 This gun, known as the "three-incher", (трёхдюймовка) was developed by Putilovski Works in Saint-Petersburg in 1902.The lead designers were L. A. Bishlyak, K. M. Sokolovskiy and K. I. Lipnitskiy.It incorporated many new features for that time - carriage with recoil devices, traverse and elevation tracking mechanisms, precision sight for direct and indirect firing, manual interrupted screw breech and single-piece ammunition loading.