The recent global trend in the use of ‘vehicles as a weapon’ in the conduct of terror attacks, presents a significant challenge to urban planners, architects, engineers, and building owners. The often-conflicting functional requirements of ‘protection’, ‘accessibility’, and ‘aesthetics’ mean that the provision of safe urban streetscapes and effective building perimeter security require careful design. PEC can support the delivery of effective protection from vehicle ramming threats with our expertise and experience in criteria development, modeling & simulation, testing, and the design of protective structures. Furthermore, as an independent consultant our design input is provided without bias towards particular protective solutions or products, ensuring that our advice is tailored to best meet the specific requirements of our clients.
PEC provides expertise and experience for:
- characterization of relevant design-basis vehicle threats,
- assessment of site layouts and geometry to determine maximum impact velocities and angles,
- development of concept mitigation schemes,
- production of technical specifications documents for barrier suppliers, and
- provision of support to the client in the selection and installation of final design solutions.
Our project team has conducted a number of Hostile Vehicle Mitigation (HVM) studies and designs for facilities in the U.S. and overseas. A list of previous projects can be provided upon request. For these projects the typical scope of services includes:
Vehicle Threat Characterization
The significance of a vehicular impact threat is directly related to the kinetic energy of the impinging vehicle. Consequently, a reasonable characterization of vehicle mass and attainable speed are critical factors to be determined as part of an impact damage assessment. Likely vehicle threats are first evaluated and characterized based on mass and acceleration characteristics, to form a vehicle threat matrix.
HVM Approach Study
Following threat characterization, an evaluation of the site layout is conducted to determine the most exposed and vulnerable areas for a hostile vehicle attack. In conjunction with this, attainable vehicle speeds are calculated for each impact location based on site topography and road layouts. Design equations are employed to account for mitigating features such as curved roads, sloped surfaces, and curb lines.
Concept Mitigation Scheme Development
To eliminate or inhibit damage associated with a given hostile vehicle attack, short-term and long-term concept mitigation schemes can be developed. These typically incorporate active (e.g., access gates, rising bollards) and passive (e.g., bollards, planters) barrier systems where necessary. To minimize the visual impact of hardening measures, landscape architecture can be integrated into the design plan. Examples of this include stonework, terraces, and hardened streetscapes, which make use of impact-resistant benches, light standards, and similar constructs. Several alternatives (systems and layouts) can be evaluated with concept designs presented to the client for review, comment, and down-selection.
Technical Specification Development
Technical specification documents can be developed outlining the product requirements for each barrier system utilized in the mitigation plans. Requirements will focus on the ability of the barriers to arrest a vehicle within a pre-determined ‘penetration distance’ from the front-face of the bollard/planter line. These specifications will ensure that the selected barrier systems will be suitable to resist the design-basis hostile vehicle threats. Typically, the ASTM F 2656-07 or PAS 68 certification standards are used to specify required barrier performance however, other schemes are available.
Selection & Installation of Final HVM Design Solutions
PEC can also support the client in the selection and installation of short-term and long-term HVM design solutions. This includes assessment of product supplier submittals, testing certificates, and response to technical RFIs (requests for information) during installation.