To keep hatch covers weathertight, effective sealing
is required between the coaming and the hatch
cover. To achieve the seal the compression bar exerts
pressure on the rubber gasket. Once properly sealed,
the hatch covers are secured in position against the
coaming during sea passages by a `quick acting cleat'
mechanism between the hatch covers and the coaming.
Cross joint wedges are used to seal panels or pontoons.
These exert pressure on the adjacent pontoon top
which in turn exerts pressure on the compressor bar
between the pontoons to achieve weathertightness.
Fig: Hatch cover vents
After each load/discharge and before hatch closure,
all coamings must be cleared of any cargo residue to
avoid damage to the hatch seals. Damage at this point
could easily compromise the weathertight integrity of
the hatch lid, resulting in damage to cargo. Drainage
pipes and non return values at the coaming corners
will need to be cleared.Hatch Jacks
After each use these jacks must be inspected for
possible leaks especially at the seals, which will soon
show signs of leakage. The pipe connections that run
under the coaming of these various joints, are also prone
to leakage (in the same manner as the jacks). This, in
turn, can lead to slippery decks and possible accidents,
including overboard discharge causing pollution.
Chains and Rollers
On older ships, the chains will have stretched through
long usage and this will, in turn, cause problems when
closing hatches as the jack-up points may not centre over
the jacks. Rollers will also show wear on the bearings
and split pins, and replacements may be required.
As with all other parts of the hatch, cross joint cleats/
wedges will need to be checked as they will suffer from
wear that can compromise the watertight integrity of
the lid. In the case of quick acting cleats, the rubber
bush will need to be replaced at regular intervals.
Owing to the natural working of the ship at sea, weather
permitting a daily check of the hatch cleats (including
hydraulic) should be made to ensure that they are tight.
These cleats should not to be bar tight as this could
cause severe compression damage of the rubber seats.
Steel hatch cover testing guideline
Corrosion prevention methods for bulk carrier
Maintenance procedure for mechanical steel hatch covers
Steel hatch cover maintaining watertightness - Classification society guideline
Structural standards & strengthening of bulk carriers
Indication of unusual motion or attitude of bulk carriers and risk management / evacuation
Deterioration of ships structure and consequences of forward flooding
Handling water ingress problems in bulk carrier, investigation and countermeasures
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Operation of sea going bulk carriers involved numerous hazards . Careful planning and exercising due caution for all critical shipboard matters are important . This site is a quick reference to international shipping community with guidance and information on the loading and discharging of modern bulk carriers so as to remain within the limitations as specified by the classification society.
It is vital to reduce the likelihood of over-stressing the ship's structure and also complying with all essential safety measures for a safe passage at sea. Our detail pages contain various bulk carrier related topics that might be useful for people working on board and those who working ashore in the terminal. For any remarks please
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