Ammunition bunker

The Department's description

Exterior description and setting

Building 1
One of 21 ammunition bunkers erected in Fincarn Glen by American military personnel in 1941-42.
Situated towards the SW corner of the glen, this single-storey, single-bay structure is aligned NW-SE with its entrance at SE. It is of rectangular plan and semicircular cross-section.
All its components are of pre-formed galvanised steel. Its roof and sides are of overlapping curved corrugated sheeting, all completely covered with earth.
The two end walls are of flat steel panels held together with flanges bolted together up their outside faces. These walls have flat tops and sloping sides which extend beyond the roof and sides to retain their earth covering. The back wall (at NW) was probably covered with earth originally, but this has been partly removed.
There were originally two outward-opening steel doors at its SE end, both of which are now missing along with a substantial portion of the wall above it (to increase the head height) and to its right. On the wall to the left of the doorway is a painted figure '3' and a partly decipherable legend reading: "Fire point no [?]/ Buckets [?]/ Stirrup pump". The figure '3' is also painted on the wall to the right of the doorway and there is also a cast-aluminium electrical junction box bearing the legend: "100 amp 660 volt flameproof junction box/ Type Walsall" 9346BX/ Groups 2 & 3. PLP 2026/ Isolate supply elsewhere/ before removing covers/ Made in England". Below the top box are two smaller ones, the covers of which read: "This box must be/ entirely filled/ with sealing/ compound". There is a concrete platform in front of the doorway.
An overgrown earthen blast berm encloses the bunker on all sides. The embankment at SE is just forward of the entrance.
The bunker , which is covered with grass and scrub, is now in use as a tractor shed.

Setting:
All the ammo bunkers were widely spaced out along the glen to minimise collateral damage should one have exploded. The nearest to this one are 100m to SW (HB01/06/019H Building 2) and 120m to NE (HB01/06/019G Building 2).
This example sits at the top of a grassy slope rising up the west side of the glen. The post-and-wire perimeter fence around the former military establishment runs along its NW end.

Building 2
One of 21 ammunition bunkers erected in Fincarn Glen by American military personnel in 1941-42.
Situated at the SW corner of the glen, this single-storey, single-bay structure is aligned NW-SE with its entrance at SE. It is of rectangular plan and semicircular cross-section.
All its components are of pre-formed galvanised steel. Its roof and sides are of overlapping curved corrugated sheeting, all completely covered with earth.
The two end walls are of flat steel panels held together with flanges bolted together up their outside faces. These walls have flat tops and sloping sides which extend beyond the roof and sides to retain their earth covering. The back wall (at NW) was probably covered with earth originally, but this has been partly removed to enable a window opening to be inserted to facilitate the subsequent use of the bunker.
There were originally two outward-opening steel doors at its SE end, both of which are now missing. On the wall to the left of the doorway is a painted figure '3' and two metal brackets (for fire buckets). The figure '3' is also painted on the wall to the right of the doorway. In front of the doorway is a small concrete platform. Part of the wall to the right of the door has been removed along with the panelling over the door head.
An overgrown earthen blast berm encloses the bunker on all sides. The embankment at SE is just forward of the entrance.
The bunker , which is covered with grass and scrub, is now in use as an animal shed.

Setting:
All the ammo bunkers were widely spaced out along the glen to minimise collateral damage should one have exploded. The nearest to this one are 85m to SW (HB01/06/019H Building 3) and 100m to NE down the slope (HB01/06/019H Building 1).
This example sits at the top of a grassy slope rising up the west side of the glen. The post-and-wire perimeter fence around the former military establishment runs along its NW end.

Building 3
One of 21 ammunition bunkers erected in Fincarn Glen by American military personnel in 1941-42.
Situated at the SW corner of the glen, this single-storey, single-bay structure is aligned NW-SE with its entrance at SE. It is of rectangular plan and semicircular cross-section.
All its components are of pre-formed galvanised steel. Its roof and sides are of overlapping curved corrugated sheeting, all completely covered with earth.
The two end walls are of flat steel panels held together with flanges bolted together up their outside faces. These walls have flat tops and sloping sides which extend beyond the roof and sides to retain their earth covering. The back wall (at NW) was probably covered with earth originally, but this has been partly removed to enable a window to be inserted to facilitate the subsequent use of the bunker.
There are two outward-opening steel doors at its SE end, the bottom halves of both of which have both been cut off. On the wall to the left of the doorway is a painted figure '3' and two metal brackets (for fire buckets). The figure '3' is also painted on the wall to the right of the doorway. In front of the doorway is a small concrete platform, with stairs up at left.
A low earthen blast berm encloses the structure on all but its SE side. The OS map indicates a berm at this end as well, just forward of the entrance, but it has been removed and no traces of it survive.
Latterly used as an agricultural shed, this former bunker now lies abandoned.

Setting:
All the ammo bunkers were widely spaced out along the glen to minimise collateral damage should one have exploded. The nearest to this one are 85m to NE (HB01/06/019H Building 1) and 115m to SW down the slope (HB01/06/019J).
This example sits at the top of a grassy slope rising up the west side of the glen. The post-and-wire perimeter fence around the former military establishment runs along its NW end. A modern industrial shed has also been constructed to its south.

Historical information

The Fincarn Ammunition Depot was constructed by American military personnel with the assistance of local labour. It was completed by May 1942 and used for the temporary storage of munitions shipped into Lisahally Port on Lough Foyle, 6km to the north. From Fincarn, the ammo was transferred to military bases such as the nearby Maydown and Eglinton airfields.
The steelwork on many of the ammo bunkers bear the legend "Armco Ingot Iron Manufactured by the American Rolling Mill Co Middletown, Ohio 2oz coating". 'Armco' is the acronym of the American Roller Mill Corporation of Middletown Ohio, founded in 1899 and a pioneer of continuous rolled sheet steel production. The name is still used generically to this day to denote cylindrical corrugated metal culverts under roads etc.
This bunker is essentially a standard Armco hut, the size of which was 50ft x 20ft x 10ft radius. Its heavy-duty galvanised steel sheeting and arched cross-section made it capable of being buried under several metres of earth. It is not unlike a Quonset hut, the American equivalent of the British Nissen hut, but without any internal framework and by a different maker.
C Company of the 1st Provisional Marine Battalion, an infantry brigade of the US Marine Corps, was based nearby at Beech Hill and performed guard duty here for a time. The bunkers may also have been used for as a chemical storage depot (known as C-910) between November 1943 and August 1944.
Although erected in the early 1940s, no buildings or structures are depicted in Fincarn Glen on the 1948-49 OS map, presumably for security reasons. All the features are, however, shown on the 1963 OS map under the caption "Disused Camp Site".

References - Primary Sources:
1. PRONI OS/6/5/14/5. OS 1:2500 map, Co Londonderry sheet 14-05 (1948-49).
2. PRONI OS/11/37/5/1. OS Irish Grid map sheet 37-05 (1966-67).
3. PRONI OS/11/37/9/1. OS Irish Grid map sheet 37-05 (1968).

Secondary Sources
1. A. Glenfield, Second World War in Northern Ireland, .
2. ARMCO history: ,, and .
3. Quonset huts: J. Decker & C. Chiei (eds), Quonset: Metal Living for a Modern Age (Princetown: Princetown Architectural Press, 2005), and .
4. Chemical storage, .

Criteria for listing: architectural interest

Not listed

Criteria for listing: historic interest

Not listed

Evaluation

This record has now been protected by scheduling under LDY014:014 and can be viewed on the NISMR database:

Building 1
A corrugated steel ammunition bunker built by the US military authorities in 1941-42 for the temporary storage of ammunition.
This ammo bunker is of architectural interest as a good example of a Second World War ammunition store. Its superstructure is of lightweight pre-fabricated components so that it could be transported easily (across the Atlantic in this case) and quickly erected using unskilled local labour. Its semicircular arch design did away with the need for an internal frame and no foundations were required as it was self-supporting. Pre-fabrication was extensively used during the war for military buildings and structures. Once fabricated, earth dug from its vicinity was used to give the store added protection against blast damage and also camouflaged it.
The bunker's setting is of special note - in a narrow glen which could be easily defended at both ends. The spacing between it and its neighbours - 100+ metres - also minimised any damage should one have exploded. It also has considerable group value in being one of 21 ammo stores and one of 24 surviving military structures in Fincarn Glen.
Historically, this bunker had a rare and unusual function. Virtually all its original fabric survives in an unaltered stare. It is a tangible reminder of the large American presence in and around Londonderry during the Second World War. The Fincarn ammo stores are probably the largest surviving concentration of their type anywhere in the Province.
Because of their specialist function, American connection and survival as a group, they are not only of local interest, but of provincial significance as well.

Building 2
A corrugated steel ammunition bunker built by the US military authorities in 1941-42 for the temporary storage of ammunition.
This ammo bunker is of architectural interest as a good example of a Second World War ammunition store. Its superstructure is of lightweight pre-fabricated components so that it could be transported easily (across the Atlantic in this case) and quickly erected using unskilled local labour. Its semicircular arch design did away with the need for an internal frame and no foundations were required as it was self-supporting. Pre-fabrication was extensively used during the war for military buildings and structures. Once fabricated, earth dug from its vicinity was used to give the store added protection against blast damage and also camouflaged it.
The bunker's setting is of special note - in a narrow glen which could be easily defended at both ends. The spacing between it and its neighbours - 85+ metres - also minimised any damage should one have exploded. It also has considerable group value in being one of 21 ammo stores and one of 24 surviving military structures in Fincarn Glen.
Historically, this bunker had a rare and unusual function. Virtually all its original fabric survives in an unaltered stare. It is a tangible reminder of the large American presence in and around Londonderry during the Second World War. The Fincarn ammo stores are probably the largest surviving concentration of their type anywhere in the Province.
Because of their specialist function, American connection and survival as a group, they are not only of local interest, but of provincial significance as well.

Building 3
A corrugated steel ammunition bunker built by the US military authorities in 1941-42 for the temporary storage of ammunition.
This ammo bunker is of architectural interest as a good example of a Second World War ammunition store. Its superstructure is of lightweight pre-fabricated components so that it could be transported easily (across the Atlantic in this case) and quickly erected using unskilled local labour. Its semicircular arch design did away with the need for an internal frame and no foundations were required as it was self-supporting. Pre-fabrication was extensively used during the war for military buildings and structures. Once fabricated, earth dug from its vicinity was used to give the store added protection against blast damage and also camouflaged it.
The bunker's setting is of special note - in a narrow glen which could be easily defended at both ends. The spacing between it and its neighbours - 85+ metres - also minimised any damage should one have exploded. It also has considerable group value in being one of 21 ammo stores and one of 24 surviving military structures in Fincarn Glen.
Historically, this bunker had a rare and unusual function. Virtually all its original fabric survives in an unaltered stare. It is a tangible reminder of the large American presence in and around Londonderry during the Second World War. The Fincarn ammo stores are probably the largest surviving concentration of their type anywhere in the Province.
Because of their specialist function, American connection and survival as a group, they are not only of local interest, but of provincial significance as well.