Report - RAF Chilmark - Wiltshire - 2012-2013 (Multiple visits)

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28DL Full Member
28DL Full Member
Oct 25, 2009
We first visited this in 2012, and found that access to the main underground part would be difficult without some special equipment. So, we returned a few months later with said equipment, and we found that the previous access had been tightly sealed. After a bit of poking around, we found another, even more difficult access route that would require an even longer piece of equipment. We came back this year with the longer piece of equipment, and began to prepare to rig it up for what would be a difficult and probably slightly dangerous descent. Luckily, however, we looked around a bit first, and found that an access route far easier than any we had contemplated so far had appeared!

These photos are a selection from those three visits, as there's 1-2 days worth of stuff to see above ground here. The place is absolutely vast, not to mention there's a whole load more of buildings plus another mine that are occupied by the International School for Explosives and Security Education (they have an old Virgin rail carriage in there too!) and a Cold War RGHQ bunker (sealed on every visit).

I've tried to imagine how this place might have worked when it was in use. Photos are from all three of us hence the varying quality...

History from

RAF Chilmark, also known as No 11 Maintenance Unit, was an armament depot opened in 1937. It closed as a depot in 1994, with further disposal of much of the ordnance undertaken until 1997. It is situated at Chilmark Quarry, which has been a stone quarry since the 9th century - part of the stone quarry to the north continues in separate civilian ownership (see record 1466497). The armaments depot comprised both underground storage and dispersed surface stores, some linked by a narrow gauge railway. During the Second World War armaments stored here included chemical weapons. By 1965 it was the Royal Air Force's only ammunition supply depot. From the 1960s the depot also handled packed petroleum, oil and lubricants.
So, the site has it's own railway yard with a branch from the main line. It had one or two of its own full gauge locos, and they would have brought the trains of ammo into this area:

Here the bombs would be unloaded onto the base's narrow gauge railway. The full size trains would be in the middle section, and the small ones on the outside:

The little trains would then travel quite a long distance, past a locomotive shed, perhaps passing by or through the large missile assembly building, which the nearby ISSEE have been using for explosives practice:

They would pass by a few other buildings covering a fairly large area:

Including this one, which I gather was some sort of processing building, with several different rooms connected by these hatches:

Some of the bombs might be unloaded from the trains, and taken by truck to the top half of the site, where there are countless sunken ammunition bunkers, along with the military police station and a couple of houses:

But a lot of them would continue on their journey, under a public road bridge, and then deep into the mine store:

This place is pretty big, although it's quite easy to find your way around. There are some bats here, and also a few places where there have been falls, so be careful/considerate...previous explorers (or the mine owner?) seem to have put handwritten signs on areas deemed unsafe for whatever reason.

The mine also has a lift with rails for the cars:

There's a couple of other interesting things above ground, including this very rickety looking building. Inside it was very strange, seemed like the whole thing was divided into two horizontally, so you could either crawl through tunnels underneath a floor or crouch on top of it. We thought it might be a training facility for firefighters.

And also this building, which looked to be some sort of chemical/decontamination centre - there were showers, separate gated sections, and ventilation equipment.

One thing I did wonder that someone might be able to answer - the layout of the site's railway, with its two mines, looked as if to get goods into the second (inaccessible) mine behind the ISSEE, trains would have to enter the first mine, go all the way through to the lift, ascend to ground level, then follow the line from there to the other mine. Seems a little convoluted?

And of course, not forgetting:
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