The Viaduct Works' Handbook

15 Tons. cwt. qrs. lbs. Vertical and horizontal bracing between girders . 3 13 0 26 Nineteen cross girders and their bolts . . . 3 21 2 Kollers and bed plates 1 10 3 0 Two rows handrailing ...........................................2 13 3 24 Total . . 33 8 2 18 or about 62 cwts. per foot run; and, taking the value of ironwork delivered f. o. b. in an English port at £16 per ton, brings the price to £5 4s. per foot run. From among numerous bridges executed from the same designs, and to which the same particulars will apply, are extracted the following :— Name. No of Spans. • Where situated, and other notes. Ebro Bridge. . . Aragon Bridge . . Tagus Bridge . . Asseca Bridge . . Mondego Bridge . Valle deEsquieras) Viaduct . . J Seisse Bridge . . 21 18 16 5 9 3 6 At Cadrieta, near Tudela, in Spain, over the river Ebro, carrying the Saragossa and Alsasua Rail- way. (Erected by Kennard Brothers.) 'At Marsilla, over the Aragon River: Pampeluna, Alsasua, and Saragossa Railway. (Erected by do.) As described above. (Erected by ditto.) fOn the Badajoz Line; piers 40 feet in blue clay. l (Erected by ditto.) Over the Mondego Biver, in Portugal. f Situate on the Second Part of Fourth Section of 1 Oporto Line of Railway. On the First Section of Oporto Line. In designing these bridges, the Messrs. Kennard have taken, as the basis of their calculations, 1 ton per foot run as the test load, which, until recently, was considered ample for such bridges; but since there has been a great increase in the weight of locomotive engines, and a still further tendency to increase their weight, they have thought it desirable, wherever convenient, that the test load should be calculated at 14 tons per foot run, exclusive of the weights of the girders, platforms, rails, &c., and that the strain should not exceed 4 tons per square inch in section in compression, and 5 tons in tension; and, accordingly, their bridges of class Fig. 2 and Fig. 4 are manufactured at the following approximate weights, exclusive of handrail:—