No. CCCXI.
EXAMPLES OF SOLID IRON SCREW PILE BRIDGES.
[Vide Plate.]
By Col. C. A. GOODFELLOW, R.E.
Built from 1871 to 1873 on the Bellary-Karwar Road, in the Dharwar and Kanara Districts, Bombay Presidency.
The general design and construction of these bridges is sufficiently ex- plained by the accompanying Plate, but some explanation of details is perhaps necessary.
Sirguppi Bridge.-A temporary bridge merely intended to span the very treacherous and muddy bed of the fairweather stream, the piles were only 2 inches in diameter; round bar iron fitted into the cut off screw bases of the old style of telegraph post socket, in use twenty years ago; screwed down by spanners 6 feet long; the piles whilst being screwed, being kept in position by means of a guide frame with a plat- form, on which the men screwing down worked; the bridge was built in just one month, having cost Rs. 3,920, it was opened for traffic in October 1871, and was washed away in September 1872; this nullah has a fall of 18 feet per mile, and a very bad reputation in the country; on this occasion it took the bridge, (owing to their being a junction of two nullahs just above the bridge, and to the fact that only one of them was in food,) almost longitudinally and completely overthrew it; all the wood- work was carried away, but not one pile was drawn, though all were bent and some twisted in an extraordinary manner. The resistance this bridge made, induced Government to consent to others of full height and strong- er construction, but similar in principle, being built on the same road on the black soil plain of Dharwar; and two such were built in 1872-73, one at Nalowda, 13 miles east of Hubli, and at Budrapur, 18 miles east of Hobli. 20 301
