Mumbai: The Mumbai Metropolitan Region Development Authority (MMRDA) achieved a significant milestone on Tuesday as it successfully launched the longest orthotropic steel deck, weighing as heavy as six large-sized aircraft, on the Mumbai Trans Harbour Link.
In engineering parlance, a material is orthotropic if its mechanical or thermal properties are unique and independent in three mutually perpendicular directions.
What are orthotropic steel decks?
The orthotropic steel deck is a longitudinally stiffened superstructure [part of the bridge that provides the horizontal span] that will carry the vehicular load more efficiantly and it will also improve carrying capacity of the bridge as compare to the concrete superstructure.
Such an orthotropic steel deck superstructure has lesser self-weight than concrete or composite, hence, preferred.
This is the second such longest engineering structure to be launched on the under-construction sea link. The earlier one was launched back in April 2022. Among the total 32 such decks to be put up on the bridge, this was the 14th and the longest one.
On achieving the milestone, MMRDA Commissioner SVR Srinivas said, “It is a significant milestone that team MMRDA has reached for MTHL. The teams are moving in sync with our catch-up plan towards commissioning the project by next year end.”
Having a length of 180 metres, the engineering structure weighs 2,400 metric tonnes. The earlier orthotropic steel deck is of similar length and equal weight.
The first steel deck was launched on January 3, which was 70 metres long.
The link will connect Sewri in Mumbai and Nhava Sheva near Ulwe in Navi Mumbai. The sea link will have interchanges at Sewri in Central Mumbai, Shivaji Nagar at Mumbai Bay and NH-4 B at Chirle, Navi Mumbai. The sea bridge will be equipped with an intelligent transport system and the other amenities required. The project cost is pegged at Rs 17,843 crore.