Shell kinematics (top: radius, middle: velocity, bottom: acceleration), as functions of time for run 3S0. The velocity points are averaged over time intervals of varying length, which correspond to shell radii differences of at least 2 cells. The shell velocity converges towards the ambient sound speed (red line). Each supernova leads to a significant acceleration of the shell (black crosses, bottom plot), followed by a comparably strong deceleration (red stars).