Back in 1985, the U.S. Department of State’s Bureau of Diplomatic Security published the original vehicle test barrier methods – SD-STD-02.01 – to assess the crash performance of perimeter barriers and gates. Since then, from the initial World Trade Center bombing to 9/11 and beyond, the rise in vehicle bombings has increased dramatically. As a result, the Bureau addressed the need to address a broader spectrum of conditions, including vehicle types, attack velocities and acceptable penetration distances.
Originally, in order to be certified by the DOS, vehicle barriers must be tested by an independent crash test facility. Certification is based on speed and penetration ratings. “K” has indicated vehicle speed during the crash test, and “L” indicated the maximum allowed penetration of the barrier by the vehicle.