What signaling device shall be provided on locomotives and shuttle cars?

The correct answer is a signaling device that includes sounding devices, which are essential for ensuring safety in the operation of locomotives and shuttle cars. Sounding devices, such as horns or bells, provide an audible alert to personnel nearby, indicating the movement of equipment. This is particularly important in environments like mines or rail yards, where visibility may be limited and the risk of accidents can increase.

Sounding devices serve as a significant warning mechanism to signal that a locomotive or shuttle car is approaching or in operation, helping to prevent accidents or collisions. They are crucial for communicating with workers in the vicinity who may not be able to see the equipment due to obstructions or distance.

While light signals, flag signals, and radio communication can also be used in various contexts for signaling and communication, the requirement for sounding devices specifically relates to the need for immediate and effective alerts in high-risk environments where locomotives and shuttle cars operate.