Facts About Trinity House and British Lighthouses
The waters of the British Isles are surrounded by 31 shipping areas, that offer protection to shipping by way of 69 fully functioning lighthouses.
In days of old, the rocky coastline and outlying islands of Britain were ' lighted ' by way of bonfires and lanterns, which were easily blown out or toppled by high winds and storms, and were there to pinpoint the entrance to ports rather than to warn of imminent danger.
A lighthouse needs to be built high enough for it's light to be seen before the danger of the peril is reached.This is assertained by way of trigonometry, by taking the square root of the lighthouse height in feet and multiplying it by 1.17, to yield the distance of the horizon in nautical miles.
Therefore a lighthouse situated out to sea on a small rock would need to be very tall in order to be spotted in time, where as a lighthouse situated atop a high cliff - face could be much shorter in height.Hence the varying designs of lighthouses across the world.
VARIOUS LIGHTHOUSE DESIGNS OF THE 1800'S
( Taken from a Finnish collection of 1909.)
In 1514 King Henry VIII organised the Lighthouse Authority of Trinity House, by royal charter, a governing body that is still in existance today.
Trinity House is responsible for all provision and maintenence of navigational aids and maritime communication systems in British territorial waters.
The organisation is a non departmental public body with it's organisational headquarters situated in Trinity Square, London in a building designed by Samuel Wyatt in 1796.
Trinity House's operational headquarters are situated in Harwich, Essex, where it's operations are supported by the three vessels, THV Alert, THV Patricia and the THV Galatea.
Trinity House also owns a small secretariat building on Tower Hill, London and two residential buildings in the London Borough of greenwich.
Today Trinity House oversees 69 working lighthouses, although many more grace the British coastline, with many now privately owned and used as dwellings or holiday homes.
TRINITY HOUSE, TRINITY SQUARE, LONDON.
When the first lighthouses were built, they were manned by one or two men or even entire families, who were known as lighthouse keepers.
It was their job to light the beacon during the hours of darkness and during storms.In those days the beacon was generally oil filled, most probably whale or vegetable oil.
In 1822, Augustin - Jean Fresnel invented his Fresnel Lens, which completely revolutionised the lighthouse lantern, making the light much brighter and more easily seen, by concentrating light from an omnidirectional, rotating lens and light source, without the weight and volume required by the previous older types of oil lamps and parabolic refractor lenses.
These lens assemblies were first manned by way of a hand crank, meaning the lighthouse keeper would have to crank the lens assembly as regularly as every two hours, before eventually going on to be powered first by diesel and then electricity.
Automation of British lighthouses began in 1910, with the invention of the acetylene gas lamp.However this proved to be unpopular due to the problems of gas carriage and storage and the danger of explosion.
Therefore in the early 1900's Swedish scientist Gustav Dalen invented his Dalen Light, an electric solar lamp which was able to turn its self on at dusk and off again at dawn, an invention that saw Dalen win the Nobel Prize for chemistry in 1912.
Modern automation began in the 1980's with all of Britain's lighthouses becoming unmanned by 1998.
The automated lighthouses today flash a white light, varying from one flash every twenty seconds to 4 flashes every 15 seconds, depending on traffic volume of the surrounding waters.
THE FRESNEL LENS.
The oldest existance of a stone built lighthouse in the British Isles is situated at Dover Castle, believed to be Roman built and dating from 183.
Britain's oldest, complete example of a lighthouse, is a chalk built structure positioned on the Yorkshire / North Sea coast at Flamborough Head, built in 1674.
Britain's tallest lighthouse is at Skerryvore at a height of 49 metres, built in 1844 by Scots civil engineer Robert Stevenson, and situated 56 kilometres from the Argyll coast in Scotland.
MUCKLE FLUGGA LIGHTHOUSE
( Image courtesy of Erik Christensen, wikimedia commons )
Britain's most isolated lighthouse is at Sule Skerry, built in 1895, it is situated 59 kilometres from the coast of the Orkney Islands in the north of Scotland.
The lighthouse situated the furthest from the British coast is Europa Point in Gibraltar, built in 1838. This is Trinity House's most southerly and only lighthouse not situated within the territorial waters of the British Isles.
Britain's most northerly lighthouse is situated on the uninhabited Shetland island of Muckle Flugga, and was built in 1858 by brothers David and Thomas Stevenson, sons of Robert Stevenson who built 15 lighthouses and 6 bridges in and around Scotland during his exhulted career.
Britain's oldest brick built lighthouse, still usable but no longer functioning as a lighthouse, is the Leasowe Lighthouse situated on the Wirral Peninsula on Merseyside, built in 1763.
The last manned lighthouses in the United Kingdom were -
England - North Foreland, Kent. 1998.
Ireland - Baily Lighthouse, Howth Head, Dublin.1996.
Scottish mainland - Cape Wrath, Sutherland.1998.
Scottish Isles - Fair Isle South, Shetland islands.
Wales - .Nash Point, Llantwit Major. 1998.
For a complete map of all Britain's lighthouses, please visit - heritage/Lighthouses/Maps/Lighthouse
Title image - The British naval ensign.
BRITISH SHIPPING ZONES
OTHER INTERESTING READING ABOUT LIGHTHOUSES.
OTHER BRITISH BUILDINGS ARTICLES BY THE SAME AUTHOR;
© D.B.Bellamy.August 2010.
Images courtesy of wikimedia commons