It was operated by the Turkish State Railways and was one of Istanbul's two commuter rail lines (the other being the Haydarpaşa suburban).

Carrying an average of 22,200 passengers daily, it was the second-busiest commuter railway in Turkey, after the Haydarpaşa suburban.

The line was closed in 2014 and all tracks have been removed for renovation and incorporation into the new Marmaray network which started operation in 2013 between Ayrılıkçeşmesi and Kazlıçeşme.

Travelling on the southern European shore of Istanbul, the line passes through several important districts, until curving north at Soğuksu to Halkalı.

25 kV AC electrification technology was quite new at the time, following the 1953 experiments in France and it made TCDD at the forefront in a suburb, seashore environment.