72 series

72 series
Consist led by KuHa 79362 in the 1960s
Technical specifications
Manufacturer(s)	Hitachi, Kawasaki Sharyō, Kinki Sharyo, Kisha Seizō, Nippon Sharyo, Teikoku Sharyō, Tokyu Car Corporation
Type of locomotive	Electric multiple unit
Constructed	1952 – 1958
Number built	1,450 cars
Dimensions	20,000 mm × Unknown × Unknown
Gauge	3 ft 6 in (1,067 mm)
Power supply	Pantograph
Electric system(s)	1,500 V DC
Traction system	Resistor control
Service information
In service	1954 – 1985
Formation	2, 4 or 8 cars per set
Number in service	None
Fleet numbers	Various
Scrapped	1976 – 1983
Preservation information
Preserved	1 car
Number scrapped	944 cars

The 72 series is a Japanese city commuter electric multiple unit operated by the Japanese National Railways from 1954 to 1985. An improved version of earlier electric multiple units, the 72 series was the definitive electric multiple unit design used by the JNR in the 1950s and served as the basis of future rolling stock models.

Description

In the 1940s, the JNR was using 63 series electric multiple units; this was a wartime design produced under duress. As a result the sets featured numerous cost-cutting features such as steel bodies and wooden roofs and were of a very crude design; they were also notably very prone to accidents, with the Mitaka incident in 1949 and Sakuragichō train fire of 1951 being major incidents involving the train types, prompting the JNR to quickly design a successor model.

This successor model would come in the form of the 72 series, a series of electric multiple units based on the 63 series but improved to fix the various issues of the previous model as well as incorporating new technologies. Highly reliable and well-liked, the 72 series cars would become the definitive electric multiple unit type used by the JNR; with the poor reputation of the 63 series cars the vast majority of them were converted to 72 series cars by 1963. The 72 series sets would come to serve as the basis of the later 101 series sets, a mainstay of JNR's commuter services from the 1950s to 1980s, and by extension the later 103 series cars, based on the 101 series design.

Many 72 series cars were converted to other cars for non-revenue use, such as the KuMoYa 90 series cars in the 1960s as well as other dedicated baggage trains; other 72 series cars would also be converted into 101 series and 103 series cars. The last non-converted 72 series cars were used on the Senseki Line until 1985.

Specifications

Based on the 63 series design, the 72 series featured largely the same basic design but was manufactured of significantly higher quality materials.

Improved versions

During the 1960s and 1970s, a number of "improved" versions of the 72 series were created, mainly in terms of improved exterior and interior designs. However, their underbody electronics were not improved and in comparison to the "new performance trains" introduced by the JNR breakdowns were frequent. All were retired by 1985 and scrapped by 1986.

The first car to receive these improvements was MoHa 72970, modified from MoHa 72587, originally built in 1954 by Nippon Sharyo. MoHa 72970 received four larger doors, similar to those seen on the 101 and 103 series cars; no further enhancements were made. The car was modified at Kōriyama. Used on the Tsurumi Line, MoHa 72970 was withdrawn from service when the trains on that line were replaced with 101 series cars; there were plans for it to be used on the Senseki Line but those plans were canceled. MoHa 72970 would ultimately be scrapped in 1981.

The next improved version was labeled the MoHa 62 series or the KuHa 66 series; these were an extensively modified version of the 72 series, featuring new bodywork similar to the 113 series and different seating, although no underfloor changes were made. The cars were intended for use on the Minobu Line. 12 cars were modified in four-car formations, with the modifications done at Kōriyama, Nagano and Takatori. The trains were used for some time after the introduction of the 115 series in 1981, but were all withdrawn in 1984 and scrapped by 1986.

Building on MoHa 72970, JNR also introduced the 72-970 and 79-600 series of improved cars, featuring the same modifications as MoHa 72970 but designed for cold weather use; these were intended for use on the Senseki Line as initially planned. Modifications were supposed to have been done at Kōriyama but were in actuality outsourced to rolling stock manufacturer Fuji Heavy Industries. The trains were used for some time after the introduction of the 103 series on the Senseki Line in 1981 but all were withdrawn by 1984.

Only the cab of KuHa 66002 was known to have survived, located at the Sakuma Rail Park; the park was closed in 2009 and the exhibits moved to the SCMaglev and Railway Park, which opened in 2011. KuHa 66002 was not one of the exhibits present and was presumably scrapped in July 2010 along with the other cars which were not planned to be displayed at the new museum.

Preservation

The following 72 series cars have been preserved:

Car number	Manufacturer	Date manufactured	Date retired	Previous sets	Location	Notes
KuMoHa 73383	Kawasaki Sharyō	1948	1984	N/A	Mure, Shikoku, Japan	Cab only, ex-MoHa 63811; planned to be moved to new location by non-profit

The following 72 series cars were preserved in the past but have since been scrapped:

Car number	Manufacturer	Date manufactured	Date retired	Previous sets	Location	Notes
KuMoHa 73001	Nippon Sharyo	1946	1985	N/A	Hiroshima Works, Hiroshima, Japan	Ex-MoHa 63143; scrapped at later date
KuHa 66002	Kisha Seizō	1947	1986	A2, A3	Sakuma Rail Park, Shizuoka, Japan	Ex-KuMoHa 73118, ex-MoHa 63724; cab only, fitted with fleet number designator "R5" (fictitious number), scrapped circa July 2010

Gallery

KuHa 66 series set A1 in 1986

Consist led by KuMoHa 73369 in the 1960s

Trivia

• The name "72 series" was not used by the JNR in any official capacity, this being just a collective term for these types of railcars with a similar design. Strictly speaking, the "72 series" moniker should only apply to the 490 railcars produced from 1952 to 1958 with this numbering scheme but can also be used to refer to the 63 series cars and the cars they were ultimately modified into.