Milwr Tunnels North Wales 25 26th Sep 2004

25 September 2004 � Milwr Tunnels, North Wales � Janna Cook, Simon Fowler, Alan Gray, Doug Harris, Paul Hodgson, Duncan Hooper, Jason Nichol, Richard Nichols, Dave Watts. Leader Kevin Morton from the Grosvenor Caving Club.

A brief history of Milwr Tunnels.
Reference The Milwr Tunnel Bagillt to Loggerheads 1897 � 1987 by Cris Ebbs (1993)

The first miners were the Romans who surface mined the Halkyn Mountain for lead. It was not until the 13th Century that mining re-started with local farmers once again surface mining for lead. In the 17th Century these surface deposits had been exhausted and flooding became a problem at deeper levels. By the late 1600�s the increase of ore prices, the driving of adits to drain the workings, the availability of coal to drive steam pumps and the introduction of black powder which allowed the tunnels to progress at a foot a day led to a massive increase in mining activity.

By the 1890�s many mines had been worked out due to the levels of water, but in 1897 work on a 10 mile long drainage tunnel was started and by 1957 this was completed. This tunnel drained over 50 veins and created a labyrinth of 60 miles of passages. The tunnel has a gradient of 1:1000and is 8ft in diameter.

In 1939 the high grade limestone from these mines was supplied to Pilkington�s of St Helens to make glass � limestone output being between 70 to 80 thousand tons per year. This quarrying continued until 1969 and created a series of impressive chambers up to 80ft high which if joined end to end would extend for 2 miles.

When lode 674 (Powell�s Lode) was intersected a large natural chamber was found - Powell�s Lode Cavern. This cavern is 130ft by 200ft and contains a lake to one side over 200ft deep. Adding this depth to the height above water level of 150ft it can claim to be the highest natural underground chamber in Britain.

The mine closed in 1986 and in early 1987 the cage guide wires of the Olwyn Goch Shaft were cut and the shaft sealed.

Today the Milwr Tunnel discharges an average flow of 23 million gallons per day rising to 36 million in wet weather.

Arrived at The Glanrafon Inn, Milwr, Nr. Holywell at 12:15 a quick meal and met Kevin Morton who was out leader for the weekend of exploration of the Milwr Tunnels. Arrived at the Hendre Quarry which is 6 miles from Milwr, by road, and were all underground by 2pm. I think that most of the party were a little concerned by the amount of ladder work that would be required this weekend.

After about 100ft of horizontal passage the lip of the Olwyn Goch Shaft was reached; this shaft used to house the mine cage but is now a vertical shaft descending for 400ft with a small stream falling away into the blackness. Onto the first of 24 ladders which descend down the left hand side of the shaft. These fixed ladders are made from wood with metal rungs and are set at a slight angle to the vertical and in between each ladder is a platform. The ladders were installed in the 1950�s as an emergency escape from the mine. At ladder 12 another stream enters from the side of the shaft and when the bottom is reached the sound of the cascading water is very loud. At the bottom of the shaft we were shown the room where the cage operator controlled the ascent and decent of the cage and it was always about 3 to 4 inches deep in water. Also near the bottom of the shaft there was a sign about 2� feet from the floor which showed the highest ever water level in the tunnel in October 2000; it must have been quite terrifying the noise of the rushing water. Then upstream through a large tunnel with a river running in it; we stayed to the left following the railway track as the water was below welly level there. In the centre of the tunnel we were told that the water could be as deep as 8ft. We first explored Lodes South heading upstream for about � of an hour. On the way there were several large rooms carved from the limestone where ammunition was stored during the Second World War. Many artefacts were seen such as ammunition boxes, tipping ore carts, and all through the tunnels were large compressed air pipes, communication cables and air ventilation trunking. In several places the veins of lead could easily be identified. At one point Doug climbed up a maypole to explore several older galleries.

We then returned to the ladder shaft and took a tunnel heading west to the limestone workings. Initially the passage is about 10ft high and as the workings are entered the roof is 80ft above with passages that are up to 80ft wide. On the way up these tunnels we passed the small diesel powered train that the Grosvenor Caving Club built which is used to provide easy non-walking access to the main tunnels. However just three days before we were due to visit the back axle sheared so we had to walk. On the way we passed two Eimco shovels that were used to remove the limestone, which were operated by compressed air. The limestone workings were magnificent � so vast. At one point, in the largest chamber it was noted that a photograph of this was on the cover of �Underground Wales by Martyn Farr, which shows a person stood on a rock bridge spanning the chamber with the passage many feet above. The end of these passages was reached and ahead was the top of a wall, at roof level, with shot holes drilled and a slope of limestone scree down to floor level. We the retraced our way halfway down these tunnels and then turned right and climbed a sloping ladder and into smaller workings. These then led to a traverse around a sloping shaft and up a few more fixed ladders and small tunnels and we were back at the Olwyn Goch Shaft at ladder 12 (half way up the shaft). A hasty climb up the ladders and we were back in daylight after 4 hours underground. A magnificent trip.

26 September 2004 � Milwr Tunnels, North Wales � Janna Cook, Simon Fowler, Alan Gray, Doug Harris, Paul Hodgson, Duncan Hooper, Jason Nichol, Richard Nichols, Dave Watts. Leader Kevin Morton from the Grosvenor Caving Club. Plus Dave and two other members of the Grosvenor Caving Club

Back down the 24 ladders in the Olwyn Goch Shaft and at the bottom headed downstream for about a mile. On the way two abandoned Diesel locomotives were passed their wheels submerged in the water from the river. Then a right turn and into Powell�s Lode and heading upstream. At several points this was interesting straddling the rails and slowly inching forward to avoid falling into the river beneath. In the river were long lengths of a fungus floating, brown in colour and the thickness of a stalk of straw, and at several points it had formed into a pure white floating matt, almost like flowers. Half way up this passage Crockford�s Shaft was entered by a difficult climb so only three of our party attempted this. Kevin told us that this was an �old working� and in some places it is still possible to see the clog imprints left by the old miners. There were many interesting fungi hanging from the rotten wood above; pure white almost looking like stal formations. In a side passage an unusual mine telephone just lay there you put your head between the two earpieces and talk into the mouthpiece which was in front of you. Along the rail track that runs by the side of the river were many abandoned man-riders that were used to transport the workers to the face they were working on. In the remains of the compressor room an old miner�s rescue stretcher had just been left on the floor. After about another � of an hour walk upstream we reached Powell�s Lode Cavern as stated above a very large natural chamber with a deep lake. At the side of the lake was a cylindrical tipper that was used to automatically empty the spoil in mining carts into the lake. A climb up a ladder led us into some older workings which eventually brought us out on the opposite side of the lake. Then to the end of these smaller workings and the blank wall with shot holes as if they were completed yesterday. Then a quick walk back to the bottom of the Olwyn Goch Shaft and up the 400ft to the surface. 6 hours underground.

A wonderful weekend. Many thanks Kevin and the Grosvenor Caving Club.

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