Mumbai Infra Watch: Last Orthotropic Steel Deck Erected On Trans Harbour Link, Overall Project Progress At 93 Per cent

The under-construction Mumbai Trans Harbour Link (MTHL) crossed another milestone on 9 May after engineers completed the task of launching the last orthotropic steel decks (OSDs) on supporting piers.

The overall progress on the project is now 93 per cent, with the authorities targeting December 2023 opening.

Orthotropic Steel Decks (OSDs)

The OSD, a steel deck superstructure being used for the first time in the country, will carry the vehicular load more efficiently and improve the load carrying capacity of the bridge, as compared to a concrete superstructure.

OSD bridge has lesser self-weight but stronger structure than concrete or composite girder bridges, which requires fewer and smaller piers.

OSD contributes to shorter construction period and mitigation of safety-risks at the project site since it is manufactured in a factory and requires lesser on-site work. Moreover, fewer and smaller piers and shorter construction period mean less impact on environment and ecosystem.

India’s Longest Sea Bridge

Financed by Japan International Cooperation Agency (JICA), MTHL Bridge is an under-construction 22-km-long six-lane marine road bridge implemented by the Mumbai Metropolitan Region Development Authority (MMRDA).

The project consists of sea crossing section of around 16.5 km and land section of remaining 5.5 km.

The link has interchanges at Sewri in Central Mumbai, Shivaji Nagar at Mumbai Bay and NH-4 B at Chirle, Navi Mumbai.

Popularly known as the Sewri Nhava Sheva Harbour Link, the sea link connects Sewri in Mumbai to Chirle in Navi Mumbai, thereby, reducing the travel time between South Mumbai and Navi Mumbai to just 20 minutes from the present two hours.

The mega project is expected to mitigate traffic congestion in the island city and promote economic development in Navi Mumbai and greater economic integration of Mumbai, Navi Mumbai, and their extended regions such as Pune, Goa, Panvel and Alibaug.

At a Glance

• 70 number of OSDs in MTHL

• 84,000 tonnes: Cumulative weight of all 70 OSDs

• 8.8 km: Total length of OSDs used in MTHL

• 180-metre: Longest OSD launched on the MTHL, giving a navigation space of 180 metres to ships traversing under the bridge without obstruction

• 04 January 2022: Launch of first OSD for MTHL

• 09 May 2023: Launch of last OSD for MTHL

Four Packages

The MTHL bridge has been split into four packages — while packages 1 and 2 are sea based, package 3 is on land.

Package-4 entails work related to installation of an intelligent transport system (ITS), toll management system, electrical works, highway illumination system, and construction of toll plazas and administrative buildings including the command control centre.

Deadline

The commencement date of three civil works packages was 23 March 2018 and the progress is 92.60 per cent in Package-1, 92.28 per cent in Package-2, and 98.09 per cent in Package-3, as of 5 March 2023.

The bridge, when completed, would be the longest sea bridge in India and would cater to 70,000 vehicles daily.