anchor it has been found that after a number of excursions into the plastic region further excursions cause contact between the beam 3 and guide beam 4 over a 1 2 inch length as the beam 3 after many cycles of stress approaches failure it is found that cracks are distributed over this 1 2 inch length when there are no guide beams the same energy is available for forming cracks confined to the immediate neighbourhood of the anchor so that the useful life of the beam 3 is much shortened the guide beams increase substantially the number of cycles of deformation for any given amplitude of deformation which can be applied to the beam before failure so that the beam has an increased capacity for absorbing energy fig3 shows a variant of the absorber of fig2 and in addition shows a varied method of mounting that could also be applied to the device for fig2 this method of mounting will be discussed later the numbering of fig3 corresponds with the numbering of fig2 1 is an anchor and the body to which it is attached is not shown and 3 is again the deformable beam and in this embodiment it is transformed into a body of lower symmetry a strip as a result it is suitable for dealing with forces only in the directions shown by the arrows it has a single line of action as an absorber guide bars 4 are fitted only on the two main faces the linkage for applying the force to the end of bar 3 is not shown it may be an analogue of parts 5 and 6 of fig2 but because of the use to which this form can.