Gretna, Hm Factory, Eastriggs Explosives Factory, Nitro-cotton Drying Area

Canmore ID 373559

NY26NE 146.0

Centred NY 25687 65008

Fifty-four moss- and grass- grown building platforms are situated in boggy ground between the Nitro-cotton production plant (NY26NE 140) to the W of the Saugh-hope Burn and the Nitro-glycerine Hills to its E (NY26NE 16.01-16.05). These cover an area extending 665m from WNW to ESE by 410m transversely. They are arranged in five rows each comprising fifteen buildings and in groups of three set about 65m apart. A group comprises a unit of two large buildings between which there is a smaller structure. This arrangement suggests that there was originally 23 units comprising as many as 68 buildings. The foundation platforms of the larger buildings are rectangular on plan and measure 39m from NNE to SSW by 5m transversely overall and up to 0.6m in height. Each has an expansion at one end, while at the other there is a slight contraction. The broader end is distinguished by three compartments, one of which contains an L-shaped concrete plinth measuring 3.5m from E to W by 2.5m transversely and 0.2m in height, while another has a threshold and was evidently a lobby. Where fragments of brick walls survive at the edge of the platform, they are no more than 0.2m in thickness and rise to 0.15m in height. There are traces of asphalt on the floors, which are broken by scars running ENE to WNW that result from the removal of internal walls delimiting small compartments. These walls do not extend the full width of the building as they seem to mark out a corridor. The smaller building platforms, which are positioned equidistant and centrally placed between these larger paired buildings, are also rectangular on plan and measure 7.5m from WSW to ENE by 6m transversely and up to 0.6m in height. Bolts and pipework are occasionally visible on their upper surface close to their edges. There is a centrally placed rectangular inspection pit 0.5m N of each.

The general area occupied by all these buildings was subsequently re-used. A narrow-gauge railway line crossed it to reach the Nissen hut magazines (NY 26SE 16.06) to the E. Another narrow gauge network with branch lines extending from it, slighted two of the larger buildings (NY 25676 65225, c.NY 25502 65073) and destroyed one of the smaller buildings (NY 26051 65018). This network served the eight steel-framed, brick-panelled explosives magazines within the general area (NY26NW 46.12: R24, R25, R26, R27, R28, R29, R32, R35) and the introduction of four of these (R27, R25, R28, R29) partly or wholly destroyed four of the larger earlier buildings. Subsequently, four roads were introduced (NY26NW 46.22).

The larger buildings are identified as ‘Quinan’ Drying Houses, while the smaller buildings are referred to as Air Apparatus Houses in the report (MMW 1919, 135-144, plan in text and two plates) given with a Ministry of Munitions of War report outlining the processes involved in the manufacture of the cordite propellant during the First World War at H.M. Factory, Gretna (Site 3). The arrangement of all 68 buildings was governed as much by the disposition of a narrow-gauge railway network that serviced these structures, as by the danger of explosion associated with the process for which they were constructed. The tapered end of the Drying Houses acted as a porch to which the narrow-gauge railway delivered wet nitro-cotton from the Screening House (NY26). From this porch it was transferred by hand to the Drying Chambers in which there were fifteen compartments each containing a drying pan into which hot or cold air was blown from the Air Apparatus Houses to complete the drying process. The nitro-cotton was then removed to a weighing room at the far end of the buildings, where the L-shaped blocks supported boot changing racks. It was then passed through another porch from which it was conveyed once again by the narrow-gauge railway network to the Nitro-glycerine Hills (NY26NE 16.01-16.05). The plan in the report (MMW 1919, 144) also shows the location of an office (c. NY 25825 64931), together with eleven women’s and two men’s lavatories which were distributed uniformly throughout the area. The two plates (622 and 623) show women working at the pans and swabbing down one of the Drying Houses. An undated plan (SUPP 10-39) held in the National Archives at Kew also shows the location of the office and the lavatories. A series of descriptions of blueprints (SUPP 10-18, 3261; SUPP 10-19, 3634), some blueprints (SUPP 10-25, 3364, 3365, 3365B, 3439, 3634, 5261), together with ground-based, contemporary official photographs taken during and after construction (MUN 5-297 pt1 167, 168, 211, 297; MUN 5-297 pt2 158A, 158B, 253, 332, 333B; MUN 5-297 pt3 360, 361, 399, 400; MUN 5-297 pt5, 717), held at the National Archives at Kew, illustrate the character of the buildings and their associated infrastructure. These sources show that the Drying Houses were either of timber or brick construction, but built to the same basic design. They were single storeyed buildings with asymmetrical ridged roofs covered with rubberoid, having a lobby at each end and standing to a height of 3.8m at wall head. There were twelve windows in the elevation furthest from the Air Apparatus House, two to each lobby and eight paired either side of three emergency doorways. In addition, these doorways had a small window above them. The opposite elevation was distinguished by a lean-to that contained the pipe work distributing the hot and cold air from the Air Apparatus House. There were sixteen windows above the lean-to’s roof and forty-five vents beneath the eaves. One gable had a doorway and a single window, while the other gable had a doorway and two windows. The former led into a porch at the tapered end of the building where the wet Nitro-cotton was delivered by a fireless steam locomotive running on narrow-gauge rails from which it was transferred to the wet lobby. A further doorway from this lobby connected with the Drying Chamber, which contained 15 compartments where the nitro-cotton was dried in batches and packed into bags. The Drying Chamber was lined with fire-retardant Uralite and the brickwork was painted white, while there were three long work benches situated opposite the fifteen compartments. A gutter running beneath these benches carried excess water to a sump outside the building from which it was conveyed to the Save-all (NY26NE 146.2). At the far end of the Drying Chamber there was a second lobby with a weighing machine, where the bagged nitro-cotton was packed into accumulator electric trucks and conveyed along a narrow-gauge railway to the Nitro-glycerine Hills.

The Air Apparatus Houses situated between the paired Drying Houses were rectangular on plan and measured 7.5m from WNW to ESE by 5m transversely (MMW 1919, 138-9). The report also indicates that these single storeyed buildings were constructed of brick, while ground-based, contemporary official photographs (MUN 5-297 pt1, 211; MUN 5-297 pt2, 253; MUN 5-297 pt3, 399) show that the WNW gable of the ridged roof was finished in timber and contained a louvre. The SSW elevation was distinguished by a single entrance with tall double doors, while two windows were situated in the WNW elevation. The men’s and women’s lavatories differed from one another in that the former comprised two compartments and were L-shaped on plan, while the latter were rectangular on plan. Again ground-based, contemporary official photographs (MUN 5-297 pt3, 360-1) show that the women’s lavatories were constructed of brick with a roof that sloped down from NNE to SSW and their entrances were protected by an L-shaped baffle extending from one side of the building.

Thirty-six buildings (9 timber, 27 brick) were offered for sale by auction as part of lot 494 on 22-5 July 1924 (HM Treasury 1924, 90-1; Carlisle City Archives, DX 170/38), when they were purchased by T. Johnstone (and others) of ‘Nether Albie’, Waterbeck, Gretna (Carlisle City Archives, DX 2040/3). An aerial photograph (M124/13 04129) flown on 19 August 1940 shows that many of the Drying Houses and their associated Air Apparatus Houses had been reduced to their foundations, while others had been unroofed. However, three Drying Houses remained intact and had been treated with a new coat of camouflage paint (NY 25782 65092, NY 25847 65073, NY 25914 65053). Another was painted white (NY 26019 64921), while one possibly remained unpainted (c.NY 25900 64742). A plan taken in 1956 (Dumfries: Eastriggs Sub Depot. Site Plan of Depot 26.06.1956, 4283 held at the Devil’s Porridge Museum, Eastriggs) shows that four of these drying Houses had been converted for use with the narrow gauge line system (NY 25782 65092, NY 25847 65073, NY 25914 65053, NY 26019 64921). All five were still standing in 1975 (39/RAF/4701 P0025, flown 6 May 1975), but two (NY 25782 65092, c.NY 25900 64742) had been destroyed by 1988 (ASS/62588, flown 13 June 1988). The three that remained were finally pulled down after 2015 (NY 25847 65073, NY 25914 65053, NY 26019 64921). However, a plan taken in 2012 (Ministry of Defence DM Eastriggs Dumfries & Galloway, MOD Boundary and Buildings Plan, 2012) shows that two of these buildings had been renumbered R18 and R19 (NY 25847 65073 and NY 25914 65053).

Drying Houses:

Unit A: NY 25475 65284, NY 25541 65265;

Unit B: NY 25610 65246, NY 25645 65233;

Unit C: NY 25745 65210, NY 25812 65192;

Unit D: NY 25878 65172, NY 25945 65153;

Unit E: NY 26013 65136, NY 26080 65119;

Unit F: NY 25449 65183, NY 25514 65164;

Unit G: NY 25581 65146, NY 25650 65126;

Unit H: NY 25718 65108, NY 25782 65090;

Unit J: NY 25851 65073 (R18), NY 25914 65053 (R19);

Unit K: NY 25984 65034;

Unit L: NY 25423 65083, NY 25486 65065;

Unit M: NY 25555 65046, NY 25621 65029;

Unit N: NY 25689 65008, NY 25755 64990;

Unit O: NY 25823 64974, NY 25889 64955;

Unit P: NY 25957 64938, NY 26024 64917;

Unit Q: NY 25393 64983, NY 25460 64964;

Unit R: NY 25527 64945, NY 25594 64926;

Unit S: NY 25661 64907, NY 25728 64891;

Unit T: NY 25795 64874, NY 25861 64856;

Unit U: NY 25930 64838, NY 25996 64817;

Unit V: NY 25634 64810, NY 25699 64788;

Unit W: NY 25766 64771, NY 25823 64750;

Unit X: NY 25901 64740, NY 25968 64718

Air Apparatus Houses:

Unit A: NY 25509 65270;

Unit B: NY 25645 65233;

Unit C: NY 25780 65197;

Unit D: NY 25911 65159;

Unit E: NY 26045 65123;

Unit F: NY 25481 65171;

Unit G: NY 25616 65133;

Unit H: NY 25752 65097;

Unit J: NY 25882 65061;

Unit K: NY 26018 65023;

Unit L: NY 25455 65070;

Unit M: NY 25590 65035;

Unit N: NY 25724 64998;

Unit O: NY 25859 64960;

Unit P: NY 25991 64923;

Unit Q: NY 25427 64972;

Unit R: NY 25562 64933;

Unit S: NY 25696 64897;

Unit T: NY 25829 64862;

Unit U: NY 25962 64825;

Unit V: NY 25668 64798;

Unit W: NY 25799 64760;

Unit X: NY 25934 64724

Visited by HES Heritage Recording (MMD and ATW), 18-19 July 2022.

NITROCOTTON PRODUCTION AREA

NY26NE 140.1 Waste Bale Stores

NY26NE 140.2 Picking, Teasing, Drying and Willowing House

NY26NE 140.3 Nitrating House

NY26NE 140.8 Boiling House

NY26NE 140.10 Beating and Potching House

The Nitrocotton Production area (NY26NE 140) is located immediately to the NNE of the Acids section (NY26SW 38) and the standard gauge railway line (NY26NW 46.10) leading SE to the Nitroglycerine Hills (NY26SE 16.1-16.5) in the First World War National Factory, Gretna (Site 3: Eastriggs). The Nitrocotton Production plant comprised cotton waste bale stores (NY26NE 140.1), the Cotton Picking, Teasing, Drying and Willowing House (NY26NE 140.2), a cotton Nitrating House (NY26NE 140.3) with its Acid Storage and Refrigerating plant, the Nitrocotton Boiling House (NY26NE 140.8), together with the Nitrocotton Beating and Potching House (NY26NE 140.10) (MMW 1919, 21-2).

Cotton waste was delivered by the Glasgow and South Western railway to two cotton waste bale stores situated at the WNW end of the plant (MMW 1919, 117-138, 141). Cotton bales were transferred from there to the Cotton, Picking, Teasing, Drying and Willowing House where they were broken open, any foreign bodies removed and the fibres teased out. The cotton was then dried and weighed before being sent to the Nitrating House. Here the cotton waste was soaked in mixed acids and washed before being sent onto the Boiling House (Vat House). Here, the soaked cotton, now termed Nitrocotton Rag, was heated in acid and alkali liquids, before being sent to the Beating, Potching and Screening building. The boiled rag was finely cut in the beating machines and any further foreign bodies removed. It was then ‘potched’ by being agitated in large washing machines to which calcium carbonate was added as a stabiliser. Thereafter, the Nitrocotton was run into blending tanks and spun in order to remove excessive water content before being conveyed to the Screening House (NY26NE 140.12), where the material was further refined, dried and bagged.

The plant that blended the acids employed in these processes was situated S of the Nitrating House, while the Nitrocotton Compound (NY26NE 140.17-19) lay to its N.

Information from HES Heritage Recording (MMD, ATW), 22 May 2023.