In the mid-19th century, American inventor Thaddeus Hyatt sought a way to illuminate spaces below ships’ decks—a safer way, that is, than the lanterns, torches, or other open-flame light sources that led to fires on the vessels of the pre-electric era.
Hyatt’s solution? Transparent glass prisms set into ship decks. The thick glass would be sturdy enough to bear weight while still transmitting light to the storage areas and quarters below deck. The small glass blocks—which would eventually become known as vault lights—eliminated some of the need for open flames during daylight hours, making ships that much safer.
It wasn’t long before the growing cities of Europe and North America adopted this embedded glass floor idea to illuminate urban spaces below sidewalk level—also known as sidewalk vaults. These vaults served as storage spaces, tunnels, and even apartments. Though useful, as one would expect, these spaces were windowless and exceptionally dark before the widespread adoption of electricity.
From Ship Decks to City Streets: Glass Blocks Light Up Vault Spaces
Cities installed vault lights in sidewalks from the 1860s through the 1930s to solve the problem of dark vault spaces. The glass prisms were often set into sidewalk concrete or interlocking discs of cast iron that would cover several feet of sidewalk space and illuminate the vault spaces. The top of these prisms (also known as “bullet glass”) often featured a flat surface that lay flush with the sidewalk. Other bullet glass prisms featured a slightly rounded top surface. Glassmakers often cut the lower part of each glass unit at an angle to disperse light throughout the vault space, including far, dark corners.
Visitors to many U.S., Canadian, and European cities can still see these beautiful artifacts—the glass often tinged gold or purple with age—on an occasional sidewalk.
Vault lights were a commonly used building material from the 1860s through the 1930s. They became largely obsolete with the invention of electricity, and as the materials broke down over time, many vault lights were eventually paved over. However, preservation-minded groups and individuals have sought to reclaim or replace these beautiful and functional panels. What’s more, architects, designers, and property owners are adopting new iterations of vault lights with an appreciation for their nostalgic appeal and contributions to sustainability and energy preservation.
Vault Lights Re-created, Improved, and Versatile
Are you looking for a replacement for vintage vault lights or a way to add exciting ground-level illumination to a new project? With design and technology we have honed over five decades, Circle Redmont offers an array of vault light products. Architects and designers have used our vault lights in projects from sidewalks to stairs, landings, bridges, and more. We offer panels and products suitable for interior and exterior applications to illuminating and beautiful effects.
Designed for varied uses, our vault light products, even those made of cast iron, composite concrete, and steel, are light enough to be used in vertical applications or overhead as skylights or barrel vaults.
Circle Redmont custom-fabricates our composite concrete and cast iron panels to your specifications for a truly customized result. Circle Redmont invites you to reimagine how to use beautiful and contemporary vault lights.