Complex sentence: On May 30,2016, new four-car Toronto Rocket (TR) subway trains were introduced on this line on which they displaced the older T1 subway trains over to Line 2 Bloor-Danforth.
Split into simpler sentences: On May 30,2016, new four-car Toronto Rocket (TR) subway trains were introduced on this line. They replaced the older T1 subway trains which were moved to Line 2 Bloor-Danforth.