3.1.1 Dredgers,
hopper dredgers and hopper barges classed for unrestricted service
are to have the minimum thicknesses required by Pt 4, Ch 1, 4 Deck structure increased by 2 mm for those areas
of the strength deck outside line of openings which are exposed to
the weather.
3.1.2 Ships
classed 100A1 extended protected waters service are to
have the minimum thicknesses required by Pt 4, Ch 1, 4 Deck structure for all strength deck plating outside line of openings.
The minimum value of s, used in the formulae, may be
taken as 550 mm.
3.1.3 Ships
classed A1 protected waters service may have the minimum
thicknesses as given in Pt 4, Ch 1, 4 Deck structure for
all strength deck plating outside line of openings reduced by 1 mm,
with an overall minimum of 5 mm. The minimum value of s,
used in the formulae, may be taken as 550 mm.
3.1.4 Strength
deck plating within the line of openings in the midship region, and
for 0,075L from the ends, is to have a thickness not
less than:
3.1.5 The
deck plating thickness and supporting structure may be required to
be reinforced in those areas of deck which are liable to be subjected
to regular, heavy, impact loads such as could occur when maintaining
or inspecting large items of dredging gear, etc. It is recommended
that consideration be given to increasing the plating thickness in
these areas to: