Which best describes the components of a firing train?

• A. Is a sequence of fuses only.
• B. Composed of initiator, main charge, and shunt.
• C. Includes stimuli, igniter, primary explosive, secondary explosive, tertiary explosive.
• D. Only a simple spark and fuse.

Answer: (C)

A firing train is the sequence that transfers energy from the triggering event to the main explosive, ensuring a controlled initiation. It begins with a stimulus (the trigger) that activates an igniter. The igniter then reliably initiates a primary explosive, which is highly sensitive and designed to detonate readily. That detonation then transfers energy to secondary explosives, which are less sensitive but much more powerful, and in more complex devices might include a tertiary explosive as well. So describing the chain as stimulus, igniter, primary explosive, secondary explosive, and tertiary explosive captures how the initiating energy is propagated through progressively less sensitive but larger charges to produce the intended detonation of the main charge. The other options are too narrow or omit essential stages, such as the multiple explosive layers and the initial triggering element.