There's something about this accident that bothers me that I've not seen addressed: unlike the glitches (fortunately nonfatal so far) on the BJ-SH route, both of these D trains and train routes were not new to the HSR system, but were established services at least for the last couple of years or since D trains have been around. So...what caused this particular accident to happen now?

--Was this track section including signal systems and power supply new, or refurbished as preparation for the rollout of the G's?
--Was either or both of the trains themselves the newer D's?
--Did the schedule just get crammed too full of trains on the route?

My first thought was that the answers to these questions was: No, no, and no. But I'm not knowledgeable on system developments in this part of China over the last few years...maybe another FT'er who frequents those routes is. Could this accident be unconnected but just coincident with the problems on the new HSR line?