33 CFR § 117.325 - St. Johns River.
(a) The drawspan for the Main Street (1/SR 90) drawbridge, mile 24.7, at Jacksonville, must open on signal except that, from 7 a.m. to 8:30 a.m. and from 4:30 p.m. to 6 p.m., Monday through Saturday except Federal holidays, the drawspan need not be opened for the passage of vessels.
(b) The draw of the Florida East Coast automated railroad bridge, mile 24.9, shall operate as follows:
(2) The draw is normally in the fully open position, displaying flashing green lights to indicate that vessels may pass.
(3) When a train approaches, large signs on both the upstream and downstream sides of the bridge flash “Bridge Coming Down,” the lights go to flashing red, and siren signals sound. After an eight minute delay, the draw lowers and locks if there are no vessels under the draw. The draw remains down for a period of eight minutes or while the approach track circuit is occupied.
(4) After the train has cleared, the draw opens and the lights return to flashing green.
(c) The draw for the Buffalo Bluff CSX automated Railroad Bridge, St. Johns River, mile 94.5 at Satsuma, Putnam County, FL shall operate as follows:
(1) The bridge is not tendered locally, but will be operated and monitored by a remote tender.
(2) The bridge shall have local and mechanical override capabilities over the remote operation.
(3) Marine radio communication shall be maintained with mariners near the bridge for the safety of navigation. Visual monitoring of the waterway shall be maintained with the use of cameras and the detection of vessels under the span shall be accomplished with detection sensors.
(4) The span is normally in the fully open position and will display green lights to indicate that the span is fully open.
(5) When a train approaches, the remote tender shall monitor for vessels approaching the bridge. The remote tender shall warn approaching vessels via marine radio, channel 9 VHF of a bridge lowering. The remote tender may also be contacted via telephone at (386) 649-8538.
(6) Provided the sensors do not detect a vessel under the span, the tender shall initiate the span lowering sequence, which includes the sounding of a horn and the displaying of red lights. The span will remain in the down position for a minimum of eight minutes or for the entire time the approach track circuit is occupied.
(7) After the train has cleared the bridge track circuit, the span shall open and the green lights will be displayed.