The Gremyashchiy class ‘Thunderous’, Russian designation Project 20385, is an update of the Steregushchiy-class corvettes of the Russian Navy at a cost of 150 million $. This follow-on project was designed by the Almaz Central Marine Design Bureau in Saint Petersburg. The first ship was laid down on 26 May 2011 and the official laying down ceremony took place on 1 February 2012. Although classified as corvettes by the Russian Navy, these ships carry sensors and weapon systems akin to frigates and, as a result, are so classified by NATO