History of Crash Testing
Crash testing provides a structured procedure to establish a penetration rating for perimeter barriers subjected to a vehicle impact. Knowing the penetration rating provides the ability to select an appropriate barrier for site-specific conditions around a facility.
Is is important to note that the barrier penetration rating does not guarantee that a barrier will perform as rated in all site conditions, approach routes, and topography. Only single-specimen tests at a specified impact location are required by this test method, and therefore, not all points of impact can be tested and validated for the penetration rating. Other impact locations may respond differently.
1.The DoS (K ratings) and the ASTM (P, PU and M ratings) offer a method to evaluate a range of vehicle impact conditions, designations, and penetration performance levels. This will allow an end user to select passive perimeter barriers and active entry point barriers appropriate for use at facilities with a defined moving vehicle threat. Security consultants may adopt and specify those condition designations and performance levels that satisfy a specific client’s unique needs. End users may also assign certification ratings for active and passive perimeter barriers based on the tests and test methodologies described herein or more so today, engineered ratings are being accepted by all types of at-risk facilities as they can cover many more site-specific conditions and have been proven to be quite reliable. Many test parameters are standardized to arrive at a common vehicle type and mass, simulations have been accepted as means to enhance test realism and replication and can produce uniform rating designations.
2. Compliance with these procedures establishes a measure of performance but does not render any perimeter barrier invulnerable to vehicle penetration. Caution should be exercised in interpreting any test findings and in extrapolating results to other than actual crash test conditions. While computer simulations are powerful tools that are useful in the development of new and improved barriers or in estimating performance under differing conditions, it is suggested that engineering calculations should also be considered along with specific site conditions. When assessing a crash rating, developers and users are encouraged to address specific or unusual site conditions as needed. Often local terrain features, soil conditions, climate, or other items will dictate special needs at specific locations. Therefore, if site conditions have not been carefully considered for a barrier’s performance, the end user in need of a perimeter barrier system should require professional evaluation by a perimeter defense specialist of all factors, including possible run-up speeds to ensure that a higher rated barrier than is really necessary is not included in a specification. Most customers are unaware of the considerable price difference that exists between ASTM-M30 and ASTM-M50 rated equipment. In most cases it can be as much as double!
3. Product/design certification using any test method can only address the ability of the barrier to withstand the impact of the specified vehicle. It does not represent an endorsement of the product/design or address its operational suitability under all conditions.
4. The consideration of possible vehicle penetration should also be of primary concern and it is recommended that a perimeter defense specialist be consulted to assist with barrier selection.