Abstract: By providing planar, auxiliary rail segments, each of which, in the stand-by state, protrudes into the commodity passageway with an upwardly-inclined posture and is pivotable to a downwardly-inclined posture upon impact from an article to be stored, the kinetic energy of the article as it proceeds down the rack is dissipated in changing the position of the auxiliary rail segment and damage to the article to be stored and any already-stored articles which is may encounter is prevented. The auxiliary rail segment may be spring biased and/or loaded to produce the desired amount of energy dissipation at each rail segment.