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Southwest Pass Area. Examples of the Known Effects to Navigation Due to Channel Narrowing. A Pilots Perspective: Truth and Consequences. Truth: Mississippi River channel m aintenance d redging is reduced Consequences: Reduced safe passing distances for ships
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Southwest Pass Area Examples of the Known Effects to Navigation Due to Channel Narrowing
A Pilots Perspective: Truth and Consequences • Truth: Mississippi River channel maintenance dredging is reduced • Consequences: • Reduced safe passing distances for ships • Reduced channel creates navigation hazards • A reduced channel equals cargo losses Associated Branch Pilots for the Port of New Orleans
Existing Channel WidthsEntrance to the Mississippi RiverSouthwest Pass Area 750’ SWP Pilot Station Jetties 650’ SWP Light 600’ Gulf Associated Branch Pilots for the Port of New Orleans
Safe Passing Distance in Existing 650’ Channel 300’ Photo: Mississippi River Trade and Transport Council Existing Safe Passing Separation Approximately 300’ Associated Branch Pilots for the Port of New Orleans
Effect of Narrowing From 750’ to a 650’ Channel Passing clearance reduced from 300’ to 195’ Associated Branch Pilots for the Port of New Orleans
600’ Channel Narrowed to 500’ 500’ Channel Narrowing 100’ Clearance Remaining Associated Branch Pilots for the Port of New Orleans
Narrowing to 400’ Channel 400’ channel No safe passing distance remaining 400’ Channel Associated Branch Pilots for the Port of New Orleans
10 Degrees of Vessel Leeway in a Narrowed 500’ Channel 50’ remaining passing distance Wind: East @ 15kn Associated Branch Pilots for the Port of New Orleans
10 Degrees of Leeway in a 400’ Channel Potential Collision Wind: East @ 15kn 400’ Channel Associated Branch Pilots for the Port of New Orleans
Crash Stop • In high current conditions, it often takes nearly 4 miles to stop a loaded down-bound ship in the Mississippi River entrance passes. • Many ships will end up stranded aground after this maneuver. Associated Branch Pilots for the Port of New Orleans
Crash Stop Loaded Tanker ~ 4 Miles to Stop in High River Crash Stop Ends Here 4 miles to sea Mississippi River Southwest Pass Exit Channel Associated Branch Pilots for the Port of New Orleans Crash Stop Starts Here
Lost Channel Depth Equals Lost Drafts and Lost Cargo for the Mississippi River • Panamax bulk carriers lose on average 179 tons of cargo per inch of lost draft. • Thus a foot of lost channel depth is equal to a loss of 2,148 tons of cargo. • Considering the recent 5 foot draft reduction due to shoaling, a typical Panamax bulk carrier would lose 10,740 tons of cargo per trip. Associated Branch Pilots for the Port of New Orleans
Thank You Pilots Consequences Lack of Channel Maintenance Dredging on the Mississippi River Associated Branch Pilots for the Port of New Orleans