(a)all parts, including the working gear, whether fixed or movable, of every lifting machine and every chain, rope or lifting tackle shall be—(i)of good construction, sound material and adequate strength and free from defects;(ii)properly maintained; and(iii)thoroughly examined by a competent person at least once in every period of twelve months, or at such intervals as the Chief Inspector may specify in writing; and a register shall be kept containing the prescribed particulars of every such examination;