Clause 24

All fencing or other safeguards provided in pursuance of the foregoing provisions of this Part shall be of substantial construction, and constantly maintained and kept in position while the parts required to be fenced or safeguarded are in motion or in use, except when any such parts are necessarily exposed in motion for examination and for any lubrication or adjustment shown by such examination to be immediately necessary, and all the conditions specified in the proviso to section 23 of this Act are complied with.