The Mumbai Metropolitan Region Development Authority (MMRDA) has reached an important milestone by successfully launching the longest orthotropic steel deck, weighing as many as six large aircraft, on the Mumbai Trans Harbor Link.

A material is called orthotropic if its mechanical or thermal properties are different and independent in three mutually perpendicular directions.

The orthotropic steel deck is a longitudinally reinforced superstructure [part of the bridge that forms the horizontal span] that will bear the vehicle load more efficiently and improve the load-bearing capacity of the bridge compared to the concrete superstructure.

An orthotropic steel superstructure is preferred because of its lower dead weight than concrete or composite.