Report - Llanberis RAF Reserve Depot (Bomb Store) - July '11

[Xan_Asmodi]

We didn't intend to go to Llanberis, even though it was on our list of possibles. Our target was Denbigh, but given the horrible amount of rain that passed through North Wales that afternoon we decided to skip it. We where already on the A55 so we decided to press on in the hope of better weather and failing that, a better site.

We had a few choices; St. Mary's campus, Ysbyty Bryn Seiont, Caernarfon or Llanberis. Given that I'd heard on the grape vine that it'd been sealed, I thought see should take a butchers. It'd be rude not to!

Getting in to Llanberis wasn't a problem, we have Google Maps after all! I hit the first marker I had entered. Which took us through the residential part of Llanberis, and down this street:

Fuck! Back down the hill we go! A quick Google Map search later and we're parked up, collecting our gear and walking towards the Bomb Store. On the way, one of us spots a man hole cover; right time to get it up. Using bits of iron scattered around the location we get the cover open and find.... an unused septic tank type thing. SCORE! Not (!) We recovered the tank and made our entrance to the site.

_______________HISTORY_______________​

Royal Air Force Llanberis was opened as an explosive storage unit in May 1941

From Subbrit:

On 18th August 1939, the Air Ministry sought approval to acquire the disused Glynrhonwy Isaf slate quarry which had closed in 1930; the quarry, near Llanberis in North Wales, was deemed suitable for the storage of 18,000 tons of bombs.

From bunkertours.co.uk

Part of the site resembles eight parallel railway tunnels opening out into a vast concrete tank about 100 metres by 60, with walls 12 metres high. The area was a cut-and-cover construction, formed in the bed of a large slate quarry. There were two levels, and the site was very compact, albeit large. A similar construction was used at Harpur Hill - but never again.

The ceiling of the lower levels forms the floor of the upper levels, which have an arched roof, covered with 8 metres depth of slate waste. One of the galleries is wider and slightly higher than the others, and has a single track railway line running into it the full length, with a wide platform on the North West side and a narrow one the other. An entire train of railway wagons could be brought in for loading and unloading. Such a train, of 27 wagons according to McCamley, was inside of 25 January 1942 when the roof of half the space collapsed, burying the wagons and blocking the only goods exits but not exploding. At the time, 14,000 tons of munitions were stored there, all suddenly inaccessible. Over the next nine months most of the bombs were recovered through the back entrance, which was an adit to another slate quarry. This was a seventy-foot deep pit, and the bombs had to be lifted out of the pit. An inspection at Harpur Hill showed signs of weakness, and much of the overburden was hastily removed. Since the level of the overburden at Llanberis today is not level with the top of the quarry pit, this may also have been done at Llanberis over the uncollapsed part.

[...]

Royal Navy divers were co-opted to investigate the contents of a large lake in one of the pits as it was suspected that it might contain some explosive items. The divers reported that the bed of the lake was littered with explosive items including a number of large bombs. Subsequently, over 20,000,000 gallons (90,920,000 liters) of water and sludge were pumped out. By April 1973 the lake was emptied revealing everyone's worst fears—it took a further two years of hard labour to recover and dispose of the explosive items revealed. Fortunately, this pit was one of those to which 38 Engineer Regiment, RE, had constructed a road, otherwise the task would have been impossible.

_______________PICTURES_______________

[1]
Our first view of the tank area

[2]
The two rail tunnels

[3]
We soon found out that what people had said about it being sealed is true

[4]
Inside the big tunnel. Kromax used as a point of reference to scale

[5]
Four higher and this would be much cooler

[6]

[7]

​

After seeing how sealed it was, we decided to go and search for the back entrance to the store in the hope of gaining access that way. We hope a fence and went for a walk down into an old quarry. Once we pushed through the trees surrounding the edge of the quarry, we where astounded by the view.

[8]

Making our way down we found an old mining tunnel

[9]

[10]

Further into the quarry we realised we'd have to go round the ridge in photo 8. After pushing through the trees behind the ridge, everything we'd seen paled in comparison to the vista in front of us. Here I move onto Kromax's pics as I neglected to take enough

Cheers, Kromax!

After we exited the pit we tried another one near by, and it was DEEP. ex0 went off for a scout around, but couldn't find a safe or suitable way down.

Before we made it back to the car I had to take a shot looking south east across the lake.

[13]

I hope you've enjoyed the pics and the read! Thanks for looking
That's not the end of the day though!​

 

[Gruesometwosome]

Nice Report :P