Loch Ken Viaduct
Located north west of Castle Douglas, Dumfries and Galloway.
It has three wrought iron bowstring lattice girder spans of 138 ft, and is built on a curve of 880 yd radius to carry the Portpatrick Railway over the River Dee. The masonry of the piers rests on cast-iron tubes up to 42 ft deep, which were sunk by a novel use of screw-piles.
Designed by B. and E. Blyth, consulting engineers. Advertised for tenders in January 1859 [1]. Constructed by Thomas Nelson and Co., Carlisle, in 1859–60. Tested in February 1861 [2]. Described in The Engineer [3]
1965 Closed. Now privately owned and used for road access.
See CANMORE entry for history, description, photos, and map[4]
The Railway Bridge over Loch Ken.—
'The railway is carried across Loch Ken, close to the ferry at Boat of Rhone, by a bridge which has no resemblance to any other railway bridge in Scotland. It is erected on piers formed of cast iron cylinders eight feet in diameter; these cylinders are screwed together and sunk in the loch - the interior being filled with rubble masonry. The cylinders are about 36 feet deep ; there are two of these cylinders for each pier; from near the level of the stream the piers are formed of red sandstone from Cove and Whitehaven, and these piers are joined by an arch which is erected on a single large pier - the top of which is built of granite firmly screwed down by strong iron bolts. The structure consists of three arches or spaces 130 feet in span, with semicircular malleable iron girders 17 feet high in the centre, stretching from pier to pier. These girders are of immense strength with diagonal braces. The roadway, borne on cross beams of iron, is secured to the arcs of the semi-circular girders. Two of these spans are nearly completed, and the whole is expected to be finished by the beginning of September. When finished the bridge will be a beautiful and stupendous structure 500 feet in length by 16 wide ; at either side of the river there is an arch for the road to the ferry which is deviated on the Kells side of the Ken. The contractor for the Loch Ken viaduct is Mr. Thomas Nelson, Carlisle, who has carried on operations with great vigour. The cost of the work is £12,288, 13s.— Dumfries Courier.'[5]