A 4-mile section of track with a 1.3% grade is categorized as?

A 4-mile section of track with a 1.3% grade is categorized as a heavy grade because the percentage of the grade (1.3%) typically indicates a significant incline that poses challenges for train operations, especially in terms of power requirements and braking distances.

In railroad terminology, grades are classified based on their steepness, which affects the trains' ability to ascend or descend safely. A grade of 1.3% is considered heavy because it requires more power for trains to climb and more caution in braking when descending. Higher grades demand particular attention to train handling techniques, including appropriate speed control and the application of brakes to ensure stability and safety during operations.

Other categories like light, moderate, or steep grades refer to varying inclines, and a 1.3% grade exceeds the thresholds for what might be classified as moderate. Hence, it aligns with the expectations and definitions utilized in train handling practices.