Report of activities at Cwmbyr Lead Mine for 2016.

The year began with further work on the horizontal timber with projecting bolts on the Dressing Floor. A fourth water wheel is known to have been on site and used for dressing the lead ores. Our best location is concentrated on this horizontal timber, each end is bolted to timber posts driven into the ground. Excavation soon found a further timber post to the west of the timber. This all points to this as the site of the fourth water wheel. Water used to turn the wheel must have flowed west between two shale block walls, Unfortunately these walls consist of loose shale blocks, roughly positioned as a wall. Not even having foundations, simply placed on the shale ground. So what happened to the water from the wheel? The answer must have been a timber slipway to clear water from the wall and into the local stream.

At a right angle running north and south the wall continues for 18 metres in a similar state of poor construction and no foundations with a width of about 1 metre. Built to mark the change in height from the wooden settling boxes to the lower Buddle floor, the wall is marked on the Ordinance Survey maps of the period. We first cleared the waste and fallen blocks from the face of the wall and traced it along to a turn near the Buddle water wheel site. During the forestry operations of the 1970s, a plough was dragged through the wall at this point and much destruction took place. One feature of the destruction was to expose some earthenware pipes just above the water wheel pit. We carried out excavation along the course of the pipes towards the Buddles. The pipes were buried in about 1 metre of shale, but pointed directly to the east side of the Buddles, suggesting a connection to clear water from the Buddles. When we excavated the Buddles an opening had been noted under the east wall, so it was re-opened to find the same earthenware pipe system below the Buddle wall. Enough timberwork remained around this opening to suggest a gate was placed to restrict the flow of water from the Buddle into the pipe system. It suggests that as the Buddle worked, sorting the lead from the waste, water would have been allowed to drain into the pipes and away north, passed the Buddle wheel and back to the local stream.

Excavation along the face of the wall also located two bright orange heaps of slimes, probably containing lead ore. With a settling box on the higher level of the dressing floor, feeding lead ore and water on to the two Buddles, then some form of wooden channel would have delivered the slimes. Made of four planks of timber these two channels must have leaked slimes on to the lower floor level, leaving two large heaps. These heaps line up nicely with the settling box and the two Buddles, suggesting poor maintenance during the later stages of the mine. Having found one system of earthenware pipes, bought back memories of a second system of pipes on the dressing floor. Further excavation soon located this second system, which proved to be smaller in diameter and to be an isolated run from a shale lined drain toward the stream. Following on from these discoveries, we want to look at more of the dressing floor to attempt to discover what water wheel number four was doing.

Many thanks to these who have worked on this excavation over the year. I hope to see you on site during 2017 when much remains to be done.

Nigel A. Chapman.   December 31 2016.

You can read more about Cwmbyr and see pictures here.