What is the 2S4 Tyulpan Supermortar and How Many Does Russia Have?

The Russian military has deployed a range of heavy artillery systems in the Donbass against heavily fortified Ukrainian positions, including the 2S4 Tyulpan (lit. ‘Tulip’) self-propelled mortar – a weapon which has its origins way back to the 1950s. What are the system’s characteristics, and what makes them so deadly? Sputnik takes a look.