Making "Large Arch"
"Large Arch" stands nearly 20 feet tall, weighs 5 ½ tons, and is made from 40 to 50 welded bronze pieces.
To make "Large Arch," Henry Moore turned to the Hermann Noack foundry (Bildgiesserei Noack) in West Berlin. However, the process of making the bronze sculpture began at Moore’s studio in Hertfordshire, England.
The Sand Cast Process
"Large Arch" was made using the sand cast method for creating bronze sculptures.
The first step in the process is making a full-size model of what you will cast. For large or complex projects, the model is divided into smaller pieces. Each piece is then hollowed out to the desired thickness.
Using the piece from the model, a sand mold is created in two frames. One frame is fitted with two channels for pouring the bronze. With the frames together, bronze is poured into the mold. After the bronze has set, the frames are removed and the pour lines are knocked out.
The pieces are welded together, and the surface is finished.
Scaling Up in Polystyrene
Using Moore’s earlier sculpture "Large Torso" as their model, Moore’s studio assistants sculpted the much bigger "Large Arch" from polystyrene, a type of plastic.
Scaling a sculpture up from a smaller model is a common practice. Henry Moore, like many sculptors, began his studies for a sculpture on a small scale that could be manipulated easily. A small model would be enlarged, studied further, changed again and again, and, perhaps eventually, cast in its final form.
Evaluating the Size in Plywood
One concern the architects had about "Large Arch" was its size in relation to the surrounding buildings.
In December 1969, project architect Kenneth D.B. Carruthers traveled to Columbus to inspect a plywood mock-up of the sculpture set up on the library plaza.
In the two photos that Carruthers took, the plywood arch stands with Eliel Saarinen’s First Christian Church in the background and with the Irwin home.
Casting, Welding, and Finishing "Large Arch"
The sculpture was made at the Hermann Noack Foundry in what was then West Berlin.
The series of photographs show welders piecing together "Large Arch" and smoothing the seams. Moore visited the foundry to inspect "Large Arch."
Moore had first worked with the famed foundry in 1958, and, according to the Henry Moore Foundation, his relationship with the Noack foundry lasted until Moore’s death in 1986.
A Final Inspection
Once the sculpture was completed, it was moved from the Noack foundry and set up temporarily in Tiergarten, a large park in central Berlin. After seeing "Large Arch" standing upright in the park, Moore gave his final approval before it began its 9,000-mile journey to Columbus, Indiana.
These photos by Reinhard Friedrich are likely the first taken of the completed sculpture.