VICKSBURG, Miss. – Inventors from the U.S. Army Engineer Research and Development Center (ERDC) in Vicksburg, Mississippi, developed a groundbreaking innovation in window systems that are resistant to blasts, ballistics and forced entry threats.
Filed in September 2019 and granted in June 2024, the patent was developed by a team of engineers from the U.S. Army Corps of Engineers under the leadership of John Judson.
Judson’s team included Research Civil Engineer Jessica Vankirk, Research Civil Engineer David Senior, U.S. Department of State (DoS)-Physical Security Division-R&D Project Manager Craig Ackerman, and U.S. Department of State (DoS) Engineering Consultant Daniel Duke.
This innovative system combines a dual-panel design, with both an exterior and interior sliding glazing assembly, ensuring not only security but also operability. The window can open and remain closed with a latch pin lock without compromising its resistance to external threats, a key feature in critical infrastructure applications.
Each panel assembly is supported by a frame that includes several gaskets and threaded sleeves to receive bolts, creating a secure seal between the window and the building, preventing unauthorized entry or damage from blasts and ballistic impacts.
Innovation in Window Design for Security
The Hardened Operable Window Systems and Methods builds on earlier advancements made in protective window technology. It derives from key concepts within the 2020 patent, which laid the groundwork for creating blast-resistant windows using layered glazing techniques.
This earlier patent introduced the idea of using ballistic-resistant glass supported by durable frames, but the 2024 version significantly expands on it by incorporating a more sophisticated system of ball transfer units for smoother operability and enhanced gasket and bolt configurations for greater protection against forced entry. The 2024 patent thus represents a natural evolution of security glazing technology, offering improved functionality and resilience in high-risk environments.
Traditional window systems are typically either fully fixed or operable at the expense of strength. The hardened operable window system solves this by providing a solution that maintains high resistance to external forces while allowing the window to be fully functional for egress and return-fire capability. This is especially useful in military installations, government buildings, and critical infrastructure, where ventilations and visibility are essential but so is protecting the occupants from potential external threats.
How the System Works
At the core of the patented system are the sliding glazing panel assemblies. Both the exterior and interior panels are designed to move smoothly, aided by ball transfer units that ensure reliable operability. Unlike traditional fixed windows, the sliding mechanism allows the window to be operable, offering the benefit of ventilation without compromising the structure’s blast, ballistic, or forced entry resistance.
The window system includes exterior and interior frame assemblies, each fitted with inside facing threaded sleeves for bolts and multiple layers of gaskets to ensure a tight, secure seal. These gaskets, positioned between the frames and the building wall, prevent any gaps that could weaken the system’s protective integrity, further enhancing its resistance to external forces.
“This project was funded by the U.S. Department of State, specifically for use in foreign embassies where threat levels can escalate quickly,” Judson explained. “Windows and doors are typically the most vulnerable points in these high-risk areas, especially overseas, so we had to design something that could effectively protect these entry points from blasts and ballistic threats.”
Advantages of the Hardened Operable Window System
1. Blast Resistance: Engineered to withstand high-intensity air blast pressures, providing protection in hazardous environments.
2. Ballistic Protection: The reinforced glazing and frame system offers high-level ballistic resistance, making it ideal for secure installations.
3. Operability: Unlike many hardened window systems that are fixed, this system allows the windows to slide open and closed, maintaining operability.
4. Entry Resistance: With multiple gasket layers and reinforced bolted frame assemblies, the system resists forced entry attempts.
5. Ease of Installation: The system includes a simplified method of installation, allowing it to compress around a rough opening and be securely integrated into existing building structures without extensive modifications.
Overall, the “Hardened Operable Window Systems and Methods” patent presents a crucial solution for environments that require a balance between security and functionality. It provides a versatile and secure operable window system, enhancing safety without sacrificing usability.