Rhydymwyn Valley Works: Lifting the lid on secret site
War-time film explained to the public what was happening on the site
By Nick Bourne
August 27 1939 - the Treasury approved a £546,000 development of a top secret World War II chemical weapons plant which, today, is a nature reserve
For years the secrecy surrounding the Rhydymwyn Valley Works Site, near Mold, served only to fuel rumour about what, if anything, could still be hidden in underground tunnels that once housed thousands of mustard gas shells during the height of production in the war years.
And speculation has been rife for the last few decades since it was revealed that the works played a role in the research into the first atomic bomb.
[That work included evaluating the atomic bomb research, codenamed Operation Tube Alloys. Many of the scientists who worked on Operation Tube Alloys worked on the Manhattan Project, which developed the first atomic bomb.]
But specialists from Birmingham University, who surveyed the site, released their findings in May 2006 - saying there were no more secrets lying hidden in the underground tunnels as they were empty.
What the experts did uncover, however, were some interesting archaeological finds after being commissioned by site owners - Department for Environment, Food and Rural Affairs (Defra) - to help provide a greater understanding of the site's history and how it came to be used during World War II.
The academics found that the site had been used from the mid 1700s for a range of industries which left behind remains of foundries, waterwheels as well as mine workings. In turn, this led to the building of a main road and a railway in the 1800s which made it a prime site by the time war-time Prime Minister Winston Churchill called on chemicals manufacturer ICI to find a secret location to begin production of chemical weapons.
ICI suggested Rhydymwyn, said the experts, because it was 30 miles away from its production hub in Runcorn, Cheshire; the amenities, including a natural water source and transport infrastructure were in place; and because it was inland and relatively safe from air attack because the site was in a valley, heavily wooded and, from the air, looked no different from other nearby valleys.
What happened on-site?
We learned about his work at 1pm on the day the dropping of the atom bomb on Hiroshima was announced, when my father told us that that was what he had been doing - working on the atomic bomb development at Rhydymwyn
Production rooms were constructed to make mustard gas but, said the experts, this didn't happen. Instead, mustard gas shells were made on-site with all the components brought together to make the shells and bombs.
And what about the part the plant played in the creation of the first atomic bomb?
Well, apparently, leading experts were sent to the site by Churchill to follow up on a scientific research paper that showed how, in theory, a massive explosion - a chain reaction of explosions fractions of a second apart - could be triggered by splitting and using components of a certain chemical. Those same experts went on to play key roles in the US in the Manhattan Project, which developed the first atomic bomb.
Today, the site is considered historically important and in summer 2008 some of the uninspiring brick buildings were given protected status by Welsh heritage society, CADW.
It is also a nature reserve. More than 60 species of bird have been identified, including kingfishers, 150 species of flowers, including the bee orchid, and signs of an otter on-site led to an articifical holt being created.
For more information visit the website of the reserve managers, North East Wales Wildlife.
Historian Dan Snow with Rosina Parry a former on-site weapons inspector
Rosina Parry, 90, is the last known person alive who worked at Valley Works as one of 50 on-site weapons inspectors.
In an interview for BBC's
The One Show
(March 2010) she revisited the site with historian Dan Snow.
She told Dan: "The bombs were laid out for us to inspect. We had to pass them, to make sure they weren't damaged in any way, that they weren't leaking before they were sent through to be packed.
"We knew you couldn't have any leaks. You only needed a little spot and you'd be burned. People in the air force were going to handle them after us so we had to be sure there was nothing wrong with them when they went out."
Rosina explained the daily routines the staff - 2,000 by 1943 - had to go through to ensure they weren't affected by the dangerous chemicals or that their clothes became contaminated.
She said: "When we first went through the gates we had to go to a big building. You had your own locker there.
"You took your clothes off and went through the shower room and into the other room where you put their clothes on.
"And then you reported to the office where they told you which particular cave you were going to go in on that particular day."
Peter Parmella, Cambridge: "We moved form the north east to Mold in 1941 when my father, a chemical engineer at ICI Billingham, was transferred to Rhydymwyn. There my father never went out except to work, I can only remember him staying at home in Mold, playing chess with me and learning some Russian. His only social activity I remember was evenings at a house called Maes Alyn where I once went and met some foreign people with strange names. I was only 8 years old. We learned about his work at 1pm on the day the dropping of the atom bomb on Hiroshima was announced, when my father although a very un-dramatic man, told us that that was what he had been doing - he had been working on the atomic bomb development at Rhydymwyn. What he and others did there precisely was never clear to me though there is a paper in the Kew Archives which he wrote at the time on molecular weights and gas density - something to do with gaseous diffusion of uranium probably - what we call enrichment today. I would like to know the focus of research there if anyone knows. We returned to the north east when the work was transferred to the USA with the results we know.
Allan Roberts, Enfield, Connecticut, USA: "My father, John (Jack) Roberts, was an ICI police sergeant who had been transferred to Rhydymywn from the Rock Savage Plant in Cheshire in 1939. We went to live in Nantalyn, above the Morris's mill. I remember the main entrance to the works being a few yards from the train station before they moved it to its present position and diverting the river. He worked there until 1941 when he was drafted into the Army. He had many stories about that time, but being young and not very attentive I have forgotten most. I would like to offer advice to all like me. Get a tape recorder. You can never trust your memory and cannot go back in time. I will regret it all my life."
Ian Smith, Chester: "My father, Les Smith, moved from Liverpool to Afonwen. He was taken on by ICI as a general mechanic fixing backup generators. He also told stories of tunnels with dividing lines down the middle, personnel in grey overalls walked down one side because they worked with toxic chemicals and other personnel kept to the other side. He told of very harsh working conditions such as operating arc welding equipment whilst up to his knees in water down long dark tunnels that had enormous steel doors. Les was in Caerwys Home Guard. Can anyone supply any more info regarding Caerwys Home Guard?"
Bob Cokayne from Sandbach, Cheshire: "My father, Ron Cokayne, worked at the Rhydymwyn site during the war as part of the government's Man Power Commission. Although I do not know the exact nature of his work he was in an area desginated 'P6'. He lodged with a Mrs Newman in a house on the road out of the village towards Pen-y-Fron."
Mike Gibson, Prestatyn: "Always been a bit mysterious this place! When I was a kid living in the Antelope Hotel, we used to get several men staying who worked there. However, they were not your average run of the mill workers, these men were from London and were obviously from the Ministry. They used to wear the traditional long black overcoats and trilbies, and would come home from work, have their evening meal, have a few pints in the bar and then to bed. They never revealed just what they did on the site - well, so my dad used to say."