ke-Nu variant, it was a tank that simply added the Type97 medium tank’s turret to a Type95 tank – but these parts were only put together in 1944, or Year o4 = Type4. The Type2 Ke-To light tank was in fact a much newer and superior light tank design. Due to this discrepancy, it will not always make sense to have gaming tank “tiers” reflect the Type model year unless the game is strictly chronological in how vehicles are introduced to the game. A Type2 Ke-To with its lower profile and newer tank gun would be in a higher tier than a Type4 Ke-Nu, if judged on all around performance, though this is debatable due to the thicker turret of the Ke-Nu and its larger gun.
Some Western sources may write “Model 2597 Medium Tank” using the entire old Japanese calendar date. Just drop the first 2 digits and note it is a “Type97 Medium Tank” (Chi-Ha). The problem with using “Model” is that this is a term used for another convention- such as the A6M2 Model 21, which is unrelated to the year introduced.
Some sources will write “Type” with a space trailing it, but others will merge the Type and the year number together into a single unit. Since Japanese does not have spaces and one would not write Type97MediumTank all in one word either, it is a matter of choice. That said, there is some value in the argument for tying the year number to Type for clarity, so the words and numbers cannot be put out of order or confused with other numbers (for example in the incorrect “Type Naval 97 20mm Chi-Ha”).
The year is not always exclusive to a vehicle type as obviously multiple vehicles could be introduced in one year. There are multiple “Type 92″ Armored Cars for example, so the distinction must then be in other parts of the name, such as “Naval”, “Sumida”, or “Chiyoda”. The Type92 Heavy Armored Vehicle is completely different than a Type92 Chiyoda Armored Car, but both might be named vaguely in some sources as “Type92 armored car”.
Note IJN is “Imperial Japanese Navy” and IJA stands for “Imperial Japanese Army”.
Hope that clears things up a bit!