Understanding Crash Ratings: What K12 and M50 Mean for Security Barriers

As the first line of defence for sensitive locations and establishments that are potential targets for terrorist strikes, there is a lot riding on the ability of security equipment such as road blockers, barriers, and bollards to prevent vehicle borne attacks (VBA). Access control equipment need to be tested in near-real-life conditions to ensure that they can do their job effectively. This is where the concept of crash tests and their associated ratings come into play.

Crash test ratings are a set of internationally-accepted standards, usually conducted by independent and unbiased rating agencies. The ratings are based on actual crash tests that are carried out in a controlled environment to assess the efficacy of security barriers to withstand VBAs.

The chief parameters that constitute a crash test assessment are the weight of the vehicle, the speed at which it travels leading up to the impact with the security barrier, and the distance it moves beyond the barrier after impact. Various permutations and combinations of these three factors decide the rating that is bestowed upon different types of safety barriers.

Types of Safety Crash Ratings

Like any other process, safety crash ratings have evolved with time, modifying and improving upon previous iterations. Also, as with any other process, there are several types of crash ratings that have evolved from multiple geographical locations. For example, while the K-Ratings and M-Ratings are prevalent in USA, the UK Standard, PAS-68, is widely used in Europe. The IWA 14-1 rating is a global standard, which merges PAS-68 and M-Ratings and is used internationally.  

In this blog, we will deep-dive into K-Ratings and M-Ratings, explaining how they are calculated and highlighting the differences between the two.

K-Ratings

K-Ratings were developed in 1985 by the U.S. Department of Defense (DoD) and were primarily meant to test and certify security barriers for military or secure government facilities. A 15,000 lb (6.8 metric tons) truck is used to test impact resilience when driven at different speeds. The standard speeds used are 30 mph (48 kmph), 40 mph (64 kmph), and 50 mph (80 kmph).

Thus, a K4 crash rating indicates a truck weighing 15,000 lbs moving at 30 mph, K8 indicates the same truck travelling at 40 mph, while a K12 crash rating means that the truck is travelling at 50 mph.

The third test parameter, distance travelled by the truck beyond the barrier after impact, is denoted by L3, L2, and L1, where an L3 rating is assigned to vehicles travelling less than 3 feet (1m) beyond the barrier, an L2 rating is assigned to vehicles travelling between 3 and 20 feet (1m – 6m), and L1, the lowest rating, is assigned to vehicles travelling between 20 and 50 feet (6m – 15.24m).

The highest rating provided by the DoD for a security barrier is K12: L3, which means that the barrier was successful in limiting the penetration of a 15,000 lb truck, travelling at 50 mph to less than 3 ft after impact.

M-Ratings (ASTM F2656-07)

M-Ratings, an improved version of K-Ratings, was developed by the American Society for Testing and Materials (ASTM) in 2007. M-Ratings are widely applied to security barriers that are used to defend  a variety of civilian establishments.

M-Ratings follow a rating system similar to that of K-Ratings. M30 is awarded to a 15,000 lb truck travelling at 30 mph, M40 when the truck travels at 40 mph, and M50 when it travels at 50 mph. Penetration ratings ranging from P1 to P4 are awarded, wherein P1, for the truck travelling less than 3.3 ft (1m) is the highest, followed by P2 for penetration distances between 3.31 ft (1m) and 23 ft (7m), P3 for penetration distances between 23.1 ft (7m) and 98.4 ft (30m), and P4 for beyond 98.4 ft (30m).

An M50: P1 rating is the highest rating indicating that a 15,000 lb truck travelling at 50 mph moves less than 3.3 ft beyond the security barrier. It is equivalent to a K12: L3 rating.

Differences between K-Rating and M-Rating

A key difference between the two ratings lies in the calculation of the penetration criteria. While K-Rating displacement measurements are calculated by how far the front end of the truck moves beyond the barrier, M-Rating measurements start from the chassis of the vehicle.

Moreover, while K-Rating certifications are not awarded for penetration beyond 50 ft, M-Ratings do not have such restriction, awarding a P4 certification for penetrations beyond 98.4 ft.

Comparison of K-Ratings and M-Ratings

The following table provides a bird’s-eye view of the two rating types.

Conclusion

Security barriers bearing K12 or M50 ratings or certifications are considered to be among the most robust perimeter protection equipment in the world. They carry with them the assurance that they can protect high-security premises with the highest levels of reliability. Prospective buyers should assess the potential threat level faced by their facilities before selecting an appropriate security barrier.

About SAB TECH

SAB TECH is a leading manufacturer of high-tech perimeter protection equipment in Saudi Arabia include high security road blockers, bollards, above ground tire killers, under vehicle surveillance systems (UVSS), and turnstiles. SAB TECH’s hostile vehicle mitigation (HVM) solutions are manufactured using heavy duty S275JR steel and carry impressive K and M ratings as well other internationally recognized ratings.

If you are interested in upgrading the security infrastructure of your secure facility, get in touch with SAB TECH today to explore your options.