Fastnet Lighthouse

The present day lighthouse on Fastnet rock is the second to be built on the island and was intended to replace the old Cape Clear light. Established in 1818, Cape Clear had been built on the highest point of the island’s southern cliffs and was regularly enveloped in mist. This coupled with the sinking of the packet ship Stephen Whitney near Crookhaven with the loss of 92 of the 110 passengers and crew on board, triggered the decision to relocate the light to a new location.

The first lighthouse to be built on the rock used the latest technology of cast iron plates bolted together with an inner lining of brick. Completed in 1854, it wasn’t long before the shortcomings of this technique in stormy conditions became obvious. A new external casing was constructed around the tower and the cavity filled with masonry. It happened that a nearby lighthouse on Calf rock at the entrance to Bantry bay had been similarly reinforced, but during a storm in 1881, the whole tower above the bracing snapped off and disappeared below the waves. Happily no one was killed, but it certainly dispelled any complacency about the strength of the tower at Fastnet and the decision was hastily made to replace the cast iron tower with a more resilient one hewn from granite.

The new tower took five years to build. Each granite block is dovetailed into its neighbour, bonding the structure into a virtual monolith. Every one of the 2,074 stones, weighing from 1¾ to 3 tonnes, was set by the Commissioners’ foreman, James Kavanagh. Despite its fortress like construction, Fastnet was designed to bow with the gales of the Atlantic. During the most ferocious storms the top of the tower can sway as much as a metre from side to side. At 30 metres above low water it is the tallest lighthouse on the Irish coast.

The lighthouse is perhaps best recognised as the midpoint of one of the world’s classic offshore yachting races, the Fastnet race, a 1,126 kilometre round trip from Cowes on the, Isle of Wight round the rock and back again to the finish at Plymouth.

Location:    51°23.358′ North, 09°36.178′ West.

Elevation:   49 m

Character:  Fl W 5s.

Range:         50 km