Section 19: Construction and maintenance of fencing

All fencing or other safeguards provided in pursuance of the foregoing provisions of this Part of this Act 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 for examination and for any lubrication or adjustment shown by such examination to be immediately necessary, and all the conditions specified in section 18 (2) of this Act are complied with.