Rail ends shall be flame cleaned then cleaned with a wire brush for a distance of how many inches from the rail end?

The requirement to flame clean rail ends and subsequently use a wire brush for a distance of 6 inches is crucial for ensuring proper thermite welding. This 6-inch cleaning area allows for the removal of any oxides, dirt, or contaminants that could interfere with the welding process, thereby promoting a strong and reliable weld joint.

The specific distance is determined based on the need to create a clean surface that provides adequate material for the chemical reaction to occur effectively during the thermite welding process. Ensuring that this sufficient area is cleaned helps improve the quality of the weld, minimizes defects, and ensures that the welded joint can withstand the necessary loads and stresses it will encounter in rail applications. This practice aligns with industry standards for maintaining integrity and safety in rail connections.