Article 23

     1. In  addition to the requirements of Article 22,  every lifting
appliance  and  every  item  of  loose  gear  shall  be   periodically
thoroughly   examined  and  certified  by  a  competent  person.  Such
examinations shall take place at least once in every 12 months.
     2. For  the purpose of paragraph 4 of Article 22 and of paragraph
1 of this Article,  a thorough examination  means  a  detailed  visual
examination by a competent person,  supplemented if necessary by other
suitable means or measures in order to arrive at a reliable conclusion
as to the safety of the appliance or item of loose gear examined.