RAF munitions storage during World War II
As a result of a serious shortage of funds during the inter-war period and a weakness of policy, the RAF was singularly ill-equipped to deal with the requirements of air warfare for the protected storage of explosives.
Similarly, at the Chilwell Ordnance Factory in Nottinghamshire, a nearby hillside was bored out with a T-shaped storage area in 1915 as part of a total £2.5 million spent on the site, but this could hold barely 300 tons of matériel.
The decision to expend the extra money to store the matérial underground was taken because the thin-walled bombs and inflammable incendiaries were extremely vulnerable to blast, much more so than artillery shells.
Each surface depot would have a capacity of around 1,000 tons and would supply armaments to the individual airfields, being positioned within 25 miles (40 km) of its recipients.
An additional pre-war site for underground storage was later created: a slate quarry at Llanberis was turned into another artificial cavern system with a large two-storey structure built for around £500,000 and opened in June 1941.
When the USAAF arrived new Forward Ammunition Supply depots were built for its needs at sites including Braybrooke (Northamptonshire), Bures (Suffolk),[1] Melchbourne Park and Sharnbrook (both in Bedfordshire).
The two wartime Forward Ammunition Depots were markedly different from the pre-war designs, relying on concealment by woodland (South Witham was actually within Morkery Woods) rather than toughness.
By early 1942 German raids were markedly less threatening than anticipated, thus the need for the additional protection of underground storage was no longer paramount, indeed the sites came to be regarded as expensive white elephants.
The collapse of Llanberis also led to the decision to remove chemical weapons from subterranean storage; these were mainly a large number of bombs containing the unstable and corrosive mustard gas.
Harpur Hill had been designated the central store for such devices in April 1940, receiving its first load in June of that year of mustard gas bombs evacuated from France.
It was found that the sheep on the moorland would consume the tarpaulins and disturb the bombs, resulting in the addition of sheep-proof fences and gates for the entire site.
There was little storage difficulty; with no prospect of air attack many of the newly abandoned airfields were turned into open stores for this ammunition prior to its disposal.
Many chemical weapons were disposed of in situ at Maintenance Units but Bowes Moor and Harpur Hill became the centres for destruction.
[2] Bulk mustard gas was graded and shipped to Rhydymwyn where any sub-standard product was loaded into 52 gallon drums and dumped either in the Hurd Deep or in Beaufort's Dyke in the Irish Sea.
[3] Almost 71,000 bombs containing tabun had been seized in Germany; these were stored in the open at RAF Llandwrog, near Caernarfon, until 1955/56 when, in Operation Sandcastle, they were transported to Cairnryan and scuttled at sea in three ships 120 miles (190 km) north-west of Ireland.
