The impact of these defects in switch design, and the failure to inform users
and suppliers of the change in criticality of the padlock, could have been reduced
by those further down the supply chain. Motherwell Control Systems 2003 Ltd ordered the IHLS from TAV but the ordering process by both parties fell short of what would be expected for safety critical equipment intended for such a high-hazard environment. The information TAV provided did not give sufficient clarity about the key aspects of the IHLS design and use, and TAV should have enquired as to the intended purpose of the switch and formed a view as to its suitability – in this case for a high-level only application. Motherwell staff were highly experienced in this field although the company itself