The Tower 55 project consisted of the construction of a 6-mile section of secondary track to increase the train capacity through the Tower 55 rail yard in Fort Worth, Texas. Tower 55 is one of the most active rail yards in the country with over 100 train movements per day. The survey effort for this project involved establishing a primary control network along the project corridor. Design survey data was collected along the corridor north and south of the rail yard, and included topographic cross-sections of the existing railroad right-of-way and as-built mapping of the rail yard. The design survey included existing ground and rail elevations, point of switch, point of frog, signalization, mile posts and whistle boards, as well as existing utilities, and overhead electric crossings within the 6-mile railroad corridor. Detailed surveys of bridge and overpass structures including abutments, bents, bent caps, footings and crash walls. At-grade road crossing surveys were performed. Creek cross-sections and drainage structures were also surveyed. The project involved three permanent road crossing closures requiring written metes and bound descriptions and exhibits submitted for approval to the city. A Digital terrain model (DTM) was produced for the entire 6-mile corridor and rail yard and delivered along with planimetric drawings to the client for use in design of the planned expansion of Tower 55.