The OSD is a steel-deck superstructure, which can carry the vehicular load more efficiently and improve the load-carrying capacity of the bridge as compared to a concrete superstructure for a similar span.
The two 120-metre-long OSDs will each weigh 1300MT. Earlier on January 3, the MMRDA had launched a 70-metre-long OSD on Package 2. There will be a total of 70 OSDs on the MTHL.
“These steel decks are being used to ensure that ships traversing the channel adjoining the MTHL have navigation space to pass under the bridge. The choice of conventional concrete decks would have meant building closer foundations for the piers,” an official said.
The official added that the steel spans are fabricated in facilities located in Japan, South Korea, Vietnam, Taiwan and Myanmar.
The MTHL is an under-construction six-lane bridge, with 16.5 kilometres over the sea and 5.5 kilometres on land. The total project cost of the MTHL is Rs 17,843 crore. The Link has interchanges at Sewri in Central Mumbai, Shivaji Nagar near Mumbai Bay and NH-4B at Chirle, Navi Mumbai.