To bring the Dragon Bridge to life and showcase its form and spirit, the mesmerizing journey of fire and water over the past decade has added to its allure, creating a unique impression whenever someone mentions the one-of-a-kind dragon spanning the poetic Han River. Few people know that the "father" of the water-spraying performance on the Dragon Bridge is engineer Phan Dinh Phuong, who poured his heart and mind into transforming water into misty streams that extend over 350 meters into the air.

Dragon Bridge spraying water. Photo: Archive

How is water delivered to the Dragon's mouth?

Chatting with engineer Phan Dinh Phuong, Director of An Sinh Xanh Science and Technology JSC, it was surprising that, contrary to the thought that engineers are dry, reticent technical professional, engineer Phuong speaks with a soft, almost poetic tone, choosing words as if crafting a melody. Occasionally, to ease the tension of a conversation between strangers, he spontaneously sings sweet, soulful songs. Amused, he shares that although he has no formal training in music theory or literature, he has composed several songs and published a poetry collection titled "The day! Tinh yeu" (That’s It! Love). Now, at the age of seventy, he spends his days inventing. He remarks with a chuckle that the "calling" of invention seems embedded in his very being—something he finds impossible to abandon.

Pausing for a moment, I brought up the story from late February 2013, when Party Secretary Nguyen Ba Thanh approached him with a request to invent a system for the Dragon Bridge to spray water. The Secretary knew of him because his reputation had already spread internationally thanks to his invention, the "AFFA 1,500" firefighting device, which could transform one liter of water into 1,500 liters of mist. This groundbreaking invention earned him four exclusive patents from the Vietnam Intellectual Property Office and the United States Patent and Trademark Office (USPTO). Additionally, it was tested, announced, and endorsed by the World Intellectual Property Organization (WIPO), gaining recognition and approval from 147 countries.

Continuing the story, he recounted slowly that at the time, the Dragon Bridge had been completed, and the fire-breathing mechanism was nearly perfected. However, the water-spraying system posed a significant "question mark". Under the scorching midday sun, as he stood observing the world's largest steel bridge, he pondered how to elevate water to the Dragon's mouth and ensure that when it was released, it would achieve an artistic effect with just the right "height" and "trajectory" to captivate viewers fully.

Thinking that way was one thing, but when he began the work, countless challenges and thousands of unexpected problems arose, nearly forcing him to abandon the project. He described that to supply water to the Dragon's mouth, the first requirement was a steel water tank approximately 15 meters long and 5 meters tall. Given the tight timeline, he searched the entire city but could not find anyone capable of fabricating it. In the end, he turned to a professor (whose name he preferred to keep private) teaching at the University of Science and Technology (University of Da Nang) for help. Fortunately, the professor agreed, and it took more than a week to craft the tank.

According to him, the tank was completed, but many people suggested galvanizing it to protect the steel structure and extend its lifespan. However, he rejected galvanizing because of its high cost and the lengthy process of coating and inspection. Instead, he thought of using asphalt. Asphalt adheres well, withstands high temperatures, and can endure water pressure. Without hesitation, he purchased asphalt, melted it, and applied it to both the interior and exterior of the tank. Next came the challenge of transporting and burying the tank beneath the head of the Dragon Bridge—a lengthy ordeal. He and his team worked tirelessly for an entire day and night before finally positioning the water tank correctly.

"The tank was ready, but where would the water come from? That raised many questions. Initially, there was a suggestion to use river water, but I dismissed it because over time, it would cause blockages in the pipes, and repairing or excavating the tank would not be easy. Therefore, I had no choice but to use the city's clean water. The problem was that the city's water pipes were located on the other side of Tran Hung Dao Street. To connect the pipes to the tank buried beneath the Dragon Bridge, my team and I had to dig up the road and splice the water pipes in the middle of the night. We spent the whole night patching and burying the pipes to meet the deadline. Then, with the tank and water ready, there was still a challenge: connecting the 0.4-meter diameter pipe to the Dragon's mouth, as the bridge had already been completed."

"Fortunately, between each span of the bridge, there were expansion joints. Taking advantage of this, I divided the large water pipe from the main tank into several smaller pipes, making it easier to thread them through the narrow expansion gaps and direct them into the Dragon’s mouth," recalled engineer Phan Dinh Phuong. He went on to say, "The water journey was basically 90% complete, and the remaining 10% was about transforming the water flow in the air to make it look beautiful and grand during the performance."

Engineer Phan Dinh Phuong

The "mist explosion water spray" technology

To be honest, he hesitated and said, this was his first time taking on a water spray invention project. Spraying water on an existing fire-fighting system is different from inventing water spray for fully completed structures. This was both a challenge and an opportunity for him to apply his imagination, without a laboratory, research room, or intermediaries. The same goes for Dragon Bridge water spray project. At the beginning, he didn’t know where to start; he just relied on his imagination to make it successful. Thanks to that, his imagination kept expanding, leading to the ideas that needed to be realized, and with that, he fixed problems and untangled knots one by one. The water spray invention on Dragon Bridge, as he initially envisioned, required the water to "fly", to "soar", just like white clouds in the sky, symbolizing the bright future of a flourishing city. Therefore, to ensure the water didn’t fall, become short, or break its path, he applied the technology of "mist explosion water spray".

“To make the technique successful, I ordered a three-piston air compressor. The air compressor was placed on the water tank to suck outdoor air and compress it at high pressure into the tank. Specifically, in the first piston, the air is compressed to 5at, which is then transferred to the second piston and increased to 10at, and then to the third piston, reaching 15at. This way, when the water is sprayed, it mixes with the air and turns into mist, traveling a long distance in a straight line. Unfortunately, if I had designed it from the beginning, I would have positioned the nozzle at a 45-degree angle for a further and more beautiful spray. By the time I took on the project, the bridge was already completed, and I had to lower the nozzle to a 30-degree angle to avoid touching the fire spray pipe. Due to time constraints, I didn’t have a chance to conduct a test spray. Fortunately, on the inauguration day, the leaders of the Party, the State, and the city attended and applauded when the water spray performance successfully debuted.”

“No one could have imagined that the Dragon could spray water, transforming it entirely into mist, rising high and traveling further than a single span of the 350-meter bridge, with a flow rate of 4,500 cubic meters of mist per minute. To this day, by his estimates, the Dragon Bridge has sprayed water over 5,000 times without a single incident,” he added.

It can be said that to make the Dragon Bridge truly come alive, during the past 14 years, fire and water performances have created a unique allure, leaving a distinct impression whenever someone mentions this one-of-a-kind Dragon. And it is thanks to engineer Phan Dinh Phuong, who poured his dedication into crafting the water’s explosive transformation into mist, adding vibrant colors to the city’s skies on weekends and during festivals and holidays, leaving a lasting impression on visitors from all corners of the globe.

Incessant Innovation

Beyond the successful water-spraying system for Dragon Bridge, at the age of 74, Engineer Phan Dinh Phuong considers his greatest life asset to be his inventions. Despite numerous challenges, he tirelessly conducts research every night, driven by the desire to create new, beneficial innovations for the community and society.

Reflecting on his journey, he shared that in his youth, he studied Petrochemical Engineering at Hanoi University of Science and Technology. Before completing his degree, he enlisted in the military and worked in the Fuel Department of the Logistics Bureau under the Air Defense and Air Force Command. His daily duties involved refueling planes with fuel, lubricants, and hydraulic oils. After the war, he left the military and returned to civilian life, taking a position at Da Nang Gas Plant.

During this period, he experimented and successfully invented devices such as acetylene generators made from limestone and coal for welding metals, as well as machines for producing fireworks for Tet celebrations. Later, he moved to work at the Da Nang Zone 5 Petroleum Company. There, he observed significant gasoline vapor loss during the transfer of fuel into large storage tanks. This inspired him to invent a gasoline vapor recovery machine. Most of his inventions focused on environmental protection, fuel conservation, and operations without the need for electricity.

The AFFA 1500 fire extinguisher he invented features groundbreaking technology that requires no external power supply. It operates without needing an engine, air compressor, foam, or downtime, ensuring it is always ready to extinguish fires immediately. Thanks to its effectiveness, the invention was elevated to become the National Fire Safety Standard TCVN7884:2008 and has been adopted by both the Ministry of Public Security and the Ministry of Defense. Additionally, he developed a gas vaporization machine and a gas cylinder washing device that operate entirely without electricity, which have been exported to countries such as India and Malaysia. Among his most notable successes is a proactive water supply system designed to safeguard nuclear reactors in the event of a complete energy blackout. This invention was introduced by the International Atomic Energy Agency (IAEA) and caught the attention of Mr. Toshimishu, President of the Japanese Nuclear Energy Federation (JINED Japan), who personally sought him out to study and implement the technology.

There was a time when the Land of the Rising Sun invited him to work there, but he declined and chose to dedicate his efforts to his homeland. His goal was to create more inventions that could serve the people and the nation. "There are no rules or boundaries for innovation. I believe that everything in life must be done with sincerity, accompanied by passion and dedication, to achieve success. I will continue to invent, to explore, and to strive to create even greater value," he said when gazing into the distance.

Reporting by HUYNH TUONG VY – Translating by HONG VAN