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How Not to Site Plan: Common Pitfalls and Mistakes in Hazards Analyses
Tyler Ross, Ph.D., P.E.; A-P-T Research, Inc.; Huntsville, AL, USA
Keywords: ECM, SDW, Fragment, Barricade, Site Planning
Abstract
Explosives safety site planning often requires planners and engineers to provide protection from
explosives hazards when standard Quantity-Distance (QD) criteria cannot be met. Properly
identifying and quantifying explosives hazards as well as selecting effective mitigation strategies
is a challenge. Mischaracterizing hazards can lead to improper proposed solutions.
Common mistakes as well as best practices are presented. Topics include improper extrapolation
of common equations, improper use and placement of barricades, improper understanding and
use of Substantial Dividing Walls (SDW), and improper application or interpretation of available
test data. Basic examples are provided for each topic.
1. Introduction
Explosives safety site planning often requires planners and engineers to provide protection from
explosives hazards when standard QD criteria cannot be met. Properly identifying and
quantifying explosives hazards as well as selecting effective mitigation strategies is a challenge.
Mischaracterizing hazards can lead to improper proposed solutions.
2. Identifying Hazards – Use of Equations
Many references exist to help site planners quantify hazard distances for blast effects. U.S.
Department of Defense (DoD) sanctioned references include DoD 6055.09-M (Reference 1),
Unified Facilities Criteria (UFC) 3-340-02 (Reference 2), Department of Defense Explosives
Safety Board (DDESB) Technical Paper (TP) 16 (Reference 3), and UFC 3-340-01 (Reference
4).
The issue at hand is the range of applicability of the equations in these references. The equations
presented in each of the listed references are empirical in nature, meaning they are tied to test
data. The available data used to generate the equations are generally sparse due to cost of testing
and limitations of testing methods and equipment. For example, an equation for predicting debris
perforation into wood targets may be based on only a few data points. These data points cannot
possibly represent a complete range of wood material types and thickness, nor a full range of
impactor shapes, masses, and velocities.
Engineers and planners are often led to use empirical equations to estimate hazards or
mitigations. Understanding the range of applicability as well as any other constraint for an
empirical equation is critical to ensuring that unintended and incorrect extrapolation does not
occur.
