Tao Zhu
In 1965, Chen Yu along with Tao Zhu (), who had been the Governor of Guangdong and First Secretary of Guangdong Committee of the Communist Party of China, proposed in the wake of the Gulf of Tonkin incident that a tunnel be built in Guangzhou for wartime evacuations and post-war metro development. Approved by the central government, the project started in the spring of 1965. Due to its confidentiality in the context of intensification of the Vietnam War, the project adopted the obscure name of "Project Nine" (), where "Nine" was the number of strokes in "", the Chinese word for "underground".