Brock Gap

In 1858, the state of Alabama tasked John Milner to survey a route across Shades Mountain for the S&N Railroad. The S&N was intended to connect the mineral resources south of Shades Mountain (coal, limestone, and iron ore) with the developing industries in the area of Jones Valley that would become Birmingham around the junction of the S&N Railroad and the Alabama and Chattanooga Railroad. Brock Gap was selected and the rail line north was constructed between 1858 and 1871, interrupted by the Civil War. At Brock Gap, workers used nitroglycerin to blast a cut 75 feet deep through limestone bedrock.^[3]

Today, the 19th century cut is actively used by the CSX Lineville Subdivision, made up of part of the former Atlanta, Birmingham and Atlantic Railway, in its route from Birmingham to Atlanta, Georgia and Florida via Manchester, Georgia. The direct successor of the S&N Railroad, the CSX S&NA South Subdivision, is carried through a more recently constructed tunnel slightly east of the 19th century cut.