Lesson Two: Characteristics of Explosive Devices

Lesson Two continues Lesson One's examination of the threat by exploring what bombs are, common characteristics of explosive devices, and what features can aid in their detection and identification. Throughout this lesson, references are made to established methods of operation used by terrorists to demonstrate how perpetrators have used bombs in actual attacks.

Topics include:

Types of Threat Devices • The Nature of Explosions • Initiation • Vapor Pressure • Common Explosives • Initiating Systems • Methods of Activation • Device Concealment

Lesson Two requires approximately 1.5 hours to complete.

Learning Objectives

Lesson Two will provide the student with an understanding of the following topics:

• The principal categories of explosive devices
• Characteristics of chemical explosions
• Vapor pressure and taggants
• Common types of explosives used in illegal bombings
• Methods of initiation used in illegal bombings
• Methods of activation used in illegal bombings
• Methods of concealment used in illegal bombings


Students completing Lesson Two should be capable of the following tasks:

1. Identify explosives and components commonly used in IEDs.

2. Identify potentially dangerous situations by considering the various methods used to activate and conceal IEDs.

Exercises and Quizzes

Lesson Two contains an interactive exercise to reinforce the importance of never touching, moving, or attempting to deactivate a suspected bomb.

Students completing Lesson Two should immediately take the interactive review quiz to test their understanding and retention of the lesson’s content. If the student correctly answers fewer than eight out of ten questions, he/she should repeat the lesson before continuing with the program.

Questions 5-10 of the comprehensive test are directly extracted from Lesson Two.

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Lesson Three


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Lesson Three

The lesson description on this page is extracted from the Bomb Countermeasures for Security Professionals CD-ROM, v2.0.