Classification System of JR Group (formerlyJNR/JGR)
Locomotives and Rolling Stock

C 56 44, type C56, three driving axles, tender locomotive. Taken at Oigawa Railway, by Hiroshi Naito.

5540, type 5500, tender locomotive with four-coupled wheels. Taken at Oume Rail Park, by Hiroshi Naito.

1 Steam Locomotive
1.1 Alphabet and figure system (established in 1928)
Alphabet: number of driving axles: B = 2, C = 3, D = 4, E = 5

First and second figures:	10 - 49:	tank locomotive
	50 - 99:	tender locomotive
	(60 - 62):	converted tender locomotive

Subsequent figures: running number of the class.
Example:
C 11 64: C (=with three driving axles), 11 (=second tank loco of the type), 64 (=64th of the class)

1.2 Figure only system (established in 1909)

1 - 999:	tank locomotive with four-coupled wheels
1000 - 3999:	tank locomotive with six-coupled wheels
4000 - 4999:	tank locomotive with eight-coupled wheels
5000 - 6999:	tender locomotive with four-coupled wheels
7000 - 8999:	tender locomotive with six-coupled wheels
9000 - 9999:	tender locomotive with eight-coupled wheels

AC locomotive EF 70 1001, type EF70. Numbered in the 1000s represents high-speed hauling of limited express passenger trains. Taken at Usui Railway Cultural Village, by Hiroshi Naito.

2 Electric Locomotive
First alphabet: E for "electric"
Second alphabet: number of driving axles:
B = 2, C = 3, D = 4, E = 5, F = 6, H = 8

First and second figures:	i) 10 - 49:	maximum speed under 85 km/h
	50 - 89:	maximum speed over 85 km/h
	ii) 10 - 19:	DC loco for freight service
	20 - 29:	DC loco ex private railways
	30 - 39:	AC/DC loco
	40 - 49:	experimental loco or rack loco
	50 - 59:	DC loco for passenger service
	60 - 69:	DC high-powered loco
	70 - 79:	AC loco
	80 - 89:	AC/DC loco
	90 - 99:	experimental loco

Subsequent figures: running number of the class.
Some variants of certain classes are designated with the running numbers of 300s, 500s, 1000s etc.
Examples:
ED 16 9: E (=electric), D (=with four driving axles), 16 (=7th DC loco for freight service with a maximum speed under 85 km/h), 9 (=9th of the class ED 16)
ED 81 301: E (=electric), F (=with eight driving axles), 81 (2nd AC/DC loco with a maximum speed over 85 km/h), 301 (=1st of the EF 81 300s, a variant of class EF 81 with an unpainted stainless steel body for the operation at the Kanmon undersea tunnel)
Note:
Before this classification system was established (principally) in 1928, the electric locos in those years had been given such class numbers as 1000, 1040, 8000, 10000 etc. (though having been originally 10000s, according to the classification of 1909), without alphabets. Then, they were reclassified under the today's system (1000 = ED 10, 1040 = ED 50, 8000 = EF 50, 1000 = EC 40 etc.).
A few locos of class AB 10 (A for Accumulation) existed, as the sole battery type. They were later rebuilt to become the normal electric locos, class EB 10.

Diesel locomotive DD 51 1157, type DD51, for main line service, maximum speed over 85 km/h. Taken at Kushiro Hokkaido, by Hiroshi Naito.

3 Combustion (Diesel) Locomotive
First alphabet: D for "diesel"
Second alphabet: number of driving axles: B = 2, C = 3, D = 4, E = 5, F = 6

First and second figures:	10 - 49:	loco for shunting or local service, maximum speed under 85 km/h
	50 - 89:	loco for main line service, maximum speed over 85 km/h
	90 - 99:	experimental loco

Subsequent figures: running number of the class.
Some variants of certain classes are designated with the running numbers of 500s, 1000s, 1500s etc.
Example:
DF 50 1 - differed from DF 50 500 - in the power and maker of the diesel engine.
DD 51 801: D (=diesel), D (=four driving axles), 51 (=2nd loco for main line service with a maximum speed over 85 km/h), 801 (=1st of the DD 51 800s and 1800s, a variant having no steam generator).

Control car ku ha 111 609, type 111, DC, suburban service railcar. At Tokyo station, by Hiroshi Naito.

4 Electric Railcar
Each example of electric railcars is classified with katakana (a Japanese syllabary) and figures, e.g. ku mo ha 103, sa ro 111 etc. And the classes composing a train set or multiple unit are grouped as series, which is designated with the number of the main railcar (i.e. of the motor coach with odd number). For example, series 481 is comprised of the five classes of mo ha 481, mo ha 480, ku ha 481, sa ro 481 and sa shi 481. What the symbol letters and figures mean are as follows:

ku:	control car
mo:	motor car
sa:	trailer
ro:	first class (second class, before 1960)
ha:	second class (second class, before 1960)
shi:	dining or buffet
ne:	sleeping
yu:	mail
ni:	baggage
e:	rescue
ru:	distribution
ya:	service or inspection

In the earlier years of the JGR (later JNR) classification system, in place of the "mo" the "de" was used, along with the numbers in three or four figures, to indicate the motor car (this sign is still today prevailing on many of the private railways). In those days, there were such classes as ho de 6100 (ho: cf. the below section of Passener Car), de ha 6340 etc.

5 Combustion (Diesel) Railcar
Each type of combustion railcars is classified with katakana (a Japanese syllabary) and figures, e.g. ki ha 20, ki ro 80 etc. And the classes composing a train set or multiple unit are grouped as series, which is designated with the number of the prototype of the series. For example, series 181 DMU consists of the five classes ki ha 181, ki ro 181 and ki sa shi 181.
What the symbol letters and figures mean are as follows:

ki:	diesel railcar (formerly including gasoline or steam type)
ki ku:	control car (without driving power unit) for DMU
ki sa:	trailer (without driving power unit) for DMU
ro:	first class (second class, before 1960)
ha:	second class (second class, before 1960)
shi:	dining or buffet
yu:	mail
ni:	baggage
ya:	service car or inspection car
wa:	freight wagon

Diesel Railcar k1 ha 112 115, modern, high-powered new serial type. At Hitachi-Daigo station, by Hiroshi Naito.

ii) 100 -399: modern, high-powered new serial type

First figure:	1, 2:	hydraulic type
	3:	gas turbine engine type
Second figure:	8:	limited express type
	9:	experimental car

Third figure: running number (0 - 9) of each type
Subsequent figure(s): running number of the class. Some variants of certain classes are designated with the running numbers of 600s, 1000s, 1200s etc.
Examples:
ki ha 2051: ki (= combustion railcar), ha (=second class), 20 (=hydraulic one-engine type), 51 (=51st of the ki ha 20).
ki sa shi 181-2: ki sa (=trailer for DMU), shi (=dining car), 1 (=modern high-powered hydraulic type), 8 (=for limited express service), 1 (=1st of this type i.e. of the "ki sa shi 18-"), 2 (=2nd of the ki sa shi 181).
Note:
Of the railcars with driving unit, the control cab is not designated in the classification (apart from the electric railcars), probably because most of conventional motorised cars had the cab.
As to the series of conventional combustion railcars the main classes which represent the serieses are not always given the odd numbers. Supposedly because the combustion railcars were constructed without regard to the idea of "series" until recent years, even though some preceding classes built unter the serial plans could be grouped as series. As such, serieses 28, 58, 80 etc. exist.
Until the 1950s the combustion railcars were classified with the symbol letters and numbers in four and five figures, such as ki ha ni 5000, ki ha 42000 (= ki ha 07) etc.
In their earlier years, to identify the steam-propelled railcars the symbol letters of ho ji, and then of ji ha, were used along with the numbers of 6000s, such as ho ji 6005, ji ha ni 6055, ki ha ni 6450 (ho: cf. the below section of Passenger Car, ji: steam).

su ha fu 32 2357 passenger car, over 42.5 t and under 47.5 t, second class, with brake cabin. Taken at Chichibu Railway, by Hiroshi Naito.

6 Passenger Car
Each type of passenger car is classified with katakana (a Japanese syllabary) and figures, e.g. su ha ni 35,, na ro 10 etc. And the group of the classes built under the same serial design is called "series", represented by the number of the prototype class. For example, series 20 consists of the thirteen classes na ro ne 20, na ha ne fu 23, na shi 21, ka ni 21 etc.

What the symbol letters and figures mean are as follows:
First letter: weight (self-weight + 50 kg ( the fixed number + 1 ton as the weight of water, batteries etc.)

ko:	under 22.5 t
ho:	over 22.5 and under 27.5 t
na:	over 27.5 and under 37.5 t
o:	37.5 t and under 42.5 t
su:	over 42.5 t and under 47.5 t
ma:	over 47.5 t and under 52.5 t
ka:	over 52.5 t

Subsequent letter(s):

i:	first class, before 1960
ro:	first class (second class, before 1960)
ha:	second class (third class, before 1960)
ne:	sleeping car
shi:	dining car
fu:	with brake cabin
te:	observation car
yu:	mail car
ni:	baggage car
ya:	car for service, test, inspection, instruction, construction or ambulance
e:	rescue car
ru:	distribution car
nu:	heating car
he:	hospital car (war time)

na ha 22000, eight-wheeled (body width 2,800 mm). Photographed in 1931 on the Sanyo Main Line (location is not known).

Wooden body type

1000 - 7999:	eight-wheeled (body width under 2,590 mm)
8000 - 9999:	twelve-wheeled (body width under 2,590 mm)
10000 - 17999:	eight-wheeled (body width over 2,590 mm and under 2,800 mm)
18000 - 19999:	twelve-wheeled (body width over 2,590 mm and under 2,800 mm)
20000 - 27999:	eight-wheeled (body width 2,800 mm)
28000 - 29999:	twelve-wheeled (body width 2,800 mm)

Tank car ta ki 43 119, loading weight over 25 t. At Negishi yard, by Hiroshi Naito.

7 Freight car
Each type of freight wagon is classified with katakana (a Japanese syllabary) and figures, e.g. wa ra 1, to ki 15000 etc.
What the symbol letters and figures mean are as follows:

First letter:	wa:	boxcar	su:	iron-sided boxcar
	te:	all-metal boxcar	tsu:	ventilated boxcar
	re:	refrigerator or insulated car	ka:	livestock car
	u:	car for pig transport	po:	pottery car
	ta:	tank car	mi:	water tank car
	to:	gondola car	ri:	gondola or hopper car for sand transport
	shi:	heavy load transporter	chi:	flatcar
	ko:	container car	ku:	car carrier
	yo:	caboose	ki:	snow plow
	ya:	service car	ke:	track scale test car
	sa:	works car	e:	rescue car
	so:	crane car	hi:	buffer car

Second letter:	(blank):	loading weight under 13 t
	mu:	loading weight 14 - 16 t
	ra:	loading weight 17 - 19 t
	sa:	loading weight 20 - 24 t
	ki:	loading weight over 25 t

Subsequent letter: fu: with brake cabin
Subsequent figure(s): class number(s), to which the running numbers of the class are added (starting from 0, in case the last figure is 0).
Examples:
wa mu 80054: wa (=boxcar), mu (=loading weight over 14 and under 16 t), 80054 (=55th of the class wa mu 80000).
to 16: to (=gondola car), without the second letter (=loading weight under 13 t), 16 (=16th car of the class to 1).
ta ki 13002: ta (=tank car), ki (=loading weight over 25 t), 13002 (=1003rd of the class ta ki 3000).
ko ki fu 50000: ko (=container car), ki (=loading weight over 25 t), fu (=with brake cabin), 50000 (=1st of the class ko ki fu 50000).
ki 103: ki (snow plow without driving unit), 103 (=4th of the class ki 100).
Note:
Regarding the class numbers, there is no remarkable numbering system, except 10000s being for freightliners etc.
Supplement
Some types of locomotives and rolling stock, such as rack locos, ex private railway electrics, coaches with wooden body, ventilated boxcars etc. etc., have been already extinct.
In 1969, the JNR introduced the mono-class system in passenger system. So, officially they call the above-mentioned first and second class cars special (in nickname "green") cars, as well as the first and second sleepers A and B (-grades) sleepers, respectively.