75 Years Supporting The Department Of Energy

With a company history of 75 years supporting the Department of Energy (DOE), Day & Zimmermann and Mason & Hanger together have provided Architecture and Design (A/E) services to protect national security assets that include Category I Special Nuclear Material in research, development, and manufacturing environments.

Mason & Hanger is proud to be the longest operating American A/E Firm. In 1947, Mason & Hanger (pre-acquisition) designed (A/E) the Pantex Plant and performed the A/E work at the plant from 1956 to 2001. That same year, Mason & Hanger started working at the plant and design for the Nevada Nuclear Weapons Test Site began.

In 1952-1956, Mason & Hanger served as A/E for AEC’s Nevada Test Site for nuclear weapons, developing some of the nation’s leading technologies for designing structures to resist dynamic loading. The structures include 300’ and 500' detonation towers and Gravel Gerties.