A Chinese railway firm has opened tenders for 351 bullet trains worth a staggering $10.6 billion.China Daily reported that state-owned China Railway Investment Corp has opened tenders for what it claims is the largest train order in history.As many as 228 bullet trains will have to reach a maximum speed of 350 km per hour, and 123 trains will need to run at 250 kilometers per hour, said CRIC, a subsidiary of China Railway Corp.