They are Anti Terrorism/Force Protection (ATFP or AT/FP) Ram Barrier Protection Specifications. These standards were established by the Department of State (DOS) to assist in quantifying the ability of a crash barrier to stop a vehicle from entering a perimeter or building for the purpose of presenting a bomb threat.
These ratings are understood guidelines that are used by facility security to establish the level of protection they wish to obtain. The ‘K’ in these rating refers to the term kinetic. The kinetic energy of an object is the energy that it possesses due to its motion. The actual stopping ability of each individual rating is highlighted below.
K4 barriers will stop a 15,000 pound vehicle traveling at 30MPH
K8 barriers will stop a 15,000 pound vehicle traveling at 40MPH
K12 barriers will stop a 15,000 pound vehicle traveling at 50MPH
These ratings can be obtained by actually crashing vehicles into the product and seeing how they respond. This method of crash testing is the highest level of barrier specification and is known as DOS Certified. Meeting this crash certification can significantly increase the cost of the system.
Another method of obtaining this level of protection is to utilize Engineered K4|K8|K12 Ratings. Engineered barriers have not undergone the DOS authorized test, but does meet engineering criteria for equivalent levels of protection. Most Non-DOS Certified systems (other than U.S. Army Corp of Engineers USACE or Military Handbook MIL-HDBK specified) will require an engineer stamp indicating compliance assuring the expected level of protection.
Tests have shown that adding a cabling system to existing chain link fence greatly restricts the potential penetration of vehicles.
AMERISTAR K8/K12 Rated Anti-Ram Security Fencing
The Impasse™ Security Fence was designed and engineered to meet the expressed needs of security specialists, consultants and engineers - the need for a value added security fence that delayed forced entry for a time period sufficient to bring secondary security measures into play.
The high-strength architectural shapes of Impasse™ components were enabled by the high-speed automation of Ameristar’s in-house roll-forming mill. Ameristar’s unique PermaCoat®(double layer) electrostatic powder coating process ensures an appearance that remains aesthetically pleasing for many years. mpasse™ is available in three different styles (triple-pointed, blunt-tipped, and outwardly curved) and four standard colors (black, white, bronze, and desert sand).
Article contributed by fence professional John Lowndes.