Report - Rhydymwyn Military Site

[theonesone]

Rhydymwyn Valley Military Site (Near Mold)
After viewing an article online about military tunnels near Mold we decided to take a trip out on a random Sunday. The website is unclear about being open to the piblic however after further research it becomes apparent you can join the society and visit the site indepently after a brief induction.
The day we arrived was a Tunnels open day for the society so we managed to drive straight in and park. Lots of people milling about and talking in groups so we just headed down a road onto the site unhindered.
The complex is littered with empty buildings (apart from the odd foot and mouth sign), the road ways etc are overgrown giving it a Walking Dead feeling.
After spending a few hours exploring (the tunnel visits were completely booked and inaccessible), we headed back to the entrance. At this point we realised access to the DEFRA controlled site is only for society members and you need to complete a H&S induction and wear a Hi Viz vest at all times...who knew!

The site is completely hidden from the road and the society website states it was a fully operational military site during WW2 and it was a mustard gas production facility.

 

[anubis]

The 'open drainage channel' bit would make me want to go in by itself :

 

[theonesone]

The 'open drainage channel' bit would make me want to go in by itself :

From what I could see and some info around the site, the open channel goes underneath parts of the site including the tunnels

 

[Polominto73]

Wonder if this place was used to dispose the foot and mouth carcasses? Especially since it's adefra site and having a toxic burial pit ?? Anyone shed any light ?

 

[tigger]

Wonder if this place was used to dispose the foot and mouth carcasses? Especially since it's adefra site and having a toxic burial pit ?? Anyone shed any light ?

The toxic burial pits were in the days of it's chemical warfare use and they were long gone before the foot and mouth disease. The site was used to store the road signs warning of foot and mouth disease (as seen in building P6 above....) but not disposal of carcasses.

The open drainage channel is a culverted section of the River Alyn....it does go under the tunnels but there is no access to the tunnels from it. For a few months of the winter water does flow in it but for most of the year the Alyn is underground at this point. The photo above is looking towards the split where part goes under the tunnels.

 

[Polominto73]

Thanks for clarifying that for me interesting place.and good report

 

[Ordnance]

The site was a WW2 'Royal Ordnance Factory' (ROF) run like others by the Ministry of Supply (MoS) for the War Office but were civilian manned and not by the Military other than visiting WD inspectors who wore the following flash

The site did indeed produce Mustard Gas which was mostly removed and dumped at sea via Barry Docks, the 'Toxic Pits' contain contaminated materials from the 1960's

The site was/is a DEFRA storage site but no carcases were buried in the area, from BSE or Foot & Mouth Disease of which there are far more around the country with minimal markings! The are also Anthrax sites here and there which is far more longer lasting - Local Farmers will tell you where or if you plan to build the council will do a seach.

 

[robham]

One of the buildings here was also used at the start of the UK's work on nuclear weapons, which was later transferred to America as part of the Manhattan Project. Defra are being funny about access at the moment because of bats, but hopefully there will be opportunity soon to get inside and take a look around. I think by all accounts it is just another empty shell though like the P45 buildings that were used for the mustard gas.

 

[tigger]

One of the buildings here was also used at the start of the UK's work on nuclear weapons, which was later transferred to America as part of the Manhattan Project. Defra are being funny about access at the moment because of bats, but hopefully there will be opportunity soon to get inside and take a look around. I think by all accounts it is just another empty shell though like the P45 buildings that were used for the mustard gas.

The three Pyro buildings are pretty much the same as each other. P6 was never fitted out for chemical processing and had some partitioning installed in one half to create offices for some of the Tube Alloys project staff. From the outside it can be seen that a wall was modified (check the camouflage paint). Inside there are the faint outlines on the floor for the five gas diffusion test rigs supplied by Metro-Vic which proved that normal gaseous diffusion was the best way to separate U235 and U238. Otherwise, yes, it looks pretty much like the other two.
As for DEFRA 'being funny' - perhaps...but the bat protocol limiting access when the bats are roosting has been in place for a long time. Some people don't respect that (so lets say that the first three images above were taken outside of the period when bats were present rather than in July).
One building is sealed for use by bats (clothing store C10) and another building, R3, is sealed as there may be a small amount of chemical contamination in one wall (it's not altogether clear and there is a hope that it will be opened at some point). It's the only Runcol production building left and is photographed above through the grilled doorway.

Your reference to "P45 buildings" is presumably a bit of confusion...Building P6 (it's original ICI designation...P1, P2 and P3 were at Randle, P4, P5 and P6 at Valley Works) was building number 45 never P45.
Though there is none of the processing equipment in any building P4 was fitted out but never used. P5 was fitted out but only used for drying Pyro from Randle and heat treatment to produce Pyro-M from Pyro. Both of the Runcol production buildings were used.

Refering to earlier comment about the open drainage in the tunnels...this photo shows the internal drains with steel covers......more than half don't have those covers any more. These drains were in case of vesicant leaks. They drain to sumps at the bottom of the ventilation shafts and the water was pumped from there to the effluent plant. These pumps were removed so the water is now just below those covers. They do not connect to the culvert that diverted the course of the River Alyn, though part of that culvert does run below the tunnels.

One of the parts with no covers.

 

[robham]

Interesting to know about what was inside P6 tigger.
We started a virtual tour of the tunnels once, but never got round to finishing it.
Where do the two small rooms at the extremities link to, are they just air shafts?
We never managed to find the tops of them in all the undergrowth at the top, but did take a look with the drone once whilst there.

This is as far as we got with the virtual tour.

http://www.conquest-drones.com/Customer_Demonstrations/rhydymwyn/Rhydymwyn-Valley-Works.html

 

[tigger]

Interesting to know about what was inside P6 tigger.
We started a virtual tour of the tunnels once, but never got round to finishing it.
Where do the two small rooms at the extremities link to, are they just air shafts?
We never managed to find the tops of them in all the undergrowth at the top, but did take a look with the drone once whilst there.

This is as far as we got with the virtual tour.

http://www.conquest-drones.com/Customer_Demonstrations/rhydymwyn/Rhydymwyn-Valley-Works.html

Nice tour gizmo and obviously relatively recent based on the LED lights the RVHS were using. Unfortunately it loads horribly slowly on my computer so I've not looked beyond the first couple of images (I'll try again later).

By 'two small rooms' I presume you mean top left and right on the small plan on your tour? If so then those rooms are where the pumps were. There are walkways across the sumps (now full of water) and then the shafts slope up to the surface to where the air vents were. The vents were capped with concrete and are visible in the fields outside the site.

I'm not sure if the RVHS has the dates online yet but DEFRA have agreed to a few more tunnel open days in 2019.

 

[Danii27]

Brilliant pictures! I grew up on leete Avenue in the corner and my back garden backed onto this site. As kids we could easily fit through gaps in the fence and spent a lot of time in the site (never got caught surprisingly!) my dad used to unbolt part of the fence to fit through so he could dump grass cuttings etc and every time he did someone would appear within a few days to fix it

I left the area before I was old enough to have a real understanding of what it was and therefore really explore the place properly or take any pictures unfortunately! I remember a lot of smaller buildings had been knocked down and buried (apparently to contain contamination but who knows). I also remember speaking to a lot of people who used to work on the site or had involvement with it and apparently the underground tunnel system is a lot larger than publicly acknowledged, most said they extended down into Mold.

I have had the opportunity to have a quick look around in recent years but only 30 mins or so when we sweet talked them into letting us in during an open day, I am hoping to get onto one of the tunnel tours this year!