Former Radar Station, Torr Road, Ballycastle, Co. Antrim, BT54

Former RAF Murlough Bay CHEL R11 ROTOR Radar Station, built 1955–56

This former Cold War radar station on the eastern slope of the east summit of Greenanmore (297 metres) was built by the Air Ministry in 1955–56 as part of the ROTOR air defence programme, a government early warning system designed to detect and intercept potential nuclear attacks by Soviet bombers. It is one of only three surviving ROTOR sites in Northern Ireland, the others being at Castlerock, County Londonderry, and Killard Point, near Strangford, County Down. Cold War radar sites of this type are extremely rare in Northern Ireland, and this station is of national significance as part of the UK's Cold War military history.

Historical Background

The ROTOR programme was developed in three stages: ROTOR 1 (1952–54), ROTOR 2 (1952–58), and ROTOR 3 (1954–57). The first two phases concentrated on the eastern coast of Britain, regarded as most vulnerable to attack. ROTOR 3 added fourteen surface sites to cover the UK's northern and western approaches, of which this station formed a part. Officially known as RAF Murlough Bay CHEL R11 ROTOR Radar Station and codenamed 'URB', the designation 'CHEL' refers to the Chain Home Extra Low radar system, used to detect aircraft flying very low over the sea to avoid conventional radar detection. 'R11' denotes the specific building type: an above-ground structure, comparable in function but not form to the underground R2-type bunkers built along the more vulnerable eastern coast of Britain. The station was equipped with a Type 14 Mk IX search radar mounted on a gantry and a Type 13 Mk VII height finder on a plinth, equipment probably supplied by Marconi's Wireless Telegraph Company. In 1958, just two years after completion, Murlough Bay was reduced to inactive status when the entire ROTOR network was superseded by the more effective Linesman/Mediator radar network, which required fewer stations. The site is first recorded, though uncaptioned, on the Ordnance Survey 25-inch map of 1971. It is now privately owned. At Crockanore, approximately 3 kilometres west-northwest, were two functionally related sites — a VHF transmitter block and a VHF receiver block — both now demolished.

Site Layout and Setting

The site extends approximately 300 metres east–west by 125 metres north–south and is enclosed by a post-and-wire security fence, with the original entrance gates replaced by a standard galvanised steel field gate. An original metal lamp standard survives just inside the left-hand side of the entrance. The various buildings are linked by a concrete track from the public road, and the ground both inside and outside the fence is open grass and heather moorland. The station's setting is highly significant: its position commands extensive, uninterrupted views across the North Channel to the Mull of Kintyre, ideal for detecting low-flying enemy aircraft.

The site comprises six original mid-20th-century buildings, three more recent additions, and a prehistoric megalith on the hill's summit. The plain, utilitarian architectural character — rendered concrete blockwork walls and metal-framed windows — is typical of Second World War and early Cold War military construction. The arrangement of the buildings and the internal room configurations of the Technical/Domestic and Standby blocks directly reflect the site's different operational functions. Externally, roofs, walls, and metal-framed windows largely survive; internally, much has been lost. The surviving fabric is historically authentic. The listed elements are the Technical/Domestic Block, the Standby Set House, the Radar Building, the Dog Kennels, and the original lamp standard.

Building 1 — Technical/Domestic Block

The main building in the complex is a single-storey, multi-bay structure approached along a track from the public road. It sits on a wide terrace cut into the east side of the hillside and comprises two principal sections connected by a corridor: the Technical Block, aligned northeast–southwest and originally housing the communications equipment, and the Domestic Block to its southwest, which contained a kitchen, rest rooms, and toilets. The entire building is now derelict, though parts are in use as animal byres.

The roofs are flat, reinforced concrete with bituminous waterproofing and oversailing eaves, arranged at three levels: the roof over room 03 is slightly higher than the rest of the Technical Block, while those over rooms 02 and 07–12 are slightly lower. The roof edges are slightly raised, behind which replacement plastic rainwater downpipes have been installed. Two vertical metal ventilators project from the roof of room 16. The walls are of cement-rendered concrete blockwork with flat-headed openings and concrete window cills. No doors survive, but all the multi-paned metal-framed windows are largely intact; some have fixed lights and others have bucket-type opening sections.

The main entrance was a sliding doorway at the northeast end of the building; the horizontal rail on which the door was mounted remains clearly visible. To its left is a 5×3-paned window serving the guardroom. To the right, the southeast elevations of rooms 19 and 20 each have large doorways, and room 20 also has a small doorway at its northeast end. The southeast elevation divides into four sections from left to right: room 06 has a 3×3-paned opening and, to its right, a modern insertion with a Perspex cover; room 03, which is slightly higher, has two 5×4-paned windows with a 3×2-paned bucket opening to the middle; set back is a corridor section with three 4×3-paned windows with 2×2-paned opening sections; and the projecting section at the right (room 02) is blank. At the right-hand end of the southwest elevation is the blank wall of room 06. The central section of this elevation comprises the linking corridor between the Technical and Domestic blocks, with an original doorway to the centre, now sheeted over. To its right is a projecting bay with a 3×3-paned window, and to its left is a 5×2-paned window. To the left of the corridor, the Domestic Block has four 1×3-paned windows to its southeast elevation and a 5×3-paned window (with 3×2-paned opening section) to its southwest elevation.

The northwest elevation has, at its right-hand end, the projecting Domestic Block with a 3×3-paned window to the middle (some frames missing) and flanking 5×3-paned windows with 3×2-pane opening sections. The northeast side of this block has three 1×3-pane windows to the left and a 5×3-paned window with 3×2-pane opening to the right; its southeast elevation has three 1×3-pane windows. The Technical Block occupies the remainder of the northwest elevation and has, from left to right: 2×3, 3×3, and 2×3-paned windows to room 18; a 3×3 window to room 17; a 5×3 window with two rectangular vent openings below, now sheeted over with corrugated iron, to room 16; a 3×3 window to room 15; and 2×3, 3×3, and 2×3-paned windows to room 14. A hole has been punched through the wall of room 13 to admit light to the interior and is covered with Perspex.

Building 2 — Standby Set House

Situated just northeast of the Technical Block and now connected to it by a modern concrete block wall, this single-storey, three-bay building originally housed a back-up engine and electricity generator for use in the event of a power failure in the Technical Block. It is now disused and derelict. The central section is aligned northwest–southeast with lower bays at the southeast and northeast. A later single-storey building has been added along the northeast side.

All three original bays have flat oversailing felted reinforced-concrete roofs and rendered concrete block walls. The southeast end has a pair of replacement double-leaf corrugated metal doors; above it is a short projecting pipe and, at top left, a projecting square metal plate. The originally exposed sections of both the southwest and northeast elevations each have a doorway with a 3×3-paned metal-framed casement overlight; the northeast doorway is now externally obscured by the later addition. Two high-level and two low-level square ventilators are set into the northwest end wall. The southwest bay has a doorway on its southeast elevation and an infilled doorway at its northwest end; the northeast bay has a large door opening on its southeast elevation only. In both cases the actual doors are missing. The later addition to the northeast has a flat felted timber roof and rendered concrete block walls, with a wooden door and two timber-framed windows along its northeast side.

Building 3 — Radar Building

This small single-storey, single-bay building is located 135 metres west-northwest of the Technical Block, near the summit of the hill. According to researcher Nick Catford, a Type 14 radar dish was originally mounted on a metal gantry directly over it; both dish and gantry have long since been removed. The building has a flat oversailing roof and cement-rendered concrete block walls. Its only opening is a doorway on the east elevation, reached by concrete steps. This opening appears originally to have been designed for a double-leaf door but has since been narrowed to accommodate a single modern door. Surrounding the building are four large rectangular concrete blocks, on top of which are the cut-off remnants of metal brackets; these were the anchor points for the angled gantry legs that supported the radar dish.

Building 4 — Dog Kennels

Just to the right on entering the site from the main road, concrete steps lead down to a small single-storey, two-bay building that originally housed guard dogs. It is aligned east–west with its principal elevation facing south. The roof is monopitched corrugated asbestos; the walls are rendered concrete block with small vents at eaves and floor level all around. A small circular vent rises from the roof of the east bay. There are no rainwater goods. Each bay has a doorway on the south elevation. The east bay has a window to each elevation, while the west bay has only one window, on its north elevation. All windows have flat concrete heads and cills, but the original frames have been replaced with corrugated transparent plastic sheeting.

Building 5 — Guard House

This building stood immediately northeast of the Dog Kennels. Only its concrete floor and a single basal course of concrete blockwork now survive. Openings along the southeast side indicate it was originally subdivided into three rooms. Vestiges of metal uprights on top of the blockwork suggest the walls may have been a sheeted metal-framed construction.

Structure 6 — Sewage Works

At the lowest, eastern point of the site is a small sewage treatment works. It comprises an underground sludge settling tank, from which a pipe conveyed liquid effluent to two contiguous filter beds. One of the steel cover plates on the tanks is marked: "The Dover Engineering Works Ltd, England, Patent No 313012." The filter beds consist of rectangular tanks enclosed by low rendered brick walls, across the bottoms of which run multiple cast-iron pipes embedded in clinker. The ends of the pipes project through the walls and are fitted with metal bungs. A further rendered brick tank sits just beyond the lower, eastern end of the filter beds. In operation, effluent was likely ducted from the settling tank at the upper, western end into the pipes within the filters, from which it escaped through perforations on the pipes' undersides, percolated through the clinker, and was then collected in the pit at the lower end before presumably draining away. The bungs on the pipe ends may have served as access points for unblocking.

Miscellaneous Features

Fifty metres northwest of the Technical Block (Feature A) is a modern guyed radio mast with two associated modern buildings enclosed by a post-and-wire fence. One is a prefabricated container with roof and sides clad in profiled metal sheeting. The other is a small single-storey building with a pitched artificial slate roof, raised gable walls, plastic rainwater goods, and cement-rendered walls; it has a pair of double-leaf doors on its north gable and a ventilation duct on its south gable and is otherwise devoid of openings.

Fifty metres west of the radio mast (Feature B) is a drive-in concrete-lined silo pit with a loading hardstand at its northwest end.

Thirty metres southeast of the Radar Building (Feature C) is a modern anemometer and a small corrugated metal hut containing weather-measuring equipment. Immediately north of the weather station is a concrete platform of unknown function, which may possibly have been the site of the Type 13 height-finding equipment operated alongside the Type 14 radar dish.

On the summit of the hill (Feature D) is a scatter of large undressed rocks containing the vestiges of a Neolithic passage tomb, now a Scheduled Monument. Just outside the southern perimeter fence (Feature E) are what are thought to be booley huts, also a recorded site on the Sites and Monuments Record.