What is the common type of ordnance handling equipment that is portable?

The correct choice highlights "Self-Propelled Equipment" as a common type of portable ordnance handling equipment. This type of equipment is designed to move independently, making it particularly useful in shipboard environments where space is limited, and maneuverability is essential for effective handling and transport of ordnance.

Self-propelled equipment often includes features that allow for easy navigation around aircraft carriers and other naval vessels, thus enhancing safety and operational efficiency during ordnance operations. This portability is critical for quick deployment and retrieval in various situations, especially during flight operations or when securing munitions in readiness for deployment.

Other types of equipment mentioned, such as static, portable, and electro-mechanical equipment, do not specifically emphasize the self-propulsion feature, which is key for portable ordnance handling on an aircraft carrier. Static equipment refers to fixed installations that do not move, while electro-mechanical equipment typically focuses more on powered operations rather than portability. Understanding these distinctions is vital for effectively managing ordnance safely and efficiently on board naval vessels.