Raheny Bridge

near Dublin

No longer extant.

This was a small road bridge over the Dublin and Drogheda Railway, and is regarded as the first true iron lattice bridge. The responsible engineer, John Benjamin Macneill had become aware of American developments in lattice bridges made of timber, and decided to construct a small example in wrought iron. The bridge was of 84 ft span and 12 ft wide. The top and bottom chords were made from angle iron riveted to flat plates. The side trusses were made from flat plate 2½" by 3/8" set about 9" apart, at an angle of 45 degrees. There was a stringer at mid height on both girders. The main contractor was Messrs Perry of Dublin. The bridge paved the way for Macneill's much larger bridge to carry the railway over the Dublin Canal

1844 'DUBLIN AND DROGHEDA RAILWAY ..... Near this [village of Killester] is a beautiful bridge thrown over the railway ; it is formed of wrought iron, 84 feet span, 56 in elevation, and having a rise of only 18 inches. In its construction Dr. M'Neil adopted the principle from our enterprising transatlantic brethren, whose bridges are, however, of wood. It is supported by a succession of cross bars; and from its lightness and tasteful appearance, combined with strength, is well worthy of closer inspection than can be afforded by a railway glance. It was manufactured by Ringsend Iron Works. The construction was found so admirable that a bridge on the same plan has been completed for the canal at Dublin. This latter was manufactured at the foundry of our enterprising townsmen of the Drogheda Iron Works, and is still more complete than the other, being a perfect level on the surface, without any arch or rise. Near the bridge on the right, at Rosevale, there is another mechanical curiosity. The waters of a rivulet are received in an iron syphon, three feet in diameter, cast at the Drogheda Iron Works. Through this the stream is carried under the railway, and up to its level on the opposite bank. Further on the left you see the pretty little church of Coolock ....'

1844 'NEW BRIDGE, OF PECULIAR CONSTRUCTION, AT KILLESTER.— The lattice bridge across the new railway at this place is eighty-four feet from abutment to abutment, and was erected by Mr. Macneill for the purpose of trying the principle upon which he proposed to erect the bridge across the Royal Canal, which is now in course of construction. The whole design is quite novel in engineering, and will effect a saving which can hardly be estimated in the cost not merely of railway bridges, but of bridges generally. Nothing can be lighter or more beautiful than the effect of this Killester bridge. The cost has not exceeded £3OO, while that of an ordinary bridge of the same span would have amounted to at least £1000 ; and there is nothing either of the suspension or arch principle involved in it. By way of ascertaining its strength, Mr. Macneill heaped upon it no less than fifteen tons of metal, without producing any sensible deflection. The Canal-bridge, on the same principle, will be 142 feet from abutment to abutment.'

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