Gun House and Magazine Stores, Orlock Coastal Battery, In the grounds of 25 Coastguard Lane, Orlock, Groomsport, Co Down BT19 6LR

Gun House and Magazine Stores, Orlock Coastal Battery, Groomsport, Co Down

Built in 1940 as part of the wartime coastal defences for Belfast Lough, this is one of only three largely intact coast artillery gun houses surviving in Northern Ireland. The structure sits in the front garden of No. 25 Coastguard Lane, Orlock, where it has recently been converted into guest accommodation for the adjacent house.

HISTORICAL BACKGROUND

At the outbreak of the Second World War, two First World War vintage coastal batteries at Kilroot and Grey Point were fully manned and an examination service — marine and coastal defences intended to inspect and verify shipping entering port — was established at Belfast Lough. During the inter-war years, defensive strongpoints had been added to Grey Point, whose wall was made pentagonal, and the fort also received two searchlight positions (known as Defence Electric Lights) and a new battery observation post. Further changes followed during the war: searchlights, redesignated Coast Defence Searchlights, were added to Kilroot, and concrete shelters for the 6-inch Mk VII guns were constructed due to the increased vulnerability of coastal batteries to air attack. With only four guns considered insufficient to protect a major port like Belfast, two new batteries were built during 1940 — one at Larne, County Antrim, and the other here at Orlock, County Down.

The Orlock battery was established in August 1940 with an initial emplacement of one 6-inch Mk VII gun; a second gun was noted as having been "mounted and in action" by the following November. Known as "C coast battery," the installation was manned by the Auxiliary Territorial Service and took over ship examination duties from the battery at Grey Point in February 1941. The site originally comprised two gun houses and two searchlight positions. The 6-inch Mk VII gun would have been mounted just forward of the open face of the concrete shelter — the shelter was designed to protect the crew, not the gun — in order to maximise the arc of fire. This area has since been built over by the addition of a north-facing bay, making it impossible to assess at present whether any remains of the original gun mounting or holdfasts survive below.

Orlock was one of five coastal batteries in Northern Ireland during the Second World War: two pre-existing sites at Grey Point and Kilroot, and three emergency batteries constructed after the outbreak of war — Orlock, Larne, and Magilligan. All except Magilligan were fitted with protective concrete gun shelters. The shelters at Larne and Kilroot were demolished after the war, leaving only those at Grey Point and Orlock standing. The westerly gun house at Orlock was subsequently converted into and considerably enlarged as a private dwelling (now No. 29 Coastguard Lane), making the present structure one of only three largely intact coast artillery gun houses remaining in Northern Ireland.

DESCRIPTION

The building is a single-storey, flat-roofed structure of in-situ concrete, rendered and painted, facing roughly northwards towards Belfast Lough. It is largely windowless. The structure is unusual in that it was originally two smaller, closely positioned but separate buildings — a gun house and magazine stores — which were linked together around the 1950s. The two formerly separate buildings are now conjoined under a single timber-framed, felted flat roof laid over the original flat concrete panelled roof. Walls throughout are rendered and painted in-situ concrete. Rainwater pipes are modern uPVC.

The building is approached from the south, where the eastern elevation — facing the more recently built house — functions as the main entrance elevation. This elevation shows three vents to the right of a door that spans what was originally the gap between the stores and the main gun house building. The western elevation is plain painted render. The southern elevation is largely plain and partly obscured by planting.

To the north elevation, a late 20th century flat-roofed addition has been constructed to enclose what was originally the open gun emplacement bay. This addition is of no architectural interest: it incorporates a uPVC sliding double door to the left, a large uPVC picture window to the right, and a decorative circular light to the east. All windows are modern uPVC.

Recent excavation work around the building's immediate perimeter has revealed that the concrete walls extend approximately 300 to 900 millimetres below existing ground level. Concrete footings and pads are partly visible below the building to the north and north-east where excavated. A mains sewer line runs somewhere to the north-north-east of the building, with a manhole visible approximately 5 to 6 metres from the original face of the gun house.

SETTING

The building's original setting allowed uninterrupted views over Belfast Lough towards Kilroot and the Copeland Islands. Views to the north and north-west remain as originally experienced. Land to the rear and to the south has since been developed with large detached houses whose gardens now overlook the lough. To the north lies a National Trust managed coastal path and foreshore. Despite these changes, the open views of the coast and lough remain largely unchanged, and are direct evidence of the building's defensive purpose and the largely intact character of its setting.

GROUP VALUE AND SIGNIFICANCE

The gun house and magazine stores have group value with the Coast Artillery Searchlight position (Defence Heritage Record DHR00330:003), which is visible from the site, and the Searchlight building (DHR00330:001) just beyond. Together these rare upstanding structures form a group of special architectural and historic interest. Their collective relationship to the lough gives this location significance in terms of understanding defence heritage structures that remain in situ in Northern Ireland.

Despite reversible additions to the interior and the later north-facing bay, the gun house and stores retain their largely original materials, form, structure, and plan. The building's significance as a simple but important military defence structure remains clearly legible. It is recorded on the Defence Heritage Record as DHR00330:002.