The silo-based SS-24 Mod-1 (15Zh60) was deployed in silos formerly occupied by SS-17 Sego ICBMs, starting on 28 November 1989, and the first regiment of silo-based missiles was activated on 19 August 1988. Altogether 56 silo-based RT-23UTTh missiles were initially deployed, with 10 at Tatishchevo in Russia and 46 at Pervomaysk in Ukraine. A total of 46 silo-based RT-23UTTh missiles located in Ukraine were phased out and dismantled in compliance with the provisions of the START-1 treaty.
