and moisture content. According to this standard, soya bean temperatures above 25°C combined with moisture contents over 13% may create conditions suitable for mould growth and indicate that the parcel of soya beans should probably be dried further. This is contrary to the moisture content specified on most commercial contracts which specify a moisture content of 14% which is much too high a tolerance for soya beans being shipped over long distances.
Since there is potential for change in temperature and moisture content during the transport and storage chain, the soya bean temperature and moisture data should be monitored throughout the inland transport chain by experienced cargo superintendents. The industry also needs to invest to improve current infrastructure and storage facilities at the export ports. Adequate drying facilities should be available at the export port to allow drying of cargo parcels suspected of having a high moisture content on any barges or truckloads arriving at the port. Suspect cargo should be re-dried prior to storage in the export bulk warehouses/silos before final loading onto vessels. Alternatively, any lots of cargo suspected to be at risk should be redirected for shipping over a shorter distance rather than longer voyages to China.
What precautions pre- loading should be carried out for vessels chartered to carry soya beans from Brazil to China?
From a shipowner’s perspective, the vessel should be fully sea-worthy with well-maintained hatch covers. A hose test/ or ultrasound test should be performed prior to loading to ensure the hatch covers are weatherproof and a record of the test must be retained. The holds should be clean and dry prior to loading and the bilges kept empty for the length of the voyage. Photographs of the loading operations and the cargo throughout loading obtained by the surveyor and the crew are an absolute must as these may provide invaluable evidence in the unfortunate event of a cargo claim.
Since P&I clubs insure cargo claims for both owners and charterers, is there anything clubs could do proactively to limit these types of claims?
If claims are high value and common, it might be prudent for the shipowners and their clubs to consider appointing experienced surveyors or cargo superintendent during loading. The superintendent can monitor truckloads/ barge loads of soya beans as they are loaded. This should ensure that obviously caked/ mouldy cargo is refused for loading. The superintendent should also monitor the cargo temperature and moisture content regularly. Temperature probes and moisture meters should be in good working order and regularly calibrated. If samples are to be obtained throughout loading, sampling should be performed in accordance with FOSFA sampling rules. This will ensure any samples collected are representative of the quantity sampled.
When there is a claim, Gard has found that many of the cases revolve around ventilation practices. What effects can ventilation have on the outcome of carriage?
There is the possibility that condensation will form on the underside of the hatch cover and drip onto the cargo surface resulting in mould growth on the surface during a voyage from Brazil to China. This is known as ship’s sweat and occurs when the warm air rising from a warm cargo comes into contact with cooled steelwork. As the air is cooled upon contact, moisture condenses onto the steelwork. This typically occurs when vessels sail from warm to cooler climates, for example sailing around the Cape of Good Hope.
Crews are encouraged to practice ventilation in accordance with accepted industry methods. Proper ventilation aims to remove warm air
within the head space to reduce the risk of ship’s sweat formation.
The two ventilation methods commonly used are the Dew Point Rule and the Three Degree Rule. It is almost impossible to accurately measure the dew point within a hold headspace during a voyage. CWA therefore recommend that ventilation practice is performed in accordance with the Three Degree Rule. This involves ventilating the cargo holds when the ambient temperature is at least three degrees Celsius lower than the cargo temperature at loading when weather conditions permit.
This relies on the cargo temperature in each hold being obtained during or upon completion of loading and compared to the ambient dry temperature at every watch without the need to measure additional temperatures in the holds during the voyage. We recommend that multiple cargo temperatures are obtained during loading, particularly towards completion, in order to calculate the average cargo temperature per hold which can then be compared to the ambient dry temperature each watch.
This ventilation regime is easier and safer to carry out as no crew member is required to enter the hold. There is also less opportunity for error as dew point calculations are not required.
Ventilation may also be required at night when ambient temperatures are at their lowest. The likely changes in the ambient temperature during the voyage should be anticipated. The point when ambient temperatures are at their lowest in the voyage is when ventilation is most likely to be required, although the weather conditions may not be deemed suitable by the Master.
It is important to maintain detailed ventilation records which state when ventilation was undertaken and why. In the event that ventilation cannot be undertaken for any reason, i.e. poor weather conditions, this should be clearly noted in the ventilation records. Ventilation is incapable of preventing self-heating and does not reduce the temperature of the bulk cargo. By reducing the risk of Ship’s sweat dripping onto the cargo surface, however, there is a reduced risk that mould will grow at the cargo surface.
82 | The Report • June 2021 • Issue 96
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