Rail Bridge Across The Godavari A Global Marvel

Indian Railways built the 3-km pre-stressed concrete & steel structure at Rajahmundry at a cost of Rs 72cr

Engineers of Indian Railways have constructed a 3-km pre-stressed concrete bridge across the Godavari river in Rajahmundry, the first rail bridge of its kind in the world.

The new bridge, built at a cost of over Rs 72 crore, has been tested with running fully-loaded goods trains and will be opened to passenger traffic in a week, once it is certified by the railways commissioner for safety.

The design of the 28-span bow string girder bridge in concrete was drawn up by Bereau BBR of Zurich, Switzerland, the consultant for main contractor Hindustan Construction Company. The railways engaged Leohardt, Andrae & Partner of Germany as the check consultant.

 

South Central Railways chief engineer R Sunderrajan told mediapersons: This architecturally elegant, structurally efficient and functionally superior structure is the result of a happy blending of the design expertise of Swiss and German engineers, and construction expertise of Indian engineers.

This is the third railway bridge across the Godavari in Rajahmundry. The first constructed by the British in 1890 is still in use. Trains are not permitted to move at a speed higher than 15 km an hour while crossing this bridge. It will be closed once the new bridge is opened to regular traffic.

The second bridge a rail-cum-road bridge was opened to traffic in 1974. The maximum speed allowed on this bridge is 60 km an hour.

The new bridge is part of a high-density rail corridor the Howrah-Chennai east coast main line with as many as 35 trains moving in each direction every day. A bottleneck in north-south traffic will be cleared with its commissioning.

Sanction for the third bridge was accorded way back in 1982, but work was delayed pending a decision whether the superstructure should be of steel, as conventionally adopted by the railways, or concrete, a fast developing technology.

The last concrete bridge by the railways was completed sometime ago in the Thane Creek, but its span size was only 58 metres. The Rajahmundry bridge required a span size of 97.5 metres, entailing extensive and comprehensive design, planning, and sequence of construction.

The design received from foreign experts had to be cross-checked. Contractors had to be motivated to take up the innovative design. All these proved time-consuming.

Railways engineers, with expertise from outside, tackled the challenging task using powerful computers.

Deputy chief engineer Ajay Kumar Sinha, who oversaw the construction at the site, said the following benefits accrued by the railways decision to opt for a concrete bridge instead of a steel one:

The cost has been cut by around 40 per cent.

Steel has to be imported for a steel bridge. No major import is involved in the construction of concrete bridge.

No maintenance is required for a concrete bridge. There is high-cost maintenance for a steel bridge, especially if it is located in a high-corrosion area like Rajahmundry.

The compact bearing system of a concrete bridge does not require maintenance.

From the point of view of passengers too, a concrete bridge is superior, as it gives a smoother ride with a minimum noise level, according to Shyam Kumar, who was earlier involved in the designing of the bridge as chief engineer and is now the user of the bridge as the divisional manager.

Railways engineers are now confident that they can construct similar bridges anywhere. We can do it in three years, said Ajay Kumar Sinha.

The bridge, according to Sinha, has been designed to last 100 years. The adequacy of the design and construction was established after load testing using hydraulic jacks, for the first time by the railways.

It is an engineering marvel and we are proud of it. The Indian Institute of Engineers has given us an award for the best designed bridge, said Sinha.