Introduction This briefing deals with loss prevention measures for reducing the frequency and consequences of cargo damage claims from the carriage of grain cargoes. This briefing is relevant to grain, barley, maize, American corn, oats, rye, sorghum, wheat, soya beans, seeds, bulk rice, millet, and other similar agricultural products. These are all cargoes where the grains or seeds have not been subjected to any mechanical or chemical extraction process. All grain cargoes and seed cargoes that behave like grains must be carried strictly in accordance with the International Code for the Safe Carriage of Grain in Bulk (International Grain Code, 1991). How grain cargoes can be damaged Heat – Other than the heat caused by self-heating associated with moisture content and cargo temperature on loading. Grain cargoes must be protected from surfaces where the temperature is likely to exceed 40°C – engine room bulkheads and any heated tank surface for example.
Infestation or contamination – The presence of live or dead insects or pests, dead rodents, dead birds, already damaged cargo, or any debris. See The International Maritime Fumigation Organization – Code of Practice. www.imfo.com
Water ingress
– The hatch covers are not weathertight or there is water ingress from below
– bilges or tank leak. See North Loss Prevention Guide
– Hatch cover maintenance and operation. Condensation
– from sweat. See North Loss Prevention Guide – Cargo Ventilation
– three degree rule for hygroscopic agricultural cargoes only. Mould
– If the average moisture content of the grain is high and the cargo temperature on loading is high
– the condition of the cargo will eventually start to deteriorate. The cargo may self-heat, go mouldy and/or become caked.
Before loading
– hold cleaning For the loading of grain cargoes the holds must be ‘grain clean’ or ‘hospital clean’. The industry accepted definitions of hospital clean and grain clean are provided by the National Cargo Bureau (NCB) as follows: 1. Hospital clean Hospital clean is the most stringent, requiring the holds to have 100% intact paint coatings on all surfaces, including the tank top, all ladder rungs and undersides of hatches. The standard of hospital clean is a requirement for only a few certain grain cargoes and trades – for example rice in bulk. Generally, these high standards of cleanliness will only be met by vessels trading exclusively with such cargoes. It will rarely be required in the tramp trades. 2. Grain clean Grain clean is the most common requirement. A ship will be required to be grain clean for all grain or seed cargoes. Ships holds will be inspected for: Previous cargo residues and ‘rub off’ stains. Loose rust and paint scale Any other contaminants Infestation Odours Moisture or leakage
1. Hospital clean
Hospital clean is the most stringent, requiring the holds to have 100% intact paint coatings on all surfaces, including the tank top, all ladder rungs and undersides of hatches. The standard of hospital clean is a requirement for only a few certain grain cargoes and trades – for example rice in bulk. Generally, these high standards of cleanliness will only be met by vessels trading exclusively with such cargoes. It will rarely be required in the tramp trades.
2. Grain clean
Grain clean is the most common requirement. A ship will be required to be grain clean for all grain or seed cargoes.
Ships holds will be inspected for:
Previous cargo residues and ‘rub off’ stains.
Loose rust and paint scale
Any other contaminants
Infestation
Odours
Moisture or leakage
1.All past cargo residues and any lashing materials are to be removed from the hold.
2.Any loose paint or rust scale must be removed.
3.It probably will be necessary to wash the hold - the holds must be dried after washing.
4.The hold must be well ventilated to ensure that it is odourfree and gas-free.
5.Flaking paintwork under the hatch coaming can result in a hold failing the grain survey.
6.Ensure that any hot bulkheads - temperature over 40°C – are protected from contact with the grain cargo.
Before loading
– average moisture content The average moisture content of grain cargoes should be between 10% and 16%. Each cargo may have different critical limits. For example corn/maize should not exceed 14% and soya beans should not exceed 13%. Check the cargo handling information for the general limit. The average moisture content does not mean this: This is just a general statement saying the average moisture content is assumed not to exceed a maximum of 14%
An average moisture content of the cargo on loading should be available – for example: This cargo of soya beans has an average moisture content declared as 11.24%.
General rule: Grain cargoes shipped with average moisture content in the region of 12 to 14% have a high risk of going mouldy during the voyage. The risk increases significantly if average moisture content exceeds 14%.
General rule: Grain cargoes with an average moisture content of 10% or below have a lower risk of going mouldy during the voyage.
Before loading
– consider appointing a surveyor Before the loading begins the Master should consider appointing a local expert surveyor to assist him. The average moisture content of the grain cargo should be obtained before loading – a surveyor may be able to help obtain this information. Before loading it will always be prudent to have the hatches tested for weathertighness by ultrasonic testing and to take photographic evidence of the cleanliness of the hatches
During loading
– continuous visual inspection Once loading begins there should be a continuous visual inspection of the cargo looking out for:
Good colour of the cargo showing apparent good condition
Changes of colour Unusual odours or smells
Infestation or contamination
Cargo temperature
Taking and storing samples– for testing should there be a claim on discharge
Loading cargo during rain or any wet weather conditions
Caked lumps of grain – possible water damage prior to loading
Continuous photographic records On many occasions there may be problems with keeping a continuous visual inspection:
There may be too much dust
It may be difficult or impractical to obtain proper representative samples if needed
It might require specialist equipment to obtain cargo temperatures There may be local knowledge in relation to the type of problems to be expected
It may be useful to have an expert to suggest when and what to photograph
Under these circumstances the Master should consider using a local expert surveyor to assist him before loading begins and during loading.
After loading
– cargo temperature taken at time of loading For most hygroscopic agricultural cargoes
- particularly where there are full or almost full holds - the cargo temperature everywhere except at the sides of the stow will change very little and often not at all during the voyage.
General rule:
If the cargo temperature is measured at the time of loading the Master can be reasonably confident that the bulk of the cargo will stay at the same temperature throughout the voyage. This temperature will also be needed to apply the three degree rule for ventilation
General rule: The higher the average moisture content % and the higher the cargo temperature on loading – the less time the cargo can be stored without risk of going mouldy. Example: Approximate storage time in days that soya bean cargoes can be stored before they start going mouldy
During the voyage
– fumigation Fumigation must be carried out in accordance with IMO Recommendations on the safe use of pesticides in ships. The only marine fumigant that can be used for in transit fumigation is Phosphine (Hydrogen phosphide). The Master must retain overall responsibility for the safety of the crew as per SOLAS V Regulation 34
Fumigation of the cargo at the load port - will be under the control of the ‘fumigator in charge’ who will discuss the fumigation plan in detail with the Master prior to fumigation and inform the Master in writing of all spaces to be fumigated and all other spaces to be considered hazardous during fumigation
Fumigation during the voyage – the fumigator in charge and the Master should produce a voyage safety plan (VSP) to ensure that all the relevant safety measures and recommendations are followed.
Degassing and checking results at the discharge port – should be done according to the guidance given by the fumigator in charge at the load port and included with the VSP. For example there should be clear written instructions on how to handle and dispose of any fumigant containers or fumigation residues
General rule: Apart from the dangers from fumigation gases – most grain cargoes may deplete the oxygen levels in cargos holds and possibly in adjacent spaces. All cargo holds and adjacent spaces must be treated as enclosed spaces and subject to controlled entry.
During the voyage - ventilation Ventilation of agricultural products should follow the ‘three degree rule’
Three-degree rule: If the temperature of the outside air is at least 3 °C below that of the cargo temperature taken at loading - Masters may safely ventilate the cargo. Provided the weather and spray conditions allow - the cargo should be ventilated if the three degree rule applies.
The temperature of the outside air will change between day and night and during the voyage. It is not difficult to measure the temperature of the outside air. It can be done simply by reading the dry-bulb thermometer on the bridge, although ideally the temperature should be measured close to the inlet ventilators. The three-degree rule does not require anyone to go into the holds during the voyage.
How effective is ventilation – Whether using mechanical ventilation or natural ventilation there are many cargoes where the average ventilation will not penetrate the stow. For all grain cargoes the best that can be achieved is for the air to circulate over or around the cargo - the ventilation system will not force air through the cargo itself
General rule: When the three degree rule applies for grain cargoes – ventilation will probably only replace air within a hold with air from outside - the air will come in at one end, move through the empty space above the cargo, and exit at the other end.
During the voyage – record keeping The Master should keep comprehensive records throughout the voyage of outside air temperature, the weather conditions, and the times of any ventilation carried out. If it is possible to effectively monitor the hold temperature or cargo temperature – these figures should also be recorded. The Master may have obtained the average moisture content of the cargo before loading and will have recorded the cargo temperature on loading. These two figures should be noted in any record keeping. Comprehensive and accurate records are essential for good contemporaneous evidence.
Discharge – consider appointing a surveyor If the average moisture content is high and the cargo temperature on loading is high – then there is a high risk that some or all of the cargo will have gone mouldy during the voyage
Ventilation may have been carried out at all times when the three degree rule allowed but only the surface of the cargo has been prevented from heating or going mouldy. Ventilation may have been prevented by weather or have been ineffective. In which case the surface of the cargo may also show signs of heating or going mouldy. On opening the hatches for discharge and during discharge there should be a continuous visual inspection of the cargo looking out for
Signs of self-heating on the surface or in the body of the cargo
Changes of colour in the cargo
Mouldy cargo
Caked or wet cargo
Unusual odours or smells
Infestation or contamination not noted during loading
Cargo temperature
Taking samples and/or testing samples – should there be a claim on discharge
Discharging cargo during rain or any wet weather conditions
Continuous photographic records
Under these circumstances the Master should consider using a local expert surveyor to assist him before the hatches are opened for discharge and during the discharge of the cargo.
Please see attached file for AMSA calculation of stability for ship carrying bulk grain.