Snapshots of slices in the ɀ-direction from the simulation of a collapsing collision between evolved 10 and 5 M_J clumps with b = 0 and υ_imp/υ_esc = 1.05. During the impact a compact region is forming behind the shock front in which the density increases by several orders of magnitude (top panels). At a later stage the collapsed region pierces through the shock front (bottom left panel) and regains hydrostatic equilibrium (bottom right panel). After the collision 77 % of the total colliding mass remains bound. Such collisions are a pathway to shorten the pre-collapse stage and influence the survival of the clumps in the proto-planetary disk.