Аннотация:It is experimental study of the formation of a horseshoe-shaped vortex from an initial direct cylindrical vortex arising in a viscous layer of a retarded flow of a liquid in a channel with an inho-mogeneous cross section. The spatial bends of the vortex filament and the action of the ambient fluid pressure form at first an arch with supports at the bottom of the channel, then a horseshoe-shaped vortex, and then a circular vortex with the destruction of the supports