Metro rail to run on steel bridge at Secunderabad

A pre-fabricated steel bridge structure manufactured in Ghaziabad is to reach the city by July. The bridge will be dismantled piece by piece and brought to Secunderabad. Work that was moving at a slow pace in the stretch from Chilkalguda to Secunderabad station is expected to gain momentum.

Meanwhile, a temporary multi-pillar support structure called “trestle structure” for a length of about 500 ft would be assembled on the leased railway land to support the launching of the bridge.

The South Central Railway (SCR) handed over one acre of railway land at Chilkalguda on temporary lease for a few months to HMRL for assembling and launching the massive steel Metro Rail bridge over the existing Oliphanta railway bridge near Secunderabad station.

N V S Reddy, Managing Director, Hyderabad Metro Rail (HMR) said, “The railways put a condition that a minimum of 28 ft height was to be maintained above the Oliphanta bridge tracks to accommodate future double-decker trains.

“The challenge was that pillars could not come up between railway tracks of Secunderabad yard or in the railway land for future railway tracks so the steel bridge was the alternative,” he added.

Of the eight Metro Rail Over Bridges being constructed in the twin cities, Oliphanta bridge construction is the toughest. The Metro Rail main obligatory span had to be accordingly designed for a length of 275 ft without any support and with a height of 60 ft (sixth floor) from road level.

Complicating further is the presence of a very sharp 128 m radius road curvature. To take care of these technical needs, a specially pre-fabricated high strength steel truss structure with special steel plates and bolts and high quality welds is being used for this bridge construction.

The entire steel bridge weighing about 1,100 tons was fabricated and assembled at an engineering factory in Ghaziabad with high precision. To withstand the high stresses of different types that will be induced by such a large span and height, the high strength steel plates are joined by HSFG (High Strength Friction Grip) bolts which will provide necessary strength for the bridge.

Originally the plan was to launch the steel bridge girders from Lekha Bhavan / Gopalapuram police station side. This would have been possible only after the completion of “Secunderabad East” Metro station (of Corridor-III) in front of Lekha Bhavan and it would have delayed the bridge construction and the Metro project by one year.

NVS Reddy suggested launching of the bridge girders from Chilkalguda side with parallel construction of the metro station and persuaded L&T to rework their launching scheme. Now with the railway authorities handing over the land to HMRL, preparatory activities for the bridge construction have commenced. Reddy has thanked GM, SC Railway Ravindra Gupta the railway land. The construction of the bridge is expected to be completed by January next year.