From the 1980 to the early 1990s, the subway introduced several new models including the DK6, DK9 and their derivatives the DK11, DK16 and GTO.
从1980年代至1990年代早期，北京地铁引入了新的车辆，包括的型号有DK6、DK9以及他们的变体DK11、DK16和GTO。