What type of transportation is least commonly used for heavy equipment movement?

The type of transportation least commonly used for heavy equipment movement is airlift. Airlifting is primarily utilized for time-sensitive or critical situations where swift delivery is necessary, such as for troops or essential supplies in combat zones. However, it is generally not feasible for heavy equipment due to significant weight limits, as aircraft have strict cargo capacity restrictions.

Usually, the size and weight of heavy equipment make it impractical to transport via air. On the other hand, rail transport, ship transport, and truck transport are more suited for moving heavy equipment, as they can accommodate larger loads and provide the necessary infrastructure for transporting such equipment over greater distances.

While airlift has its valuable applications in specific situations, when considering routine heavy equipment movement, it is indeed the least common mode of transportation among the options provided.