An initial survey of the bridge site was made on 17 February 1851 by
George Turnbull, Chief Engineer of the
East Indian Railway Company: he determined that the river then was feet across — the completed bridge was feet across. He settled on the site near Pures "
where the banks are well defined, and the channel had evidently for ages been confined within certain limits, proved by the existence of old Hindoo temples, far before the Mohammaden works at Muneer, built about 200 years [before 1851]." George Turnbull inspected the bridge and judged it complete on 4 November 1862. On 11, 12 and 13 December 1862,
"a set of experiments with couple engines, testing the Keeul, Hullohur and Soane bridges, with an assembly of Government engineers, and our railing engineers; all very satisfactory." On 5 February 1863, a special train from
Howrah took Turnbull, the
Viceroy Lord Elgin, Lt Governor
Sir Cecil Beadon and others over two days to
Benares: they alighted at the bridge and inspected it. In Benares there was a
durbar on 7 February to celebrate the building of the railway and particularly the bridging of the Sone, the largest tributary of the Ganges. ==New Koilwar Bridge==