The NDJ3 "Great Wall", previously labeled the "Harmony Great Wall" is the only higher-speed diesel multiple unit that is still operating in China. It was first designed to be used for passenger transport in the 2008 Olympics, and has become a mature technology platform with export orders to Nigeria despite initial flaws related to overheating of electrical cables in the power car.

Line S2 of Beijing Suburban Railway (BCR) is a commuter rail line in Beijing. The main line runs from Huangtudian railway station in Changping District to Yanqing railway station in Yanqing District, following the old Beijing–Baotou railway, and provides faster, more frequent and convenient service than preexisting trains. The line is 108.3 kilometres (67.3 mi) in length. The train locomotives are marked "Great Wall".