Here is how the math to calculate the grade works out:
Grade = Rise/Run x 100
10 feet is 120 inches, and this is our run, 3 1/4 (3.25) inches is our rise.
Rise/Run = 3.25/120 = 0.02708333...
0.02708333... x 100 = 2.708333...
So therefore the grade is just a little bit under 2.8%, which is steep, but not extreme. Preparations for helpers should be made for weak and/or light engines.
Grade = Rise/Run x 100
10 feet is 120 inches, and this is our run, 3 1/4 (3.25) inches is our rise.
Rise/Run = 3.25/120 = 0.02708333...
0.02708333... x 100 = 2.708333...
So therefore the grade is just a little bit under 2.8%, which is steep, but not extreme. Preparations for helpers should be made for weak and/or light engines.