Ladder Tracks. At one or both ends of the body tracks, there is a
diagonal track which is called the ladder track which connects the body tracks
to a main or running track. The angle the ladder track makes with the body
track should equal the frog angle. Where space is a problem, tandem ladder
tracks, with angles twice or triple the frog angle, should be used. Ladder
tracks shall have a minimum of 15 feet between centers from other tracks.
Parallel ladder tracks shall have a minimum of 20 feet between centers.
Gradients. Wherever practicable, gradients should be level on
tracks used for standing of cars. Maximum yard gradients shall not exceed 1.5
percent without prior approval of NAVFACENGCOM.
Reverse Curves. The minimum allowed tangent distance between
reverse curves, including crossovers, shall be according to the AREA Manual,
Chapter 5, Part 3, Reverse Curves. The desirable tangent distance between
reverse curves in yards and terminals should be 100 feet or more.