Ma Chaolong Photo: Courtesy of Longmen Grottoes

As the summer tourist season approaches, Ma Chaolong finds himself increasingly occupied, with growing visitor numbers presenting new demands to conservation efforts. 

Ma is a research librarian at the Longmen Grottoes Academy. The Longmen Grottoes is a UNESCO World Heritage Site with over 1,500 years of history. 

Located in Luoyang, in Central China's Henan Province, this marvel of Chinese stone carving art features 2,345 caves and niches. Initiated during the Northern Wei Dynasty (386-534) and flourishing in the Tang Dynasty (618-907), the grottoes reflect over 400 years of craftsmanship.

On any given workday, one could find Ma mapping the grottoes and monitoring their condition. Spotting moss on a statue, he noted with concern, "There's a leak here. Leakage can cause microbial growth, endangering the stone relics." This vigilance is central to his work, identifying risks to inform archaeological reports and guide protection efforts. 

The Guyang Cave, the earliest in the complex, holds special significance for him with its vivid statues and inscriptions. 

The Vairocana Buddha at the Longmen Grottoes Photo: IC

'Doctor' for grottoes 

The Grotto Conservation Center serves as a "hospital" for the Longmen Grottoes, with Ma as its "chief physician." He monitors the "health" of the caves, tackling issues like water seepage and unstable rocks. 

"When visitors admire the Vairocana Buddha, they see its beauty," Ma said. "But I check for potential risks." 

It sounds easy, but it's far from simple in practice. Knowing which caves are prone to water seepage, which parts of the cliff have unstable rocks - these are things one must keep in mind, and such knowledge can only "be gained through years of being with them day in and day out." 

Archaeological reports are like "writing histories" for each grotto, sorting out their origins and developments. 

Although the process is lengthy, they can scientifically and systematically preserve the complete information of the Longmen Grottoes, boasting permanent academic value.

Unlike other grottoes, he added, the rocks of the Longmen Grottoes are limestone, which is suitable for elaborate carving on the one hand, but increases the difficulty of protection on the other hand.

The protection of cultural heritage requires patience and care, as well as scientific professionalism. Only by combining traditional techniques with modern scientific and technological means can the principle of "restoring old as old" be guaranteed.

Technology meets tradition

When looking back, the first restoration for the Vairocana Buddha started in 1971 and lasted 15 years due to technical limitations at the time. 

Today, the Longmen Grottoes entered "restoration mode" again, and this time, the empowerment of technology has brought a qualitative leap to everything. 

In 2021, Fengxian Temple, the largest cave, was draped in scaffolding and protective nets, with cantilevered poles used to avoid wall damage. "We wanted visitors to still see Vairocana Buddha's smile," Ma explained. Using X-ray fluorescence spectrometers, his team discovered gold and silver elements, and pigment residues on the statue for the first time.

The stone statues of the Longmen Grottoes we see today all retain the original color of the stone. 

However, more than a thousand years ago, in the eyes of people in the Tang Dynasty, they were all colorful.

What's more, the rain-shielding stone slabs, drainage ditches, and other structures left by craftsmen back then, are still playing an important role in protecting the grottoes, demonstrating the wisdom of the ancients. 

Brillian craftsmen of the Tang Dynasty dug a "herringbone" drainage ditch above Fengxian Temple. They built a drainage network by following the natural slope of the mountain to drain surface runoff from rainfall. This idea of "using natural forces to solve natural problems" coincides with the concept of "environmental coordinated governance" in modern protection. 

In the current Fengxian Temple protection project, the team systematically analyzed the hydrogeological conditions of the entire area where the caves are located, and designed new drainage ditches connected to the original ones, enhancing the drainage capacity and realizing the integration of "ancient and modern drainage systems." 

Additionally, the lime plus glutinous rice adhesive used in the Song Dynasty (960-1279), when repairing the Buddha's pedestal, has been proven to have good air permeability and weather resistance. It still has important reference significance and provides valuable ideas for the research and development of modern restoration materials.

Modern technology has revolutionized Ma's work. In the past, people relied on the naked eye to "diagnose" cultural relics. 

Now, non-destructive tools like ultrasonic devices and portable microscopes diagnose issues, while 3D scanning and digital archives preserve detailed records. 

A monitoring system tracks environmental factors, and international collaborations with institutions like the University of Chicago enhance these efforts through technology sharing and research. 

For Ma, a 50-year-old craftsman, preserving the grottoes is a race against natural decay. "The core spirit lies in protection and inheritance," he said. "Inheritance means keeping them authentic; protection involves using traditional and modern means to ensure their survival." Through their dedication, the Longmen Grottoes endure as a vibrant link to China's cultural heritage.