Roche's Point Lighthouse

Roche's Point Lighthouse

Roche's Point lighthouse seen from the Swansea-Cork ferry
Roche's Point Lighthouse
Ireland
Location Cork Harbour, Ireland
Coordinates 51°47′34.8″N 8°15′16.6″W / 51.793000°N 8.254611°W / 51.793000; -8.254611
Year first constructed 1835
Automated 1995
Construction masonry
Tower shape cylindrical tower with balcony and lantern
Markings / pattern white painted
Height 15 metres (49 ft)
Focal height 30 metres (98 ft)
Range 20 nautical miles (white light)
16 nautical miles red light
Characteristic Fl WR 3s
Fog signal deactivated in January 11, 2011
Admiralty number A5718
NGA number 6356
ARLHS number IRE-061
Ireland number CIL-0250[1]
Lightbulb inside Fresnel lens at Roche's Point
Second order Fresnel lens at Roche's Point lighthouse

Roche's Point Lighthouse is situated at the entrance to Cork Harbour, Ireland. A lighthouse was first established on 4 June 1817 to guide ships into Cork Harbour. The original tower was deemed too small and in 1835 was replaced by the larger present tower which is 49 feet high with a diameter of 12 feet.[2]

Light

The original light apparatus consisted of ten Argand oil lamps and ten catoptric reflectors. In 1876 the optic was changed to a Second Order Fresnel lens, which is still in use. The lighthouse was converted to electric in 1970. The character of the light was occulting 20s (on for 15 seconds and off for 5 seconds). This was altered on the 15 August 1993 to Fl WR 3s (one white and red flash every three seconds). From April 1978 the light has been exhibited in conditions of poor visibility while the fog signal was sounding. Roche's Point has red sectors built into the main light to mark navigational hazards approaching the harbour. The sectors are as follows:[2]

The part of the light that is seen from land is unintensified so as not to disturb those on shore. The light at full intensity (facing sea) has a range of 20 nautical miles for the white light (37.04 km) and 17 nautical miles for the red sector (31.5 km). The light is 30 meters above high water and continues to be exhibited by day in periods of poor visibility. The lighthouse and adjacent buildings are painted white for daytime conspicuousness.

The Roche's Point lighthouse was automated in 1995.[3] Apart from the engine house and adjacent building, all the other buildings were sold at public auction.

Fog signals

A bell was established at Roche's Point in 1864 to warn mariners in poor visibility.[2] This was replaced by a siren fog signal on 1 December 1898.[2] The fog signal changed again in 1949 when a diaphone was installed with a character of one two-second blast every thirty seconds.[2] In 1995 when the lighthouse was automated an electric fog signal (ELG 300-04) replaced the diaphone.[2] This electric fog signal was connected to a fog detector which activated the fog signal if visibility fell below three nautical miles. On 11 January 2011 the Commissioners of Irish Lights, despite much opposition, discontinued all Irish fog signals.[2] This brought an end to a long era of fog signaling at Roche's Point.

Lighthouse Keeper

William Jervis James was the lighthouse keeper from 29/10/1934 to 17/08/1936.

References

  1. ↑ Roche's Point Lighthouse Commissioners of the Irish Lights
  2. 1 2 3 4 5 6 7 "Lighthouses". Roches Point. CIL. Retrieved 24 January 2012.
  3. ↑ McStay, M.B. "Automation of Lighthouses". Engineering Works. CIL. Retrieved 24 January 2012.


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Coordinates: 51°47′35″N 8°15′17″W / 51.7930°N 8.2546°W / 51.7930; -8.2546

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