Background, abbreviated from https://www.coflein.gov.uk/en/site/85487/details/diffwys-slate-quarry-blaenau-ffestiniog
Diffwys is part of the Ffestiniog group of slate mines/quarries and is immediately south of the much better known Maenofferen.
The quarry has been called the mam-chwarel (mother quarry) of Ffestiniog and was developed around 1760 by Methusalem Jones, allegedly as the result of a dream.
Although worked to some extent as four separate quarries there was a unified series of tips and levels on the south side, still visible today, and it was the first quarry to produce slate for export rather than local needs.
It’s also thought to be one of the earliest quarrys in the industry to use ’integrated mills’ for processing slate on a sort of production line.
However it lacked a water supply of its own - the early industrial revolution was almost entirely water powered - so its mills were steam powered after ca 1850.
Output exceeded 5000 tons per annum in the 1820s but then declined with extraction continuing on a small scale until 1925. Untopping work to recover more rock begun in the 1980s.
Explore. This place is partly responsible for the huge piles of slate waste which threaten to swamp the bottom part of Bleanau Ffestiniog.
My strategy here was to zig-zag up the waste piles armed with a 1918 map looking for interesting holes.
The difficulty is that the area has changed quite a bit since 1918, and continues to change as more of it gets ground up into aggregate.
Several of the old entrances (adits) seem to have been covered over and some areas near the top of the workings have collapsed completely.
I didn’t have time to look for all the adits, in particular a few to the east - the Chwarel Newydd area - but did eventually find some nice slatey caverns with a few things in them.
There don’t seem to be any reports on here for this slate mine.
Recent satellite view and an old map, with the approximate area explored in the red rectangle.
Most of the above ground pictures were taken on an elderly phone.
Some winding stations on the way up - these hauled goods up and down ramps made out of slate (inclines).
There were usually two tracks, with a descending train of carts loaded with slate pulling up an empty train.
Each train was attached by rope (or cable) to the same drum, one rope wound over the drum and the other under.
Gravity inclines like these usually had long brake handles so the operator could stand far enough away to see down and control the load.
An old adit next to a small incline.
This one didn’t go very far before ending in a collapse in one direction and a wall containing a drain in the other.
Ruins of a mill with a drumhouse in the background.
Another drumhouse with an old adit next to it, but this one didn’t go more than 50 yards either.
Up to the level of the main mill (1859).
Slate blocks were wheeled in on the right-hand side where they were reduced to a manageable size, then cut on saw tables arranged down the middle, with splitting and dressing on the left-hand side.
Waste came out on the left into rubbish wagons to be carted away to the tips.
Another winder - this is a single track one for hauling stuff up, powered by steam.
Diffwys is part of the Ffestiniog group of slate mines/quarries and is immediately south of the much better known Maenofferen.
The quarry has been called the mam-chwarel (mother quarry) of Ffestiniog and was developed around 1760 by Methusalem Jones, allegedly as the result of a dream.
Although worked to some extent as four separate quarries there was a unified series of tips and levels on the south side, still visible today, and it was the first quarry to produce slate for export rather than local needs.
It’s also thought to be one of the earliest quarrys in the industry to use ’integrated mills’ for processing slate on a sort of production line.
However it lacked a water supply of its own - the early industrial revolution was almost entirely water powered - so its mills were steam powered after ca 1850.
Output exceeded 5000 tons per annum in the 1820s but then declined with extraction continuing on a small scale until 1925. Untopping work to recover more rock begun in the 1980s.
Explore. This place is partly responsible for the huge piles of slate waste which threaten to swamp the bottom part of Bleanau Ffestiniog.
My strategy here was to zig-zag up the waste piles armed with a 1918 map looking for interesting holes.
The difficulty is that the area has changed quite a bit since 1918, and continues to change as more of it gets ground up into aggregate.
Several of the old entrances (adits) seem to have been covered over and some areas near the top of the workings have collapsed completely.
I didn’t have time to look for all the adits, in particular a few to the east - the Chwarel Newydd area - but did eventually find some nice slatey caverns with a few things in them.
There don’t seem to be any reports on here for this slate mine.
Recent satellite view and an old map, with the approximate area explored in the red rectangle.
Most of the above ground pictures were taken on an elderly phone.
Some winding stations on the way up - these hauled goods up and down ramps made out of slate (inclines).
There were usually two tracks, with a descending train of carts loaded with slate pulling up an empty train.
Each train was attached by rope (or cable) to the same drum, one rope wound over the drum and the other under.
Gravity inclines like these usually had long brake handles so the operator could stand far enough away to see down and control the load.
An old adit next to a small incline.
This one didn’t go very far before ending in a collapse in one direction and a wall containing a drain in the other.
Ruins of a mill with a drumhouse in the background.
Another drumhouse with an old adit next to it, but this one didn’t go more than 50 yards either.
Up to the level of the main mill (1859).
Slate blocks were wheeled in on the right-hand side where they were reduced to a manageable size, then cut on saw tables arranged down the middle, with splitting and dressing on the left-hand side.
Waste came out on the left into rubbish wagons to be carted away to the tips.
Another winder - this is a single track one for hauling stuff up, powered by steam.
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