A Filling Factory was a munitions factory which specialised in filling various munitions, such as bombs, shells, cartridges, screening smokes, etc.
In the UK, in World War I, such a factory belonging to the Ministry of Munitions was known as a National Filling Factory. In the UK, in World War II, such a factory belonging to the Ministry of Supplyy was known as a Royal Ordnance Factory (ROF).
Filling factories had a large number of buildings. Buildings were needed on the various Groups for filling of munitions. Explosives magazines were required by each Group to store the incoming explosive materials and to store the outgoing filled shells or gun cartridges, usually packed in ammunition boxes. Storage buildings were also needed on each Group to store the incoming empty shells, or cartridges, and the empty ammunition boxes.
For safety purposes, munitions were segregated into different compatibility Groups. A World War II Filling Factory would generally fill several different Groups of Munitions; and these Groups would be located in different geographical areas within the Danger Area of the Filling Factory.
The World War II Groups were:
Group 1: Initiators, such as caps and detonators for primers and fuzes.
Group 2: Fuze pellets, exploder pellets, exploder bags.
Group 3: Filling of fuzes.
Group 4: Blending of gunpowders for time fuzes.
Group 5: Filling of cartridges, such as filling cordite into cloth bags or into brass cartridge cases.
Group 6: Manufacture of smoke producing compositions.
Group 7: Small arms filling.
Group 8: Filling of shells or bombs.
Group 9: Large magazines, filled ammunition awaiting dispatch.
In addition, a Filling Factory would have provision for limited proofing and testing of its munitions; and burning grounds for disposal of waste explosive material.
Outside of this Danger Area, but still within the factory site, would be located:
administration offices;
pay offices;
workshops;
a medical centre;
changing rooms;
contraband storage (for items prohibited in the Danger Areas, eg matches, tobacco, etc);
search rooms;
canteens (as many as 40 in some of the large factories).
ROF Featherstone was filling factory no. 17
