Air draft restrictions when passing under the river Boyne Viaduct at Drogheda Portís town quays
To: Owners, Operators, Managers, Masters, Pilots, Agents and Stevedores
Attention is drawn to vessels Masters bound to and from Drogheda Port town quays of the need to allow sufficient air draft to pass safely under the river Boyne Viaduct.
Masters are reminded that the river Boyne Viaduct has a vertical clearance height of 26m referenced to Highest Astronomical Tide.
Details in respect of the river Boyne Viaduct are noted on British Admiralty Chart 1431, plan ĎBí.
Masters should note that the tidal predictions for any given tide may be affected by particular weather conditions which will impact on air draft calculations i.e., southerly winds and low barometric pressure may increased the tidal level above prediction, while northerly winds and high barometric pressure may reduce the tidal level below prediction. Additionally, high fresh water flows on the river Boyne may impact on air draft calculations.
It is strongly recommended that a minimum of one metre under bridge clearance should be allowed on calculating an air draft for passing safety under the river Boyne Viaduct.
Capt. Martin J. Donnelly