First off about the Sturmtiger itself: the Sturmtiger is a slow Tier V tank destroyer equipped with a 380mm mortar.
The Sturmtiger gun is really special and unique. To get a fair amount of destruction out of it, we implemeted a new mechanic called "Shock Waves" for all High-Explosive rounds. They will be used for HE damage calculations in the future.
This new mechanic spreads the shock of the explosion in realtime, making it possible for fast tanks to avoid damage, if they can get out of the epicenter in time. Depending on the size of the round, the damage shown in the ammo information window will be spread in a specific area. The bigger the round, the bigger the area. The hit position is called the epicenter. From there a shock wave is spreading out, dealing massive damage near the epicenter, and really low damage far away from the center.
A big shockwave takes about 2 seconds to spread. While this might be a bit unrealistic, it gives smaller tanks the chance to escape the massive damage blast.
In the following GIF you can see the Sturmtiger creating a massive shock wave by hitting basically nothing:
The shock wave spreads out and destroys the barrels next to it after a few seconds. It also damages the Sturmtiger, since it stood too close to the explosion.
This time the shock wave is shown without explosion effects of the rounds, just to demonstrate it:
And as you can see again, the wave spreads out quickly and destroys any map objects in its way. It damaged the Sturmtiger itself again as well.
Of course there are still many things to consider before releasing this new mechanic to the game. What about obstacles like bunkers? Should they protect you from the wave? What's about teamkills caused by this? And what happens if the HE round penetrates a tank instead of exploding on the outside? Should it create a shock wave as well? Either way, the mechanic will be released with the new update, together with the Sturmtiger and other new Tank Destroyers. So stay tuned, the next update isn't that far away anymore!
Keep in mind that the shown changes are not final yet. They may still get reworked or completely abandoned at any time without further notice. The Devblog series is just here to inform you about the latest development plans of the game.