Wolf Rock Lighthouse is on the Wolf Rock, a single rock located east of St Mary's, Isles of Scilly and southwest of Land's End, in Cornwall, England. The fissures in the rock produce a howling sound in gales, hence the name. The lighthouse is in height and is constructed from Cornish granite prepared at Penzance, on the mainland of Cornwall. It took eight years, from 1861 to 1869, to build due to the treacherous weather conditions that can occur between Cornwall and Scilly. The light can be seen from Land's End by day and night, and lies about one third of the distance from Land's End to the Isles of Scilly. It has a range of and was automated in 1988. The lighthouse was the first in the world to be fitted with a helipad.
Geology
Situated between Cornwall and the Isles of Scilly, the Wolf Rock is a small plug of phonoliticlava formed during the early part of the Cretaceousperiod and is unlike any rock exposed on the Cornish mainland.
History
The Gabrielle of Milford Haven was wrecked on the Wolf Rock in 1394. Her cargo, worth £1000, was washed ashore in Cornwall and collected as wreck.
Earlier seamarks
In 1790, the Corporation of Trinity House received a patent of the Crown to build a lighthouse on Wolf Rock. The rights were leased to a Lt. Henry Smith; but the project was transferred to the less exposed location of the Longships, where construction of a lighthouse proceeded. On Wolf Rock, rather than a lighthouse, Lt. Smith went on to build a high wrought iron daymark, in diameter and supported by six stays. A metal effigy of a wolf was placed on top; but by 1795 the daymark was washed away. In the late 1830s John Thurburn built a beacon, which was completed on 15 July 1840, and in November of that year was wrecked by storms when the pole and globe on its top were washed away and not replaced until 1842 but they were once more washed away in a storm on 9 October 1844. Trinity House engineer James Walker constructed a high cone-shaped beacon, which took five years to build. Made of iron plates and filled with concrete rubble this was completed in 1848, it can still be seen next to the lighthouse.
Construction of the lighthouse
In April 1860, Trinity House applied to the Board of Trade for funds to build a lighthouse on Wolf Rock. Approval was given and Walker, as engineer-in-chief, drew up designs for a masonry tower, tapering in diameter from at the base to at the top. Details of the design followed closely that of other Walker-built lighthouses: the recently completed Bishop Rock and Hanois lights, and the Smalls. While his designs were inspired by Smeaton's third Eddystone Lighthouse, Walker introduced new innovations, not least the use of vertical as well as horizontal dovetail joints. Nicholas's son James Douglass was appointed as resident engineer, and in July 1861 he arrived and surveyed the rock. The following March work began on excavating the foundations. In October 1862, James Walker died. James Douglass replaced him as engineer-in-chief to the Trinity House; James's younger brother, William Douglass, then became resident engineer at Wolf Rock. William himself laid the first stone of the new tower on 6 August 1864. Masonry construction was completed on 19 July 1869. The finished tower was topped by a lantern storey manufactured by Chance Brothers of Smethwick to James Douglass's design. The lantern had previously been exhibited at the Paris Exhibition of 1867 as an example of the latest in lantern technology, using curved rather than flat panes of glass and helical rather than straight glazing bars. James Chance of Chance Brothers had designed a large rotating multi-panel optic for installation in the tower, high by diameter. In order to differentiate the light from the nearby St Agnes lighthouse and from Les Hanois Lighthouse it was resolved that the Wolf Rock light should revolve and flash alternately red and white; in order to achieve the required characteristic it was planned to install 'ruby' coloured panes of glass over half the panels on the optic. It was known, however, that the intensity of a light was reduced when shone through coloured glass, so Chance conducted experiments to measure the precise difference. It was concluded that the comparative intensity of clear glass to red was 21 to 9 ; therefore the red-covered panels on the optic were made wider than the others by the same proportion, in order to maintain an even intensity across the colour-change.
Operational summary
The light first shone in January 1870 and flashed red and white as planned. The completed optic was described by Douglass as "probably the most perfect for the purpose that has yet been constructed"; it continued in use for the next hundred years. The optic was rotated by a clockwork drive, that required winding every four hours. A 7-cwt bell, hung from the lantern gallery, was sounded in fog; driven by a separate clockwork mechanism, it rang three times every fifteen seconds. The Wolf Rock was the site of a hake fishery in the 1870s, especially by fishermen from St Ives with 400 employed in October 1879. In 1904 a reedfog signal was installed; it remained in use until after the Second World War. In 1955 electrification came to Wolf Rock Lighthouse: a 15 kW tungsten filament lamp was installed in place of the oil lamp, within the old optic, and a set of diesel generators were installed. Then, in 1972 Wolf Rock became the first lighthouse in the world to be fitted with a helipad ; this greatly eased the challenge of getting keepers to and from the lighthouse in heavy seas. The last keepers left Wolf Rock in July 1988, when the lighthouse became fully automated; an electric emitter replaced the diaphone fog signal at this time. Fifteen years later the lighthouse was converted to solar power, with photovoltaic cells being installed around the exterior of the helideck support structure.
Present day
The lighthouse continues in operation; its solar-powered lamp has a range of ; it flashes once every 15 seconds and is remotely monitored from the Trinity House Planning Centre in Harwich, Essex.
