1.1使用表1中列出的有限手动工具清单，相对于三级强迫进入威胁评估围栏系统的强迫进入阻力。它还建立了一个系统，用于评估这些系统的强行进入阻力（见表2）。指定用于在每个威胁级别进行测试的工具是那些已知对结构及其子组件具有最大破坏性影响的工具，并且易于被归类为构成该威胁级别的攻击者使用。 1.1.1 低威胁级别（L） — 低（L）威胁等级类别的可用工具清单中特别豁免的是电动工具（汽油、电动或液压）和需要一人以上运输和操作的设备。 1.1.2 中等威胁级别（M） — 需要外部电源的电动工具或需要两人以上运输和操作的自给式汽油或电池驱动的工具和装置特别免除了中等（M）威胁级别类别的可用工具清单。 1.1.3 攻击性威胁等级（A） — 高（H）威胁级别类别的可用工具清单中明确豁免了需要两人以上运输和操作的装置。 1.2围栏系统能够提供保护，使其免受步枪或手枪发射的子弹的伤害，这将特别有益于边境围栏地区，因为在这些地区，安全人员可能成为巡逻活动的目标。因此，使用.38专用手枪和7.62毫米步枪进行有限测试，以确定围栏系统是否提供了任何级别的保护。 1.3围栏系统能够以适中的成本提供4000磅重、以20英里/小时的速度行驶的车辆的冲击阻力，这将为安全围栏系统在抵抗低冲击情况下的强度提供相对指导。 ====意义和用途====== 任何试图强行渗透围栏系统的成功或失败取决于三个主要因素，这些因素共同定义了威胁 使用的工具和设备、攻击者的数量及其复杂程度。 通常，这一范围的测试程序将得到多年实验室测试的支持，旨在鉴定并准确再现各种工具、工具和装置的破坏性影响。然而，快速变化的社会条件迫切需要建造抵抗不断演变的强行进入技术的构件。 因此，本文介绍的程序更多地基于现场经验，而不是实验室分析。它们更具代表性，而非包容性，旨在为使用强制穿透程序、弹道测试和冲击测试对不同围栏系统进行比较评估提供基础，并且主要不用于确定或确认绝对防止强迫进入。

1.1 The forced entry resistance of fence systems is evaluated relative to three levels of forced entry threat using the limited hand tool inventory outlined in Table 1. It also establishes a system for rating the forced entry resistance of those systems (see Table 2). The tools specified to be used for testing at each threat level are those that are known to have a maximum destructive effect on structures and their sub-assemblies and are readily available to aggressors categorized as posing that level of threat. 1.1.1 Low Threat Level (L) — Specifically exempted from the inventory of available tools for the low (L) threat level category are power tools (gasoline, electric or hydraulic), and devices requiring more than one person to transport and operate. 1.1.2 Medium Threat Level (M) — Specifically exempted from the inventory of available tools for the medium (M) threat level category are power tools requiring an outside power source or self contained gasoline or battery driven tools and devices requiring more than two persons to transport and operate. 1.1.3 Aggressive Threat Level (A) — Specifically exempted from the inventory of available tools for the high (H) threat level category are devices requiring more than two persons to transport and operate. 1.2 The ability of a fence system to offer protection from bullets fired from a rifle or handgun would be beneficial particularly in Border Fence areas where security personnel can be targets during patrol activities. Accordingly, a limited test using a.38 Special handgun and a 7.62-mm rifle is performed to determine if any level of protection is provided by the fence system. 1.3 The ability of a fence system to provide impact resistance from a 4000 pound mass vehicle moving at a velocity of 20 MPH at a modest cost will provide relative guidance as to the strength of a security fence system in resisting low impact situations. ====== Significance And Use ====== The success or failure of any attempt to forcefully penetrate a fence system is dependent upon three primary factors that collectively define the threat the tools and devices employed, the number of aggressors, and their level of sophistication. Normally, a test procedure of this scope would be supported by years of laboratory testing intended to qualify and accurately reproduce the destructive effects of a variety of tools, implements, and devices. However, rapidly changing social conditions have created an immediate need for building components resistant to evolving forced entry techniques. Accordingly, the procedures presented herein are based more on field experience than laboratory analysis. They are more representative than inclusive, are intended to provide a basis for the comparative evaluation of different fence systems using forced penetration procedures, ballistic tests and impact testing, and are not primarily intended to be used to establish or confirm the absolute prevention of forced entries.