Interview Question & Answer - Mechanical hazard

 

1. Q. In the context of work equipment what is a trap?
     A. A trap is where a part of the body can get 

         caught in part of the mechanism and cannot be 

         removed without injury.

2. Q. With plant that has restricted visibility, particularly while carrying out reversing operations, suitable warning devices, or sight seeing devices mustbe fitted, list four such devices?

     A.  • CCTV
          • flashing beacons
          • convex mirrors
          • audible alarm.

3. Q. List four means of power transmission?

     A. • A simple shaft or direct drive
         • Power Take Off (PTO)
         • Speed changing mechanism
         • Gears
         • Belts and pulleys
         • Chains and sprockets.

4. Q. Other than Fixed guards, Distance guards, Adjustable guards and Interlocked guards, name four types of guards?

    A. Automatic guards
        Self-adjusting guards
        Trip guards
        Two-hand control devices.

5. Q. When may it be required to remove or override a guard. Give four instances?

    A. May be required during:
        •    Maintenance operations
        •    Lubrication
        •    Tool setting
        •    Gauging
        •    Removing jams.

6. Q. What are trip mechanisms / interlocks?

    A.  Devices that:
        •   Automatically cut the power from the 

            machine
        •   Operate an emergency brake to stop the 

             machine, if the guard is opened while the 

             machine is operating.

7. Q. Name four types of safety proximity detection devices?

    A. • Photoelectrical sensors (light curtains)
        • Ultrasonic detectors
        • Infrared sensors
        • Electrical pressure mats
        • Mechanical devices such as trip wires or push 

          bars (EN 418: 1993).

8. Q. What is the maximum period between which every air receiver shall be
thoroughly cleaned and examined by a competent person?

      A. At least once in every period of twenty-six 
          months.

9. Q. Name six types of mechanical hazards associated with work equipment and
give an example of each?

    A. Traps –
        Nips
        Shearing
        Crushing
        Impact –
        Ejection
        Entanglement
        Contact.

10. Q. Outside of knifes, list six cutting edges associated with work equipment?

       A.  •   Circular saw blades
            •    Planing machines
            •    Meat slicers
            •    Rough surfaces
            •    Grinding wheels
            •    Sanding belts
            •    Guillotines
            •    Shredding machines.

11. Q. Name eight drive mechanisms which you would associate with in-running
nips?

      A.   •    Belt
            •    Chains
            •    Gear drives
            •    Conveyor systems
            •    Revolving shafts, couplings, spindles, 

                  mandrels, bars and flywheels
            •    In-running nips between pairs of rotating 

                  parts
            •    In-running nips of the belt and pulley type
            •    Projections on revolving parts
            •    Discontinuous revolving parts
            •    Revolving beaters, spiked cylinders and 

                 revolving drums
            •    Revolving cutting tools
            •    Reciprocating needles.

12. Q. List eight areas where you might see “entanglement”?

       A.  •    Drill chucks
            •    Couplings
            •    Screw drives
            •    Smooth rotating shafts
            •    Conveyor systems
            •    Revolving shafts, couplings, spindles, 

                  mandrels, bars and flywheels
            •    In-running nips between pairs of rotating 

                  parts
            •    In-running nips of the belt and pulley type
            •    Projections on revolving parts
            •    Discontinuous revolving parts
            •    Revolving beaters, spiked cylinders and 

                  revolving drums
            •    Revolving cutting tools
            •    Reciprocating needles.

13. Q. List eight hazards that can arise from the use of abrasive wheels?

       A.  •    Improper selection of wheel
            •    Improper mounting
            •    Over speed
            •    Inadequate guarding
            •    Rotating parts
            •    Flying particles
            •    Source of ignition
            •    Imbalance
            •    Dust
            •    Noise.