Builders of bowstring bridges

Keeping on the trail of Napier Bridge (Miscellany, November 3) has been reader V.Viswanathan and he has come up with the fact that work on the first bowstring bridge began during the governorship of Lord Erskine and that the bridge was declared open by Governor Sir Arthur Hope. 

The bridge was constructed by Gannon Dunkerley & Co, a major construction company at the time, and the work was supervised by the Madras Port Trust. Who built its clone, inaugurated in 2000, reader Viswanathan is still trying to find out.

Henry Gannon and J H Dunkerley had separate trading establishments in India from 1895. Whether these were in Bombay or Delhi is not very clear, but they were merged in 1918 to become Gannon Dunkerley & Co. (GDC). 

The firm was incorporated as a private limited company in 1924. It passed into Indian hands in 1946 and two years later become a public limited company headquartered in Bombay.

It was in the early 1930s that GDC moved from trading into civil engineering and was particularly active in the South. There it became known for the RCC bowstring bridges it built to its in-house design. 

It also built several other bridges, aqueducts, and civil requirements for irrigation and hydroelectric projects, besides numerous factory buildings. One of the firm’s best known projects was the first ghat road from Tirupati to Tirumalai. During World War II it built several airstrips and runways. 

Then, in the 1950s, it constructed numerous bridges for the Western and Central Railways.

Today, its branch offices in Delhi, Bombay, Hyderabad and Calcutta handle assignments in their respective regions. But there was in the 1950s a Gannon Dunkerley (Madras).

S . Muthiah, H: 24 Nov 2014

The early Napier bridges

Writing to me from the United States, V. Viswanathan says that D.H. Rao’s research into the bridges of Madras reminded him that around 1940, when he was a child, his father, M.S. Venkataraman, took him to see the Napier Bridge under construction near the War Memorial.

 With his father at the time the Traffic Manager of the Port, he wonders whether it was a site visit to a job being undertaken by the Madras Port Trust.

 Or was it just a bit of sight-seeing?

 In which case, who built the bridge?

The first ‘modern’ bridge across the Cooum, with only railings on its side, was built c.1870 when Lord Napier was Governor (1866-72) and, naturally, took his name (Nothing changes, does it?). 

This bridge was strengthened very likely around 1915, during the Great War, with large iron girders on the sides (not unlike the Elphinstone Bridge over the Adyar) and became known as the ‘Iron Bridge’, the iron dominating the whole scene. 

With World War II necessitating a still stronger bridge to handle all the wartime traffic from the Port, the bridge was rebuilt again.

Work on the bridge with the “bowstring girder design” seen today began in 1939 and was completed in 1943.

 It is recorded that this was the first pre-stressed concrete bridge in India. 

With motor traffic growing phenomenally from the 1980s, the bridge needed to be widened. Instead, it was duplicated and the parallel bridge was opened in February 2000.

The pair of bridges, still called the Napier Bridge, is one of the more elegant official engineering constructions in Madras and should be on any Heritage List.

H :S Mutiah :3 nov 2014