The comprehensive
modernisation of the Royal Navy in preparation for an impending war was a
priority for Winston Churchill in the years following his appointment as
First Lord of the Admiralty in 1911. Amongst Churchill's many aims
was to increase the effectiveness of naval weaponry by improving the
quality of the propellants used and ensuring that they could be produced
in sufficient volume.
To this end, in 1914, he ordered the construction of a
large facility for the production of high quality cordite exclusively
for the Royal Navy, it was to be named the Royal Naval Cordite Factory (RNCF).
A number of sites were
considered for the new factory project. A large site was required
which could provide, amongst other things, an area of gently sloping
land ideal for the production of nitroglycerine, a highly explosive
liquid which relied on the
influence of gravity to flow from one process to another as safely as
possible. Significant quantities of water would be required on
site for the various processes involved in the production of cordite.
Good transport links would be essential in order to bring in bulk raw
materials and to dispatch the finished cordite to the various naval
shell filling stations. A sizeable workforce would need to be
mustered from the locality while ensuring that the factory did not pose
a risk by being sited too close to centres of population.
The site eventually chosen was on the shores of Poole
Harbour at Holton Heath in Dorset, which was subsequently bought from
the Lees Estate of Lytchett Minster, the local landowner. Black
Hill provided the required gradient for nitroglycerine production as
well as a suitable location for a reservoir. The site was
immediately adjacent to the London and South Western Railway and a pier
was constructed to enable access to the sea. The local towns of
Bournemouth, Poole, Wimborne and Wareham would provide much of the required
labour force.
Building work on the
400 acre site began in 1915 and the factory was up and running in
January 1916 - an extraordinary feat achieved by a huge construction
workforce (up to 500 bricklayers alone) and driven by the needs of war.
Despite the pace of construction, it is evident that quality was not
compromised, as many of the fine buildings erected at the time survive on
the site to this day.
Sulphuric acid was made from the burning of iron
pyrites (iron sulphide), and the sulphur dioxide produced converted to
sulphur trioxide by passing it over a platinised asbestos catalyst and
absorbing it into dilute sulphuric acid. A plant for the
reconcentration of used acid was built during World War II.
Nitric acid was produced by the action of sulphuric
acid on saltpetre (sodium nitrate) in 12 cast iron stills. Nitre
cake was a by-product of the process and was sold to Harpic Ltd for use
in the manufacture of their famous household cleanser.
Nitroglycerine (NG)
The manufacture of NG was an extremely hazardous
process where mixed acids and glycerine were combined to form a
colourless liquid. Initially, the NG was made in batches of around
1½ tons. Following a serious explosion in
1931 when 10 workers were killed, a newer, continuous process (Schmid)
was adopted.
Guncotton (GC) / Nitrocellulose (NC)
GC and NC were produced by the action of mixed acids
on cotton waste or paper.
Cordite
Cordite
was made by mixing guncotton or nitrocellulose with nitroglycerine.
The resulting solid was rolled and cut to fit hydraulic presses.
The extruded cordite would then be cut to the required length.
During World War I, Cordite MD was manufactured and consisted of 30% NG,
65% GC and 5% mineral jelly. Acetone was added during the mixing
processed to aid incorporation.
Cordite SC contained a larger percentage of NG and
carbamite replaced the mineral jelly. Acetone was no longer
required for making cordite SC.
Flashless cordite (NF) used a large proportion of
picrite, but required the use of acetone for mixing. Picrite was a
white crystalline powder made by the action of mixed acids on guanidine
nitrate, which itself was made from the fusion of ammonium nitrate and
dicyandiamide. The addition of picrite was to reduce muzzle flash
and barrel wear.
Tetryl
Tetryl was unconnected with cordite production but
utilised the available supply of mixed acids, blending them with
dimethylaniline to form a yellow, crystalline explosive used as an
intermediary between detonator and explosive charge in bombs and shells.
The quantity of electrical power required for a
production facility on this scale was not available locally in 1915, and
so a power station was built adjacent to the London and South Western
Railway line. Coal was brought in by rail and an overhead conveyer
belt system continuously transferred it to the 24 boilers housed in the
340 ft long boiler house. The steam produced was used to drive
generators as well as being piped around the site for heating and other
purposes.
Gas
Coal gas was produced on site and stored in two
circular gas holders.
Water
As the Holton Heath site lacked an adequate source of
suitable water, a pumping station was constructed at Corfe
Mullen, close to the River Stour, and a 16 inch pipeline connected it to a reservoir
built within the factory.
The reservoir was semicircular in shape and could hold up to 3 million
gallons, sufficient for about 4 days' normal production. During
the second world war, a 375 ft deep borehole was sunk at the eastern end
of the site to provide an emergency water source if the main supply
failed.
An extensive railway network within the factory
provided a means by which goods and materials could be transported to
and from all areas. The standard gauge network alone totalled 5
miles of track and comprised sidings adjacent to the main railway line
as well as lines to buildings including locomotive maintenance
facilities. The narrow gauge system added up to 14 miles of track
and served most buildings.
Due to the dangerous nature of the work at RNCF,
careful consideration had to be given to operations carried out in the
production or "danger" area. Fireless locomotives were used which
relied on a reservoir of pressurised steam and hot water to power them.
Periodically, they would need to be recharged and this could be carried
out at various locations around the site. Later, electrically
powered locomotives were used which would return to a building outside
the danger area for recharging. In some cases, wooden rails made
of teak were used in the immediate vicinity of buildings where highly
dangerous work was being carried out, to minimise the risk of sparks
being generated.
Sea
The proximity of Holton Heath to the shores of Poole
Harbour made the transportation of goods by sea an obvious choice.
A pier was built at Rocklea (opposite today's Rockley Sands) and a
standard gauge railway line connected it to the factory. Shallow
draft sailing barges were used to transport cordite to the filling
stations which served the principal Naval dockyards of the day.
The RNCF's black railing fence extending along the A351 road will be
remembered by many local people as virtually the only visible evidence
of the factory's existence. The 12 foot high barrier encircled the
site with a total length of 3¼ miles.
During construction, the Dorset Constabulary was
responsible for the security of the site. For the rest of the
duration of the First World War, the Metropolitan Police assumed
responsibility for security which was common practice for all munitions
factories at that time. The Royal Marines police took over the
role in 1919 when a hostel, and later married quarters, were built to
house the force and their families.
In the late 1930s, when war was once again looming, plans
were afoot to expand Naval propellant production. A massive new
facility, the Royal Naval Propellant Factory (RNPF), was built on a 2000
acre site at Caerwent, South Wales. Even though Caerwent had twice
the capacity of Holton Heath, it was necessary for both factories to run
in parallel to satisfy the Royal Navy's wartime requirement for cordite.
At the end of the war, it was decided that production should continue at
Caerwent and that Holton Heath should be closed. Some processing continued at Holton Heath until the late 1950s when the site was
decommissioned and most of the land transferred back to the original
landowner. English Nature currently lease a large proportion of
the redundant land.
An enclave of XX acres was retained at the western end
of the site to house the Admiralty Material Laboratory which had been
set up in 1947 and which occupied some of the redundant RNCF buildings
at that time. Defence research continued at Holton Heath until
1997 when the work was transferred to other sites run by the Defence
Research Agency. The remaining land was sold by the Ministry of
Defence in 2003.
Building work on the
400 acre site began in 1915 and the factory was up and running in
January 1916 - an extraordinary feat achieved by a huge construction
workforce (up to 500 bricklayers alone) and driven by the needs of war.
Despite the pace of construction, it is evident that quality was not
compromised, as many of the fine buildings erected at the time survive on
the site to this day.
Cordite
was made by mixing guncotton or nitrocellulose with nitroglycerine.
The resulting solid was rolled and cut to fit hydraulic presses.
The extruded cordite would then be cut to the required length.
During World War I, Cordite MD was manufactured and consisted of 30% NG,
65% GC and 5% mineral jelly. Acetone was added during the mixing
processed to aid incorporation.
An extensive railway network within the factory
provided a means by which goods and materials could be transported to
and from all areas. The standard gauge network alone totalled 5
miles of track and comprised sidings adjacent to the main railway line
as well as lines to buildings including locomotive maintenance
facilities. The narrow gauge system added up to 14 miles of track
and served most buildings.