K4 bollards will stop a 15,000-pound vehicle traveling at 30mph
The ‘K’ rating is a Crash Test Certification issued by the Department of State (DOS) to a bollard. It indicates the impact penetration of a vehicle of a specific weight at a specific speed during the crash. The K rating is used to measure the power a bollard has in order to arrest vehicular crash of certain weight and speed.
The K refers to the term kinetics. The kinetic energy of an object is the energy the object possesses due to its speed. Therefore, the rating is based on the vehicle speed a bollard can stop. The K12 for 50mph, K8 for 40mph and K4 for 30mph.
The crash rating design can be verified by either physical test (full scale test) or by computer simulation (Engineered). However, the certificate will be issued to physical test only. Simulation test can be used if minor changes considered in the bollard after the full scale test.
The K4 security rating provides secure protection like every other rating. It can however only stop vehicles at the 30mph speed. K4 bollards will stop a 15,000-pound vehicle traveling at 30mph. This rating is gotten by crashing vehicles into the bollards type and see how it responds. The crashing method of testing is the highest level of barrier specification and has been certified by the Department of State, U.S.
While the older DOS SD-STD-02.01 standard, K-Rating, is now discontinued, other alternative standards used to test these bollards include:
- SD-STD-02.01 Rev. A (2003)
- ASTM F2656-07 (2007)
- BSI PAS 68 (2013)
- ISO IWA 14-1 (2013)
Although these standards show bollard effectiveness in their own rating designation, it is ultimately based upon impact energy absorption capacity of the bollard.
During installation of bollards, it’s important that some bollards penetrate deep into the ground. However, some certain sites where underground facilities don’t permit such installation. The best method to use in such situation is wide shallow base bollards.