# DUNE cryostat construction begins a mile underground, using tank technology from LNG ships - Published: 2026-11-12 - Author: [Engineering News](https://engineeringnews.io/author/engineeringnews-io.md) - Topics: [News](https://engineeringnews.io/news.md) - About: Deep Underground Neutrino Experiment (DUNE), [Fermi National Accelerator Laboratory (Fermilab)](https://www.fnal.gov/) - Based on: [Construction begins on massive underground neutrino experiment designed to unlock the secrets of the universe](https://www.globenewswire.com/news-release/2026/11/10/3399817/0/en/construction-begins-on-massive-underground-neutrino-experiment-designed-to-unlock-the-secrets-of-the-universe.html), GlobeNewswire, 2026-11-10 - Based on: [LBNF/DUNE Cryostats and Cryogenics Infrastructure for the DUNE Far Detector, Design Report](https://arxiv.org/abs/2312.09104), arXiv, 2023-12-14 - Based on: [Excavation of colossal caverns for Fermilab's DUNE experiment completed](https://sanfordlab.org/news/excavation-colossal-caverns-fermilabs-dune-experiment-completed), Sanford Underground Research Facility, 2024-02-01 - Source: https://engineeringnews.io/news/dune-cryostat-construction-underground-south-dakota/ - Publication: Engineering News - Publisher: Connectively (Terkel, Inc.) - Editorial policy: https://engineeringnews.io/editorial-policy/ - AI use: Connectively's automated system wrote this article with AI from a press release issued by Fermilab on November 10, 2026, linked under Sources. Statements about the company and its products are the company's. The illustration was generated with AI. The article was assembled and published automatically, without an editor's review. Report errors to corrections@connectively.us. DUNE cryostat construction began in early November nearly a mile underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota. Crews from Fermilab, CERN and SURF are erecting the steel shells of two insulated tanks that will each hold about 17,000 tons of liquid argon at roughly minus 300 °F. ## Key points - Fermilab announced on November 10, 2026, that installation crews had begun building the two far-detector cryostats for the Deep Underground Neutrino Experiment (DUNE) in SURF's South Cavern. - The two cryostats will use 2,600 steel beams, each carried down from the surface one at a time; the more than 6,200 tons of steel are an in-kind contribution from CERN. - Each cryostat measures 216 feet long, 62 feet wide and 60 feet high on the outside, according to Fermilab. - Steel for the second cryostat is already being lowered into the North Cavern, where Fermilab says assembly is expected to start next year. - Fermilab plans to finish the underground space by 2029, the detectors in 2030, and to send the first neutrino beam to South Dakota by 2031. ## What kind of tank holds 17,000 tons of liquid argon? A membrane cryostat, the same containment technology used to store and ship liquefied natural gas (LNG). In the 2023 [LBNF/DUNE cryostat design report](https://arxiv.org/abs/2312.09104), Fermilab and CERN engineers describe a sealed liner of corrugated type 304L stainless steel only 1.2 mm thick, whose folds absorb the shrinkage and growth that come with cooling to argon temperature. The liner hands its load outward. The [design report](https://arxiv.org/abs/2312.09104) passes it through 0.8 m of polyurethane foam insulation, a thin aluminum-and-fiberglass secondary barrier that holds the argon if the main liner leaks, a 12 mm steel plate that keeps water vapor out, and finally a room-temperature frame of 1.1 m tall I-beams. That insulation limits the heat entering each cryostat to 48.7 kW, a level the report calls acceptable. The loads that frame takes are large: the [same report](https://arxiv.org/abs/2312.09104) puts about 20 t/m² on the floor and roughly 8 kt of hydrostatic force on each long wall. The steel frame was designed mainly with ANSYS finite element analysis to Eurocode 3, checked against U.S. codes through a safety equivalency review. The project picked [Gaztransport & Technigaz (GTT)](https://www.gtt.fr/), a French supplier of LNG membrane systems, for the cryostat design. ## How is DUNE cryostat construction done a mile underground? Piece by piece. SURF runs the shaft and logistics, sending every beam and the installation equipment down to the work site 4,850 feet below ground, and CERN leads the cryostats' design, construction planning, logistics and installation, working with a structural steel contractor from Minnesota, Fermilab says. The [design report](https://arxiv.org/abs/2312.09104) explains why the frame was drawn that way: every component can be bought and prepared on the surface, ready to go down the shaft, so steel erection does not depend on the civil works in the caverns. Those caverns are already dug. [SURF reported in February 2024](https://sanfordlab.org/news/excavation-colossal-caverns-fermilabs-dune-experiment-completed) that close to 800,000 tons of rock had been removed to make them. > We have been lucky to see several milestones occur recently, such as the arrival of steel for both cryostats in Rapid City from Houston, to the celebration earlier this year marking the start of steel being lowered underground in Lead. > > — Jolie Macier, Project Manager for the Far Detectors and Cryogenics, DUNE ## When will DUNE start taking data? Fermilab expects the detectors to be complete in 2030 and the neutrino beam to reach South Dakota by 2031. The beam will come from Fermilab in Illinois, 800 miles away, driven by the laboratory's PIP-II accelerator upgrade; a second, nearer detector at Fermilab will measure the particles as they set out. Together, the two sites make up the Long-Baseline Neutrino Facility, and DUNE's collaboration counts more than 1,500 researchers. > This massive experiment is slated to run into the late 2040s, with the potential to impact science for generations. > > — Mike Headley, Laboratory Director, SURF, and Executive Director, South Dakota Science and Technology Authority ## What can engineers take from the DUNE cryostats? Our analysis: DUNE is a case of commercial cryogenic hardware moved into a place it was never designed for. The [design report](https://arxiv.org/abs/2312.09104) treats GTT's packaged insulation panels as a "cryostat in a kit", and the warm steel frame as a structure that can be prepared on the surface and lowered through the shaft. For structural, cryogenic and underground-construction engineers, that combination is the lesson: when the only way into a site is a mine shaft, the design has to be broken into pieces the shaft can carry before it is drawn as a whole. It is also a test of transatlantic delivery. Fermilab says this is the first time CERN has contributed on this scale to an experiment outside Europe, with CERN supplying the steel, the design and the installation management for a vessel built in South Dakota. ## Frequently asked questions ### How far underground are the DUNE cryostats? They are being built 4,850 feet (1,478 meters) below the surface at SURF in Lead, South Dakota, according to SURF. ### Who supplied the steel for the DUNE cryostats? CERN. The more than 6,200 tons of steel are an in-kind contribution from the European laboratory, Fermilab says. ### How long is each DUNE cryostat? 216 feet (65.8 meters) on the outside, according to Fermilab, with an inside length of 62.0 m in the [2023 design report](https://arxiv.org/abs/2312.09104). ### When does work on the second cryostat start? Its steel is already going down into the North Cavern, and Fermilab says assembly there is expected to begin next year. ## Sources - [Construction begins on massive underground neutrino experiment](https://www.globenewswire.com/news-release/2026/11/10/3399817/0/en/construction-begins-on-massive-underground-neutrino-experiment-designed-to-unlock-the-secrets-of-the-universe.html): press release from Fermilab via GlobeNewswire, 10 November 2026. - [LBNF/DUNE Cryostats and Cryogenics Infrastructure for the DUNE Far Detector, Design Report](https://arxiv.org/abs/2312.09104): design report by Fermilab and CERN engineers for the LBNF/DUNE project, posted to arXiv on 14 December 2023. - [Excavation of colossal caverns for Fermilab's DUNE experiment completed](https://sanfordlab.org/news/excavation-colossal-caverns-fermilabs-dune-experiment-completed): news from the Sanford Underground Research Facility, 1 February 2024. - [Gaztransport & Technigaz](https://www.gtt.fr/): the cryostat designer's website.