Construction and maintenance of installations
All parts of the floating cage unit need to be designed
and constructed to provide suitable anchorage,
buoyancy, strength and stability to ensure the
installations safety.
When deciding on the adequacy of these features it is
necessary to take into account the likely loads imposed
by vehicles, equipment, fish food etc, and the effect of
waves and wind. Continued safety of the installation will
depend on regular routine inspection combined with a
maintenance inspection, normally at least once a year
and after storms.
Easily understood written instructions on the operation
and maintenance of the installation should be available
to operators. Site supervisors need to have ready
access to the name and address of the manufacturer.
Provision of guardrails, footrails and safe working surfaces
A suitable and secure walkway needs to be provided
around the exterior of each fish cage with a
recommended width of at least 600 mm. It is also
recommended that internal walkways be at least 900
mm in width. In the case of existing circular cages
which currently have no walkways, it is expected that
suitable walkways will be fitted at the earliest
opportunity.
Walkways can be fitted when cages are removed from
the water for maintenance or, in some circumstances,
while still in use. Where the manufacturer can confirm
that a cage has insufficient strength to withstand the
additional stresses imposed by the sea on a fixed
walkway, work around the exterior of the cage will need
to be carried out from a suitable workboat or
independent floating walkway so that people do not
have to walk on the buoyancy rings. In such cases a
full walkway will not be expected, but it will be
necessary to fit enough landing platforms, not less than
2 m each in length, to ensure safety when boarding
from a boat or independent floating walkway is
required. All new cages need to be designed and
equipped with an exterior walkway (this should be taken
into account by users at the time of purchase).
Guardrails need to be provided, to the greatest extent
practical, along open edges in order to protect against
falls from height or into the water. They are of particular
importance at the inside edge of cage walkways and
the open edges of gangways, feed or accommodation
barges and similar structures. Intermediate guardrails
are optional, except where the upper guardrail has
been vertically offset to a position outside the line of the
edge being protected, or where a person may fall 2 m
or more.
Guardrails are optional at the outside edges of cage
walkways where boat landing takes place, unless a
person falling from the walkway would be likely to suffer
personal injury due to the height or design of the
installation. In such cases suitable guardrails need to
be fitted at sections where the risk of falling is greatest,
eg at T junctions and corners, where the length of the
guardrail would be at least equal to the width of the
walkway that it faces.
Guardrails can be made from wood, metal or other
suitable material, and should be rigid, smooth and able
to withstand the weight of people falling against them.
Where guardrails on two or more adjacent installations
meet each other, they need to be designed so that
dangerous trap points are not created as the cages
move with the waves. Where necessary, guardrails can
consist of taut wire or chain - rope is not suitable.
Footrails need to be fitted at the inside edge of cage
walkways to provide bracing and to prevent workers
feet slipping from the walkway when nets are being
hauled up. A suitable design will prevent fish food or
water becoming trapped on the walkway.
Further Information
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Source: Health And Safety Executive - February 2006
