DISCUSSION. ON UNIFORM STRESS IN GIRDER WORK, ILLUSTRATED BY REFERNCE TO TWO BRIDGES RECENTLY BUILT
Minutes of the Proceedings of the Institution of Civil Engineers
Mr. REILLY said, that he did not bring forward these bridges as examples of perfect construction; on the contrary, he had little doubt forms could be devised which would more perfectly fulfil the conditions contended for; but he thought that Engineers would consider the subject an important one, and on that account these examples would, perhaps, be of some interest. The ironwork of No. l bridge was manufactured at the Canada Works, Birkenhead. All the rivet holes at the web joints were drilled,
... oints were drilled, and the edges of all the plates were planed. The price for the wrought iron was $17. 7s. 6d. per ton, and for cast iron, all of which was more or less machined, S14. 10s. No. 2 bridge was manufactured by Messrs. James Taylor and Co., at the price of $18. 10s. for wrought iron, and $14 for east iron, in both cases delivered free on board, or a t the railway station. At the time the latter contract was taken, iron bars were about 308. per ton higher than they were at present. He did not desire to be understood as condemning the trough form of section unconditionally. He thought it might. be reasonably contended, that the trough might be made partially to fulfil the condition of uniform stress, providing the joints of the web bars, with the trough, were designed with that object, which, however, had not yet been attempted, so far as he was aware. Of course, it was impossible to make the centre of pressure of a joint coincide with the centre of gravity of the section of the trough ; but, probably, the desired result might be effected, to a certain extent, Downloaded by [ University of Sussex] on [13/09/16].