Hyperradiant Fresnel lens

The lantern of Makapuu Point Light, showing the hyperradiant lens within; note the people on the gallery

Hyper-radial or hyperradiant Fresnel lenses are Fresnel lenses used in lighthouses. They are larger than "first-order" lenses, having a focal length (radius) of 1330 mm (52.36 inches). The idea was mentioned by Thomas Stevenson in 1869<ref name=usls/> and first proposed by John Richardson Wigham in 1872, and again proposed by Thomas Stevenson in 1885 (infringing Wigham's patent).<ref>Template:Cite journal</ref>

The hyper-radial lens was made in 1885 by the F. Barbier Company in Paris as a test lens for the lighthouse illumination trials then going on at the South Foreland Lighthouse in the United Kingdom (UK). Chance Brothers Glass Company made their first hyper-radial lens in 1887 in the UK.<ref name=usls>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

These lenses were originally named biform, and later triform and quadriform lenses, by Wigham. Thomas Stevenson used the term hyperradiant lens, and later they were renamed the hyper-radial lens by James Kenward of the Chance Brothers Glass Company.

The hyper-radial Fresnel lenses were the largest ever put into use and were installed in about two dozen major "landfall" beacons around the world. The recipients include Makapu'u Point lighthouse on Oahu Island in Hawaii, Cabo de São Vicente in Portugal, Manora Point in Karachi, Pakistan, the Bishop Rock off the coast of Cornwall (in the UK), Cabo de Santa Marta in Brazil, and Cape Race, Newfoundland.<ref name=usls/> By the 1920s, high-intensity lamp technology had rendered lenses of this size obsolete.

Lighthouses

Template:Geogroup Hyperradiant optics were installed in thirty-one lighthouses around the world. A large proportion were destined for lights around Great Britain and Ireland, with another four used at sites around Sri Lanka. Despite the improvements in lighting technology, a number are still in use. Others are in museums, either on display or in storage. The remainder have been broken up or lost.<ref name=usls/><ref name=bness>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name=flannan>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Name	Image	Location Coordinates	Country	Company	Date	Notes
Barberyn	Error creating thumbnail:	Barberyn Template:Coord	Sri Lanka	Chance	1888	The optic gave a flash of white light every minute.<ref name=gaz>Template:Cite news</ref><ref name=usls/>
Bazaruto	File:Bazaruto Lighthouse.jpg	Bazaruto Island Template:Coord	Mozambique	Barbier et al.	1913	Still in situ, but badly damaged.<ref name=usls/>
Beiyushan	File:HRDB-023 Tower Pei-Yu-Shan BBT.jpg	Yushan Islands Template:Coord	China	Barbier et al.	1895	Made up of four panels, "each lens panel has two partial bull's-eyes giving a double group-flashing characteristic". It is not in the lantern room anymore, the fate of the optic is not known.<ref name=usls/>
Bell Rock	File:Bell Rock Lighthouse showing reef (cropped).jpg	Inchcape Template:Coord	United Kingdom	Henry Lepaute	1902	Lens removed in 1964. Made up of two panels, one panel is in the Signal Tower Museum, Arbroath. The location of the other panel is unknown.<ref name=usls/>
Berlenga	File:Farol da Berlenga 01.jpg	Berlengas Template:Coord	Portugal	Barbier et al.	1897	Made up of three panels, it was taken out of the tower in 1985. Two of the panels went to the Lighthouse Directorate Museum in Lisbon, one is on display, the other stored but damaged. The third was taken to the museum in the Santa Marta Lighthouse, Cascais.<ref name=usls/>
Bishop Rock	File:National Maritime Museum Cornwall (8826).jpg	Isle of Scilly Template:Coord	United Kingdom	Chance	1887	Following automation in 1992 the bi-form lens was split, the lower tier remains in use, the upper tier is on display in the National Maritime Museum Cornwall.<ref name=usls/>
Buchan Ness	File:Buchan Ness Lighthouse 03.jpg	Boddam, Aberdeenshire Template:Coord	United Kingdom	Chance	1910	A combined first order and hyper-radial optic, taken out in 1978 and stored at the Museum of Scottish Lighthouses.<ref name=usls/><ref name=bness/>
Bull Rock	File:Bull Rock Lighthouse.jpg	Dursey Island Template:Coord	Ireland	Barbier et al.	1888	Bi-form lens was removed in 1991 by the Commissioners of Irish Lights.<ref name=usls/>
Cabo de São Vicente	File:Portugal M Suessen-2324.jpg	Cape St. Vincent Template:Coord	Portugal	Barbier et al.	1906	Still in situ and in use.<ref name=usls/>
Cap d'Antifer	File:HRDB-010 Lens Cap d'Antifer BBT 1889.jpg	La Poterie-Cap-d'Antifer Template:Coord	France	Barbier et al.	1894	Made up of six bullseye panels. It was lost when German soldiers demolished the entire lighthouse at the end of Occupation of France in August 1944.<ref name=usls/>
Cape Race	File:Cape Race Light.jpg	Cape Race Template:Coord	Canada	Chance	1907	Still in situ and in use.<ref name=usls/>
Dondra Head	File:Dondra Head Lighthouse - ATennakoon.jpg	Dondra Head Template:Coord	Sri Lanka	Chance	1888	The optic gave a flash of white light every twenty seconds.<ref name=gaz/><ref name=usls/>
Fair Isle North	File:Fair Isle North lighthouse (geograph 3079981).jpg	Fair Isle Template:Coord	United Kingdom	Barbier et al.	1892	Made up four panels, it was taken from the lighthouse in 1980, but its location is not known.<ref name=usls/>
Flannan Isles	File:Flannan Isles- close-up of the lighthouse (geograph 3201960).jpg	Flannan Isle Template:Coord	United Kingdom	Henry Lepaute	1899	Made up of two panels, in a clamshell configuration. Broken up in 1971, a fragment of one of the prisms is on display in the Museum of Scottish Lighthouses.<ref name=flannan/><ref name=usls/>
Great Basses Reef	File:Greatbasses1.jpg	Southern Province Template:Coord	Sri Lanka	Chance	1888	Broken up in the 1960s.<ref name=usls/>
Hyskeir	File:Oigh Sgier - geograph.org.uk - 119673.jpg	Hyskeir Template:Coord	United Kingdom	Chance	1904	Still in situ and in use.<ref name=usls/>
Kinnaird Head	File:Kinnaird Head Castle Lighthouse 20110520 light.jpg	Kinnaird Head Template:Coord	United Kingdom	Chance	1902	Still in situ in the original tower which is part of the Museum of Scottish Lighthouses, which has been superseded by a modern lighthouse.<ref name=usls/>
Little Basses Reef	File:Little Basses Reef Im1876ev22-p355.jpg	Southern Province Template:Coord	Sri Lanka	Chance	1888	Broken up in the 1960s.<ref name=usls/>
Makapuu Point	File:Makapuu-Lighthouse-Oahu-Hawaii.jpg	Oahu Template:Coord	United States	Barbier et al.	1887	Still in situ and in use.<ref name=usls/>
Manora Point	File:Hyperradial Lens.jpg	Manora Template:Coord	Pakistan	Chance	1908	Made up of four bullseye panels, it is still in situ and in use.<ref name=usls/>
Mew Island	File:The Great Light (night view), Titanic Quarter, Belfast (November 2018) (Geograph 5966944 by Albert Bridge).jpg	Copeland Islands Template:Coord	United Kingdom	Barbier et al.	1928	The original 1887 Tory Island tri-form lens was re-engineered to create a bi-form lens. Taken out in 2014, it was renovated and has been relocated to the Titanic Quarter in Belfast as a tourist attraction known as the Great Light.<ref name=usls/>
Nólsoy	File:Nólsoy Lighthouse (1204455017).jpg	Nólsoy Template:Coord	Faroe Islands	Barbier et al.	1893	Still in situ and in use.<ref name=usls/>
Orfordness	File:Orford Ness Lighthouse - geograph.org.uk - 1457108.jpg	Orford Ness Template:Coord	United Kingdom	Chance	1909	Two secondary sector light panels, removed in 2014, as the tower is endangered by coastal erosion.<ref name=usls/>
Pakri	File:9496 Pakri tuletorn.jpg	Pakri Peninsula Template:Coord	Estonia	Barbier et al.	1889	The lighthouse was badly damaged and the lens was lost in 1941 during World War II.<ref name=usls/>
Pladda	File:Taighsolaisairpladaigh.jpg	Pladda Template:Coord	United Kingdom	Chance	1901	Made up of three bullseye panels, it was taken out of the tower, but its location is unknown. Reportedly moved to the Arran Heritage Museum.<ref name=usls/>
Round Island	File:Round Island Lighthouse - geograph.org.uk - 932637.jpg	Isles of Scilly Template:Coord	United Kingdom	Chance	1888	Bi-form, each tier made up of six panels. Removed in 1966, location not known.<ref name=usls/>
Rua Reidh	File:Gairloch - 1991 (geograph 3807617).jpg	Wester Ross Template:Coord	United Kingdom	Chance	1909	Made up of six panels. Removed in 1985, on display at Gairloch Heritage Museum.<ref name=usls/>
Santa Marta	File:FAROL DE SANTA MARTA. LAGUNA-SC, BRASIL.JPG	Laguna Template:Coord	Brazil	Barbier et al.	1891	Still in situ and in use.<ref name=usls/>
Spurn Point	File:Lighthouse at Spurn Head.jpg	Spurn Template:Coord	United Kingdom	Chance	1895	Location not known.<ref name=usls/> Made up of six lens panels it was removed in 1957 when the lighthouse was automated.
Sule Skerry	File:The lighthouse on Sule Skerry (geograph 6164846).jpg	Sule Skerry Template:Coord	United Kingdom	Barbier et al.	1895	Removed in 1977 and stored at the National Museum of Scotland.<ref name=usls/>
Tory Island	File:Lighthouse, Tory Island (geograph 2493032).jpg	Tory Island Template:Coord	Ireland	Chance	1887	Original 1887 tri-form was re-engineered by dividing up the bullseye panels, and creating a new bi-form optic for use at Mew Island in 1928. The second set of panels were used to create a second bi-form optic that is still in situ and in use.<ref name=usls/>

External links

• Wikimap showing lighthouse locations
• Makapuu Point Template:Webarchive