A gantry crane loads cargo onto a freight train bound for Central Asia at the Jiaozhou Bay International Logistics Harbour in Qingdao, east China's Shandong Province, May 7, 2018. As of Tuesday, a total of 3039 freight trains from China to Central Asian countries have departed from Qingdao, a nodal city on the economic corridor linking China, Central Asia and Europe. Qingdao will also host the 18th Shanghai Cooperation Organization (SCO) Summit in June. (Xinhua/Guo Xulei)

A gantry crane loads cargo onto a freight train bound for Central Asia at the Jiaozhou Bay International Logistics Harbour in Qingdao, east China's Shandong Province, May 7, 2018. As of Tuesday, a total of 3039 freight trains from China to Central Asian countries have departed from Qingdao, a nodal city on the economic corridor linking China, Central Asia and Europe. Qingdao will also host the 18th Shanghai Cooperation Organization (SCO) Summit in June. (Xinhua/Guo Xulei)

A railway staff signals as a freight train bound for Central Asia departs from the Jiaozhou Bay International Logistics Harbour in Qingdao, east China's Shandong Province, May 7, 2018. As of Tuesday, a total of 3039 freight trains from China to Central Asian countries have departed from Qingdao, a nodal city on the economic corridor linking China, Central Asia and Europe. Qingdao will also host the 18th Shanghai Cooperation Organization (SCO) Summit in June. (Xinhua/Guo Xulei)