Les Hanois Lighthouse
| Les Hanois Lighthouse | |||
.jpg) Les Hanois Lighthouse during a volcanic ash sunset | |||
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| Location | |||
| Location: | Les Hanois | ||
| Location: | 49°26’6"N, 2°42’8"W | ||
| Characteristics | |||
| Height: | 118 feet | ||
| Tower shape: | tapered cylindrical tower, with helipad | ||
| Tower marking: | white tower | ||
| Light: | White group flashing twice, 3.2 seconds apart, every 13 seconds | ||
| Intensity: | 89,900 candela | ||
| Focal height: | 108 feet | ||
| Range: | 20 nautical miles | ||
| Admiralty No.: | A1580 | ||
| History | |||
| Built 1862 | |||
| Information | |||
Les Hanois Lighthouse was constructed between 1860 and 1862 to a new design by James Douglass, and was first lit on 8 December 1862. It is sited on the rock known as Le Biseau,[1] or Le Bisé,[2] part of the reef Les Hanois one mile north west of Pleinmont where the Trinity House cottages were built. It was erected in response to an increasing number of shipwrecks on the treacherous rocks off the western coast of Guernsey, including the wreck of HMS Boreas in 1807.[3] An article appeared in The Times on 15 July 1850 asking about the necessity of a Lighthouse at Pleinmont Point[4]
Construction
The lighthouse was constructed in Cornish granite rather than stone from Guernsey. Cornish masons were employed to dress the stone on the castle pier in St Peter Port.[2] Construction workers were accommodated in Fort Grey.
The tapered granite tower, painted white, is notable in terms of lighthouse engineering because it was the first to be built with all the stones dovetailed together both laterally and vertically, thereby making the construction a single solid mass. The cement mortar in the joints formed between stone faces lock the dovetails so that the stones cannot be separated without being broken. This method, used for the first time at the Hanois Lighthouse, became the pattern adopted for subsequent lighthouses built on sea rocks.
The helicopter pad on top of the lighthouse was built in 1979. The lighthouse was demanned in January 1996 following automation. Conversion to work from solar power required a slowing down of the optic, changing the character of the light, so as to reduce the power requirement and deliver the 20 nautical mile range required.
Purpose
The role of the light is to provide a mark warning of the reefs and rocks to the west of Guernsey and providing a position fix for vessels entering the Channel Traffic Separation Scheme.[5]
The reef Les Hanois includes, besides Le Bisé and numerous small rocks, the following major rocks: Le Grand Hanois, Le Petit Hanois, La Percée, Round Rock and La Grosse Rocque.[2]
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("Wikimedia Commons" has material about Les Hanois Lighthouse) |
References
- ↑ "Le Hanois Lighthouse". Guernsey Scenes. http://www.cwgsy.net/private%2Fbaf/htm_files/hanois.htm.
- ↑ 2.0 2.1 2.2 Coysh, Victor (1985). Channel Islets. Guernsey: Guernsey Press. ISBN 0902550128.
- ↑ "100 men lost: HMS Boreas, 28 November 1807". http://www.priaulxlibrary.co.uk/articles/article/100-men-lost-hms-boreas-28-november-1807.
- ↑ "SHIP NEWS Pleinmont Point, Guernsey, Necessity of a Lighthouse.". The Times: p. 7a. 15 July 1850.
- ↑ "Les Hanois Lighthouse". Trinity House. http://www.trinityhouse.co.uk/lighthouses/lighthouse_list/les_hanois.html.
| Lighthouses of Trinity House |
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Great Britain: |
| Channel Islands and Gibraltar: Casquets • Europa Point • Les Hanois • Sark |