What is a "dolly" used for in switching operations?

A "dolly" in switching operations refers to a small wheeled device designed primarily to facilitate the movement of equipment or provide support for train cars. It is often employed in situations such as coupling or uncoupling cars, allowing for easier maneuvering and more efficient handling of rolling stock within a rail yard or during maintenance activities. The functionality of a dolly is crucial in ensuring the safe and reliable operation of switching procedures, as it helps to stabilize the train cars being worked on and minimizes the physical strain on workers.

The other choices relate to different aspects of rail operations. Safety mechanisms are important for maintaining safe train operations but do not directly pertain to the function of a dolly. Signals, while essential for guiding train movements, serve a distinct purpose separate from physical equipment handling. Similarly, storage areas for trains are necessary for operational efficiency but are not directly related to the mechanics of moving or supporting train cars. Thus, the definition and purpose of a dolly clearly align with option A.