What is the required stopping sequence for a train operator when approaching standing cars in a barn?

The required stopping sequence for a train operator when approaching standing cars in a barn emphasizes a gradual and controlled deceleration to ensure safety and minimize the risk of accidents. The correct sequence starts with the longest distance and progressively decreases, allowing the operator to have ample time to react and adjust as needed.

Starting with three car lengths provides a significant buffer for the operator to assess the situation ahead and prepare for the final stages of stopping. Following this, the sequence includes fifty feet, which helps to further slow the train down while still maintaining a considerable distance from the standing cars. The next step of ten feet allows for more precision in the reduction of speed, enabling the operator to make minor adjustments if necessary. Finally, two feet serves as a final approach distance, ensuring the train has slowed sufficiently to come to a complete stop in a controlled manner without risk of colliding with the standing cars.

The other options do not follow this systematic approach to stopping, which is crucial for safety when navigating through areas with stationary vehicles. Maintaining such a sequence helps ensure that the operator can stop effectively while taking into account factors like train speed and braking distance.