For those who have seen my previous partial report on the site, I'd skip the history as its pretty similar here, just with better images.
Most history and reference images sourced from SCMC “Below” Journal (Issue 2020.3)
History & Background
Aberllefenni Quarry was the last working slate mine south of Blaenau Ffestiniog. The Aberllefenni quarry consisted of four sites Foel Grochan, Hen Gloddfa Ratgoed and Cenuant Ddu, all mining on the narrow vein, all convinently shown on the bellow maps.
The site has been quarried in some capacity since 1500 and continued operation up until 2003, although it seems by this time less than 5 people actually worked the mine. Shown below is a photo from 2003 showing some of the last workers of the quarry standing outside the now sealed (see right photo) level 8 adit.
Although the level 8 adit is sealed, access is still possible through adits 7 and above. Mining on the site began on the upper levels eventually working down with a external water balanced incline going between levels 1 to 7. With level 8 being at valley level at this point once this level was reached slate was taken out directly through the adit onto the tramway to the mill house.
Given the near vertical path of the slate vein on the narrow vein, the workings are near vertical, many of which being broken through to ground level.
There is a full map/plan in existence for this system as shown in the background of SCMC journal and listed on the BGS website as owned by the coal board, have emailed both of these and if I get my hands on the full map I will post it as a reply, but in the meantime these figures from the SCMC journal are the best you're gonna get.
The explore
(peoples collection wales, 2015)
As before access is through the partially collapsed adit on level 7 (was uncollapsed as recently as 2015)
looking back from past the entrance gate, think the gate may be original as looks pretty similar to the level 8 gate visible in the 2003 pic, although I may well be wrong.
looking into the system from the south end of the level 7 adit once past the gate
looking into the first big chamber, Twll Golau which is although feeling massive is only between levels 8 and 5
Looking back from north side, a couple unaccesable adits are visisble, likely leading to the chambers on the 8th level
you then pass under a reassuringly modern I beam supported section
Looking back into Twll Golau from the underhang section, with an old chain used to hoist slate hanging across
Continuing along the level 7 adit heading north
Along the level 7 adit you pass various collapsed sections, these lead to chambers where the roofs where collapsed to access more of the slate vein
Some of these chambers with roofs intact have instead have no floors, leading to these deep vertical chambers
One of which was named lucifers lake, a lovely holiday destination
section featured some interesting graffiti, some on the right can be seen to be drilled into the slate itself
At the north end of the level 7 the ladder installed in the 60s on order of the mine inspectorate as an escape route between levels 7-8.
This is where I previously ended my trip, however coming more prepared I popped on down
Looking back up the ladder at my unwilling accomplice, from the floor 3/4 of the way down
The last 15m or so, of the other ladder the other 1/4 down
down on the level 8 adit looking south into the workings, with some ladder rings on the right
was about up to ankle depth, but water line would indicate that this wouldn't be the nicest walk if its had rained a bit
had brought myself a builders portable worklight sorta jobby, place certainly looks pretty mint in the warmer light
Past there are the blast chambers, which surprisingly may once have been used to store explosives!
Chamber 10 is then flooded down to level 9, there is a relatively stable gantry that stretches out over the water, accessible from a ladder into a tight chamber housing the winch
heading further along and messing around with the lighting
next is a brilliantly preserved self loading locomotive thingy, in previous pictures I have seen the carts attached to the rear, however they currently appear further south in the adit
to the right is the flooded bottom of the alma chamber, stretching back up to level 4. Within is the butter bros derrick installed in the 80s to haul slate from the lower levels, now wedged up against the far wall
in the chamber along, which is once again flooded down to level 9, is a considerably more basic crane
rounded wall sections from being drilled through
The carts usually with the loader, where further north, thought about pushing them back but that seemed like an awful lot of effort.
Eventually you end back at the bottom of Twll Golau to the blue lagoon
-Continued from here-
Most history and reference images sourced from SCMC “Below” Journal (Issue 2020.3)
History & Background
Aberllefenni Quarry was the last working slate mine south of Blaenau Ffestiniog. The Aberllefenni quarry consisted of four sites Foel Grochan, Hen Gloddfa Ratgoed and Cenuant Ddu, all mining on the narrow vein, all convinently shown on the bellow maps.
The site has been quarried in some capacity since 1500 and continued operation up until 2003, although it seems by this time less than 5 people actually worked the mine. Shown below is a photo from 2003 showing some of the last workers of the quarry standing outside the now sealed (see right photo) level 8 adit.
Although the level 8 adit is sealed, access is still possible through adits 7 and above. Mining on the site began on the upper levels eventually working down with a external water balanced incline going between levels 1 to 7. With level 8 being at valley level at this point once this level was reached slate was taken out directly through the adit onto the tramway to the mill house.
Given the near vertical path of the slate vein on the narrow vein, the workings are near vertical, many of which being broken through to ground level.
There is a full map/plan in existence for this system as shown in the background of SCMC journal and listed on the BGS website as owned by the coal board, have emailed both of these and if I get my hands on the full map I will post it as a reply, but in the meantime these figures from the SCMC journal are the best you're gonna get.
The explore
As before access is through the partially collapsed adit on level 7 (was uncollapsed as recently as 2015)
looking back from past the entrance gate, think the gate may be original as looks pretty similar to the level 8 gate visible in the 2003 pic, although I may well be wrong.
looking into the system from the south end of the level 7 adit once past the gate
looking into the first big chamber, Twll Golau which is although feeling massive is only between levels 8 and 5
Looking back from north side, a couple unaccesable adits are visisble, likely leading to the chambers on the 8th level
you then pass under a reassuringly modern I beam supported section
Looking back into Twll Golau from the underhang section, with an old chain used to hoist slate hanging across
Continuing along the level 7 adit heading north
Along the level 7 adit you pass various collapsed sections, these lead to chambers where the roofs where collapsed to access more of the slate vein
One of which was named lucifers lake, a lovely holiday destination
section featured some interesting graffiti, some on the right can be seen to be drilled into the slate itself
At the north end of the level 7 the ladder installed in the 60s on order of the mine inspectorate as an escape route between levels 7-8.
This is where I previously ended my trip, however coming more prepared I popped on down
Looking back up the ladder at my unwilling accomplice, from the floor 3/4 of the way down
The last 15m or so, of the other ladder the other 1/4 down
down on the level 8 adit looking south into the workings, with some ladder rings on the right
was about up to ankle depth, but water line would indicate that this wouldn't be the nicest walk if its had rained a bit
had brought myself a builders portable worklight sorta jobby, place certainly looks pretty mint in the warmer light
Past there are the blast chambers, which surprisingly may once have been used to store explosives!
Chamber 10 is then flooded down to level 9, there is a relatively stable gantry that stretches out over the water, accessible from a ladder into a tight chamber housing the winch
heading further along and messing around with the lighting
next is a brilliantly preserved self loading locomotive thingy, in previous pictures I have seen the carts attached to the rear, however they currently appear further south in the adit
to the right is the flooded bottom of the alma chamber, stretching back up to level 4. Within is the butter bros derrick installed in the 80s to haul slate from the lower levels, now wedged up against the far wall
in the chamber along, which is once again flooded down to level 9, is a considerably more basic crane
rounded wall sections from being drilled through
The carts usually with the loader, where further north, thought about pushing them back but that seemed like an awful lot of effort.
Eventually you end back at the bottom of Twll Golau to the blue lagoon
-Continued from here-
