Nagpur Metro's 257-metre engineering feat

Nagpur Metro's Phase-II expansion has reached a crucial construction stage, with MahaMetro building a 257-metre-long elevated bridge over busy railway tracks at Uppalwadi, nearly 80 feet above the ground. The technically challenging structure is being constructed using a specialised engineering technique that allows workers to build the bridge section by section without putting up scaffolding beneath it. According to a TOI report, the bridge is being constructed using the balanced cantilever method, also known as the CLC technique. The project forms part of Reach-2A, a 6.92-km stretch connecting the existing Phase-I endpoint to Lekha Nagar near Asha Hospital on the Kamptee route. It is the longest corridor under Nagpur Metro's Phase-II expansion.Nagpur Metro bridge to cross three major railway linesThe 257-metre structure will pass over three railway lines: Godhani-Kalamna, Chhindwara-Nagpur and Khaparkheda; falling under the South East Central Railway. The busy railway corridor makes this one of the most technically demanding components of the Nagpur Metro Phase-II project.Read more - Nitin Gadkari says no challan for speeding up to 20% over the limit: What he told officials, when challans should be issued & what motorists must knowThe bridge will have a central span measuring 110 metres directly above the railway tracks. It will be flanked by two additional spans of 74 metres and 73 metres, respectively. The Metro rail level will be approximately 24 metres above the ground.MahaMetro has completed the substructure work, while construction of the superstructure has started from the Kamptee end, officials confirmed.How is Nagpur Metro building the bridge without scaffolding?The project uses the balanced cantilever construction technique, which allows engineers to extend the bridge horizontally from supporting pillars without relying on extensive temporary structures underneath.Under this method, concrete segments are cast successively on either side of a supporting pier and connected using post-tensioning technology. This helps maintain the structure's balance as the bridge gradually extends outwards.A 150-tonne crane is being deployed to lift steel rods and other construction materials to the top of the supporting pillars. Each concrete segment measures between 2.5 metres and 3.175 metres in length, while its thickness ranges from 3 metres to 6.25 metres, depending on structural requirements.Specialised 40-tonne machine to construct bridge sectionsAt the Nagpur end, construction workers are preparing a 10.5-metre-long concrete platform, known as a hammerhead, on top of a supporting pillar.Once the platform is ready, a specialised machine called a form traveller, weighing around 40 tonnes, will be installed on it. The equipment will help engineers cast and extend the concrete bridge sections progressively towards the railway crossing.The technique is particularly useful at Uppalwadi, where the railway lines and surrounding traffic leave limited scope for conventional construction arrangements. By avoiding scaffolding beneath the bridge, engineers can minimise obstructions at ground level while work continues above the operational railway corridor.Nagpur Metro Phase-II construction progresses in day and night shiftsConstruction is progressing in both day and night shifts as the project enters the critical superstructure stage. The completion of the bridge will help MahaMetro overcome a major railway-crossing challenge on the Kamptee route.Once operational, the Reach-2A corridor will extend Nagpur Metro connectivity towards Kamptee, improving access for commuters along the route. The 257-metre bridge is among the key engineering structures required to take the city's expanding Metro network beyond its existing Phase-I limits.Inputs from TOI