Peggie'S Bell

Peggie's Bell is a shell whose geometry is designed to be an acoustic resonating chamber activated by the human voice for the use of singers, choral groups, and others on campus seeking a place for conversation, contemplation, and playing with sound. The reflective surfaces and varied acoustic focal points immerse participants in resonant harmonic sound. The Bell is located on a part of the campus called the Sacred Grove, and adds to the ambience of that space. The Bell was constructed by students from Lehigh University College of Engineering and Lehigh University Department of Art, Architecture,and Design using a new technique derived from Catalan vault building methods brought to this region of the United States by Rafael Guastavino. Rather than forming two arches and then spanning between them with the shell in the traditional way, a single central arch was formed and the shell built outward from the central arch. The initial layer of the shell form was built off this central arch with exterior grade ceramic tile, placed edge to edge with quick setting gypsum mortar. Conventionally, the initial shell would have been strengthened by adding alternating layers of cement mortar and tile until sufficient strength was achieved in the Catalan method. In this case, we added all the cement mortar in one layer of about 2.5 inches (6.25 cm). Steel rods do double duty as visual formwork and as structural reinforcing. They are two or three feet apart, and don’t represent additional cost or weight relative to the savings in weight, cost, and time over additional layers of tiles. The shell form was designed to create multiple acoustic focal points in a curved space with a highly reflective surface. The remarkable resulting resonances were inspired by the antiphonal singing that takes place in the sweet spots of tiled subway vaults.