SUPPLEMENTARY INFORMATION:

BNSF, bridge owner, requested that the BNSF Swing Bridge across the Columbia River, mile 105.6, remain in the closed-to-navigation position to marine vessel traffic for maintenance and component replacement activities. The BNSF Swing Bridge provides 39 feet of vertical clearance above Columbia River Datum 0.0 while in the closed-to-navigation position. This deviation allows the BNSF Swing Bridge to remain in the closed-to-navigation position, and need not open for maritime traffic as listed in the table below:

The subject bridge operates in accordance with 33 CFR 117.5. The bridge shall operate in accordance to 33 CFR 117.5 at all other times.

Waterway usage on this part of the Columbia River includes vessels ranging from large ships to commercial tug and tow vessels to recreational pleasure craft including cabin cruisers and sailing vessels. Vessels able to pass through the bridge in the closed-to-navigation position may do so at any time. The bridge will be able to open for emergencies during this closure period if a one hour notice is given except on March 6, 2018 and March 8, 2018, and there is no immediate alternate route for vessels to pass. We contacted known river users, and requested objections to reschedule BNSF's maintenance period. We have not received any objections to this deviation. The Coast Guard will also inform the users of the waterways through our Local and Broadcast Notices to Mariners of the change in operating schedule for the bridge so that vessels can arrange their transits to minimize any impact caused by the temporary deviation.

In accordance with 33 CFR 117.35(e), the drawbridge must return to its regular operating schedule immediately at the end of the designated time period. This deviation from the operating regulations is authorized under 33 CFR 117.35.

83 FR 9429