The morning sun shines on the magnificent Jinghong Dam as a passenger vessel， 20.1 meters long， 4.1 meters wide and weighing in at 24.8 tons， is carried across the dam by a ship elevator， before continuing its journey upstream.

On Dec. 18， 2016， China's first independently developed hydraulic shiplift began operation at the Jinghong Hydropower Station in Xishuangbanna， Yunnan Province. It enabled vessels to be lifted across the dam for the first time， marking not only a substantial advancement in ship-lifting technology but also a resumption of the waterway that links China’s Simao Port to Thailand’s Chiang Saen via Laos and Myanmar.

Technological Breakthroughs

“The shiplift overcomes the problem of vertical instability， making the ship-lifting operation safer， more stable and more economical，” said Cao Yinan， vice chief engineer at the Kunming Survey and Design Institute of the Power Construction Corporation of China （POWERCHINA）.

In terms of both size and technological advancement， the shiplift leads its peers around the world. As the first new-type shiplift independently developed by China， it marks a bold attempt in the development of high-dam navigation technology.

But such achievements did not come without difficulty. To maximize its safety， senior engineers Li Zichong and Ma Renchao from the Kunming institute， alongside Professor Hu Ya’an from the Nanjing Hydraulic Research Institute and Professor Wu Yihong from the China Institute of Water Resources and Hydropower Research， devoted painstaking effort to overcome technological bottlenecks concerning flow control and the braking system， so as to enable the shiplift to adapt to quickly-changing downstream water levels.

The safety of shiplifts is an issue of wide concern for people from both inside and outside the industry.

Compared to traditional lift locks， the hydraulic shiplift is hydraulic-driven and does not use the traditional electric method， which is more complicated. The hydraulic system has not only simplified its controlling systems， but also enhanced its safety， reliability and adaptability by avoiding the risk of power cuts. It represents a new type of energy-conserving and environmentally-friendly shiplift. The hydraulic shiplift was designed to be able to maintain balance even when the vessel it lifts leaks or capsizes.

Designed by the Kunming institute of POWERCHINA， the ship elevator took 12 years to complete. The first of its kind， it is a symbol of China’s original technology in the hydropower sector. It is capable of lifting ships weighing up to 500 tons. The entire lift process takes 17 minutes， and it is estimated that it can carry more than 1.2 million tons of cargo annually.

Lancang-Mekong Navigation

“As soon as the Jinghong Hydropower Station was completed， we began to seek the safest and most economical method for ships navigating along the Lancang River to cross the dam，” Cao said. “As the hydraulic shiplift began operation， we fulfilled our promise to resume navigation of the river.”

The shiplift began on-site debugging in 2011， and overcame all technological problems in 2015 after several years of careful testing. It was officially put into operation in 2016 after passing national authentication requirements.

“In addition to resuming navigation， the ship elevator also improves navigability downstream through water level adjustment. This allows vessels to avoid submerged rocks and reefs，” Cao added.

When a vessel approaches the dam of the Jinghong Hydropower Station from downstream， it enters a type of lock gate known as a caisson. The gate facing the lower reach is locked. The caisson ascends until its water level reaches that of the upper reach. Then， the gate on the opposite end of the caisson opens， and the vessel reaches the upstream part of the river.

The Jinghong Hydropower Station is the sixth of a series of eight hydropower stations constructed in the middle and lower reaches of the Lancang River. Its total installed capacity is 1，750 megawatts， and each generating unit has an installed capacity of 350 megawatts. As the third hydropower station that has begun operation along the Lancang River， it is a key project of China’s “Western Development Strategy” and “West-to-East Power Transmission Program.”

The hydropower project also houses the first generating unit that was put into operation in Yunnan Province during the 11th Five-Year Plan Period （2006-2010）. In the very beginning， the hydropower hub was designed according to the standards of a Class-V Waterway， which enabled 300-ton vessels to cross the dam. Currently， vessels below 500 tons can easily cross the dam with the help of the hydraulic shiplift， which operates free of charge， 24 hours a day. This enables easy travel to Thailand or the hydropower stations along the Nam Ou River in Laos by boat.

The international Lancang-Mekong River navigation improvement plan for 2015-2025， formulated by China， Myanmar， Laos and Thailand， aims to make the river more navigable for 500-ton cargo ships sailing the 890-kilometer international waterway from Simao Port in China’s Yunnan Province to Luang Prabang in Laos.