In Japan, trains are operated by dividing main tracks into block sections, with Ministerial ordinance stipulating in principle that two or more trains are not to be operated simultaneously within the same block section. Therefore, blocking devices are installed in block sections.
The types of block systems installed on JR lines are shown in Table 3.
The automatic block and cab signal block systems account for 73.7% of all lines, and these block systems are used on trunk and auxiliary trunk lines. Special automatic block systems are used on branch sections, and other block systems are being converted to one of the above systems when installing color light signals or otherwise modernizing facilities.
2. The cab signal block system is used on ATC sections and includes the 2,036.5 km of Shinkansen track.
5 Automatic Block System
The automatic block system uses signals (home, departure and block signals) to automatically display stop signals using track circuits installed in block protection areas when trains or cars are present in block sections or overlapping sections.
There are a number of types of automatic block systems, allowing a suitable system to be selected in line with the traffic demand over the railway division in question.
(1) Block systems for double-track sections
Double-track sections are divided into in-bound and out-bound tracks with trains constantly operated in the same direction over a single track. Therefore, blocking applies only to continuing trains. In Japan, Ministerial ordinance stipulates that the three position signal (red, yellow and green) type automatic block system must be used on all double-track sections other than ATC sections.
