The Hengtong Group terrestrial cable project in Zhoushan has achieved a historic milestone by completing China’s first terrestrial cable crossing between two islands. The 10 kV, one‑kilometer‑long cable now connects Zhoushan and Shangyuanshan Islands in Zhejiang Province, marking a major leap in the country’s island‑to‑island energy transmission technology.
According to China Daily, traditional inter‑island power transmission in China relies on submarine cables. However, coastal regions like Zhoushan experience high ship traffic and dense waterways, increasing the risk of anchor damage to undersea lines. To overcome this challenge, the Hengtong Group worked with the State Grid Zhoushan Power Supply Company to design a deeper‑buried terrestrial cable system—a safer and more durable method for energy transfer between islands.
Li Zhen, head of the project’s design team, explained that the team aimed to reduce both costs and construction complexity by adopting a terrestrial approach. They created a pre‑laid channel beneath the seabed, ensuring the cable remained stable and fully protected.
To minimize tension and friction, engineers used a wire rope traction system, forming a type of “exoskeleton” around the cable. They also applied pipeline lubrication materials during installation to reduce drag. Together, these measures ensured the cable’s integrity throughout the laying process and boosted installation efficiency.
Zhen stated that this technology could be applied widely to islands separated by short or medium distances of up to 2 km. Over time, the approach could scale to longer connections across broader stretches of China’s coastline. The successful Hengtong Group terrestrial cable project in Zhoushan sets a precedent for future island‑linking projects and supports the country’s goals for improved coastal energy networks.
Learn more about Hengtong Group’s latest projects at hengtonggroup.com.