In early 1960, the Central Committee approved a request from the Ministry of Petroleum Industry. Tens of thousands of oil workers from across the country, with 30,000 demobilized soldiers, gathered at the new oilfield in Daqing for the “Daqing oil battle” (Daqing shiyou huizhan). The campaign headquarters was set up on April 8, 1960. On June 1, the first trainload of crude oil left Daqing. In the first winter, workers lived in holes dug into the ground.