Both ROBs have 60m long bow string span with a deck width of 12m. One ROB is on Kanpur-Allahabad section (NCR) between Fatehpur & Kurusthikalan railway station and second one is on Allahabad-Unnao section (NR) between Dalmau-Lalganj railway station. The alignment crosses the railway tracks at skew angle of 6⁰ in Lalganj and straight at Fatehpur. At Fatehpur, in-addition to two nos. electrified tracks of NCR, two nos. non-operations DFC tracks are also present.  At Lalganj, three nos. NR electrified tracks are present.

Due to the failure of the connection between hanger and bottom chord, Bow String Spans are under distress and it is decided to dismantle them. Before starting dismantling process, bottom chord is supported on several numbers of cribs after taking care of Railway SOD.

Non-structural dead load (e.g. wearing coat, railing, crash barrier, footpath etc.) is removed before proceeding with real dismantling. Thereafter, entire dismantling scheme is divided in two stages. In first stage, upper portion of steel bow and hangers are removed. In second stage, concrete deck slab and bottom chord (Steel Tie Beam) along with steel cross girders are removed. Full length of span is divided into number of parts suitable to the capacity of the crane. The location (thus capacity) of the crane is decided precisely after locating the crane considering requirements of clearance from live railway tracks. The removed parts are firstly stacked on the approach spans and broken into small pieces before disposal. All this dismantling work was done during Railway’s traffic and power block.

CREDITS:

Client                                 : National Highway Authority of India

Contractor                         : Constructora Sanjose S. A.

Consultant                         : Chetan Infratech Consultants Pvt. Ltd. Bangalore

Dismantling Consultant    : B&S Engineering Consultants Pvt. Ltd.