Mumbai, May 15 (IANS): Marking a significant achievement, the BrihanMumbai Municipal Corporation installed the second gigantic Bow Arch String girder connecting the Mumbai Coastal Road (MCR) project with the Bandra Worli Sea Link (BWSL), in the Arabian Sea off Worli, officials said here on Wednesday.
This is the second Bow Arch String girder installed -- after the first one on April 26 -- and now the MCR and BWSL are connected on both sides, which will prove to be a boon for traffic movement in each direction.
Top officials of the BMC including Municipal Commissioner Bhushan Gagrani, Amit Saini and others were present to witness the feat at dawn which was completed smoothly in tandem with the tidal wave conditions.
Compared with the first girder which was 136 metres long, 18-20 metres wide and weighed 2,000 tonnes, the second girder is bigger at 143 metres length, 31.7 metres wide, 31 metres tall and weighs 2,500 tonnes.
However, erecting it was a huge challenge as the space was very cramped beside the BWSL bridge and positioning the second girder just 2.8 metres away from the first was a complex task.
For the first girder, the engineering teams had flexibility and ample space needed for a smooth setup, unlike this time but the teams overcame all the risks and executed the mission carefully, starting at 3 a.m. and successfully completing it at 6.07 a.m., before Mumbai woke up.
An official of Freight Wings Pvt. Ltd. tasked with the mammoth challenge of installing both the girders, said it had deployed an array of specialised equipment, a fleet of 250-class barge with tugs, 120 self-propelled modular transporters, 32 strand jacks each with a capacity ranging from 200-980 tonnes, quick lowering long-stroke tidal jack of 5,000 tonnes, heavy duty tower modules, mooring winches, rapid ballast systems and leg-mating units.
The second girder, like the first one, was also manufactured in pre-fab parts in Ambala (Haryana), and then transported in over 500 trailer trucks to Mazagon Docks in Mumbai.
It was assembled at the Mazagon Docks and on Sunday, it was loaded onto a barge of around 25,000 tonnes which departed from there for a 62-km long voyage to the BWSL where it reached early on Wednesday for the setup.
For the first time in India, the contractor opted for the float-over method due to the shallow draft and anticipated weather conditions, including wave heights reaching upto 1.5 metres, and leg-mating units in the open sea for superstructure installation.
The groundwork and other technical preparations for the installations of the two girders had started in January, and after overcoming all hurdles including inclement weather conditions, the two girders were finally installed at the designated spots on April 26 and May 15.
The BMC said that now the concretisation for the road on the girders will be taken up using Japanese technology to prevent corrosion before the new links are opened for traffic.