Train automatic stopping/stop-position controller (定位置停止装置) (TASC) is the name of a train protection system/automated stopping aid currently used only in Japan. It allows trains equipped with TASC to stop automatically at stations without the need for the train operator to operate the brakes manually, preventing stopping errors and SPADs. TASC is also compatible with automatic train control (ATC) and automatic train operation (ATO), where in the latter case it acts as its auto-braking function.
The first incarnation of TASC was originally developed in the 1950s and 1960s as a way of ensuring that trains stop properly at stations, although problems with brake responsiveness, among other issues with the existing technology of that time, meant that it was never put into practical use. From the 1970s, technological improvements in computing and railway technology, especially the advent of one man operation and automated guideway transit (AGT) systems and more recently, platform screen doors, made TASC increasingly viable both as a train protection system and as a precursor or complement to railway automation. The first full-scale implementation of TASC was on the Tokyo Metro Ginza Line, the oldest subway line in Japan, where it, along with a new CS-ATC cab signalling system, replaced the line's previous mechanically-operated automatic train stop (ATS) system in 1993,[1] enabling a massive upgrade of the line's route capacity and frequency between trains.[2]
Examples of train lines that have TASC.