Report - - RAF Bowes Moor chemical weapons storage and disposal facility - November 2016 | Military Sites | 28DaysLater.co.uk

Report - RAF Bowes Moor chemical weapons storage and disposal facility - November 2016


28DL Full Member
28DL Full Member
The Tan Hill Inn. The highest pub in the UK, and one of the finest: coal fires, superbly kept Old Peculiar, stone floors and low ceilings. Miles from anywhere at the head of Arkengarthdale, just off the Pennine Way, and a great place to stay. Mountain biking through the bleak expanses of Cotherstone Moor, Arkengarthdale Moor, Bowes Moor, and Stainmore Forest was the order of this late November weekend – and we were pretty much guaranteed to have the landscape to ourselves. Over a pint of two of Masham’s best, dark, brew the usual banter involved in route planning ensued.

“If we return southbound on the trail into Deep Dale towards the A67, then we’ll pass this curious-looking site” said one of my friends who was far wiser than I when it came to knowing the limit between a fun day out and an epically back-breaking day of carrying bikes through peat bogs. “What site?”, I said. “There isn’t one marked on my map!”. At which, of course, eyes lit up knowing that perhaps we’d stumbled across something with a military legacy stuck out in the geographic centre of no-where. This had to be interesting!

The next day dawned with mighty fine weather for the time of year. A great ride was had with surprisingly few up-to-your-knees-in-a-bog-with-a-bike-on-your-back incidents. And then we saw it – or what little there was left to see. Stuck in the middle of a piece of moorland, surrounded by barbed wire, there was a red and white sign proclaiming that:


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“The sheep look OK”, remarked one of us. “And there aren’t any more carcases than normal!” Must be OK then. So we vaulted the gate and wondered in, sticking to the now-decaying concrete tracks. There were low-lying brick walls were everywhere, encircling huge concrete plinths. There were the skeletal remains of a building with a lightweight blast roof. And there was a notable lack of any graffiti. Mind you, we reasoned, that's hardly surprising since the 360-degree panorama consisted of moorland dotted with a few sheep.

What was this place?

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The answer to that question was found after a bit of post-visit research. The state of total warfare that existed in World War 2 (WW2) pushed humanity to some very dark places, arguably none more so than the creation and refinement of weapons of mass destruction. In the early 1940s, when nuclear weapons development with both the Axis Uranverein and the Allied Manhattan Project was still in its early stages, chemical weapons were (unfortunately) tried, tested and proven. Chemical weapons were being produced, and stockpiled, by both Allied and Axis: from a UK-standpoint the horrors of such weapons would only ever have been used for retaliation rather than first strike [1]. Nonetheless, the instructions from the War Cabinet to the Air Ministry were utterly unambiguous [1]:

“Should the enemy initiate chemical warfare, HM Government intends to retaliate in kind with unrestricted heavy-scale bombing against centres of German population best calculated to bring about the collapse of German morale.”
The British chemical weapons portfolio chiefly consisted of mustard gas (Cl – CH2 – CH2 – S – CH2 – CH2 – Cl), elemental chlorine, phosgene (COCl2), lewisite (As [Cl]2[CH-CH-Cl]) and Paris Green (Cu4[As3O6][CH3-COO]) [2]. The design, commissioning and operation of mustard gas production facilities was overseen by ICI and, in 1937, the first plants came into being on Wigg Island on the northern edge of Runcorn [3]. Phosgene was manufactured on ICI’s nearby Rocksavage site. By 1939, 5 mustard gas plants were in operation producing 316 tonnes per week of two mustard gas variants: 216 tonnes per week of ‘Pyro’, 96% pure mustard gas, and 100 tonnes per week of ‘Runcol’, a mixture containing 60% mustard gas and 40% T (bis[2-(2-chloroethylthio)ethyl] ether). In 1940, production of mustard gas and other agents was moved to a more secure, underground, facility in the Alyn Valley, Wales, close to the village of Rhydymwyn. The ‘Valley Works’, as this facility became known, played the leading role in UK chemical weapons production during WW2. It was also was home to crucial parts of the Manhattan Project [4] – specifically research on the rates of gaseous diffusion of Uranium-238 and Uranaium-235 compounds, presumably UF6, which would have led to the development of gas centrifuges to enrich uranium to military grade.

So what does this have to do with a derelict site in the middle of Co. Durham’s finest peat bogs?

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The answer to that question is “everything”. With hundreds of tonnes per week of mustard gas being produced, it had be stockpiled somewhere: by late 1941 over 632,000 tonnes of storage capacity was being sought [5]. There was considerable nervousness that chemical agents were being stored in underground storage sites such as Harpur Hill: the lack of ventilation in, and tortuous means of escape from, these underground facilities coupled with fear of collapse was akin to creating a death trap. Moreover, mustard gas was corrosive, and the bombs containing it were thin-shelled and prone to leakage. A remote site in open moorland was sought as an alternative [5] – Bowes Moor, Co. Durham was chosen and it became the UK’s dedicated reserve depot for chemical weapons.

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RAF Bowes Moor came into being in December 1941, with the first deliveries of mustard gas bombs. The collapse of the underground high explosives storage facility in Llanberris in March 1942 led to the removal of all chemical weapons from the similarly-constructed Harpur Hill facility – all of which ended up at RAF Bowes Moor. At first, the mustard gas bombs at Bowes Moor were stored in the open under tarpaulins. Despite being well ventilated, a key drawback was the clandestine activities of the local sheep population:

“…these sheep, true to their reputation of eating almost anything that confronted them by means of gastronomic experiment, quickly consumed the tarpaulins covering stacks of 65lb bombs, and then attempted to make alfresco meals of the bombs themselves, puncturing many of the thin-cased weapons, much to their ultimate disadvantage.” [5]

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As WW2 progressed, the storage facilities at RAF Bowes Moor were upgraded – to prevent sheep attack – and expanded. “Disasters Underground” gives a detailed map of the facility on page 152 – however many of the buildings listed there are no longer visible on the ground. The map shown below is an attempt to illustrate the purpose of the ruins that are still visible today. The abbreviation “SCI” refers to aircraft-mountable spray-tanks – essentially the military version of crop sprayers, but equipped with mustard gas rather than pesticides. It’s worth noting that the Axis-developed agents Tabun and Sarin were derived from research into pesticides, so this analogy isn’t as trite as it first appears. The abbreviation LC refers to “Low Capacity” – essentially mustard gas bombs triggered by high explosives. I have no idea what the “C1 component stores” were though.

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Up to 17,000 tonnes of chemical weapons were stored at Bowes Moor during WW2 [6]: long term weapon storage was, however, problematic. The corrosive nature of mustard gas, coupled with very low turnover, meant that within 6 to 8 weeks the shells became unsafe. They were prone to leakage and became very fragile to handle [5]. It became increasingly clear that long-term storage of pre-made munitions was unviable. This led to the development and commissioning of five “forward filling stations”, which were dotted around the UK: mustard gas was stored in a number of either 250 tonne or 500 tonne underground tanks at these facilities, with bombs and spray tanks being quickly filled on an on-demand basis.

Thankfully, chemical weapons were not used on the European battlefields during WW2 [7]. Post war, RAF Bowes Moor became the central disposal point for the RAF’s chemical weapons, under the guidance of No. 81 Maintenance Unit. In addition the inventory that had accumulated there during the war years, shipments inbound to Bowes Moor were vast. In October 1945 alone, 2,500 tonnes of mustard gas was received from the various forward filling stations. The initial answer to disposal was incineration: incendiary bombs doused in petrol were dispersed within the sheds of mustard gas and (by now) lewisite [9], which were ignited from a ‘safe’ distance with a few hundred rounds of tracer ammunition from a Sten gun [5]. The resulting inferno, and billowing clouds of black smoke, were believed to destroy the active compounds.

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Burning mustard gas at RAF Bowes Moor, January 1947 [8,10]

Realistically, however, only partial destruction would have happened: substantial residue of organic arsenic compounds would have remained along with unburnt mustard gas. By the end of 1945, RAF Bowes Moor could not cope with the volume of mustard gas and lewisite that had to be incinerated. An alternative plan was made and the weapons were dumped into Beaufort’s Dyke, a 300m deep trench in the sea between Scotland and Northern Ireland [5]. It is estimated that today well over a million tonnes of munitions lie at the bottom of this trench, consisting of both conventional and chemical weapons along with nuclear waste [11].

Some accounts online of RAF Bowes Moor suggest that Tabun gas captured from Nazi Germany was also stored at Bowes Moor after WW2. I cannot find any corroborating evidence for this assertion: Operation Dismal, the capture of Nazi chemical weapons post WW2, resulted in the capture of 14,000 tonnes of Tabun and Sarin. Part of this was stored at Llandwrog airfield near Llanberis and disposal took eight years: thankfully reacting Tabun with caustic soda resulted in its neutralisation [5]. It is very sobering to realise that the organophosphate nerve agents, Tabun and Sarin, were both pioneered during pesticide research in 1936 at IG Farben, the German equivalent of ICI. They were 1,000 times more deadly than mustard gas and 3000 tonnes per month was produced at Dyhernfurth in Poland [5]. Had WW2 gone chemical, the consequences are unthinkable…

With the legacy of chemical weapons storage and destruction, RAF Bowes Moor was (is?) a highly contaminated site. There are reports of mustard gas shells being recovered as recently as the 1990s, with folk involved being exposed to chemical agents [12]. Operation ‘Cleansweep’ was launched by the MOD in 2007 to provide ‘reassurance’ that former chemical weapons sites did not pose a risk to public health. Of the 46 sites initially considered, 14 required detailed investigation – this included RAF Bowes Moor [13]. The report on Operation Cleansweep was completed in 2011 with an MOD briefing document being released [10,14] which states that “…no indication of significant risk to public health…" and "…the sites are suitable for their current use…”. Several freedom of information requests have since been made for the complete report’s release [15]. I cannot find the full text of this report in any place I have searched to date.

The conclusion? It wouldn’t be unreasonable to surmise that there is still probable mustard gas and arsenic contamination at RAF Bowes Hill. A large number of low-lying structures still exist – presumably earth works to remove them could release trapped contaminants. Mustard gas is denser than water, is immiscible with it and 3.5 times more viscous than it [16]. Moreover, its vapour pressure is only 9.3 Pa at 20 degrees Celsius – that is to say 0.01% of an atmosphere. This stuff isn’t going to evaporate, will dissolve into fat-based matter, will lie underneath any water layers but won’t dissolve in it. In short, it isn’t going anywhere fast… …and as for the Arsenic-containing lewisite residues? I’ll leave that to your imagination…

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Thank you for looking, and let's never forget.

1. Wg Cmdr Wooldridge M., “Explosives”, The Royal Air Force Historical Society Journal, 35, 41-53, 2005. [https://www.rafmuseum.org.uk/documents/Research/RAF-Historical-Society-Journals/Journal-35-Seminar-Supply.pdf]
2. https://en.wikipedia.org/wiki/Chemical_weapons_and_the_United_Kingdom
3. https://docs.wixstatic.com/ugd/8c9498_6c17361f831b4d0c97a423efb25b7228.pdf
4. https://www.atomicheritage.org/article/manhattan-project-spotlight-rhydymwyn-valley-works
5. McCamley M. J., “Disasters Underground”, Pen & Swords Books, Barnsley, 2004.
6. https://www.theguardian.com/environment/2011/jul/24/mod-chemical-weapons-factories-contamination
7. https://www.un.org/disarmament/wmd/chemical/
8. https://discovery.nationalarchives.gov.uk/details/record?catid=8864913&catln=6
9. Preuss J., “The Reconstruction of Production and Storage Sites for Chemical Warfare Agents and Weapons from Both World Wars in the Context of Assessing Former Munitions Sites”, In: Friedrich B., Hoffmann D., Renn J., Schmaltz F., Wolf M. (eds) One Hundred Years of Chemical Warfare: Research, Deployment, Consequences. Springer, Cham, 2017.
10. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/33233/23069Diologueissue2Interactive.pdf
11. https://en.wikipedia.org/wiki/Beaufort's_Dyke
12. https://www.pprune.org/archive/index.php/t-369767.html
13. https://www.theguardian.com/environment/2011/jul/24/mod-chemical-weapons-factories-contamination
14. https://robedwards.typepad.com/files/mod-briefing-on-project-cleansweep-july-2011.pdf
15. https://www.robedwards.com/freedom_of_information_ap.html
16. https://pubchem.ncbi.nlm.nih.gov/compound/Mustard-gas#section=Viscosity

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Stay Safe
A well presented report - well done:

I was involved in UK EOD in the 1980's and have visited this site in the past!

WW1 chemical shells are still being ploughed up in Belgium & France which are very much still active.

DSTL Porton Down still disposes of chemical munitions found within the UK


Destruction of Chemical Weapons
Each year small quantities of old chemical weapons are found in the UK. Dstl possesses the only licensed UK facility for the receipt, storage, breakdown and safe disposal of old chemical weapons. We currently have around 1,000 munitions that are in the process of being safely disposed of.


28DL Full Member
28DL Full Member
Thank you for your kind comments - and that's absolutely fascinating. It certainly serves to remind us how recent, in relative terms, WW2 and related events are. Anyone involved in EOD, past and present, has my greatest respect.


28DL Full Member
28DL Full Member
Thanks fella - much appreciated. I think that it's amazing that you can still stumble across (into!) places like this today.

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