Construction of 80 m Steel Open Web Girder Over Gaddigodam Railway Span in Nagpur—A Lean Approach

The Nagpur Metro Reach-2 viaduct project is a unique project from many aspects. The project team overcame all kind of challenges including the global pandemic COVID-19 and was truly focused to achieve the given target. The project team used various innovative techniques, did detailed planning, adopted time saving approaches by adopting Lean approaches and team work to achieve the stiff target of completion of 3 months for the erection of 80 m open web girder over the railway tracks. The safety and quality parameters were given highest priority during the process of superstructure erection. Unique challenges and working on new methodology and continual guidance from specialists motivated the team to accomplish the job. Apart from presence of railway tracks and OHE lines, launching methodology and time constraint, transportation of oversized and heavy components of truss was one of the problems which was mitigated by prior checking of route by dry run of ODC trailer. The 80 m steel span launching included assembly of members over temporary structures in three parts, pulling of assembled part over railway tracks and assembly of balance members over temporary structures. Part 1 and Part 2 of the structure were assembled over temporary supports in parallel, thereby reducing the waiting time for successor activities. The project team analysed the total workflow and the cycle time in order to remove the waste to achieve the minimum time required for superstructure erection. The findings in this paper demonstrate that through effective application of Lean methods waste can be removed from the workflow and stiff completion targets can be achieved.