U.S. Army Engineer Research and Development Center (ERDC) Geotechnical and Structure Laboratory (GSL) Research Civil Engineer Justin Roberts recently made improvements to a previous patent that will enhance protective shelters leveraged by the Department of State (DOS).
Roberts received a patent in the second quarter of fiscal year 2021 for these new inventions, which make the Modular Anti-Ballistic, Blast and Forced Entry Resistant Shelter (MABFERS) more robust and weather resistant.
His dual-purpose “Flashing Systems And Methods for Modular Blast, Ballistic and Forced Entry Resistant Shelter” significantly contributes to the MABFERS’ performance in both static and dynamic environments. The recently patented improvements include weather seals to prevent rainwater from seeping into the structure and leakage of conditioned air. Additionally, mild steel flashing serves as a structural connection, providing strength and rigidity between units to prevent overturning during a blast event.
These latest inventions are “a continuation, in part, of the Hardened Alternative Trailer System (HATS),” Roberts said. “The MABFERS expands the HATS technology into a structural building system using 40-foot ISO [internationally standardized] freight container-compatible components. Two basic component types — an end unit and a middle unit ― provide the building blocks for assembling one-or-two story structures that are 40 feet in length by infinite widths in 8-foot increments.”
With improved weather resistance and stronger structural connections, the HATS system is used by Department of State (DOS) in high-threat locations to protect its occupants against car bombs, rocket and small-arms attacks or angry mobs.
“The HATS became a go-to structural solution for the Department of State,” Roberts said. “The ease of logistics, installation and the high levels of protection offered for the price not only fulfilled their requirement for high-threat locations but exceeded their expectations.”
“This system offers a sizable solution to the location and functional need while providing exceptionally high levels of blast, ballistic and forced entry protection,” Roberts continued, adding that it was initially developed by GSL engineers and ERDC’s Directorate of Public Works team members.
He also noted the DOS quickly realized the endless possibilities for expanded and unobstructed spaces for conference rooms, dining halls and a myriad of other functional uses, including a two-story option that would allow the DOS to double their protected space on limited real estate sites while staying within the temporary structure.
Roberts pursued the inventions after GSL engineers witnessed the separation and overturning of several units during early testing of the MABFERS in November 2017 at Fort Polk, Louisiana.
“We were already aware of the weatherproofing issue due to the nature of the connecting units; however, as a result of experimentation, we quickly realized the need for additional structural connections to prevent overturning,” Roberts said.
“We created a model of the HATS flashing component and inserted it into the MABFERS model. Several different load cases were run to evaluate the performance of the flashing. Each iteration allowed us to optimize the design until we arrived at the most economical solution that offered the desired level of confidence.”
The final test of the MABFERS, with inclusion of HATS flashing, was conducted in March 2018.
Roberts and his team, including invention colleague Craig Ackerman, a blast effects and special project initiatives program manager in the Physical Security Division of the DOS, will be recognized at a future patent plaque presentation ceremony by the Office of Research and Technology Transfer, which processes patents for ERDC.