Staff Reporter
A defining moment in the history of India’s Metro Rail construction will be witnessed when Prime Minister Narendra Modi inaugurates remaining routes of Nagpur Metro Phase-1 on Sunday. Metro routes from Kasturchand Park to Automotive Square (Line-1) and Jhansi Rani Square to Prajapati Nagar (Line-2) will be dedicated to the nation. A major attraction will be the opening of four-level transportation corridor formed out of a 18.9 M wide steel girder launched across live railway tracks at a height of 28 M from ground level.
Such unique multi-level transportation network will be seen for the first time in the country. An existing vehicular and pedestrian underpass forms the bottom level. Forming the second level, there are railway tracks on top of it. The National Highway and the Metro Line will form the third and fourth levels respectively. This will be part of Asia’s longest double-decker viaduct spanning 5.3 km.
Afcons had erected this 80 M double-decker steel span, weighing 1,650 MT, in a record time of two months. The steel superstructure was placed over Gaddigodam railway bridge, where more than 150 trains and over one lakh vehicles passed the construction site every day. Launching of a gigantic 18.9 M wide girder is probably a first in Indian Railways.
Dr Brijesh Dixit, Managing Director, Maha Metro, recalled the tense moments during the construction stage as the project was quite enormous and full of challenges. It’s now a momentous moment for Nagpurians that Phase-I of Nagpur Metro is now being opened fully on Sunday onwards. The four-layered transport system is something unique and quite an engineering feat, he added.
“The double-decker Open Web Girder (OWG) created with 1,650 MT structural steel with 8,000 structural elements, was placed over the busy Gaddigodam Railway Crossing last winter. All the activities were done in extremely tight railway block hours, given how busy this route is. The span stands at a height of 28 M above ground. Such a critical and complex task has never been attempted before in India,” said Arun Kumar, Project Manager, Afcons.
Apart from the 80 M steel span, two adjacent composite girders with RCC deck slab, each of 25 M span, had to be completed. During the preparatory stage, the team manoeuvred the project's technical complexity amidst space constraints at site, severe winter, unseasonal rains, the pandemic as well as a tight deadline.
“We really had to dig deep into our reserves. All forces collaborated to make this once-in-a-lifetime challenge a success. Apart from our colleagues at site and Head Office, we also enlisted expert support from our Chenab Railway Bridge Project to critically review our preparedness. Manpower and machines were mobilised at an unprecedented pace,” reminisced Amarsinh Raut, Project Controller. Four 250-500 T cranes, one super lift arrangement, 22 torque wrench machines were deployed, and special lowering arrangements were made for the entire operation.