Article 20

     1. All  necessary measures shall be taken to ensure the safety of
workers required to be in the hold or on a cargo deck of a  ship  when
power vehicles operate in that hold or loading or unloading operations
are taking place with the aid of power-operated appliances.
     2. Hatch  covers and beams shall not be removed or replaced while
work is in progress in the hold under the hatchway.  Before loading or
unloading takes place,  any hatch cover or beam that is not adequately
secured against displacement shall be removed.
     3. Adequate  ventilation  shall  be  provided in the hold or on a
cargo deck by the circulation of fresh air to prevent risks of  injury
to  health  arising  from  the  fumes  emitted  by internal combustion
engines or from other sources.
     4. Adequate arrangements,  including safe means of escape,  shall
be made for the safety of persons when dry bulk cargo is being  loaded
or unloaded in any hold or `tween deck or when a worker is required to
work in a bin or hopper on board ship.