Cordite Milling Incorporation Houses ...
These buildings were surveyed as 'Narrow Cordite Milling Houses' (NMH) and initially were thought to be
rolling houses where cordite paste was mixed and then rolled out as sheets. In fact, they appear to
be where the raw Ballistite jelly (Cordite MD) from the Expense Magazines was thoroughly mixed and
blended with Vaseline jelly and possibly with Nitroguanidine (Carbamide). The result was a Cordite Paste
or 'Cordite Dough' that was then bagged and taken round to adjacent Pressing and Rolling Houses for
further milling into Cordite rods and granules.
As indicated in the Cordite Milling page, each NMH was paired with a Wide Milling House (Press
Houses), three pairs per Unit, with the Double Sided Milling House (possibly the Cordite Paste Rolling House)
adjacent. All three Incorporation Houses have survived in Unit 1 (Southwick), but in Unit 2 (Edingham) it
was only recently realised that only two Incorporation Houses survive. The missing one was in the (July 2006)
currently open and unused section of the Edingham Industrial Estate, the site having been completely levelled.
Archaeological Evidence at the Incorporation Houses (Narrow Milling Houses) :
The NMH buildings have three main sections :-
- A Back Passage, accessed by a rear door or by a central passage from the Veranda. This holds a dozen concrete
bases with studs for electric motors, each with a shaft-drive through to its adjacent Incorporation Room. At ceiling level
there was also a fume extraction ventilation system, the motor (and possible fumes condenser) being in a porch-like
projection from the back of the building near the main entrance to the veranda. As the floor was bare concrete, the Back
Passage seems to have been kept separate to the actual process rooms.
- Fourteen Incorporation Rooms, each with a fume extraction fitting in the back wall near the ceiling, and with a safety
light mounted in the upper centre of the back wall and the front wall, with an entry for a shaft drive in the back wall
and a wide doorway closed by two unequal-width doors at the front. The floor was covered in acid resistant gritless asphalt
except in one large irregular patch towards the back of the room, bare concrete and presumably for the Incorporator. Wall
bolts on the wall to the left of the door marked the position of some kind of control panel. There were no obvious signs of
radiators or other heating fittings, but from the Wide Milling Houses it is possible that preparing the rooms for storage
of ammunition after 1945 destroyed the evidence. As an example, the drive shaft entries from the back passage were bricked up
and painted over, in one of the few examples of alterations by the Royal Navy. By chance, this also covered up the metal plate
of the emergency motor cutout, which in Unit 1 Incorporation House 3 was seen under peeling plaster in rooms K to N.
- Veranda enclosed at the front by a sectional reinforced concrete frame shrouded in panels of corrugated asbestos cement.
Like the rooms, floored with gritless asphalt. Openings into three angled passages to the backs of the adjacent bays holding
the Ballistite Expense Magazines (Embanked Bays).
Thanks to the Baker-Perkins Historical Society (BPHS) and the Australian War Memorial websites, the writer was able to identify
the equipment used in the Incorporation Houses as the Baker-Perkins Incorporator and by analogy with the terminology at
Carsegowan Black Powder Factory (M/S Factory Carsegowan) to title NMH buildings as Incorporation Houses.
Inferred Operation of Narrow Milling Houses (Incorporation Houses) :
Ballistite from one of the Expense Magazines was brought in bags to one of the nearest Incorporation Rooms and
emptied into a Baker-Perkins Incorporator, a 'Universal Mixer' similar to a commercial baking mixer. The lid was then lowered
onto the Incorporator and closed with latches. Staff would be cleared from the room, the foreman starting the Incorporator
and running it for about three hours, then additives such as liquefied Vaseline (Petroleum Jelly) and Picrite (Nitroguanidine)
were measured and poured in. From BPHS illustrations, it is evident that some Incorporators were fitted with fume extraction
lids and ducts to extraction systems. Although this would certainly have reduced the risk of acetone and nitric oxide fum
poisoning, it is suspected that the need to conserve acetone was more important at Dalbeattie and that the ventilation
system was used to control the fume level during loading and unloading of the Incorporator. At ICI Deer Park in Melbourne
Australia, additional acetone and water were added.
After the first stage of incorporation, the mixture should be termed 'Cordite Paste' and on completion its consistency
changes and it is strictly called 'Cordite Dough', although these terms are almost interchangeable in practice.