As the Mid-Autumn Festival and National Day holidays approach, multiple large heavy-lift drones are taking off and landing in rotation at the Xiejiagou Bridge construction site within the Jinping Tunnel Group of the Xinjin section of the Yibin-Panzhihua Expressway, precisely hoisting steel bars, cement, steel frames, and construction machinery to a slope over one hundred meters high.

Construction workers are employing an innovative aerial operation model combining "cable cranes plus heavy-lift drones" to overcome the construction challenges of high mountain cliffs and to sprint toward the goal of opening the entire line to traffic by the end of the year.

The Xinjin section of the Yibin-Panzhihua Expressway features high mountains and deep valleys with extremely steep terrain, making construction exceptionally difficult. Among the challenges, the entrance of the Xinjie Tunnel in Xinshi Town, Pingshan County, Yibin City, has a vertical drop of approximately 260 meters on a sheer cliff face, equivalent to the height of more than 80 stories.

Due to extreme terrain constraints, large machinery cannot access the site, and traditional scaffolding transport methods are difficult to implement, becoming a major bottleneck restricting the progress of construction along the entire line.

To break through these construction difficulties, the Party member technical research team of Yanjiang Yijin Company conducted multiple on-site surveys and repeated simulations. Combining detailed geological data and inviting authoritative experts for review and verification, they innovatively adopted a combined transport system of "cable cranes plus heavy-lift drones," opening a new material transport channel at a height of over one hundred meters and clearing obstacles for high slope construction.

Amid the roar of drones, construction workers are operating on the high slope. At the Xiejiagou Bridge construction site, multiple heavy-lift drones are taking off and landing in rotation, precisely delivering steel bars, cement, steel frames, and construction machinery to the working face on the slope over one hundred meters high, with a maximum single-load capacity of 200 kilograms.

On the left-line high slope of the bridge, protective netting installation, scaffolding erection, and anchor cable construction are being carried out simultaneously. The human-machine coordinated aerial construction scene has become the most striking picture of hard work at the site.

According to Hu Jiang, the on-site drone project manager, the entire high slope treatment project relies on heavy-lift drones for material hoisting. This team of drone pilots, with an average age of 24, is staying at their posts during the holidays, hoisting 50 to 60 tons of materials per day on average, fully ensuring the continuous progress of cliff face construction.

During peak construction periods, 10 heavy-lift drones are operating simultaneously on site, with one drone taking off or landing every minute or so on average, greatly improving transport efficiency and effectively solving industry pain points such as difficult material delivery, high safety risks, and slow progress in high slope construction.

The multi-drone coordinated high-altitude operation model is truly rare in mountainous expressway construction. It is understood that the Yibin-Panzhihua Expressway is expected to open to traffic by the end of this year.

Once the project is completed, it will further improve the expressway network structure in the southern Sichuan and Panxi regions, break through regional transportation bottlenecks, shorten the travel time between Yibin and the Panxi region, and provide solid transportation support for industrial development, rural revitalization, and high-quality regional economic development along the route.