Llyn Fawr Tunnel.

Engineer · Jun 15, 2008

Some new and old pics of a water supply tunnel feeding the Rhondda Valley, constructed about 1913 by enlargeing a natural lake and tunneling through the Rhigos mountain ridge.
The tunnel has subsided and there is a pump that keeps the central section dry, (sometimes).
Length about 1.25 miles.

South entrance.

North entrance.

Reservoir discharge.

Steps down from north entrance.

Looking down steps.

Pump.

Pump starter.

Overflow tunnel.

Sorry about the pic size, will try harder next post.

ashless · Jun 15, 2008

Alright!
Nice pics mate, I love the Welsh dams and reservoirs. Visited Craig-goch reservoir and Caban-coch last year, very photo-able but I don't think my other half would of appreciated me wandering off for an explore! :mrgreen:

BigLoada · Jun 15, 2008

Impressive bit of engineering that. Looks like a few old film photographs amongst that lot too.

Urban Mole · Jun 15, 2008

I was gonna say the same BL, looks like some scanned photos there.
Didnt you actually get in there yourself?
Doesnt look like theres much stopping you....get in there.... :mrgreen:

Engineer · Jun 15, 2008

Llyn Fawr Tunnel

Urban Mole said:
I was gonna say the same BL, looks like some scanned photos there.
Didnt you actually get in there yourself?
Doesnt look like theres much stopping you....get in there....

Been there, done it, 1985ish, first trip water 4 feet deep for about 500 yards, no pics, the scans are from pics on the second entry.
The digital pics are from a recce in November 2007, all new pics when I get some time.