The Shipowners Club along with McAusland Turner released an advice on effective hatch cover maintenance for dry cargo ships including preventative action against ingress of water.
ccording to the club, one of the key requirements in cargo vessel operations is ensuring that the cargo is delivered to the discharge port in the same condition in which it was loaded.
Despite improvements in the methods for ensuring that hatch covers are weathertight, Members continue to experience claims for wetted cargo that has resulted from water ingress through hatch covers.
CLOSURE AND SECURING OF HATCH COVERS
In order to ensure that hatch covers are closed sufficiently it is vital that the correct procedures are followed every time the hatches are closed and opened.
This can be achieved by ensuring that crew are duly familiar with the manufacturer’s operating instructions, the company’s on board operation procedures, risk assessments and any other relevant policies related to these operations.
Occasionally, charterers or shippers may request that additional measures are taken to seal the hatch covers, regardless of their condition.
Such request should always be treated with caution as temporary sealing measures such as Ram-Nek tape, expandable foam or tarpaulin (if not part of the vessel’s certified design) often imply that there is an underlying defect with the hatch cover securing arrangement.
It cannot be emphasised more that these measures should be resisted with charterers, with the best course of action being to demonstrate the weathertight integrity of hatch covers without said additional temporary measures.
Poor maintenance can greatly increase the likelihood of hatch covers failing and leaking during periods of heavy weather. Whilst the hatch cover sealing rubber plays an important role as a barrier against sea water ingress, it is not the only means of preventing water from entering the cargo hold.
Cargo is protected from minor leaks through inner drainage channels which will direct water away from the holds to drainage points, preventing the wetting of cargo. It is therefore crucial that not only is the compression bar on which the hatch rubber sits in good condition, but also that the inner sill of the drainage channel is free from damage.
Damage or warping to the inner sill can be caused by contact with the cargo itself or cargo gear such as grabs, chutes or chains. In these cases it is strongly recommended that permanent repairs are carried out as soon as possible.
While the hatch cover seals themselves may be well maintained, if other parts of the hatch cover sealing arrangement are in poor working condition or compromised, cargo wetting could occur, resulting in exposure to high quantum claims.
It is also essential that this drainage system does not become blocked as if it does, the water has no path to drain into and may spill over into the cargo hold, damaging the cargo.
The water in this drainage channel should pass through a non-return valve installed at the end point and not through an open pipe or section of fire hose. It must be noted that if a non-return valve is not fitted, heavy seas can flow in the opposite direction, into the cargo hold. These non-return valves should be removable or enable easy access for cleaning to prevent blockage of drainage pipes.