Final answer:
Armed escorts are required when transporting CAT I and CAT II ammunition, which include high-risk items like missiles, rockets with complete warheads, grenades, and certain explosives, to ensure public safety and secure transport.
Step-by-step explanation:
When considering the transportation of ammunition, there are specific safety protocols and regulations that must be followed, which include the need for armed escorts. The categories of ammunition that require an armed escort are determined by the level of risk and security sensitivity associated with them. Specifically, CAT I (Category I) and CAT II (Category II) ammunition are the ones that typically require an armed escort due to their high risk and potential for destruction if they were to be compromised.
CAT I ammunition includes items like missiles and rockets with a complete warhead, while CAT II includes ammunition like grenades, mines, and certain types of explosives. The increased security measures are to ensure the safe and secure transport of these items to prevent any incidents that could pose a risk to public safety.