King’s Wood Adit, Buckfastleigh, Devon.

This mine was begun on 2 shafts on the hillside close to Bowerdon Farm possibly as a trial for copper.
In 1918 the adit was driven from beside a track and a small stream that run through King’s Wood in the valley bottom at the grid reference given. Dines reports that after driving 27 fathoms (heading a little west of north), an east-west lode was cut, bearing copper and zinc ores. This lode was developed for about 2 fathoms to the west and 3 fathoms to the east. At the limit of the eastern branch a winze was sunk. The drive continued for a further 21 fathoms to where another copper lode was cut which trended just off the course of the adit. A short drive was made from the crosscut in the area of the winze, which also cut this lode. Dines goes on to say that the adit was driven on along the course of the second lode. This second lode also contains a lens of pitchblende (uranite).



In the present day the adit is easy to find as an ochrous stream runs from the portal. Beside the portal is a small round tip, a shallow linear tip runs along the stream bank opposite the portal and there is a third tip is heaped against the hillside just below the adit portal.

The first 5 metres or so of the adit has a thick ochre sludge on the floor but thereafter the floor is solid and without standing water as far as the crosscut. The passage winds slightly but generally keeps the northward heading and is in most places 5 to 6 feet in height and 2 to 3 feet wide. My estimation of the distance from portal to crosscut is 50 metres, which agrees closely with Dines who gave the distance as 27 fathoms (49 metres).

The crosscut is as described by Dines. The eastern branch is open as far as the winze, which is flooded to floor level. A small excavation heads northward from the winze but is full off deads. Similarly the western branch is filled almost to the roof with deads.

Dines gives the length of the adit beyond the crosscut as being 21 fathoms to where the second lode was cut, a distance agreed with by my observation.

Where the lode is cut a chamber has been excavated approximately 4m along the line of the drive by 3m wide. A short drive of maybe 3m has been made as stated by Dines on the trend of the lode apparently on a heading directly back to the winze. The lode, which contains green copper secondaries and black patches of pitchblende with yellow surface secondaries, can be seen crossing the roof of the chamber at a slight offset from the direction of the drive. A large part of the left hand wall is also rich in pitchblende, though here it has been covered over by ochre deposits and there is a large lens of rotted pyrite.

Beyond the chamber the adit floor is covered in rubble, which has formed a low dam flooding a length of the passage beyond. This section is however totally unremarkable and ends simply at a blind face with no evidence of the lode other than a small area of limonitic stalagmites. This is in contrast to the description offered by Dines who indicated that the adit followed the lode for 20 fathoms though here I would disagree and put the distance at maybe only 15 fathoms. The overall length of the adit is therefore in my opinion 63 fathoms (115m).

The presence of the pitchblende has raised the level of radiation over a wide area. Outside the adit mouth at a distance of 200m the background radiation level in the area is around 12 counts per second. Outside the adit entrance this rises to 25c/s, and to 50c/s in the first metre of the adit. This level remains about the same throughout the length of the adit except in the chamber containing the pitchblende where the counts generally exceed 1000/second and climb to over 2000c/s where pitchblende is exposed. Given these high levels of radiation within the adit it is probably not safe to enter.
A thorough sweep with a Geiger counter found that the small round tip apparently contains no pitchblende. The shallow linear tip along the stream bank gives high Geiger counter readings but this is apparently due to uranium rich dust or powder in the tip and does not come from a single lump. The tip just below the adit portal produced a large slate groundmass (approx 7 inches by 7 inches and 3 inches thick), which was about 1/2 pitchblende and gives counts greater than 1000/s with the detector at a distance of 30cm. No other hotspots were detected. Pitchblende could easily be recovered from the adit but the exposure to ambient radiation and the risk from breathing radioactive dust make this unacceptably hazardous. In addition, a golf ball sized piece of smokey (black) quartz with well formed points was found in the tip beside the stream.

Refs:
1. Dines H.G. (1956) The Matalliferous Mining Region of South-West England.

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