Report - Ministry of Supply Factory Valley, Rhydymwyn, Flintshire, October 2017

[A man called Martyn]

Site history
The site occupies around 35 hectares of the Alyn Valley, to the south of the village of Rhydymwyn (centred on SJ 205 668). Once part of the extensive Gwysaney Estate, the Parish of Rhydymwyn was established in 1865. Lead mining in the area is known to have been extensive, and a foundry associated with nearby mines is depicted on several early maps for the area. Following the closure of the foundry land use on the site was largely agricultural in character. However, in 1939 the land was purchased by the ministry of supply and developed as a purpose built chemical weapons factory and storage facility.

Over 100 specialised buildings were constructed across the site, linked by an extensive rail network established around a spur off the Chester to Denbigh mainline. Other major landscaping undertaken at this time included the canalisation and culverting of the River alyn, and the excavation of a complex of interlinked subterranean, rock-cut tunnels and caverns. During WW II the plant produced ordnance containing mustard gas, and was associated with the development of the Atom Bomb. In the immediate Post-War period the site was used to store German nerve gas, and it was not until the 1950s when Britain relinquished its chemical weapons (CW) capability that the site as a chemical storage facility was defunct. However, the site remains on the international Chemical Weapons List, and is still monitored as such.


Chemical weapons programme
In the late 1930s the Chamberlain Government planned that the United Kingdom should be in a position at the beginning of any war to retaliate in kind if the Germans, as expected, used mustard gas. In April/June 1939 the Alyn Valley was surveyed by the Department of Industrial Planning on behalf of the Ministry of Supply (MoS), and Imperial Chemical Industries (ICI) who were tasked with managing this programme.

The Treasury approved the sum of £546,000 for initial work on 27 August 1939, and work began in October 1939 on the storage tunnels in the Limestone hillside, in the Alyn valley close to rhydymwyn The factory, to be called M.S. Factory, Valley, opened in 1941. The government authorised the expenditure of £3,161,671 and ICI's construction fee was £80,000.

Production was intended of both Runcol and Pyro variants of mustard; records reveal that only the purer and more stable Runcol was made in bulk.

In 1940-1959, it was involved in either the manufacturing, assembly or storage of chemical weapons, or mustard gas in bulk containers. During 1947-1959 the tunnel complex held the majority of the country's stock of mustard gas.The underground storage chambers continued to house bulk mustard supported by the facilities of a loading bay and the laboratories until 1958 when work started to remove the remaining stockpile. Dismantling and decontamination of all remaining equipment was completed by April 1960.

Research has shown that whilst the attrition rate of certain building types has been quite high across the site, there is no other CW production, storage and assembly site surviving within the UK in such a complete and readily understandable state. This makes the Valley Site as a whole a place of national significance, but of particular rarity and importance are the surviving production buildings, which are, as far as can be ascertained, unique survivals.

Nuclear weapons
On accepting the findings of the Maud report in 1941, the government of the day needed to verify that a cost effective Atomic bomb could be manufactured. This required verification that a gaseous diffusion process would work on an industrial scale to provide enough fissile material to manufacture a cost effective and timely Atomic Bomb.

One of the surplus Pyro buildings at Valley (P6) was adapted for the testing of apparatus for uranium isotope separation in 1942 in an early phase of the Tube Alloys project before this was moved to America (developing later into the Manhattan project). Four prototype gaseous diffusion plants were ordered from Metropolitan-Vickers, at Trafford Park, Manchester at a cost of £150,000 and installed in the P6 building at Valley. Test equipment was installed in the P6 building at Valley and experiments continued until 1945 when the equipment was moved to Didcot and Harwell. The results of the experiments led to the building of the gaseous diffusion factory at Capenhurst, Cheshire. Building P6 is now a Grade II listed building and is of international importance; for a very brief period it was at the leading edge of nuclear physics.



The Ministry of Public Buildings and Works assumed responsibility for maintaining the site in 1964. From the 1960s the site was used as buffer depot for the storage of a variety of non-perishable foodstuffs such as sugar and flour. Transfer of responsibility to the Ministry of Agriculture, Fisheries and Food occurred in 1992 and the use of the site as a buffer depot ceased in 1994, since when the buildings have remained empty.

In 1994 the site was closed, and a programme of demolition was undertaken. This involved the dropping of buildings onto their footprints, and the rubble being mounded over with topsoil. Several major structures, and many ancillary buildings, still survive across the site.

The surviving buildings are a reminder of a huge building programme that changed the face of Britain forever and the site remains as unique today as it was at its inception.

 

[dweeb]

Toxic burial pit?!

What an awesome thing that is!

 

[Kirkymole]

So that's what I've gotta do when the Mrs wants round two...

 

[mw0sec]

The greatest hazard on the site today are the bat police!

 

[Ordnance]

As stated in post one, part of valley was handed over to MAFF and by the mid 80's the following foods were held :

• Plain (Bakers) Flour - This was a special high protein, low moisture content flour which was turned over every 4 to 5 years.
• Yeast - Packed in tins with an expected life of 10 years.
• Granulated White Sugar - Held in 56lb sacks and turned over if it started to deteriorate (mainly due to poor storage - about 10 years)
• Fat/Lard - Known as `Ministry Marge' with an expected shelf life of 20 years.
• Biscuits (Hard Tack) - Biscuits in large tins baked in the 1960s. and also used by the military in field rations (Biscuits Brown)

Turned over supplies were sold by auction to the food trade. Sharp eyed members may notice that this is mainly the basis for baking bread!

Other depots (about 70) in the country stored Water purification powder, Grain, Meat (both tinned & frozen), Tea, Cake mix and other sundries.

Like Green Goddesses (Dept of Trade), MAFF also held trucks & mobile kitchens & bakery trailers in reserve at Marchington and other locations such as the Army vehicle depot at Ashchurch.

# Green Goddesses would be used in conjunction with field kitchens to supply water from lakes etc.

All MAFF buffer depots were disposed of by the end of 1995 - Today plans are to commandeer civil food supplies - warehouses & supermarkets!

 

[Mrs Fezziwig]

I lived directly opposite this site in 2006. You may not have noticed the tiny cottage tucked away directly opposite the gates. I spent many hours here picking wild garlic and counting bats. At that time the tunnels were covered with gates and I got to go in one. I spoke to women who worked here and they explained that you had to have full security clearance tests just to be a secretary in the office, typing up results that meant absolutely nothing to them. She only found out that dangerous chemicals were being used when one of the test staff was hurt in a chemical accident that was so severe the sirens went for everyone to go into the air raid shelter.

She remained in the village until she died in 2010. She taught me some lovely knitting patterns and told me numerous stories that I am now writing a novel which will include mention of these incidents. I also know that the site was used in the 1980’s to store butter or margarine, maybe both; I think the incident was called ‘The Butter Mountain’ or something similar!

I thought this site was now open for visitors on selected days.

 

[tigger]

....She only found out that dangerous chemicals were being used when one of the test staff was hurt in a chemical accident that was so severe the sirens went for everyone to go into the air raid shelter.

Two accidents occurred which involved multiple casualties and involved the alarm being raised and staff having to go to the shelters (for chemical protection the shelters had canvas curtains which were soaked with sodium carbonate solution). Both were related to the handling of toxic effluent and neither incident involved serious injury

I think the incident was called ‘The Butter Mountain’ or something similar!

There were butter mountains, grain mountains, wine lakes and assorted other ludicrous waste to artificially keep prices high.

I thought this site was now open for visitors on selected days.

The site is open during the day, seven days a week but it is managed access. A very peaceful site that is under-used...as well as being of historical interest/importance. Short tours of the storage tunnels (which are normally kept sealed) were held on several days this year and DEFRA (who own the site) have agreed to allow another series next year (details are on the Rhydymwyn Valley History Society website).

 

[Mrs Fezziwig]

Two accidents occurred which involved multiple casualties and involved the alarm being raised and staff having to go to the shelters (for chemical protection the shelters had canvas curtains which were soaked with sodium carbonate solution). Both were related to the handling of toxic effluent and neither incident involved serious injury


There were butter mountains, grain mountains, wine lakes and assorted other ludicrous waste to artificially keep prices high.


The site is open during the day, seven days a week but it is managed access. A very peaceful site that is under-used...as well as being of historical interest/importance. Short tours of the storage tunnels (which are normally kept sealed) were held on several days this year and DEFRA (who own the site) have agreed to allow another series next year (details are on the Rhydymwyn Valley History Society website).

Wow, thanks for the info! That’s amazing. I knew the site was using chemicals and I am glad to know more about it. The couple who used to help me were Jim and Val. Jim was the bat guy and Val was involved in doing the paperwork to get the site looked after. I was there the day the site was ‘signed over’ or something to a working group in Rhydymwyn. I thought it meant that the site was protected and I am glad it has been. I loved it there because it was linked to the war effort, there was amazing wildlife and plant life. I saw flowers I had only read about in books, I wish I could remember the names. The feeling of bats swooping low over my head is a memory I can never forget and I often dream about.

Thank you again for the update, it seem ridiculous to feel so strongly about a place we only spent 6 months in!

 

[mw0sec]

The Valley group have a copy of a WW2 training film for the production of the chemical weapons. If visiting the site, ask if you can see it - very interesting!

 

[A man called Martyn]

A few from yesterdays Tunnel tour