Site Name:
Birtley, National Projectile Factory/Royal Ordnance Factory
https://twsitelines.info/SMR/13373
Not just an ordnance manufacturer, e.g:-
Marked on the bed: R.O.F.B., this 8 mm watchmakers' lathe was manufactured during WW2 in the Royal Ordnance Factory in Birtley.
More here:-
http://www.lathes.co.uk/rofb/