The Llanberis bomb store was built by the air ministry in the eastern pit of the disused Glynrhonwy Isaf slate quarry, the quarry was deemed suitable for the storage of 18,000 tons of bombs and construction of the bomb store was completed in 1941.
Because of the great depth of the quarry the bomb store was built with 2 levels. The lower level and a conventional flat reinforced concrete ceiling which also formed the floor of the upper level. Standard and narrow gauge railway lines entered the lower level of the depot through the original quarry access tunnels, while three electric lifts transported bombs to the upper floor. The deep pits to the west of the depot were later used for burning and dumping redundant and dismantled ordnance.
Overhead protection was given by forty feet of broken slate. In 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.
The depot remained in use after the war but all functional stock was removed by March 1955 and the depot closed in July 1956.
Explore - We've wanted to have a look at this place for years but never seemed to get round to it on previous visits to the area. We were passing while on a night away so thought we'd finally tick it off. While it's been posted a lot we were quite surprised by the place, it's much bigger than expected and the underground storage bays are impressive. Access is very easy and It made for an enjoyable wander for a couple of hours.
Thanks for looking
Because of the great depth of the quarry the bomb store was built with 2 levels. The lower level and a conventional flat reinforced concrete ceiling which also formed the floor of the upper level. Standard and narrow gauge railway lines entered the lower level of the depot through the original quarry access tunnels, while three electric lifts transported bombs to the upper floor. The deep pits to the west of the depot were later used for burning and dumping redundant and dismantled ordnance.
Overhead protection was given by forty feet of broken slate. In 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.
The depot remained in use after the war but all functional stock was removed by March 1955 and the depot closed in July 1956.
Explore - We've wanted to have a look at this place for years but never seemed to get round to it on previous visits to the area. We were passing while on a night away so thought we'd finally tick it off. While it's been posted a lot we were quite surprised by the place, it's much bigger than expected and the underground storage bays are impressive. Access is very easy and It made for an enjoyable wander for a couple of hours.
Thanks for looking
