‘S’ for success at historic S-Site

Rebuilding history at the Lab’s national park

May 1, 2022

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The cultural resources team measures S-Site walls Los Alamos National Laboratory

Established in 2015 as a partnership between the National Park Service and the U.S. Department of Energy, Manhattan Project National Historical Park tells the story of one of the most transformative events of the 20th century.  

S-Site, before preservation work
S-Site, before preservation work

Several Los Alamos National Laboratory original structures are a part of the park. When the Manhattan Project came to Los Alamos, its leaders developed a high-explosives area away from the primary technical area near an old sawmill site, where a large pile of sawdust remained from former lumber operations. Thus, this location received its name: “S-Site,” or “Sawmill Site.”  

Today, this landscape is vastly different. One of the remaining structures is a one-story, single-room storage building, known as a “magazine.” The structure comprises a reinforced-concrete floor and walls with a wooden roof. A protective earthen berm encircles the magazine.  

The cultural resources team created a rehabilitation plan to save this structure through disciplined operations and a focus on site longevity. According to historic buildings specialist JT Stark, maintaining the wood plank decking was a high priority since the original construction crew used it to form the concrete walls. The remnants of the magazine’s original concrete are still visible on the ceiling. The team made sure this part of the structure was protected from weather hazards and replaced the roof. LANL carpenters reconstructed wooden wing walls based on the original dimensions and design plans from the Manhattan Project.  

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S-Site, after preservation work

“When conducting our research on these Manhattan Project structures, we found that most were covered with a green colored, triple-sealed gypsum board,” said historic buildings expert Jeremy Brunette. Needing to protect the gypsum board from the weather while eliminating the asbestos hazard, the team covered the gypsum board with modern wooden shingles. They also recreated the visual accuracy of the building by painting the exterior the same green used during the war years.
Although the building has been safely rehabilitated, maintenance work will continue to ensure future generations are able to see this piece of history as it appeared in the past. The cultural resources team is in the process of rehabilitating other structures across the Lab, including V-Site, the Q-Site High-Speed Photography building, and the Quonset Hut. The preservation projects’ ongoing successes are the result of extensive collaboration among park leaders and many craft specialists, insulators, carpenters, painters, operators, laborers, sheet metal workers and roofers. 

Want to know about the art and science of Manhattan Project preservation? Check out this month’s Periodic Table on May 16 at the Bathtub Brewing Co-op in Los Alamos, featuring the Lab’s cultural resources team.