The railway was completely electrified in 2006. On April 18, 2007, the new CRH bullet train was introduced on the upgraded railway as part of the Sixth Railway Speed-Up Campaign. A day-time train D31 served the route, departing from Beijing at 10:50 every morning, and arriving at Shanghai at 20:49 in the evening, travelling mostly at 160–200 km/h (up to 250 km/h in a very short section between Anting and Shanghai West). In 2008 overnight sleeper CRH trains were introduced, replacing the locomotive-hauled Z sleeper trains. With a new high-speed intercity line opening between Nanjing and Shanghai in the summer of 2010, the sleeper trains made use of the high-speed line in the Shanghai–Nanjing section, travelling at 250 km/h for a longer distance. The fastest sleeper trains took 9 hours, 49 minutes, with four intermediate stops, at an average speed of 149 km/h.