Poster, London Midland & Scottish Railway, Greenisland Viaducts by Norman Wilkinson, about 1935. Train passing over upper viaduct in foreground. Text: County Antrim Northern Ireland. by Norman Wilkinson. R.I. The Greenisland Loop Line on the Northern Counties Committee, opened in 1934, was constructed to obviate the necessity of trains to and from Belfast and stations in the North running via Greenisland. The new line is approximately three miles in length and has a continuous gradient of 1 in 75. The Main Line Viaduct which is the largest reinforced concrete railway viaduct in the British Isles, is 630ft. long and has a maximum height of 70ft. above the level of the stream. The Main Arches in the Main Line and Down Shore Line Viaducts have a span of 89ft. Over 32,000tons of concrete, reinforced with 700tons of steel, were required for the construction of the two viaducts. Other ids: ERO 53351. Format: double royal. Dimensions: 40 x 25 inches, 1016 x 635 mm.