1885 - Ely Bridge - Taff Vale Railway - 'This bridge, Plates CCLVIII. and CCLIX. (see below), the Penarth branch of the Taff Vale Railway across the Ely, a tidal river at this part. It supersedes a wooden viaduct which had been erected some twenty-five years previous, but only carried two lines of railway, the new bridge carrying three. As this bridge was erected on the eastern side of the old viaduct and a siding laid down to convey the material and plant to the work, all interference or delay to the traffic over the old viaduct was avoided ; the road also was improved, from a curve of twenty five chains radius to straight with a curve of thirty chains radius at either end.
Much difficulty was experienced in getting out the foundations owing to the tidal water, which rose on an ordinary spring tide some twenty-five feet. Coffer-dams could not be raised that height on account of interfering with the water-way. To remedy this, coffer-dams were built to a height of eight feet above the mud line, and as the tide receded they were pumped out by pulsometers, which were found to be well adapted for that class of work, the foundations being cleared of water in about three-quarters of an hour. The excavations for the abutments were sunk through the clay for a depth of thirty feet, at which point gravel was found, which from it looseness the excavations had to be continued down another five feet, at which depth the gravel was found to be of sufficient hardness for the foundations. Concrete was then laid for a depth of twenty-four feet for the abutments and five feet for the piers.
The masonry consisted of Pennant stone and Aberthaw lime mortar. As the work proceeded stout hoop-iron cut into lengths was placed in layers five feet apart throughout the whole work until the high water-line was reached. The girder beds, string courses, and cap stones were of Radyr stone, a red conglomerate of great durability found in the neighbourhood. The flooring consisted of pitch pine timber six inches thick, laid longitudinally on the cross girders, the distance between the centres of the latter being four feet ; the timber was thoroughly tarred before being placed in position. The outside girders weighed thirteen tons each and the inside ones fifteen-and-a-half tons each. The cross girders were laid on the bottom flanges of the outside girders, and as the inside girders were kept down so as not to increase the six-feet distance between the roads, stools were placed under the cross girders to maintain the correct level. All the ironwork was planed and drilled, and covered with three coats of red oxide paint.
The ballast used on the bridge was limestone metalling broken small, which was laid to a depth of nine inches. The total weight of ironwork used in the construction of the bridge was 232 tons. The cost of the bridge was £ 20,600. The bridge was designed and the work carried out by Mr. H. O. Fisher, the Company's engineer. The contractor for the masonry was Mr. J. E. Billups, of Cardiff, and the ironwork was supplied and erected by Messrs. Handysides, of Derby.' - The Railway Engineer v.6 [1045] [499] March 1885. |
