The Tannah Viaduct was the first railway bridge to be constructed in India, it was a vital link in the section of the Great Indian Peninsula Railway from Thana to Callian (later named Kalyan) which opened in May 1854. The construction of this portion was difficult as it involved a two-line Tannah Viaduct over the estuary and two tunnels 
This section of the line was the first contact awarded to Messrs. Wythes and Jackson, Construction Contractors.
The Tannah Viaduct comprised a number of masonry arches and an iron bridge section, imported from Britain, to allow navigation.
The Railway Times of 15 January 1853  carries the following account:-.
“On the opening of the Bombay - Thana line”
This enterprise will shortly be opened for traffic as far as Tannah, twenty-one miles from the Bombay terminus. A double line is laid the entire distance, and the Tannah viaduct is nearly completed, except the two piers through which the navigation passes. The iron bridge for this opening is on its way out by the 'Balcarras.' The embankments, which have been exposed to the monsoon storms and rains, stand remarkably firm, even better than embankments in England. The Indian Government have approved have approved of the line being extended to Shahpoor, on the Thull Ghaut road, twenty-nine miles from Callian, where it will intercept all the traffic which descends by the Thull Gaut. The locomotives have arrived out, and are being fitted preparatory for placing on the line. In a few weeks, therefore, the iron road that is probably destined to change the habits, manners, customs, and religion of Hindoo, Parsee, and Mussulman, will commence its work in the Indian Peninsula
- Wikipedia “Great Indian Peninsula Railway – The Sahyadi crossed”; Retrieved 28 Jun 2016
- Grace's Guide The Engineer 11th Dec 1867 page 316, pdf page 8; Retrieved 28 Jun 2016
- Grace's Guide "Wythes and Jackson"; Retrieved 6 Jul 2016
- Reproduced by the Indian Railways Fan Club (IRFCA)from Railway Times, 15 January, 1853, p.59”; Retrieved 28 Jun 2016