Haulbowline Lighthouse, Greencastle, Newry, Co Down, BT34

Haulbowline Lighthouse is a granite ashlar tower lighthouse standing in Carlingford Lough, County Down, designed by George Halpin Senior and built under his direction by the Dublin Ballast Board. Its light was first exhibited on 1 September 1824. It was converted to electric operation and de-manned in 1965, making it possibly the first lighthouse in Ireland to be automated.

The tower stands approximately 38 metres above high water level on a rock that is exposed only at spring tides. It sits inside the Bar — a shallow limestone rock sill crossing the mouth of the lough, through which a channel has since been cut to allow deep-draught vessels to pass. The tower's base flares outward in a bell-mouth splay, a profile specifically designed to reduce the impact of wave action. This feature is not found on land-based lighthouses and reflects the tower's wave-washed position.

At the base, a landing stage of large pre-cast concrete blocks incorporates a vertical metal ladder. A short vertical metal ladder, affixed to the tower wall above the stage, leads up to a projecting granite balcony supported on four moulded granite brackets. This balcony formerly had a cast-iron railing — the base markings of which survive — now replaced with a galvanised metal rail. A pair of wooden doors opens into the interior. To the left of the ladder is a galvanised steel derrick.

Halfway up the tower on the seaward side is a small projecting structure known as the half-tide room. It has six canted sides and a curved roof surmounted by a ball finial. The sides are horizontally divided into three sections: the lower two bands are infilled with metal sheets, each bearing a motif cast in relief on both the outside and inside faces — harp, Boadicea, sextant, rigged schooner, globe, map and compass, and anchor. The top band is glazed, with the exception of one infilled panel. A very narrow balcony runs around the outside of the half-tide room, fitted with a white-painted handrail composed of vertical and diagonal cast-iron elements in a Chinoiserie style that mimics bamboo. At each corner post of the room, level with the bottom of the glazed section, is a decorative projecting cast-iron Chinese dolphin.

Around the top of the tower is a deep moulded cornice. The inner skin of the tower continues upward to form a parapet wall on the inside. Around the outer rim of the cornice is a white-painted handrail in the same Chinoiserie bamboo style as that of the half-tide room. The balcony formed between this inner parapet and outer handrail, running around the full circumference of the tower top, is accessed through a pair of metal doors from the seventh floor. On the County Down (Cranfield) side of the balcony, a small wooden platform sits over the handrail with a flagpole beside it; this was formerly used for semaphore signalling. On the seaward side of the balcony, a vertical foghorn sits on a concrete platform cast in situ on top of the stonework. A radio communications mast is also present. The parapet has a moulded cornice, above which sits the lantern.

The lantern is a 16-sided white-painted cast-iron framework with glazing to all sides. The corner posts are fluted, and each side is divided into three glazed panels. At the bottom corner of each top panel is a decorative Chinese dolphin projection to the corner post, which may have served as handles when cleaning the exterior glass. The lantern is surmounted by a shallow cornice, above which rises a ribbed curved metal roof topped by a cylindrical ventilator — reflecting the tower's origin as a paraffin-burning light. The lantern can be accessed from the balcony by a vertical metal ladder attached to its outside. A lightning conductor runs from the lantern down the outer face of the tower to below the watermark.

Internally, the spatial organisation follows the characteristic lighthouse arrangement of one function per floor. Although the original workings have been removed — as has been a continual requirement to ensure continued operation of such structures — the tower retains vestiges of its original equipment, notably the lantern ventilator and a lead-weight wall recess. Other original details survive including the semaphore platform and a wall recess for the range on the mess floor, both of which record the building's formerly manned status.

Also associated with the lighthouse are two leading lights situated to the east, both of which are included in the listing. Each comprises a white-painted structure supported on a metal skeleton, containing a small light (now gas-lit) and a large red alignment triangle. The more easterly of the two, near Green Island, is set higher than the other to ensure it is not obscured by the western light on Vidal Bank. A vessel wishing to pass through the deepened section of the Bar aligns the two leading lights and maintains that course with the lighthouse to port. Once the turning light on the lighthouse becomes visible, vessels alter course towards the middle of the channel and proceed to Greenore and Warrenpoint. The first leading light is located at grid reference J 2518 1064 and the second at J 2481 1095.

The lighthouse takes its name from the rocky bank on which it stands, a Norse name meaning "haunt of the eels." Although a lighthouse at Cranfield Point had been operating since 1803, its position proved ineffective in guiding vessels safely through the lough. In 1817, a group of Newry merchants petitioned the Dublin Ballast Board to erect a new light, resulting in the present structure. The original light was a fixed white paraffin light, accompanied by a half-tide light halfway up the seaward face of the tower and a fog bell. During daylight hours, when the water was high enough to cross the Bar, a black cone was displayed in place of the fixed white light; the half-tide light served the same purpose during darkness. This arrangement became redundant in 1868 when the Carlingford Lough Commissioners deepened the channel through the Bar. The fixed white light was subsequently superseded by an occulting light and then a flashing light. In connection with the new deepened channel, two screw-pile leading lights were erected to the west of the lighthouse and first exhibited in 1873; these were converted from oil to acetylene in 1922. From 1824 to 1922, the lighthouse keepers and their families lived at Cranfield Point. They then moved to new dwellings at Greencastle.

The half-tide room is the only such feature on any lighthouse in Ulster, and directly recalls the navigational constraints imposed by the Bar before the channel was cut in the 1860s. The lighthouse is one of only three wave-washed lights in Northern Ireland, the others being the Maidens off the County Antrim coast and South Rock off the County Down coast, making it a rare example of an unusual structural type. It is also one of eleven lighthouses in Northern Ireland that were originally manned, the others being, from south to north: St John's Point, South Rock, Donaghadee, Lighthouse Island (two lights), Mew Island, Black Head, the Maidens (two lights), and Rathlin (two lights).

The Greenore Point harbour light on the County Louth side of the lough was also erected by George Halpin Senior, in 1830, though it was abandoned in 1986.

The lighthouse is well-proportioned and well-executed in its architectural character, and is enhanced by the unusual embellishment of the half-tide and lantern balconies. Its setting is further enhanced by the fact that it is entirely surrounded by water yet clearly visible from the shore. It also has group value in association with the two leading lights and the Bar channel. Its presence at the mouth of Carlingford Lough reflects the historical importance of Greenore and Newry as active trading ports up to the early 20th century.