The derailment disrupted train operations on a key railway route in Tamil Nadu, while timely intervention by a gatekeeper helped prevent a possible major accident. Tirupattur: Seven empty railway coaches, which rolled away unattended from the railway yard at Jolarpettai Junction in Tamil Nadu s Tirupattur district, travelled nearly six kilometres without an engine before derailing near Thamaleri Muthur, disrupting train services between Bengaluru and Chennai.