Crash-Ratings: Quick Guide

Cable Barrier Crash Testing — Cable Barriers Crash Testing

Introduction

With the increasing frequency of vehicle ramming incidents and the heightened concern for potential terrorist attacks and crime, the deployment of vehicle barrier systems has become a top priority for medium to high-security locations.

Of course, not all barrier systems are created equal regarding effectiveness and impact resistance. Perimeter security is crucial for protecting critical infrastructure and relies heavily on standards such as ASTM F2656. ASTM provides a standard framework for evaluating the crashworthiness of vehicle security barriers of many shapes and sizes. Whether you're an engineer, a security professional, or simply interested in learning more about these standards, understanding their implications is essential for effective security outcomes.

What is a Crash Rating?

A crash rating for an anti-ram barrier is a standardized measure of its ability to withstand vehicular impacts based on vehicle size/speed and penetration depth upon impact of the barrier. These ratings, typically expressed in terms of K-ratings or M-ratings, evaluate the barrier's performance under various collision scenarios.

For example, a K12 barrier can stop a 15,000-pound vehicle traveling at 50 miles per hour with minimal penetration beyond the barrier. Similarly, an M40 barrier can halt a vehicle of the same weight at 40 miles per hour. Understanding these crash ratings is essential for selecting optimal barrier systems to protect critical infrastructure, public spaces, and other vulnerable locations from unauthorized vehicular access, and aggressive vehicle security breaches.

K-Ratings vs. M-Ratings

K-Ratings

The K-rating system originated back in 1985 and was later revised in 2003 in response to terrorist attacks across the United States. Unlike the M-rating, which was formulated by a civilian organization, the K-rating was created by the Department of Defense specifically for assessing military-grade security products.

K12 is rated to stop a 15,000 lb truck traveling at 50 mph (80 kph)
K8 is rated to stop a 15,000 lb truck traveling at 40 mph (65 kph)
K4 is rated to stop a 15,000 lb truck traveling at 30 mph (48 kph)

The K-rating scale also provides penetration ratings determined by the distance the front bumper travels past the barrier after coming to a stop. These ratings are identified by the letter L, where a higher number signifies less penetration.

L1 certification stops vehicles with between 20 to 50 feet of penetration
L2 certification stops vehicles with between 3 to 20 feet of penetration
L3 certification stops vehicles with less than 3 feet of penetration

The most robust barrier, as indicated by K-ratings, is classified as K12: L3. In this scenario, a 15,000-pound vehicle traveling 50 miles per hour penetrated the barrier by less than 3 feet. To decipher K-ratings, consider the "K" number to correlate to the test vehicle's speed and the "L" number to the distance it traveled beyond the barrier.

M-Ratings

In recent years, M-ratings have supplanted K-ratings in the private sector, following standards established by the American Society for Testing and Materials (ASTM). Unlike K-ratings, which primarily focus on the distance a vehicle's front travels upon impact with a barrier, M-ratings assess the distance traveled by the vehicle's payload beyond the barrier. Despite this distinction, both M and K ratings are determined based on similar factors such as vehicle size, speed, and travel distance.

M50 is rated to stop a 15,000 lb truck traveling at 50 mph (80 kph)
M40 is rated to stop a 15,000 lb truck traveling at 40 mph (65 kph)
M30 is rated to stop a 15,000 lb truck traveling at 30 mph (48 kph)

M-ratings are further subdivided into additional classifications, which are determined by the distance the vehicle travels beyond the barrier.

P1 - traveled 3.3 feet or less
P2 - traveled between 3.31 and 23 feet
P3 - traveled between 23.1 and 98.4 feet
P4 - traveled farther than 98.4 feet

One thing of note is that M-ratings closely mirror K-ratings in terms of their numerical designations. For instance, a K4 rating aligns with an M30 rating, while a K8 rating corresponds to an M40, and a K12 rating matches an M50. These equivalencies indicate that vehicles subjected to K-rated and M-rated tests traveled at speeds of 30, 40, and 50 miles per hour, respectively. Given these parallels, M-ratings and K-ratings can be used interchangeably in most cases.

Tested vs. Certified vs. Engineered

Something that can be confusing is the different terminology used in describing these ratings. Make sure to pay attention to terms like "tested," "certified or rated," and "engineered" as they carry different implications and levels of importance. Understand the context of each of these terms:

Tested

Exercise caution with labels claiming a product is "crash-tested." Merely being labeled as "tested" doesn't guarantee that a barrier has passed the test or meets the requirements of a specific rating. Despite being labeled as "tested" at a particular K- or M-rating, the product may not genuinely meet that standard, which can be misleading.

Certified or Rated

The label "certified" or "rated" is more reliable and accurate. If a barrier is certified at a specific rating, it means it has successfully passed the relevant test and achieved that rating. Prioritize looking for barrier products labeled as "certified" or "rated" to ensure their compliance with established standards.

Engineered

When a product is "engineered" to meet a particular standard, it implies that it was designed to pass the test based on calculations or computer models. However, note that such products may not have undergone real-life testing. Keep this in mind when considering their effectiveness in practical scenarios.

Ultimately, focus on seeking out "certified" M-ratings and K-ratings for the highest level of assurance. If you encounter labels like "tested" or "engineered," inquire further to ascertain whether tested products met the designated standards and if engineered products underwent actual physical testing. Without such verification, there's little guarantee that the products will withstand real-life crashes effectively. If you aren't sure if your barrier is "tested," "certified/rated," or "engineered," The Department of Defense publishes a list of certified barriers that can help you verify. You can also contact Sloan Security Group for any questions you may have.

Conclusion

While both K and M ratings provide valuable insights into a barrier's performance, understanding the distinctions between them is essential. Whether it's the K-ratings developed by the Department of Defense or the more recent M-ratings introduced by ASTM, each system offers subtle differences.

The terms "tested," "certified/rated," and "engineered" also carry different implications in the context of barrier security. While certified products ensure meeting specific standards, caution is warranted with labels claiming products are simply "tested" or "engineered." Ultimately, prioritizing certified M and K ratings offers the highest level of confidence in selecting barrier systems that effectively mitigate risks and protect our critical infrastructure.

Sloan Security Group offers an extensive array of crash-rated barriers with various types of configurations and ratings. From bollards to security fences, wedges to rising beams, Sloan's comprehensive selection is designed to meet diverse security needs. Whether your attempting to protect critical infrastructure, government facilities, or commercial properties, Sloan's range of crash-rated barriers provides the perfect solution to a variety of threats. With a commitment to innovation and quality, coupled with a wealth of experience in the security industry, Sloan Security Group stands as a trusted provider of cutting-edge solutions for perimeter security and access control.

About Sloan Security Group, Inc. Sloan is quickly becoming the global leader in safe and effective perimeter security for distinctive brands and institutions such as Facebook (Meta), DoD, and DoS. Sloan specializes in vehicle barriers, access control, and intrusion detection.

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