21176

 

II  

Designated  

17/12/1998  

17/12/1998  

Torpantau tunnel - E portal  

 

Powys  

Talybont-on-Usk  

 

Taf Fechan  

305633  

217132  

 

On the mountainside within a forestry plantation almost due W of Pont Blaen-y-glyn and below the summit of Coetgae-llwyn.  

Transport  

 

Part of Brecon and Merthyr Railway constructed 1860s, the line substantially supported by Brecon bankers and the de Winton family of industrialists with the aim of transporting coal and iron from the industrial valleys to S. First section between Brecon and Pant near Dowlais opened 1863, later extended to Dowlais; branch line to Merthyr from Pontsticill Junction followed Taf Fechan River opened 1868. Engineer for Brecon/Pant section Henry Conybeare and for Pontsticill to Merthyr Alexander Sutherland. The engineering achievement of this line is described by Barrie as "the famous Seven Mile Bank, constructed throughout on a shelf cut into the hillside and falling towards the Usk for the first half-mile at 1 in 68 and then for 61/2 miles at 1 in 38 so that southbound trains have to overcome a rise of 925 feet in seven miles". Closed 1960s.  

Semi-circular arched portal of coursed rock-faced stone, prominent rock-faced voussoirs with diamond shaped ends and dressed tooled edges, similar to quoins; rockfaced string, angled end piers and large rockfaced coping blocks. Inside the tunnel portal the sides are of giant rockfaced stone blocks to impost level, tooled above, with coursed rubble vaults. Some brick further inside tunnel and then cut directly into rock.  

 

Listed together with the W portal as a good example of C19 railway engineering and a surviving feature of the Brecon and Merthyr Railway.