Press Releases - back to Press                                                                                 5th October 2005

 

Sounding Out

In January 2005, the three General Lighthouse Authorities (GLAs) of the UK and Ireland issued a consultation document following a joint review of Aids to Navigation of the coasts of the United Kingdom and Ireland.

The Review addressed the current and future requirements of national and international shipping and those of Mariners. Each Aid to Navigation – light, buoy or beacon - was studied in isolation, as well as in relation to the other Aids to Navigation in its vicinity. As part of this process the Northern Lighthouse Board also reviewed the need for the provision of fog horns. The conclusion was that audible fog signals had a significantly reduced role in the modern marine environment, as a result of the widespread use of electronic position finding aids and radar, and the adoption of enclosed bridges on many vessels. Accordingly, the Board have taken the decision that all of Northern Lighthouse Board's Fog Signals are surplus to requirement, as such the few remaining systems have been decommissioned and the very last Scottish fog horn was switched off on 4 October 2005 at Skerryvore lighthouse.

This marks the end of a long history of operating fog signals, which in their day drove the introduction of advanced technology in the form of the internal combustion engine into lighthouses, and included very complex lengths of air pipe at sites such as Hyskeir and the Isle of May lighthouses.

Notes for Editor:

Images are available of Skerryvore Lighthouse and of a traditional fog horn by contact Lorna Hunter Tel: 0131 473 1300.

Fog horns were first introduced in Scotland in 1876 at St Abb’s Head Lighthouse.

The reason for the initial introduction - when fog or mist rises the light loses its value therefore a warning signal other than a visible was provided. At many stations this was in the form of a fog signal, either in the form of a siren or a diaphone. The compressed air operated signal was worked by means of three powerful diesel oil engines which drew the air into attached compressors, the air passes into other receivers placed outside the engine room and was thereafter forced down to the horn house which was normally situated as near to the sea as practicable. A clockwork arrangement opened a valve and allowed the air, at pressure, to start a small motor, which in turn caused the siren to operate. This clockwork arrangement also opened and shut the valves which regulated the duration and frequency of the blasts. Like lights, fog signals also possessed different characteristics for identification purposes. The diaphone worked on a similar principle except that the air from the operating valve caused a slotted piston to reciprocate in the cylinder instead of the motion being rotary as in the case of the siren. From the 1970’s onwards the large air driven fog signals were progressively replaced by small electric powered sound emitters. The fog horn at Skerryvore was a small electric sounder, and sounded every 60 seconds.

Skerryvore is the tallest lighthouse in the United Kingdom, standing 48 metres high. It is situated on a submersible reef 10.5 miles south-west of Tiree and is only accessible at low tide.

All Scottish lighthouses are automatic, the last to be automated was Fair Isle South. Skerryvore was automated in 1994, for more information on Skerryvore check out www.nlb.org.uk/ourlights/history/skerryvore.htm.

The Northern Lighthouse Board operates under statute - the Merchant Shipping Act 1995 - and is the General Lighthouse Authority for Scotland and the Isle of Man.

The Board currently operates: 212 Lighthouses, 154 Buoys, 47 Beacons, 4 Differential Global Positioning System Stations and 1 Loran-C Station on trial.

The Northern Lighthouse Board is funded entirely from the General Lighthouse Fund, sourced by "Light Dues", a levy paid by shipping. The Board receives no direct funding from the Exchequer or taxpayer.

The other General Lighthouse Authorities are the Commissioners of Irish Lights (Republic of Ireland and Northern Ireland) and Trinity House Lighthouse Service (England, Wales, the Channel Islands and Gibraltar).

The Northern Lighthouse Board is certificated to ISO9001:2000 standard for the provision of navigational aid services to seafarers and other organisations around the coast of Scotland and Isle of Man. Certification covers the design and maintenance of navigational aids and systems, logistical support and associated technical services including consultancy. The Board is also certified to The International Safety Management Code, (ISM Code) in respect of our ships and marine management systems and OHSAS 18001.

For further information, please contact:

Northern Lighthouse Board
Lorna Hunter, Information Officer
Tel 0131 473 3100
Fax 0131 220 2093
Email: enquiries@nlb.org.uk
www.nlb.org.uk