7.1.1 Cargo and other hatchways in ships to which
the International Convention on Load Lines, 1966, applies should comply
with regulations 13, 14,
15, 16 and 26(5) of this Convention.
7.1.2 Hatchways in fishing vessels to which the
1993 Torremolinos Protocol applies should comply with regulations II/5 and II/6 of
this Protocol.
7.1.3 In decked fishing vessels of 12 m in length
and over but less than 24 m in length hatchways should comply with
the following:
7.1.3.1 All hatchways should be provided with
covers and those which may be opened during fishing operations should
normally be arranged near to the vessel's centreline.
7.1.3.2 For the purpose of strength calculations
it should be assumed that hatchway covers other than wood are subject
to static load of 10 kN/m2 or the weight of cargo intended
to be carried on them, whichever is the greater.
7.1.3.3 Where covers are constructed of mild steel,
the maximum stress according to 7.1.3.2 multiplied by 4.25 should
not exceed the minimum ultimate strength of the material. Under these
loads the deflections should not be more than 0.0028 times the span.
7.1.3.4 Covers made of materials other than mild
steel or wood should be at least of equivalent strength to those made
of mild steel and their construction should be of sufficient stiffness
to ensure weathertightness under the loads specified in 7.1.3.2.
7.1.3.5 Covers should be fitted with clamping
devices and gaskets or other equivalent arrangements sufficient to
ensure weathertightness.
7.1.3.6 The use of wooden hatchway covers is generally
not recommended in view of the difficulty of rapidly securing their
weathertightness. However, where fitted they should be capable of
being secured weathertight.
7.1.3.7 The finished thickness of wood hatchway
covers should include an allowance for abrasion due to rough handling.
In any case, the finished thickness of these covers should be at least
4 mm for each 100 mm of unsupported span subject to a minimum of 40
mm and the width of their bearing surfaces should be at least 65 mm.
7.1.3.8 The height above deck of hatchway coamings
on exposed parts of the working deck should be at least 300 mm for
vessels of 12 m in length and at least 600 mm for vessels of 24 m
in length. For vessels of intermediate length the minimum height should
be obtained by linear interpolation. The height above deck of hatchway
coamings on exposed parts of the superstructure deck should be at
least 300 mm.
7.1.3.9 Where operating experience has shown justification
and on approval of the competent authority the height of hatchway
coamings, except those which give direct access to machinery spaces
may be reduced from the height as specified in 7.1.3.8 or the coamings
may be omitted entirely, provided that efficient watertight hatch
covers other than wood are fitted. Such hatchways should be kept as
small as practicable and the covers should be permanently attached
by hinges or equivalent means and be capable of being rapidly closed
or battened down.