China's CHIEF1900 Pushes Hypergravity Research to a Record 1,900 g-tonnes

A Record Machine Beneath Hangzhou

Fifteen meters beneath Zhejiang University's campus in Hangzhou, China has installed a centrifuge with a capacity of 1,900 g-tonnes, the highest reported for a hypergravity research machine. Called CHIEF1900, it was delivered on December 22, 2025, and its installation was completed late that month. Its purpose is to let scientists study enormous structures and slow environmental changes through smaller experiments conducted under extreme forces.

Shanghai Electric Nuclear Power Group built the machine for the Centrifugal Hypergravity and Interdisciplinary Experiment Facility, or CHIEF. The project was approved in 2021 with a budget of 2 billion yuan, approximately $285 million, and developed over five calendar years through 2025.

CHIEF1900 follows the university's CHIEF1300, which came online in September 2025 with a capacity of 1,300 g-tonnes. That machine had surpassed the approximately 1,200 g-tonnes available at the US Army Corps of Engineers facility in Vicksburg, Mississippi. The latest installation puts China's two machines at the top of the reported global capacity rankings.

Engineers intend to use the facility to examine dam failures, earthquakes, landslides, pollution moving through soil and the behavior of materials under demanding conditions. Instead of waiting decades to observe a foundation settling or a contaminant spreading underground, researchers can recreate selected processes in a controlled laboratory.

As of March 17, 2026, construction and installation are complete, and the machine has been described as operational. Peer reviewed experimental results from CHIEF1900 have not yet been published. Its scientific performance and the accuracy of its predictions will be assessed through experiments and their published findings; no publication date has been given.

What Does 1,900 g-tonnes Mean?

CHIEF1900's capacity is expressed in g-tonnes, a measurement that combines two things: the acceleration applied to a sample and the sample's mass. The letter g represents Earth's normal gravitational acceleration. A sample experiencing 100 g is subjected to acceleration 100 times that normal level.

A capacity of 1,900 g-tonnes corresponds to applying 1,900 g to a sample weighing one metric ton. The combined measurement matters because researchers need to know both how strongly a machine can load an experiment and how much material it can carry. Larger models and stronger acceleration both place demands on the equipment.

A household washing machine provides a familiar comparison. Its most aggressive spin cycle produces no more than about 2 g-tonnes, compared with CHIEF1900's 1,900. Using those figures, the research machine's combined capacity is about 950 times greater, nearly one thousand times the washing machine figure.

CHIEF1900 also increases capacity by approximately 46 percent over CHIEF1300. The difference between 1,900 and 1,300 g-tonnes is 600 g-tonnes. That extra capacity allows researchers to work with larger models or harsher loading conditions, with the prospect of cleaner measurements during sensitive experiments.

Zhejiang University's complex contains multiple centrifuges and six specialized testing chambers. The investment therefore supports a research facility with several kinds of experiments, including simulations of active earthquakes under extreme gravitational conditions. CHIEF is described as one of four major dynamic centrifuge complexes worldwide with that capability.

How Rotation Makes a Small Model Behave Like a Large Structure

CHIEF1900 generates its experimental conditions by spinning samples attached to massive rotating arms. As the rotor turns, samples experience an outward force that acts like stronger gravity within the experiment. Researchers can then observe how soil, water, structures and other materials behave under that loading.

The scientific explanation draws on the equivalence between gravitational acceleration and inertial acceleration, a principle associated with Albert Einstein's theory of general relativity. In simple terms, acceleration can produce effects that resemble those of gravity. The centrifuge uses rotation to create an environment far more demanding than ordinary conditions at Earth's surface.

A dam model illustrates why that is useful. A wall three meters tall, tested at 100 g, can experience structural stresses corresponding to those in a full sized dam 300 meters tall. Increasing the acceleration compensates for the model's smaller dimensions, letting scientists investigate a structure that would be far too large to bring into a laboratory.

Researchers use established scaling laws to connect the model with the structure it represents. Those rules describe how size, loading and time relate in an experiment. They make it possible to study crack formation and foundation settlement in hours instead of following the corresponding behavior over decades.

Space and time compression, in this setting, means bringing large distances and lengthy physical processes within practical experimental limits. The machine provides a way to observe changes that are normally too slow, too large or too difficult to measure directly, while keeping the test controlled and observable.

From Approval to the New Capacity Record

Zhejiang University's CHIEF project moved from approval in 2021 to successive centrifuge milestones in 2025. Shanghai Electric Nuclear Power Group, a manufacturer with experience in heavy engineering and nuclear systems, constructed CHIEF1900 as part of that development.

The main dates show how quickly the capacity record changed during the final months of the project:

• 2021: The CHIEF project received approval with a budget of 2 billion yuan, approximately $285 million.
• September 2025: CHIEF1300 came online at 1,300 g-tonnes, exceeding the roughly 1,200 g-tonnes of the US Army Corps of Engineers facility in Vicksburg.
• December 22, 2025: Shanghai Electric Nuclear Power Group delivered CHIEF1900 to Zhejiang University.
• Late December 2025: Installation of the machine with a capacity of 1,900 g-tonnes was completed.
• March 17, 2026: CHIEF1900 was described as operational, while publication of its peer reviewed experimental results was still pending.

CHIEF1300 had already demonstrated capabilities including reproducing pressures found at substantial seabed depths and simulating the effects of tsunamis measuring 20 meters on ocean floors. CHIEF1900 adds capacity for models and loading conditions beyond those of its predecessor.

The succession of the two machines marks a shift in the location of the world's largest hypergravity research equipment. Their value to engineering and environmental research will depend on the experiments they support, including whether model observations accurately describe the corresponding behavior of real structures and landscapes.

Why the Machine Sits 15 Meters Underground

Zhejiang University placed CHIEF1900 15 meters below ground to reduce interference from vibrations. Traffic, construction and natural seismic activity can disturb sensitive measurements. Researchers studying tiny movements need confidence that their instruments are recording the sample's behavior rather than motion arriving from outside the experiment.

Soil liquefaction is one example of a process requiring close observation. During an earthquake, soil can lose the strength needed to support structures and behave more like a fluid. A controlled centrifuge experiment lets researchers examine that change alongside the movements of foundations or other structures.

Concrete experiments present another measurement challenge. Small fractures can appear before a structure fails. Detecting those changes under extreme loading requires a stable setting, especially when the deformation being measured is minute.

The underground location works alongside precision balancing mechanisms within the centrifuge. Slight differences in how samples are arranged can produce unwanted oscillations during rapid rotation. Balancing protects the quality of measurements and helps prevent severe mechanical failures caused by an uneven rotating load.

Zhejiang University assembled a specialized team spanning civil engineering, automation, thermodynamics and environmental science to address these demands. At this scale, many standard engineering approaches were insufficient. Components had to withstand rapid motion while keeping complex experiments stable and controlled.

Keeping Extreme Rotation Cool

CHIEF1900's rapid rotation creates heat through friction and air resistance. If temperatures rise too far, they can affect the machine's stability and change the properties of the material being tested. Temperature control therefore serves both the equipment and the experiment.

Engineers developed a vacuum based temperature control system combining liquid coolant circulation with forced air ventilation. The arrangement is intended to maintain stable operating temperatures during rapid rotation, when heat management becomes particularly demanding.

The system incorporates specialized glacial refrigerant fluids and a flange described as having the largest diameter used for such applications. A flange is a connecting rim that joins parts of an assembly. Its scale forms part of the engineering needed to support this unusually large cooling system.

Cooling and vibration control address different problems with the same practical consequence: researchers need the experiment to behave as intended. A sample warmed by the machinery or disturbed by an uneven rotor could respond differently from the conditions scientists set out to study.

The completed installation brings together these thermal, mechanical and measurement systems. Building a machine able to rotate samples weighing multiple tonnes while reaching a combined capacity of 1,900 g-tonnes required coordinated work across the project's engineering disciplines.

Testing Disasters Without Putting Communities at Risk

CHIEF's six specialized testing chambers cover slope and dam engineering, seismic geotechnics, deep sea engineering, deep earth environmental studies, geological processes and materials treatment. Each research area involves physical behavior that can be difficult, dangerous or impractical to study at full scale.

Dam engineers can investigate how a structure responds to a major earthquake, including the behavior of its foundations and the formation of cracks. Slope experiments can examine failures during extreme rainfall. Underground structures can be tested for their response to seismic waves.

Tunnels, mountain highways and coastal defenses are among the infrastructure models that can undergo trials combining extended service conditions with severe weather or earthquake loading. Engineers can use the observations to examine failure mechanisms and safety margins before construction begins.

CHIEF also supports studies of railway tracks designed for high speeds and their interaction with the surrounding ground after millions of load cycles. Repeated loading, vibration, settlement and resonance can affect passenger comfort and maintenance schedules. A controlled model gives researchers a way to follow those processes without waiting through years of railway operation.

These experiments connect observations of small physical changes with decisions about large structures. A crack, a shifting foundation or a weakening slope can be studied as it develops, helping researchers understand the sequence that leads to damage or failure.

Following Pollution and Energy Resources Underground

Pollutants moving through soil provide another use for accelerated experiments. CHIEF can track how contamination passes through different layers and into aquifers, the underground formations that hold water. Such movement can threaten drinking water supplies far from the original polluted area.

Researchers aim to observe in days processes corresponding to decades, centuries or even thousands of years. Hypergravity can accelerate the separation of fluids and solids, allowing experiments on contaminant migration and the performance of cleanup strategies over extended periods.

Environmental tests can supply measured evidence for regulatory decisions and remediation plans. Computer models can predict how pollution might spread, while physical experiments provide observations against which those predictions can be checked. Conventional field observation often cannot cover the timescale needed for these questions.

Deep sea experiments include the behavior of natural gas hydrates and methods for extracting methane hydrates. These studies examine energy resources under the pressures found beneath the sea, alongside the stability of the surrounding environment.

Underground caverns proposed for nuclear waste storage can also be studied for behavior over millennia. Geological carbon storage is another application: researchers can investigate the stability of sites intended to retain carbon underground. Both involve decisions whose consequences extend far beyond a normal construction or monitoring period.

Energy extraction, carbon storage and waste containment involve different materials and objectives, yet all require a detailed understanding of what happens below the surface. CHIEF's combination of pressure, acceleration and model testing is intended to bring those otherwise inaccessible processes into view.

Chen Yunmin's Vision for Shared Research

Chen Yunmin, chief scientist for the CHIEF project and a professor at Zhejiang University, has described a scientific ambition extending across extremely small and large scales. He said the team wants to study processes ranging from rapid events to changes lasting tens of thousands of years:

We aim to create experimental environments that span milliseconds to tens of thousands of years, and atomic to kilometre scales, under normal or extreme conditions of temperature and pressure. It gives us the chance to discover entirely new phenomena or theories.

CHIEF operates as a shared research platform, inviting researchers from universities, research institutes and industry in China and internationally to conduct experiments. The team has encouraged international collaboration, with an approach comparable to the shared use of major telescopes and particle accelerators.

The facility's range allows different research disciplines to use the same major infrastructure. Civil engineers can investigate foundations and earthquake damage, environmental researchers can follow contamination, and materials scientists can examine treatment and behavior under extreme conditions.

CHIEF1900's engineering completion gives those researchers a larger experimental capacity than its predecessor. The next stage is scientific validation through measured results, publication and comparison of model predictions with the behavior they represent.

As of March 17, 2026, the central achievement is the installation of a machine with a reported capacity of 1,900 g-tonnes, supported by underground vibration isolation and specialized cooling. Its broader contribution will take shape through the experiments conducted by the researchers who use it.

The Essentials

• CHIEF1900 at Zhejiang University in Hangzhou has a reported capacity of 1,900 g-tonnes, corresponding to 1,900 g applied to a sample weighing one metric ton.
• It exceeds CHIEF1300's 1,300 g-tonnes by approximately 46 percent and the roughly 1,200 g-tonnes of the US Army Corps of Engineers facility in Vicksburg.
• Shanghai Electric Nuclear Power Group delivered the machine on December 22, 2025. Installation was completed late that month, 15 meters underground.
• The CHIEF project was approved in 2021 with a budget of 2 billion yuan, approximately $285 million, and developed over five calendar years.
• Six specialized testing chambers support research into dams, slopes, earthquakes, deep sea conditions, underground environments, geological processes and materials.
• Applications include railway settlement, pollution migration, methane hydrate extraction, nuclear waste storage and geological carbon storage.
• A vacuum based cooling system, liquid coolant circulation, forced air ventilation and precision balancing support stable experiments.
• The facility welcomes researchers from China and internationally. As of March 17, 2026, peer reviewed results from CHIEF1900 had not yet been published.