33 CFR § 117.253 - Anacostia River.
(a) The draw of the Frederick Douglass Memorial (South Capitol Street) bridge, mile 1.2, need not be opened for the passage of vessels.
(b) The CSX Railroad Bridge, mile 3.4.
(1) The draw of the bridge to be operated by the controller at the Benning Yard office shall open on signal:
(i) At all times for public vessels of the United States, state and local government vessels, commercial vessels and any vessels in an emergency involving danger to life or property.
(ii) Between 9 a.m. and 12 p.m. and between 1 p.m. and 6 p.m. from May 15 through September 30.
(iii) Between 6 p.m. and 7 p.m. from May 15 through September 30 if notice is given to the controller at the Benning Yard office not later than 6 p.m. on the day for which the opening is requested.
(iv) At all other times, if at least 48 hours of notice is given to the controller at the Benning Yard Office.
(2) The CSX Railroad Bridge shall not be operated by the controller at the Benning Yard office in the event of failure or obstruction of the motion sensors, laser scanners, video cameras or marine-radio communications, In these situations, a bridge tender must be called to operate the bridge on-site.
(3) Except as provided in § 117.31(b), opening of the draw shall not exceed ten minutes after clearance of rail traffic.
(4) A horn will sound one prolonged blast followed by one short blast to indicate that the CSX Railroad Bridge is moving to the full open position for vessel traffic. During open span movement, the channel traffic lights will flash red until the bridge is in the full open position to vessels. In the full open position to vessels, the bridge channel traffic lights will flash green.
(5) A horn will sound five short blasts, the channel traffic lights will flash red, and an audio voice-warning device will announce bridge movement during closing span movement. Five short blasts of the horn will continue until the bridge is seated in and locked down. When the bridge is seated and in locked down position to vessels, the channel traffic lights will continue to flash red.
(6) The owners of the bridge shall provide and keep in good legible condition two board gauges painted white with black figures not less than six inches high to indicate the vertical clearance under the closed draw at all stages of the tide. The gauges shall be placed on the bridge so that they are plainly visible to the operator of any vessel approaching the bridge from either upstream or downstream.