Carreghofa Aqueduct
Near Llanymynech, Montgomeryshire
This impressive iron aqueduct is easy to miss, despite being directly alongside the B3498, 700m west of Llanymynech.
The aqueduct was built in the mid-1860s to allow the Potteries, Shrewsbury and North Wales Railway Nantmawr branch to pass under the Ellesmere Canal The 3¾-mile Nantmawr branch, opened on 13 August 1866, linked Llanymynech, on the Cambrian Railways (CR) main line, to quarries at Nantmawr. Immediately south of the B3498 and the aqueduct was Carreghofa Halt, opened by the Great Western Railway on 11 April 1938 to serve trains that ran between Llanymynech and Llanfyllin. Immediately after the aqueduct the line split, heading west to Llanfyllin and north to Blodwell Jc. via Rhydmeredydd[1]
The canal underwent a very short deviation while the aqueduct was being built, and the arms of this diversion can still be seen.
Both the aqueduct and the road bridge are highly-skewed. These bridges provide the only suggestion that there was ever a railway here.
The aqueduct is very strongly constructed. The slope-sided trough is made from riveted wrought iron plates, and is apparently water-tight. A series of thirteen wrought iron I-beams runs between the abutments, parallel to the axis of the canal. Nine of these support the base of the trough directly. The sloping sides are suported by triangular cast iron frames, whose bases sit on pairs of I-beams (photo 4). There are no less than fourteen of these triangular frames on each side. The I-beams are supported at mid-length by a cast iron I-beam. This is in turn supported by ten cast iron columns, bolted to large masonry blocks. Impressive.