Differences between ATC and non-ATC versions of JR trains

[NGT6 1315]

Hello,

 

having just had a look over several types of JR EMUs I noticed how there is a distinction between subtypes either fitted or not fitted with ATC - the 103 series appearing to be a prominent example. However, are there any externally visible differences between ATC and non-ATC versions?

 

Thanks in advance!

[marknewton]

I suspect the most obvious difference would be the ATC sensor/pick-up and its associated cabling.

[NGT6 1315]

I suspect the most obvious difference would be the ATC sensor/pick-up and its associated cabling.

 

Yes, of course - however, I was thinking whether the ATC installation might have been just one of several modifications which may have been dependent on one another and were thus carried out at the same time.

 

If I understood the Wikipedia articles correctly, ATC installation on the Japanese narrow gauge network did not begin until 1961 - were there no train protection systems at all before that year?

[bikkuri bahn]

One thing to keep in mind is that ATC means cab signaling in Japanese railway practice (such as on Shinkansen lines).  Otherwise the prevalent form of train protection is ATS, which utilizes lineside signals.  Actually, the organization that pioneered ATS use in Japan was not JNR, but the Tokyo Subway, which installed ATS on the Ginza line in 1927.  Apparently JNR (or rather IJGR as it was called at that time) had started ATS installation in 1941, but ceased with the start of the Pacific War.  In 1951 JNR tested an ATS system on a stretch of freight-only tracks on the Tokaido Line between Tsujido and Chigasaki.  Then in 1954 an ATS system (ATS-B) was installed on the Yamanote and Keihin Tohoku Lines, later expanding to other electrified commuter lines (Kokuden) in the Tokyo and Osaka Metropolitan areas.