1.0 Introduction In Appendix 1 of this report general procedures for the design and evaluation of vibration isolation, systems. are reviewed. It is shown that in general., a: vibration isolation system is adequate only when it enables a human operator to meet the objectives of some system by performing a task well enough and for long enough. If the vibration intrudes too far upon the operator's performance and endurance the system of which he is a part will not meet its objectives. There still remain examples today where inadequate vibration isolators limit the performance of a system. The agricultural tractor is one of these. It is not uncommon to see a tractor driver supplementing the tractor tyre spring by using his own vibration isolators - his legs.