Rathlin West Light, Keeble Td, Rathlin Island, Co. Antrim

Rathlin West Light is a lighthouse complex built by the Commissioners of Irish Lights between 1912 and 1916, designed by Charles William Scott, Engineer to the Commissioners of Irish Lights from 1900 to 1930. It is located halfway down the cliff face at Bull Point, at the western tip of Rathlin Island, surrounded on three sides by inaccessible sea cliffs and to the east by undulating moorland. The complex is unusually complete, retaining virtually all its original fabric, and represents one of the finest intact examples of a 20th century lighthouse in Northern Ireland.

The use of mass concrete for all the buildings and structures — with the exception of the lantern itself — was innovative for its time. Most strikingly, the lantern sits at the base of the tower rather than its top, making this unique among lighthouses in Northern Ireland. This was a deliberate engineering decision: at over 100 metres above sea level, a conventional lantern placed at the top of the accommodation tower would have risked obscuration by sea mist. Positioning it at the base of the cliff-face tower solved this problem. The complex is arranged across several vertical levels connected by an internal staircase and an external glacis (a massive concrete ramped structure built against the cliff face), and is described here from bottom to top.

TOWER, LANTERN, PLATFORMS AND STORE

The tower stands six storeys high and was formerly used to accommodate lighthouse keepers and workmen. It is constructed entirely of mass concrete, with painted white walls and band-rusticated quoins. The flat roof is covered with a waterproof membrane and has a low parapet, rendered chimneys to the north and south sides with narrow string courses and oversailing caps, and a moulded bracketed cornice at the eaves. The four lowermost floors are built directly against the vertical cliff face; the fifth connects with the engine house; only the top floor is fully exposed on all four sides. The top floor is marked by a wide string course, which continues eastwards as a cornice around the engine house roof, and has a moulded cill course running around it.

All openings have flat heads. Those on all floors except the top also have stucco architraves. Each floor except the top has a 2-over-2 sliding timber sash to each exposed side lighting the main rooms, with smaller 2-over-2 sashes to the right of the south elevation and up the left of the north elevation lighting the landings and half-landings respectively. There are two exceptions to this pattern: on the south elevation, the main windows on the second and third floors are 4-over-4 sashes and there is no ground floor landing window; on the north elevation there is no half-landing window between the second and third floors.

The lantern sits at the base of the west side of the tower. It is of cast-iron construction, painted white, and rests on a low 16-sided concrete base painted black. The lower half of the metal section is also 16-sided, with circular ventilation holes around its top that are adjustable from inside, and a small projecting observation window on the cant facing west out to sea. The upper half is circular, vertically divided into 16 sections, 12 of which are fenestrated with three rows of curved window panes facing north, west and south. The four rear segments facing east into the tower are blanked off to prevent the beam from reflecting back off the tower wall. A stage at cill level provides access around the windows for cleaning, reached from the north and south by vertical steel ladders, with brackets on the window frame mullions for additional handholds. The lantern is surmounted by a conical metal roof, topped by a raised ventilator with a decorative wrought-iron finial that also serves as a lightning conductor. An ogee cast-iron gutter runs around the rim of the roof and empties into a small downpipe at the rear. The roof is accessible via a vertical steel ladder from the top of the linking porch, with circular hand- and foot rails affixed to it for safe maintenance access. The tower and lantern are connected by a small mass concrete porch with a flat roof and a painted timber door on its south elevation.

Concrete platforms extend to the north and south of the lantern. To the east they are bounded by a high mass-concrete wall built against the cliff face; to the west (the seaward side) by a single strand of wire rope on metal posts. The north platform carries a red emergency light, provided for use should the main lantern lamp fail. At the north end of the south platform is a small flat-roofed concrete store with a painted timber door on its north elevation.

FORMER ENGINE HOUSE, PLATFORMS, TANKS AND STORE

One level up from the lantern platform, accessible via the tower's internal staircase and also by steps down the glacis, is the former engine house. This single-storey, two-bay building is aligned northwest to southeast and adjoins the tower's fourth floor on its east side. It is of reinforced-concrete construction with a flat roof covered with a waterproof membrane, two small ventilators, and a low parapet. The painted walls have a slightly advanced base course, band-rusticated quoins, and a moulded cornice. All openings have flat heads and stucco architraves. Painted timber doors are located on its south, southwest and northeast sides; single windows are on the west, southwest and southeast sides; and three windows face northeast. All window openings have 2-over-2 sliding timber sashes with concrete cills. A small timber lean-to shed abuts the northeast elevation.

Platforms flank the engine house to the east and west. A concrete wall runs along the west sides of both platforms; a replacement modern steel railing runs along the east side of the east platform. At the north and south ends of the east platform stand small concrete water tanks, with larger tanks directly behind the southeast end of the engine house. These stored rainwater collected from the glacis for general use, for cooling the engines, and in later years for the central heating system. Drinking water was drawn from a spring at the base of the glacis and stored in a galvanised metal cistern, which has long since been removed. The four compressed-air tanks that were also sited on this platform are similarly gone. On the west platform, at its southwest end, is a small flat-roofed concrete building with a single painted timber door, now used for general storage.

GLACIS

The glacis is a shuttered mass-concrete structure built against the 45-degree slope between the engine house platform and the top platform. Two sets of steps provide access. The first runs straight up from the engine house platform to a balcony on the glacis, with an intermediate landing. From the balcony, three staggered staircases run diagonally up to the top platform. The straight staircase has two-bar tubular metal railings on both sides; the three staggered staircases have railings on their outer edges; and a three-bar railing encloses the intermediate balcony. From the balcony, a concrete path also runs up the west side of the upper half of the glacis before making a dogleg turn to reach the south end of the oil store, with a two-bar railing along its outer edge. An original painted cast-iron compressed-air pipe runs up the face of the glacis from the engine house below and into the base of the top platform.

OIL STORE, FOG SIGNAL HOUSE AND TOP PLATFORM

At the top level of the complex, accessed by a single-lane unsurfaced track from the public road, the former oil store sits just below the top platform at the head of the glacis. It is a single-storey, three-bay reinforced-concrete building aligned north to south, with its principal elevation facing west. The flat oversailing roof has five raised skylights (now with modern metal grilles over them), a two-bar tubular steel railing around its perimeter, and three cast-metal downpipes along its west side. The south end has a double-leaf door; the west elevation has two doors and four windows. All doors are painted timber; the windows have 2-by-3-pane metal frames with concrete cills and stucco architraves. The north end is blank and the east elevation is likewise blank, being cut into the slope. A narrow walkway runs along the frontage.

The fog signal house stands at a slightly higher level than the oil store and projects northwest from the edge of the top platform. It is a single-storey, single-bay reinforced-concrete building with a flat roof, its only opening being a double-leaf painted timber door on its southeast elevation. There is no internal public access. A narrow platform on the northwest side of the building is enclosed by a two-bar tubular metal railing. A painted metal fog horn brought from elsewhere was mounted on a circular concrete plinth in front of the building in 2015 for visitor display purposes; the original fog horn was housed inside. The top platform is bounded along its west edge by a concrete wall, with a gap — now glazed over — that was formerly used for hoisting goods and materials up and down the glacis by means of a hand-operated winch (long removed). Along the east side of the top platform is a modern single-storey RSPB visitor centre of stone, concrete and glass, built in 2015, with the area between it and the platform edge newly concreted.

ENTRANCE GATES AND PERIMETER FENCE

An unsurfaced single-lane track runs southeast from the top platform to the site entrance, which consists of a concrete wall and two square gate posts, all of rendered concrete. The site boundary is marked by a two-bar tubular metal railing on concrete posts.

HISTORICAL BACKGROUND

The idea of a lighthouse at this location was first explored in 1902, but construction did not begin until 1912. Because of the restricted space and limited access at Bull Point, it was impossible to accommodate lighthouse keepers' families on site; separate housing was therefore provided at the East Light. The substantial engineering works required included re-profiling the cliff face and constructing the glacis. Building was also accompanied by the construction of a pier and inclined tramway at Cooraghy, 1.2 kilometres to the southeast, for the off-loading of construction materials delivered by boat, as well as a single-track connecting the two sites. Although construction was completed in 1916 at a cost of £400,000, the First World War delayed the first exhibition of the light until 10 March 1919.

The light initially used vaporised paraffin as its illuminant, stored in vertical cylindrical tanks in the oil store. On 15 July 1925, a diaphone (compressed-air) fog signal came into operation — a 15-second blast every minute in conditions of low visibility. The compressed air was stored in four external metal tanks on the platform to the north of the engine house and piped up the face of the glacis to the signal house. The engine house contained several Ruston and Hornsby engines operating the compressors. The paraffin oil light was replaced by an electric lamp on 15 June 1986, and the Ruston and Hornsby hot-bulb engines were superseded by Lister diesel engines linked to generators charging batteries to power the lamp. The same tanks used for paraffin storage were later also used for the diesel fuel and subsequently for the central heating boiler oil.

On 17 April 1982, the diaphone fog signal was replaced by an electric one, triggered by a fog detector in the tower during misty conditions. This signal was discontinued on 30 November 1995. From that point, though the light had previously operated only during hours of darkness, it also began operating in daylight at times of reduced visibility. The lighthouse was de-manned on 30 November 1983 and became fully automated. It was initially monitored remotely from Rathlin East Light and is now monitored from Irish Lights' Dun Laoghaire headquarters. A part-time Attendant continues to look after the premises. Mains electricity was installed in November 1996, the engines and generators were scrapped, and a small Lister-Petter engine was installed in the former oil store to charge back-up batteries in the event of mains failure.

The character of the light is a 0.4-second red flash every five seconds across a 210-degree arc. It sits 62 metres (204 feet) above mean high water spring level and has a nominal range of 22 nautical miles (approximately 25 statute miles). In the event of simultaneous failure of both the main lamp and its back-up, an emergency light at the edge of the lantern platform provides a 0.5-second red flash every five seconds.

For a number of years the engine room was used by the Royal Society for the Protection of Birds as a visitor exhibition space, and the flanking platforms were opened to the public for observing nesting seabirds on the cliffs. In 2015 a new visitor centre was built at the top of the glacis and the entire premises — with the exception of the lantern interior — were opened to the general public as part of a joint initiative between Irish Lights and the RSPB under Irish Lights' Great Lighthouses of Ireland all-Ireland tourism programme.

The West Light has group value with Cooraghy Pier, the South Light, the East Light, and the ancillary lighthouse buildings on the eastern shore of Rathlin Island.