Facts About Fog
Fog can sometimes affect shipping in the Port of Newcastle.
Fog is formed when air is cooled to a temperature at which it becomes saturated (dewpoint) by the water vapour which is present within it. Normally it is classified as fog when the resultant restricted visibility is less than one kilometre. The fogs that form at Newcastle are usually of two types:
· ‘Radiation Fog’ which occurs when relatively warm, moist air is cooled by contact with cold land surfaces, particularly in the Hunter Valley and around the plains near Williamtown
· ‘Advection or Sea Fog’ which occurs when warm moist air flows over a relatively cold sea surface that cools the air flow below its dewpoint.
Radiation fogs that form in the Hunter Valley can extend to Newcastle Harbour and occur normally in winter, early spring and occasionally in summer. Radiation fogs can occur in early spring off the port.
Shipping movements are not normally commenced in restricted visibility. However, should a pilotage of a ship be in progress within the harbour when restricted visibility occurs, appropriate precautions are taken.
Shipping movements are generally rescheduled until the fog thins.
A fog horn is located on the Newcastle city side of the Hunter River near the ferry wharf. This horn is primarily to aid the movement of Newcastle ferries.
A second fog horn is located on Nobbys Headland. The horn is faced to sea to aid the navigation of vessels through the port.
The fog horns are maintained by Newcastle Port Corporation and activated from within the Vessel Traffic Information Centre at the Pilot Station on Wharf Road.