At the Three Gorges Dam, the ship, the water surrounding it, and the steel lifting frame don't move separately. They rise as one balanced system — 15,500 tonnes, vertical, enclosed, and precisely synchronized across the full 113 m water-level difference the dam creates on the Yangtze.

That scale of synchronized hoisting — not raw lifting capacity — is what makes the Three Gorges ship lift the largest and most technically demanding structure of its kind in the world.

113 m
Total lift height
15,500 t
Total moving mass
3,000 t
Ship capacity
169 m
Tower height (×4)
Phase 1 — The ship-chamber system
One mass, not a ship alone
The ship chamber measures 120 m long, 18 m wide, and 3.5 m deep. Once a vessel enters and the chamber is sealed, the ship, its supporting water, and the chamber's mechanical systems become a single moving mass of roughly 15,500 tonnes — the actual load the lift mechanism has to move.
Phase 2 — Rack-and-pinion hoisting
Four gear sets, four racks
The chamber is driven by four sets of open gear mechanisms that climb vertically along four racks fixed to concrete column walls — engineered with an oversize gear modulus of 62.667 mm and nut columns with a 1,450 mm pitch diameter to carry the load without excessive deformation.
Phase 3 — The four-tower support structure
Column-wall-column composite design
Four reinforced concrete towers, roughly 169 m tall, use a "column-wall-column" composite structural system purpose-built for heavy load-bearing capacity, minimal deformation, and the construction precision a rack-and-pinion system this size demands.
Phase 4 — Synchronized ascent
Levelling 15,500 tonnes across four lift points
Throughout the 113 m rise, the four gear-driven lift points must stay in continuous synchronization to keep the chamber level — any imbalance across a mass this size, moving this precisely, would compromise both the vessel inside and the structure itself.

Fifteen thousand five hundred tonnes rising in perfect synchrony — the ship, the water, and the steel frame moving together as one balanced system.

The Three Gorges ship lift cuts a dam transit that takes roughly four hours through the adjacent five-stage lock down to about 40 minutes — though the lock remains necessary for cargo vessels beyond the lift's 3,000-tonne capacity. As a reference case, it demonstrates that at sufficient scale, hydraulic and mechanical synchronization — not brute lifting force — is what actually moves thousands of tonnes safely and precisely.

For further reading, see Erection Engineering in Industrial Construction, including synchronized heavy-lift systems.

Related case studies: Shenghong Refinery Lift · Zhejiang Reactor Lift · ITER Tokamak Assembly

Sources: China Three Gorges Corporation — owner and operator: 3,000-tonne vessel capacity, 113 m lift height, 256 steel cables, and synchronisation held within 2 cm; KREBS+KIEFER — the German engineering firm that planned the lift, giving chamber dimensions and design history; Infrastructure Global — 15,500-tonne total lift weight. Figures are reported as published.

Frequently Asked Questions

The ship chamber, its mechanical systems, and the water inside it together weigh approximately 15,500 tonnes, all raised or lowered as a single synchronized mass. The chamber itself measures 120 m long, 18 m wide, and 3.5 m deep, and can carry vessels of up to 3,000 tonnes displacement.

The Three Gorges ship lift uses a rack-and-pinion, climbing counterweight-balanced design. The ship chamber is driven by four sets of open gear mechanisms that climb along four racks fixed to concrete column walls, engineered with an oversize gear modulus of 62.667 mm and nut columns with a 1,450 mm pitch diameter to handle the load and precision required.

The ship lift is supported by four reinforced concrete towers roughly 169 m tall, using a "column-wall-column" composite structural system designed for heavy load-bearing capacity, minimal deformation, and high construction precision.

The ship lift can move a vessel through the dam's full 113 m water-level difference in around 40 minutes, compared to roughly four hours to transit the adjacent five-stage ship lock — though the lock remains necessary for larger cargo vessels beyond the lift's 3,000-tonne capacity.