Many cavers spend a large proportion of their time on digging projects aimed at discovering new caves or re-opening old lead mines. Long-term projects can involve several years work requiring a host of specialist skills, not to mention the large amounts of tools and materials required such as timber, scaffolding, battery drills, ventilation and drainage systems etc. . Digging work is normally being carried out at a number of sites at any one time in North Wales.
Some caves have not yet received the attention they deserve. Amongst these are a few personal favourites..........

Glan Alyn Dig Loggerheads Country Park

This area of the River Alyn's stream-bed suffered serious leakage via swallets into the mines. Many swallows were identified and excavated by Halkyn Mines in the 1930s before being filled and sealed. Dye introduced into swallows at the Glan Alyn area in the 1930s took 20 hours to re-appear in mine workings on the Llyn-y-Pandy vein, 1.7 miles to the north. One of these swallows was excavated by miners to a depth of 7m from where they drove a horizontal passage under the north bank. After a few metres they encountered a small chamber "through which all feeds in the area appeared to pass". A passage "at times of small capacity" led off which they explored for 22m before filling the entire cave with “slimes & ashes“ (see first photo below).

In the early 1980s, cavers were granted consent by Clwyd County Council to dig a shaft from the river bank directly downwards in the hope of holing through the chamber roof. The diggers blasted through solid rock to a point just 1m from the chamber, but flooding at the bottom made further work impossible and the entrance shaft was refilled, It is subsequently discovered that the dig dries out. Consequently, GCC re-negotiated access in about 1998 and re-commenced excavation. Unfortunately it now appears that the chamber is not where shown on the 1930s plan and the dig has been abandoned.

Dozens of swallows were excavated by Halkyn District United Mines (HDUM) in the 1930s, but nearly all degenerated into impenetrable fissures. The Glan Alyn site was the only one known to have encountered an active cave passage.
The main body of the unpublished 1938 HDUM report is available as a PDF download on Page 15: Springs, Sinks and Shakeholes (see under "Alyn Gorge Swallows").

Inside the small chamber found in the 1930s.
Photo from an unpublished HDUM report of 1938

Survey of the old dig (pale brown), the latest dig (darker brown) and
the chamber and
watercourse found by miners in the 1930s from the shaft in the river-bed
(Based upon the original 1930s report by HDUM)

1980s cavers close-timbered entrance shaft

1998 project at a depth of 25 feet showing ventilation pipe


Gas Pot Esclusham Mountain

An old dig from the 1980s on the Aber Sychnant. Blasted vertically downwards to a depth of 130 feet. Work was made easier by being able to utilise the many open fissures as dumping sites for waste rock. Each visit involved blasting followed by scaffolding to enlarge and stabilise. At the base of the dig a stream was encountered which followed the dip of the basement beds almost horizontally, but in this area the boulders were larger than cars to a height of almost 80 feet above rendering the scaffolding ineffective and the dig was abandoned. Well over 3000 man-hours were spent on the project, plus tons of scaffolding and timber, not to mention the many pounds in weight of explosives. Cavers later discovered the cave system that this dig drains into, via nearby mine workings. The cave is now north wales' largest and longest cave system Ogof Llyn Parc.
Note: It was at one time common for cavers to hold explosives licences. Today the safety requirements are far more stringent making the obtaining of a licence far more difficult.

Looking vertically down at a depth of 60 feet

A short horizontal section at a depth of 100 feet


Park Day Level Minera

This drainage level intersects natural feeders entering from the Minera Master Cave. One mile along the tunnel however, a collapse prevented access to the area of potential new cave. In order to dig through the fall in the late 1970s, rails were re-laid for hundreds of metres and a mine wagon was purpose-made. This then enabled heavy concrete lintels to be transported to the working face. After digging into the blockage, waste was then trammed back almost half a mile, then the lintels were erected to secure the roof. After successfully digging through after two years work, a more intimidating area of shale collapse was found beyond and the dig was abandoned.

Brick-lined section of the level not far from the portal

Taking a break in the miners 'cabin' near the working face

Almost through