4.6.1 Machinery essential for the safety of the
                           unit should be provided with effective means for its operation and
                           control.
                        
                        
                        
                      
                     
                     
                     
                        
                        
                         
                           4.6.2 Automatic starting, operational and control
                           systems for machinery essential for the safety of the unit should,
                           in general, include provisions for manually overriding the automatic
                           controls. Failure of any part of the automatic and remote control
                           system should not prevent the use of the manual override. Visual indication
                           should be provided to show whether or not the override has been actuated.