Indian Bridges. (Additional Correspondence, and Replies of the Authors).

Abstract

CORRESPONDENCE ON INDIAN BRIDGES. 185 '' Indian Bridges." ADDITIONAL CORRESPONDESCE, AXD REPLIES OF THE AUTHORS. Mr. C. 0. BURGE remarked that Mr. Stoney's Paper on the New Mr. Burge. Chittravati Bridge was especially interesting t o him as describing the reconstruction of one of a series of large bridges on the northwest line of the Madras Railway, of which, with one exception, he had charge when he was Resident Engineer on a maintenance division of that railway, and one of which, that over the Hugri, he partly constructed. They were the Cheyair Bridge (38 openings), the PBpagini Bridge (201, the Chittravati Bridge (40j, the Pennar Bridge (24), the Hugri Bridge (34), and the Tungabhadra Bridge (58 openings). These openings measured 70 feet from centre to centre of the piers, or about 64 feet clear between them. The original bridges were remarkable for having a great number of comparatively small spans, and for the cheapness of their construction, the cost per lineal foot being less than one-third of that of the bridge described in the Paper; the PenniLr Bridge for example, only costing R.153, the Chittravati Bridge R.149, and that over the Toongabudra R.168 per lineal foot. The adoption of small spans made it possible to erect the girders at the back of the abutments, and roll them in sets of two continuous spans, over the piers to their respective places, and considerable economy was effected in this manner. The piers were of three types, viz. : (1 j masonry built direct in the solid ; (2) masonry on a group of