A time of fiery battles amidst the green forest.

Nestled amidst the mountains and forests of Thanh Hoa province, the Hai Van Resistance Blast Furnace (NX3 Blast Furnace), with its fiery days, contributed to writing the epic victory of Dien Bien Phu, a victory that "shook the world" and resonated throughout the five continents of Vietnam.

Hai Van Resistance Blast Furnace: A Time of Fiery Flames Amidst the Green Forest The Hai Van blast furnace, once ablaze during the resistance war, was used to produce weapons for the battlefield.

Traveling approximately 40km southwest from Thanh Hoa City, through Nong Cong to Ben Sung town (Nhu Thanh district), visitors will encounter Dong Muoi Mountain – a mountain range belonging to the chain running from Sam Neua (Laos) to Thanh Hoa. Located near Song Muc Lake, Dong Muoi Mountain is low, like a secluded yet rugged valley, surrounded by towering mountains. Perhaps this is why Dong Muoi was chosen as the historical site for the construction of the Hai Van Resistance Blast Furnace more than 70 years ago.

Going back in history, in 1945, the August Revolution succeeded, and President Ho Chi Minh read the Declaration of Independence, giving birth to the Democratic Republic of Vietnam. However, the French colonialists at that time did not abandon their ambition to invade our country. Therefore, on the night of December 19, 1946, President Ho Chi Minh, on behalf of the Central Committee of the Party and the Government, issued a Call to Arms for National Resistance. His call rallied the strength of the entire nation to unite and fight the enemy to protect the achievements of the revolution and preserve the beautiful land of our ancestors. He affirmed that the resistance would certainly be victorious but would be protracted and arduous, thus requiring self-reliance and self-sufficiency.

For a protracted resistance war, self-sufficiency in the production of weapons and ammunition to supply the army and guerrilla militia was indispensable. And to produce weapons, the military industry played an extremely important role. At that time, the Military Industry Department and the Central Vietnam Mineral and Industrial Department decided to choose Cau Dat - Song Con (in Con Cuong district, Nghe An province) as the location for the blast furnace. Later, the blast furnace was moved to Cat Van (also in Nghe An). However, the blast furnace in Cat Van was discovered by the enemy while it was still under construction and about to become operational, and they bombed and destroyed it.

According to documents, at that time, the head of the Central Vietnam Department of Minerals and Industry, Vo Quy Huan, had to go to Viet Bac to seek guidance from the Central Committee on selecting a location for the blast furnace. Two locations were considered: Thai Nguyen or Thanh Hoa. However, according to General Vo Nguyen Giap, Thai Nguyen could not be chosen because the French colonialists would attack there. Therefore, the Thanh Hoa region was chosen as the location for the blast furnace. After surveying, the hilly area of Nhu Xuan district (at that time, Nhu Thanh district had not yet been separated from Nhu Xuan district) with its advantages of being surrounded by hills, convenient water and land transportation, proximity to ore sources, and readily available charcoal for burning ironwood to fuel the furnace, was considered ideal for building a blast furnace.

In late 1949, the blast furnace from Cat Van (Nghe An) was officially moved to the mountainous forest area of Dong Muoi, Nhu Xuan district, Thanh Hoa province (Dong Muoi was formerly part of Hai Van commune, hence its name, Hai Van Resistance Blast Furnace). In 1950, the construction of blast furnaces NX1 and NX2 in Nhu Xuan district began in the lim forest area of Dong Muoi mountain. More than a year later, the first batch of pig iron was produced under the canopy of Dong Muoi forest - marking a turning point for the metallurgical industry. In the two years of 1952-1953, nearly 200 tons of pig iron were produced at Dong Muoi to manufacture weapons for the battlefield.

However, despite careful planning, the operations of blast furnaces NX1 and NX2 hidden in the cypress forest could not escape the notice of the French colonialists, who relentlessly bombarded them day and night. Relocation was once again considered. After careful observation and investigation, Comrade Tran Dai Nghia, Director of the Ordnance Department, decided to move all production machinery into Dong Muoi Cave (about 1km from the old location) – thus, blast furnace NX3 was established. Moving the blast furnace into a cave would prevent detection by the enemy, and even if discovered, a production facility inside a cave would be very difficult to destroy.

The memorial plaque introduces the Hai Van Resistance Blast Furnace historical site.

However, despite the advantage of seclusion, bringing a blast furnace with its bulky machinery and equipment into a mountain cave was no easy task. Approximately 400 explosive charges were detonated to widen the cave entrance. Furthermore, the machinery had to be modified to suit the cave's structure; the system for venting steam, toxic fumes, and smoke had to be designed to be discreet and undetectable by the enemy; and unforeseen problems arose, such as the intense noise from the machinery and fans banging against the cave walls, making it impossible for workers to hear; and the release of dangerous toxic gases from chemical reactions that could endanger lives. A series of problems arose, forcing engineers and workers to rack their brains and find solutions.

Amidst the countless difficulties of the actual production conditions and the urgency of the battlefield, the engineers and workers here, with their iron will and intelligence, finally completed the installation of the NX3 blast furnace in Dong Muoi cave at the end of 1953. From here, in the Dong Muoi mountain cave, surrounded by lush green forests, there were continuous months of intense production, fueled by fervent enthusiasm. Poems of proud praise were written: “Dong Muoi in the green forest / How many days of resistance, how much affection / This cave embraces the blast furnace / Expanding the history of steel, the pride of the workers.”

From the NX3 blast furnace in the Dong Muoi mountain cave in Thanh Hoa province, hundreds of tons of cast iron were produced and used to cast grenades, mortars, pans, and military cooking pots... Particularly during the 1953-1954 Winter-Spring campaign and the Dien Bien Phu campaign, the Dong Muoi blast furnace played a significant role in ensuring the front lines could confidently fight the battle.

And during those fiery months of the Hai Van Resistance Blast Furnace's historical mission, this place bore the imprint of the intelligence and efforts of generations who were ready to dedicate themselves to making history, such as Professor Tran Dai Nghia; engineer Vo Quy Huan...

Seventy years have passed, and the fiery days of the Hai Van blast furnace in the Dong Muoi forest have faded into the past – "living" alongside the heroic years of the nation's history. Nevertheless, the Hai Van blast furnace remains, its remnants of the "drying furnace," "iron annealing furnace," and "hot air furnace" still present; along with slogans like "Dig deep, remember well, review achievements, write complete and specific autobiographies"; or "Emphasize mutual assistance, boost production, help each other review achievements, write good autobiographies"... These are not only an affirmation of the spirit of life, struggle, and tireless labor of the cadres, engineers, and workers who worked at the blast furnace in the past. These remnants are still silently "telling stories" to the next generation, about a glorious time of fiery struggle alongside the nation.

Leading us on a tour of the Hai Van Resistance Blast Furnace (NX3 Blast Furnace), Mr. Nguyen Danh Tuyen, 75 years old, a resident of Doi De neighborhood who has looked after the site for the past 30 years, shared: “In 1962, my father took me into the blast furnace for the first time. Although the people had left, the machinery remained. The feeling at that time was truly overwhelming because I saw firsthand the machinery and equipment installed inside. I kept wondering how they could have brought so much machinery into the cave and operated such a large-scale blast furnace for such a long time… The overwhelming feeling and admiration were certainly not just for me, but for anyone who visited the Hai Van Resistance Blast Furnace during those years. Like a foreign scientist who visited here exclaimed, ‘It’s truly magnificent beyond our imagination.’ As a soldier who experienced battle, I believe that it was these seemingly impossible ‘greatness’s” that created the strength for the entire nation.” "Our people are heading towards the day of final victory."

Text and photos: Khánh Lộc

Source