Arising from an interest in the use of laterally compressed metal tubes and rings as impact energy absorbing components, the role played by inertia in the deformation of systems of such components is examined experimentally. Crossed-layered systems of metal tubes undergoing low speed impact in a drop hammer are considered briefly. The paper is principally concerned with the response of one-dimensional ring systems tested in a simple high speed impact apparatus over a range of conditions. An account is given of various features of the modes of deformation which occur and an explanation is offered which highlights the mechanisms controlling the deformation process. Reference is made to a structural shock wave theory which is suggested by the results of the tests.