Single pull macgregor type hatch cover.pdf - Cochin University of ...

force by the 1967 Merchant shipping Act from which the merchant shipping (load
line) rules 1968 were made the rules for the constructions of ship laid down by
Lloyds register of shipping are consistent with the convention, as are those of other C
classification societies.
3.2 GENERAL CONSIDERATIONS FOR ACCESS EQUIPMENT
3.2.1 Coaming height
Minimum coaming height, derived from the 1966 LLC, is laid down by Classification
Societies. Height are measured above the upper surface of the deck, and any sheathing
that may be fitted, and for hatchway closed by portable covers secured water tight by
tarpaulins and battening devices, they must not be less than:
600 mm (23.5 in) for Position 1;
450 mm (17.5 in) for Position 2,
Coaming of hatchways closed by steel covers fitted with direct securing
arrangements are usually as indicated above, taking into account any sheer or camber
when assessing minimum height. They may, however, be lower, or even omitted
entirely, if the safety of the ship is not impaired by doing so, provided the
Administration of the country concerned consents.
The scantling and securing arrangements of flush hatch covers or those having
less than standard height coamings are treated as special cases. Such arrangements
have been approved in the past. Dock safety regulations generally require a minimum
coaming height of about 760 mm (2 ft 6 in), otherwise additional fencing must be
fitted to prevent personnel falling through the hatchway.
It is rare for ship to have coamings of lower height than those stipulated,
unless they are completely flush. Flush weather decks are required in a variety of
circumstances. For instance, vehicles, wheeled cargo, or containers must sometime be
stowed over the full deck area including the hatch covers, and clear decks for
recreation are desirable in passenger ships. Satisfying the flood ability requirement for
B-100 and B-60 ships may result in coaming being increased in height on such ships
to meet loadline and subdivision regulation.
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