Though easily said, this technique is impossible to execute without modern FCS and automatic loaders. The FCS calculates the time interval between successive firings and lays the gun at the required firing angle. The time duration between the successive firings may be at a maximum of 2-3 seconds. So, within 20-30 seconds, the entire firing can be completed and the SPG can move even before the enemy recovers from the shell shock. Typically, if four SPGs fire on a single target in this fashion, it is possible that a total of twenty shells land on the target at the same time to annihilate it in no time.
Apart from this indirect fire, the SPG also retains some direct fire capability. For this it has an electronic sight, as in the case of a tank, but with limited functions. When the direct fire mode is selected, the gunner puts the target on the crosshairs and the FCS accordingly lays the gun. This direct fire mode is very rarely used. For direct firing the gun will be almost parallel to the ground. Engaging a moving tank in this position will be out the limits of the FCS of SPGs.
Having understood what big guns actually do and how, and crew protection systems in the first part, this part described various fire control systems. The concluding part next month will cover various types of smart shells and anti-tank missiles.
To be concluded next month
The author is a techno-strategy analyst pursuing doctorate in military electronics. Several of his articles on this subject have been published in this magazine since 2006