Dams under construction. The operation building for the navigation lock at Watts Bar has been completed ahead of the rest of the project to permit the passage of river transport during construction. The left wing contains control machinery on the first floor and the commanding officer's work space on the second. The center of the upper level is a sheltered observation space for visitors who are received and accommodated in the right wing of the structure, and for access to the right end of the roof. All lock operation buildings are designed for maximum view of the lock chamber and the up- and downriver approaches by the operators and the public