Former World War I National Filling Factory, Banbury


Heritage Category:
Scheduled Monument
List Entry Number:
Date first listed:
Location Description:
The monument is located on land to the east of the M40, south of the Overthorpe Road bridge over the M40, east of Banbury.


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The building or site itself may lie within the boundary of more than one authority.

Location Description:
The monument is located on land to the east of the M40, south of the Overthorpe Road bridge over the M40, east of Banbury.
South Northamptonshire (District Authority)
National Grid Reference:


Standing, buried and earthwork remains of Unit No.1 of the WWI National Filling Factory, Banbury.

Reasons for Designation

Unit No.1 of the National Filling Factory, Banbury, is of national importance and is scheduled for the following principal reasons:

* National Importance: the diverse range of documentary sources provides a detailed profile of the physical remains of NFF Banbury and of the significant contribution it made to the British armed forces at a time of international conflict. Its contribution to the war effort and to the outcome of WWI make it a site of national and international significance. * Rarity: All filling factories were reduced to footings when decommissioned and almost all sites were redeveloped. NFF Banbury is one of only two lyddite filling factories dating to WWI which retain evidence of the complete process flow of the industry.

* Archaeological Interest: 75% of the plan form of Unit No.1 survives as earthworks and has the archaeological potential to add significantly to our understanding of the construction, use and subsequent abandonment of the site. * Diversity and Group Value: the diversity of the features and the inter-relationship of the different elements of the factory increase the group value of the site and enhances the national importance of the monument as a whole.


At the outbreak of the First World War in 1914, the filling facilities for high explosives were limited to the Royal Arsenal Woolwich and factories at Lemington Point and Derwenthaugh (Newcastle Upon Tyne), belonging to the armament manufacturers Armstrong and Whitworth and Co. Ltd. By 1915, the British Army found itself on the Western Front with insufficient ammunition; the demand for filled shells exceeded production. The National Filling Factories (NFF) were conceived by the new Ministry of Munitions, formed under Lloyd George in June 1915. Their layout utilised elements of modern factory production with a logical flow of materials and a production line. Principles of scientific management were applied to the workforce including 'dilution', where skilled work was broken down into individual repetitive tasks which could be performed by unskilled or semi-skilled labour. In the NFFs this meant the innovative use of female labour which reached 90% of the total labour force in some factories.

Though part of a national network financed by the government, there was no rigid design template imposed on each site. Certain principles were laid down following good practice at Royal Arsenal Woolwich, but many aspects of the Home Office guidelines were relaxed. Plan form was influenced by topography and the architect's own ideas. Four explosives filling factories, including that at Banbury, were designed, built and managed by their managing directors but the construction of the factories generally depended on local firms, though the Office of Works erected those at Banbury and Perivale (London).

NFF Banbury, Northamptonshire, was one of the earliest purpose built by the Ministry of Munitions and was known as NFF No.9. It was commissioned in November 1915 and responsibility for its construction and management was given to Mr Herbert Bing, and the building contract was let in January 1916, to Messrs Willet of Sloane Square. The first lyddite was run on 25 April 1916. Initially the factory comprised only the northerly No. 1 Unit, designed to fill 100 tons of lyditte per week. In 1916 over 1400 local people were employed, a third of them women. The basic operation of the filling factory is evident in the plan. Empty components were bought into one side of the unit and the explosives into the other side, and the filled shells were moved to a storage magazine before they were either moved off-site or moved for temporary storage in an Army Ordnance Department store. Shells were moved between production areas by an internal tramway. Inside the factory were box stores and the empty-shell store, where on arrival the empty shells were cleaned and painted before they were issued to the filling houses. At the centre is a series of 22 melt houses which served eight filling sheds. Picric acid for melting was held on the eastern side of the group in long sheds and when ready for use, it was bought into the stores at the southern end of the group and then sifted before melting. After filling, the shells were moved by tramway to the two filled-shell magazines to the east.

The factory's capacity was doubled with the construction of No.2 Unit to the south giving a total area of 132 acres. This was built within a year or so of the No.1 Unit. Experience in operating the first unit brought modifications to improve the flow of materials through the second, including a clearer flow of materials from the empty shells stores on the south western side, through the paint shops to the filling houses, and on the opposite side from the long picric acid stores through the sifting houses to the melting houses.

On May 30th, 1917 a notice was issued to the effect that all shells used by the British batteries in the battle on the Italian front came from No.9 Filling Factory. the quality of the ammunition that was produced was highly praised and factory employees were encouraged and exhorted to continue their good work (Lester, 1983).

When demand for lyddite declined by September 1917 as the army switched to TNT, sections of the factory were converted to filling naval mines and shrapnel shells and, early in 1918, part of the factory was given over to the filling of chemical shells with mustard gas although it is unclear which sections were affected. Around 1919 the factory was purchased by Cohen of London who used it for breaking down surplus war ammunition. This activity continued until 1924 when the factory closed. It is believed that the factory underwent 'thermal remediation' (sections of the site were deliberately burnt) which was the standard way of ensuring that no explosive residuals were left in former explosives handling buildings. It is possibly that it was this action which reduced the buildings and contributed to the formation of earthworks.

During the Second World War the site of the abandoned factory is believed to have been used as a military training area although no field evidence of purposely dug trenches or other training features was identified on site.


The No.1 Unit

The site of the Filling Factory at Banbury (Unit no.1) survives as a series of well defined earthwork, standing and buried remains, and is currently used as rough grazing for cattle. The monument has been truncated by the M40 motorway, which has obliterated elements on the extreme western side of Unit no.1.

The No.1 Unit lies to the east of the motorway with approximately 75% of the site surviving as earthworks. This part of the site was arranged in an elongated rectangular plan which was subdivided into a number of small compartments, each of which housed a group of four melt houses and two filling sheds. In operation, cleaned shells were brought to the northern end of the group and explosives into the eastern side, the two were then brought together in the filling sheds at the centre of the group before the filled shells were moved eastwards to the storage magazines on the extreme east of the complex. The buildings in the factory were generally timber-framed and weather-boarded or covered in uralite (brown asbestos sheeting), set on brick foundations or concrete slabs. Larger buildings, generally stores with roof widths of no more than 12m, were spanned by Belfast trusses. To the east, the site is defined by the earthworks of a standard gauge railway line that served the picric acid stores, filled shell magazines, and to the north the exploder store.

The buildings used in the filling process (within the danger zone) were all surrounded by earthwork traverses the ends of which were revetted by double brick walls infilled with a concrete core. The earthwork traverses survive up to a height of around 4m, with the standing remains of the gable revetments surviving to a similar height. Linking the buildings are the earthwork remains of the factory's internal narrow gauge tramway. Where the line passed through earthwork traverses they are lined with brick and concrete portals. Numerous examples of the portals are visible around the site. It is clear from the height of these, particularly in the northern half of the site, that there is a build up of debris and the original ground level is possibly in places up to 2m below the current ground level. There is also documented evidence of rubbish dumping in the1920/30s at the extreme northern end of the site, which may help to explain this. Around the edge of the filling units are the earthwork remains of standard gauge sidings. Between the picric acid stores and the lines of the tramways are the well-preserved remains of Medieval ridge and furrow. More also survives to the west between the melt houses and the motorway.

South of the danger area were offices, changing rooms, mess rooms and lavatories which survive as less well defined earthworks; though concrete building platforms are visible in places and survive just beneath the turf cover in others. Aerial photographs indicate the location and survival of these platforms and help to illustrate the process flow of the industry and how this is manifest in the landscape. Traces of ridge and furrow are also evident in this area. Approximately half-way down and to the west of the complex was a boiler house, locomotive shed and oil store, but these buildings were removed for the construction of the M40 motorway, as were a number of store buildings which were located on the extreme west side of the main group.

The Army Ordnance Department storage magazines

In the field to the south-east of the factory are the earthwork remains of the storage magazines which were controlled by the Army Ordnance Department (AOD). These were a feature of most filling factories and were under military command; until the point at which the shells were ready for delivery to the army, all raw materials were controlled by the civilian Ministry of Munitions. Finished shells after inspection became the responsibility of the AOD. Although an important element in the landscape these structures are of a standard design and are not directly involved in the process of the filling factory and are therefore not included in the scheduling.

The No.2 Unit

The No. 2 Unit lies to the south of No.1 Unit and is bisected by the M40 motorway. Earthworks to the east of the M40 are similar in plan to those of the No.1 Unit but are not as clearly defined. The earthwork survival may be indicative of the modifications introduced during its construction to improve the process flow. The revetted earthwork traverses which are so characteristic of the northern, No.1 Unit are only clearly evident around the picric acid stores in the No.2 Unit. This may be due to a gradual degradation of the earthworks or disturbance during the construction of the M40 but equally may indicate that these were no longer considered necessary around the other process buildings. To the west of the M40 a filled shell magazine was recorded in April 2012, comprising of a revetted traverse, pierced by three tunnels or portals surrounding three sides of the earthwork remains of the magazine. This feature has subsequently been degraded by machine leaving only a raised rounded mound. Also evident in this section of the site are a series of low tramway embankments curving from the south towards north-west. These appear to terminate at a low, rectangular mound believed to be the remains of a locomotive shed. The remains of Unit No.2 are considered to be of National Importance but given that approximately 50% of the site has been obliterated by the M40 and that further remains of Unit No.2 are heavily degraded this area of the site is not included in the scheduling.


A detailed history of the factory complex is documented in the National Archives, Kew, this contains annotated plans and sections of the buildings. An unannotated plan of the factory may also be found on the 1922 Ordnance Survey map of the area.

Extent of Scheduling

The scheduling encompasses the buried, earthwork and standing remains of Unit No1 of the National Filling Factory, Banbury. From the north-eastern corner the line of designation follows the field boundary southwards to the east of the tramway earthworks and filled shell magazines. It continues south to include the picric acid stores and the 'domestic' buildings at the southern end of the site. A field boundary crosses the site south west to north east but the line of scheduling extends a further 50m south of this to capture the full extent of the domestic buildings. The line picks up a further field boundary and follows this northwards at the foot of the M40 embankment. Approximately 200m south of the northwest corner of the field the line crosses the field north of the remains of the melt houses. A 35m wide strip on the eastern side of the field retains well preserved remains of the tramway embankments and is included in the scheduling.


Books and journals
Cocroft, W, Dangerous Energy The Archaeology of Gunpowder and Military Explosives Manufacture, (2000), 170-176
Lester, E, 'Banbury Guardian' in The vital role of our gas factory, (January 13th 1983)
History of No.9 NFF Banbury ,
Title: Ordnance Survey Map 25" Oxfordshire VI.9 Source Date: 1922 Author: Publisher: Surveyor:


This monument is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 as amended as it appears to the Secretary of State to be of national importance. This entry is a copy, the original is held by the Department for Digital, Culture, Media and Sport.

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