Trevose Head Lighthouse

Construction

The site was surveyed by order of the Trinity Board in July 1844 with a design submitted that November and approved February 1845. Building began in that May with the laying out of the road and contract entered into with the builders the next month.^[4] During gales on 20–21 November 1846 scaffolding attached to the tower was blown away.^[6]

After completion of the first tower, it was determined that the light was under certain circumstances liable to be mistaken by mariners. A second lower light^[7] was therefore proposed and (the decision having been taken in June 1847) it was constructed, 50 feet in front of the first light, with a covered passage between them for use by the lighthouse keepers.^[4] Only the first built 'high' light now remains.

Designed by engineer James Walker^[7] the two original lights, 'high' and 'low', were constructed under the supervision of Henry Norris^[7] by builders Jacob & Thomas Olver of Falmouth.^[8][4][7] They were provided with a pair of first-order fixed optics by Henry Lépaute of Paris^[7] and each had an oil lamp with 4 concentric wicks manufactured by Messrs. Wilkins & Co. of Long Acre.^[4][7]

The light was first lit on 1 December 1847.^[7][9]

Later developments

In 1882, under Engineer-in-Chief James Douglass, the 'high' light was changed to an occulting light, now with a six-wick lamp, and the 'low' light was put out of use.^[10] Under the new arrangement the high light was eclipsed (for three seconds) three times in quick succession every minute.^[11]

From 1911 a series of further improvements were made. First, the keepers' dwellings were upgraded.^[10] Then, in 1912 the light was again updated and a rotating optic (weighing 3.6 tons) was installed, which would remain in service for over a century.^[12] At the same time, the addition of a red filter to the lamp meant that (as from 1 August 1912) the lighthouse displayed one short red flash every five seconds.^[13]

Work also began on installing a fog signal: a 5-inch siren attached to a 36-foot-long acoustic horn, which came into service in 1913; it was nicknamed 'Lord Rayleigh's trumpet' after its designer, the eminent physicist and acoustician.^[14] The trumpet and siren were built on to the roof of a new engine house, containing a pair of Hornsby oil engines, the air compressor, reservoirs and other equipment.

In 1920 a paraffin vapour burner replaced the oil lamp; it continued to show one red flash every 5 seconds.

The fog signal equipment all remained in service until 1963, when the trumpet and siren were replaced by a set of eight 'supertyfon' air horns mounted in a metal turret on top of the engine house. New diesel engines and Reavell compressors were provided.^[14] The light was electrified in 1974.^[10]

In 1995 the lighthouse was automated and became unmanned.^[15] The red colour was removed from the light at this time and the rotation speed of the optic was slowed.^[10] By this stage the engine house was suffering cracking due to erosion; with automation a new fog signal was installed (a stack of electric emitters placed at the foot of the lighthouse) whereupon the old engine house was demolished.^[14]

The fog signal was decommissioned in 2012.^[16] In 2023 the revolving optic was removed, having been in service for over 110 years.^[17] It was replaced by a fixed LED lantern, which now produces the required flash. At the same time nominal range of the light was reduced from 21 to 18 nautical miles.^[18]

The former keepers' cottages (arranged in two semi-detached pairs) are nowadays available to rent as holiday accommodation.^[19]