Inishmore was established in 1818 but unfortunately it was positioned too high, over 400 feet (122m) above sea level, and more often than not was shrouded in cloud or mist. Also it did not cover the North and South entrances to Galway Bay. Inishmore was replaced in 1857 by lights on Eeragh and Inisheer.
Three years before Inishmore was discontinued, the islanders anticipated losing what was, as well as a main sea light, a very useful guiding light for the harbour and bay of Killeany. Their request for a harbour light on Straw Island was favourable received by Inspector George Halpin Junior and fully supported by the Ballast Board who agreed to approach the Board of Trade in London stating that the cost of the new light could be included in the 1855 estimates. The Board of Trade replied by turning down the request as an unnecessary expense on the Mercantile Marine Fund. This finding was conveyed to the islanders.
Mr Thomas Thompson, the Agent for the Digby Estates on the Aran Islands took up the case for the islanders and addressed a strong letter to the Corporation pointing out that the locals had a vested interest in a lighthouse which they had enjoyed for over thirty years. He also enquired if the Inishmore light was to be removed and the harbour left in the dark. Mr Thompson?s letter was referred to the Board of Trade who in their reply, January 1855, still maintained that a new light could not be supported at the expense of the Mercantile Marine Fund.
Further approaches for a light on Straw Island were made in 1858 and 1859 when the islanders offered to relieve the Mercantile Marine Fund from the rent of the Inishmore lighthouse, ?21 together with the renewal fine of ?10.10.0 on each life. The Ballast Board wrote to the Board of Trade in May 1859 ? they did not even reply!
In November 1859, Mr Thompson once again wrote to the Board just simply reiterating his previous remarks and offer to relieve the rent. The Board, as before, were very sympathetic, wrote again to the Board of Trade asking them to consider a lighthouse on Straw Island and quoted part of a letter of Captain Bedford, RN, Coast Guard, that a light on Straw Island would be invaluable to local fishermen especially the 3,000 vessels from the Claddagh and others running for shelter, also it would render Gregory?s Sound available to vessels. The Ballast Board estimated a cost of ?453 to build and maintain the proposed light.
This time the Board of Trade were not so adamant in their reply the following month. They stated that they could see no reason why they should depart from their opinion that the proposed light is wanted for local rather than for passing trade but as passing vessels not bound for Galway often took shelter in Killeany Bay, a light on Straw Island might be useful. A light would be sanctioned if the locals paid two thirds of the annual maintenance but the Ballast Board would cease to maintain the light if local contributions were not paid.
Mr Thompson obviously did not think very much of the proposition, much preferring his own suggestions, but their Lordships in London could see no reason to alter their opinion and would not be justified in sanctioning a larger contribution from the Mercantile Marine Fund.
Almost six years passed before the subject was raised again, this time by the Board of Trade, stating they had received a memorial from an islander, Mr J. O'Flaherty, praying for a light on Straw Island. Towards the end of 1867, their Lordships considered the memorial, the sum of ?12 Mr Thompson said the locals could raise towards the maintenance and surprisingly plans and an estimated cost of £1,505 submitted by Mr J.S. Sloane, Engineer-in-Chief. Needless to say, the Board of Trade turned the request down.
Undeterred, Mr O'Flaherty wrote to the Board of Trade again in July 1868. A copy of his letter was sent to the Commissioners which was referred to the Inspecting Committee. In their report the following month, they stated that the subject of a light on Straw Island had been, on more than one occasion, brought to the Commissioners notice and they had strongly advocated a light, also the Merchant Shipping Act of 1854 stated that the Board of Trade undertook to maintain all existing harbour lights. They pointed out that the light on Inishmore did serve as a harbour light. During their recent visit, they had been made aware of numerous casualties including loss of life and thought perhaps a pile light similar to Dundalk or Spit Bank would be the answer. They concluded their report by mentioning the proprietors of the island were willing to forego the rent they received for the ?old? lighthouse and had no hesitation in recommending the application for favourable consideration. The report was referred to the Board of Trade who within two weeks stated that an application should be made to Trinity House in the usual manner together with costs.
By December 1868, Inspector Roberts submitted plans and a cost of £1,143. After a further report by the Secretary Mr Lees and the Inspector, Trinity House were advised in January 1869, who in their reply requested cost of erection, maintenance and deductions, and whether any toll could be made on fishing boats in Galway Bay. They also pointed out the high chimneys on Mr Sloane?s drawing would make the lantern sooty. By July 1871, Trinity House had conveyed their statutory sanction followed by the Board of Trade in October who also stated the light would be exempt from tolls.
Further plans were submitted by Mr Sloane in January 1872 which were approved by the Inspecting Committee. Tenders were invited for building in June and August without success so the Board suggested building the lighthouse and dwelling themselves. This was approved by the Board of Trade in May 1874 providing the title had been satisfactorily settled. The Deed of Conveyance for Straw Island is dated 4th September 1873 and on the same day, the premises at Oghil, where the Inishmore Lighthouse was, were surrendered.
Progress in building was very slow and eventually a Notice to Mariners was issued in August 1878 stating that a fixed red light would be established on 1st September 1878. The overall height of the small eight-foot (2.4m) internal diameter tower is thirty-five feet (10.6m). It was and still is painted white. Messrs. Edmundson and Co., Dublin supplied the fifth order optical apparatus with an oil lamp light source. The focal plane was thirty feet (9.1m) above high water.
The light was changed from fixed red to occulting white on 1st March 1905. The apparatus was supplied by Edmundson, using their original lens, and operated on the ventilation principle, that is, hot air from the oil lamp revolving the occulting shade.
For his efforts in saving the crew of the ?Hector? which was wrecked on Straw Island on 4th November 1911, Mr B.R. Jeffers, P.K., was awarded ?2 and an inscribed pair of binoculars by the R.N.L.I. and ?5 from the owners of the vessel.
Between 1913 and 1920, an Assistant Keeper instead of a Principal Keeper was in charge of the station. In each case, if the keeper was married, his wife acted as a Female Assistant; if the keeper was unmarried then he was assisted by a Supernumerary Keeper.
The light was converted to unwatched acetylene on 30th September 1926 having been recommended by the Inspecting Committee on Tour in 1923. A water to carbide acetylene generator was set up in what was the parlour of the dwelling and Chance Brothers supplied the 3,000 candelas apparatus which replaced the original lens. The new optic was rotated by an acetylene gas operated pecker mechanism. The character of the unwatched light was two white flashes every five seconds.
All redundant rooms of the dwelling were removed in 1938 leaving the generator house, a short corridor to the tower and two stores against the back wall.
Conversion to electric was effected on 23rd September 1980 when the acetylene generating plant was replaced by an Aerowatt 300 watt, 24 volt wind generator mounted on top of a steel mast in the lighthouse compound. The light source is an electric Pharos PRB46 Mk1 revolving lamp array. The generator charges batteries which supply current for the optic lamps.