DFW High C Gates Demolition and Replacement - Core & Shell Jigsaw Puzzle DFW High C Gates Demolition and Replacement - Core & Shell Steel cleared for landing! The new High C Gates concourse at Dallas-Ft. Worth International Airport (DFW) was constructed a mile from the terminal site in six massive pieces, each of which the team moved into place using self-propelled modular transporters (SPMTs). Time and space constraints couldn’t slow down this modular structural steel project.