  The presence and structure of an Orr-like inviscid mechanism is studied in
fully developed, large-scale turbulent channel flow. Orr-like `bursts' are
defined by the relation between the amplitude and local tilting angle of the
wall-normal velocity perturbations, and extracted by means of wavelet-based
filters. They span the shear-dominated region of the flow, and their sizes and
lifespans are proportional to the distance from the wall in the logarithmic
layer, forming a self-similar eddy hierarchy consistent with Townsend's
attached-eddy model. Except for their amplitude, which has to be determined
nonlinearly, linearised transient growth represents their evolution reasonably
well. Conditional analysis, based on wavelet-filtered and low-pass-filtered
velocity fields, reveals that bursts of opposite sign pair side-by-side to form
tilted quasi-streamwise rollers, which align along the streaks of the
streamwise velocity with the right sign to reinforce them, and that they
preferentially cluster along pre-existing streak inhomogeneities. On the other
hand, temporal analysis shows that consecutive rollers do not form
simultaneously, suggesting that they incrementally trigger each other. This
picture is similar to that of the streak-vortex cycle of the buffer layer, and
the properties of the bursts suggest that they are different manifestations of
the well-known attached Q$_2$-Q$_4$ events of the Reynolds stress.
