Page 104 - ΝΑΥΤΙΚΑ ΧΡΟΝΙΚΑ - ΣΕΠΤΕΜΒΡΙΟΣ 2022

A few decades ago, only a few types of hatch Cargo should not only be carried and delivered
covers were made, but today there is a wide vari- in time and good condition but should also be
ety of hatch covers are available to accommo- transported in an environmentally friendly man-
date the requirements of specific ships, trades, ner. Given the size and weight of hatch covers
and cargoes. Nowadays, the most common types and that many types are still operated by hydrau-
of hatch covers for general cargo ships, Handy- lic systems, they have a polluting potential in the
size, Panamax, and Capesize bulk carriers are event of failure and associated spillage.
folding hatch covers (general cargo & Handy- When carrying out an inspection, look for
size) and side rolling hatch covers (Panamax & physical damage:
Capesize). For container vessels, we generally • Significant corrosion, cracks, and distortion
see lift-away type pontoons installed. in covers and coamings; these should be
Ultimately, the shipowner, in concertation with well painted and free of such damage
the shipyard, classification society, flag admin- • Holes and permanent distortion in the plating
istration, and charterers, will be the one who • Distortion in beams or stiffness on the
decides which hatch cover type is more suited underside of the top plate
to the potential charterers’ business model best. • Corrosion around welded connections of
Eventually, hatch covers that are right for the beams or stiffeners
ship, trade and cargo will be developed around • Cracking of connecting joints and welds
specific key parameters. Items that may influ- • Hatch movement; this should be smooth. If
ence the design are the size of hatches are, violent movement is observed, investigate
among others, the size of the hatches, carriage and remove the cause.
of deck cargoes, strength requirements, avail- • Hydraulic system leakage
able crew for preparing hatches to go to sea, The following precautions should be taken in
and opening/closing methods. rough or heavy weather, when high swells are
Hatch cover designs have evolved from very expected, or when it is likely that water will be
basic and relatively lightweight designs to huge, shipped on deck.
heavy, and moving pieces of equipment. Hatch Prior to Rough Weather
covers are considered heavy-duty shipboard • Check that hatch cleats are properly secured
equipment due to their material, which can and adjusted. In rough weather, hulls are sub-
withstand rough handling and does not need jected to high racking forces, so hatch covers
constant care and maintenance. In fact, modern must be held in place but allowed to flex.
hatch covers are high-tech equipment whose • As a precaution, briefly pressurise the hydraulic
very small tolerances should be observed. Their system to ensure that it is fully charged and
maintenance is type-specific, and their opera- that the piping is filled with oil. This has two
tion should be considered a risk. Therefore, it is benefits; first, it prevents seawater from enter-
essential to understand how hatch covers work ing loose couplings or seals, and secondly, it
and how to maintain and operate them. eliminates any creep which may have occurred.

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