Japanese National Railways Standards (JRS)
1. Japanese National Railways
Japanese National Railways (JNR) was the public corporation which operated the government-owned railways of Japan from 1949 to 1987. JNR operated about 20,000 km of railway network all over Japan except Okinawa, and was the largest railway operator in Japan.
However, JNR was privatized and divided into several railway companies on April 1, 1987 to release it from a large debt and to streamline management.
2. Standardization of Goods in JNR
Japanese National Railways Standards (JRS) were standards on goods of railways established by JNR. Goods which JNR purchased were not general-purpose industrial products but specific products for railways including rolling stock, signalling equipment, and sleepers. Since JNR itself had to establish original standards, the standardization of goods is the important theme for JNR. In 1957, JNR established the Goods Standardization Committee and formulated framework to promote standardization by JRS.

  1. Identification number: The first five-digit number represents name of goods, and the second number following hyphen represents classification in detail.
  2. Revision code: The letter "A" represents the first edition. If the standards are revised, the letter is changed in alphabetical order (e.g. The letter "B" represents the second edition.).
  3. Auxiliary code: The first number represents the department that established the standards. The following letter represents category and the basis of the standards. The last number represents the lower digit of standards' establishment year.
  4. Classification code: The letter represents additional classification of department.
3. Privatization of JNR and Abolishment of JRS
In 1987, JNR was privatized and divided into several railway companies. At the same time, JRS was abolished. The number of JRS were about 2,800 during the last stage of JNR.
Some abolished JRS were converted into JIS. However, several railway products are still based on specifications of JRS.