Report - WW2 Bomb Store, Llanberis, Mar17

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28DL Regular User
Regular User
Apr 20, 2013
Just going through a load of pics and thought I'd stick em up. Popped here on the way home of work one night. Can't see much ever changing with the place other than the graffiti. Still, interesting wander.


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.

On 25th January 1942, two-thirds of the structure collapsed within seconds under the weight of the overlaying backfill, completely engulfing a train of twenty seven wagons which was in the process of unloading. The collapse buried over 14,000 tons of bombs which at the time represented 14% of the total RAF stock.

Most of the bombs were recovered and although the remaining tunnels were eventually cleared of debris, no ammunition was ever stored underground at Llanberis again.

In 1969 a decision was taken to clear the entire site of explosives and explosive debris. The task was given to 71 Maintenance Unit EOD Flight from Royal Air Force Bicester. By the time the task was completed in October 1975 the personnel of the Flight had become expert in lifting tons of explosives from the quarry pits and lakes and in the handling of special mechanical equipment. They had also learnt the arts of tunneling and rock climbing, which in the earlier days had been the only ways of gaining access to some of the pits and their surrounding ledges.

On completion of the task, 71 Maintenance Unit EOD Flight had moved approximately 85,000 tons of slate and debris, recovered and disposed of 352 tons of explosive items together with 1,420 tons of non-explosive ordnance debris.













28DL Full Member
28DL Full Member
Nov 13, 2015
It's a cracking little place this, I was in-between jobs when I went so I didn't have a great amount of time. On my list for a revisit.


28DL Full Member
28DL Full Member
Feb 1, 2012
Been visiting this since the 80's. I can remember when it was clean with no graf. Why do idiots have to smash & paint everything?

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