Located deep in the mountains of Yuanling County, Huaihua City, Hunan Province, the former State-owned Wuyi Machinery Factory, State-owned Wuer Machinery Factory and State-owned Wusan Machinery Factory were three secret military enterprises directly under the Ministry of Aviation during the "Third Line" construction period. In the 1980s, the third-line construction entered a period of adjustment, and in the early 1990s, Yuanling third-line factories moved out one after another. How to deal with the dilapidated old site affects the hearts of third-line workers. In the 1960s and 1970s, the slogan "Prepare for war, prepare for famine and serve the people" became a household name in China, accompanied by slogans such as "Good people should go to the third line at once" and "Dig deep pits and accumulate more grain". Since 1964, facing the complex changes in the international situation, the country has launched a large-scale "third-line construction" in the mountainous areas of 13 provinces, such as Hunan in the central and western regions. More than 4 million builders have built 1 100 large and medium-sized industrial and mining enterprises, scientific research institutions and universities. Authoritative data show that the so-called three lines, that is, coastal and frontier areas are the first line, and inland areas such as Sichuan, Yunnan, Guizhou, Qinghai, Shaanxi, Gansu and Ningxia are the third line. The central areas such as Henan, Shandong and Hunan between the first and third lines are the second line. Hunan, covering 43 counties and cities such as Xiangxi, Huaihua, Shaoyang, Yiyang, Yongzhou and Changde, is the key area of the third-line construction. According to the principle of "depending on the mountain, dispersing and hiding", the State No.3 Machinery Department sent experts and technicians to build state-owned Wuyi Machinery Factory, State-owned No.52 Machinery Factory, State-owned No.53 Machinery Factory and its supporting 0 13 hospital aero-engine base, Xiangjiang Machinery Factory (33 1 factory) and other military enterprises in Yuanling mountainous area. Yuanling County, located in the northwest of Hunan Province, at the northern end of Huaihua City, swims in the Yuanshui River. It is located at the intersection of the southern foot of Wuling Mountain and the northern end of Xuefeng Mountain, with the highest elevation of more than 2000 meters. Known as "the gateway to western Hunan" and "the key to southern heaven". Yuanling is the largest county in Hunan Province, accounting for 2.86% of the total area of the province. In addition, Yuanling County is rich in resources, overlapping mountains, criss-crossing rivers and rich in hydropower, making it one of the top ten hydropower bases in China. More than 20 kinds of gold, tungsten, copper, antimony, lead, zinc and iron sulfide have been proved. There are 1 1 kinds of minerals with proven reserves, including 3 kinds of large-scale deposits, and the top ten reserves in China are phosphate rock, coal mine and other minerals. 1September, 1965, the Ministry of National Machinery Industry issued a document confirming that the site of the May Day meeting was chosen in Changchong 'ao, Chengguan Town, Yuanling County today. 1May, 966, May 1st Factory of Aviation Gear Factory was completed and put into operation. At the same time, today, the 52 nd factory, which is located deep in the mountains of Yuanling Town, started construction. Factory 52 is an aero-engine factory with the military code "3 10". Since then, the fifth and third factories in Masipu Town have also started construction. The site selection personnel believe that Yuanling can not only provide raw materials and even develop nuclear materials for military enterprises, but also resist nuclear attacks. The cover layer at the top of the preparation tunnel is 200m thick, which can prevent the air explosion impact of 1 10,000 tons of hydrogen bombs and the direct hit attack of 1 10,000 pounds of bombs, and can resist the damage of an earthquake of magnitude 8. In particular, there are mountains in front of the cave, and there are photoelectric control doors calculated according to the shock wave of the atomic bomb in the cave. At that time, due to the need for confidentiality, many lines were rerouted here, taking caves instead of leveling the ground, and there were no stations nearby. These three military enterprises all have their own code names, and the names of their communes are hidden on the map. The third factory was once extremely mysterious and brilliant, and each arsenal ranged from thousands to tens of thousands. A prosperous military enterprise is a fully functional "military city". Take 52 factory as an example. Factories are scattered in several canyons. The factory, living quarters and caves are built around the mountain, and there are various supporting facilities such as staff quarters, staff clubs, auditoriums, basketball courts, kindergartens, nurseries, primary schools, junior high schools, hospitals, post offices and bazaars. At night, the lights are bright. In the early 1980s, according to the changes in the international situation, the construction of the "Third Line" entered an adjustment period, and integration of defense and civilian technologies moved as a whole. After the founding of New China, No.52 Factory produced the well-known "750" water-cooled tricycle with excellent military technology. Since 1983, 38 third-line military enterprises in Hunan Province have moved out of the mountainous areas in central, southern and western Hunan and moved to economically developed areas such as large and medium-sized cities. By 2005, they had to adjust their relocation. 1985, the State Council Third Line Office issued a document to list the third factory, such as Wuyi Factory, in the relocation project of the Seventh Five-Year Line. 1992, Wuyi factory moved to Wangcheng District, Changsha City, Lei Feng's hometown. After the relocation of Wuyi factory, the bustling Zhongnanmen Wharf in Yuanling nearby became depressed. Now, the vast factory area is desolate everywhere. 199 1 year1kloc-0/month, the 52nd factory was moved to Lengshuipu, Yueyang City, Hunan Province. Later, No.52 factory was transformed into "China Hangfa Changjiang Electric Power Co., Ltd.", which belongs to China Aviation Engine Group Co., Ltd. On July 5, 20 17, China Hangfa Changjiang Electric Power Co., Ltd. was transformed into China Hangfa Changjiang Electric Power Co., Ltd. (hereinafter referred to as "China Hangfa Company"). At present, the company is the only professional company in China that develops and produces metal sealing structures for aero-engines and gas turbines. After the three arsenals moved away, the original factory was handed over to Yuanling County for escrow. Most buildings are idle now, and some buildings have been demolished or rebuilt. In the past, they were as prosperous as a cloud, and the special mark of the third-line factory still exists. 2065438+August 2008, China Hangfa Company organized some employees to visit the former site of No.52 Factory. They looked at the empty and lonely old site and the dilapidated and vicissitudes of the building, filled with emotion. As of 20 18 and 10, no industrial heritage in Huaihua city has been listed as a cultural relic protection unit. Yang Zhiyong, deputy director of Huaihua Museum, participated in the investigation of industrial heritage. He said that the existing large-scale industrial sites in Huaihua include Yuanling Wuyi Factory, Wuer Factory, Wusan Factory, Yun Jian Group and Xuefeng Machinery Factory. Times have changed, and these factories have either moved away, stopped production or closed down, or sold to private individuals, and the factory area has changed beyond recognition. (Image source network)