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Cargo hold cleaning standards in bulk carrier -Surveyors requirement prior Grain loading
The term grain includes wheat, maize (corn), oats, rye, barley, rice, pulses, seeds and their processed forms which may behave in a similar way to grain in its natural state. Many grains are shipped in large quantities in bulk for use either as foodstuffs or for oil extraction while others may be shipped in smaller quantities in bags. Some grains, valued for their medicinal or other properties, are handled in small quantities only in superior quality bags or well-made cases. Grain in bags occupies 8% - 10% more space than the bulk commodity.
Grain Stowage Factors
The stowage factor for a particular grain may vary considerably for a number of reasons including the quality or the density of a grain, pea, bean or seed which can vary according to grade, crop, season and country of origin as well as whether it is shipped early or late in the season. Thus, the factors quoted for grains under the individual entries in Part 3 are approximations only, as no figure can be relied upon to express the actual space to be occupied by any grain or seed in all seasons and from all ports.
Stowage factors of bagged grain also vary according to whether the compartment is large or small, deep or shallow, square or pointed, the presence of obstructions, and on whether the bags are well-or slack-filled.
While the quoted stowage factors will be sufficient to estimate the capacity of a ship or compartment within a reasonable margin, the stowage factor that is required to be provided by the shipper will provide a more accurate estimate prior to loading.
Preparation of a cargo hold prior grain loading is not just a question of sweeping, cleaning or washing down the hold. There are a number of matters to consider, and failing to adhere to good practice can result in failure to pass cargo hold inspection.
Preparing Holds for Grain
While the IGC is not concerned with cleanliness it is obvious that a high standard is required for both the handling and carriage of grain. Invariably, prior to loading, the ship will be subject to inspection by an independent surveyor, who will require details of at least the previous three cargoes. Holds will be inspected for cleanliness and infestation as well as the presence of any material that might cause infestation.
Thus, in order to pass survey in accordance with the governing charter party and/or statutory requirements at the load port it is essential that the holds are properly prepared for the reception of the grain cargo. Failure to pass survey will result in costly delay to the ship while the short-coming, be it cleanliness, damage, etc., is corrected. In some ports, the crew may not be permitted to carry out further cleaning and it will be necessary to bring in shore labour at greatly increased cost.
Holds, bilges and hatch covers must be clean and dry, free of previous cargoes and rust scale, free of taint and infestation. Previous cargo residues must be removed from between frames, stringers, deck beams and hatch cover beams by washing or sweeping. Cargo residues are easily dislodged by the motion and vibration of the ship to fall onto the new cargo, thus causing it to be contaminated. Any signs of insect infestation must be dealt with by spraying with appropriate insecticides or by sealing the holds and treating with an approved fumigant. Any timber or dunnage remaining in the holds must be removed. All bilge suctions must be thoroughly clean, free from previous cargoes and dry.
While a cargo surveyor will normally confirm the readiness of the ship for loading, some administrations will also be involved in issuing a certificate of cleanliness, e.g. the United States Department of Agriculture.
Some national administrations also require the Master to submit stability calculations for all stages of the proposed voyage. Some administrations (e.g. Australia, Canada, the USA) also set stricter parameters for stability than those required by the IGC which must, of course, be adhered to if loading in such a port. In the USA, the National Cargo Bureau is empowered by the Government to approve the grain loading calculation and also has the option of inspecting the holds, but will not approve the calculation until the cleanliness certificate has been issued.
In the dry bulk trades, there are essentially five grades of hold cleanliness:
- hospital clean, or stringent cleanliness
- grain clean, or high cleanliness
- normal clean
- shovel clean
- load on top
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 certain cargoes, for example kaolin/china clay, mineral sands including zircon, barytes, rutile sand, ilmenite, fluorspar, chrome ore, soda ash, rice in bulk, and high grades of wood pulp. 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.
Grain clean is the most common requirement. A ship will be required to be grain clean for the majority of bulk and break bulk cargoes, such as all grains, soya meal and soya products, alumina, sulphur, bulk cement, bauxite, concentrates, and bulk fertilisers. Some ports and shippers may allow a different standard of cleanliness.
Normal clean means that the holds are swept clean, with no residues of the previous cargo, and washed down (or not, depending on charterers requirements), that is, cleaned sufficiently for taking cargoes similar to or compatible with the previous shipment. Shovel clean means that all previous cargo that can be removed with a Bobcat or a rough sweep and clean with shovels by the stevedores or crew. The master should clarify what standard is expected.
Load on top means exactly what it says the cargo is loaded on top of existing cargo residues. Usually, this means grab cleaned. This standard will commonly be required where a ship is trading continuously with the same commodity and grade of that commodity. This will typically occur when a ship is employed under a Contract of Affreightment to carry, for example, a single grade of coal over a period. With such a trade, there is no commercial need for holds to be cleaned between successive cargoes, and each cargo is simply loaded on top of any remaining residues from the previous cargo. With load on top, guidance may be necessary for the master on any cleaning requirements, including the use of bulldozers and cleaning gangs.
What is Grain clean ?
The most common cleanliness requirement for bulk carriers is that of grain clean. It means clean, swept, washed down by fresh water and free from insects, odour, residue of previous cargo (incl. coal petcoke, clinker.)/loose rust scale/paint flakes etc. dried up and ready to receive charterers intended cargo subject to shippers/relevant surveyors inspection. If the ship fails hold inspection by shipper/relevant surveyor, the ship to be placed off hire until accepted in all holds, and any extra costs/ expenses/time included stevedores stand-by and/or cancelling charges, therefrom to be for owners account.
The usual instructions a master of a tramping conventional bulk carrier will receive, particularly if his ship is unfixed for next employment, is Clean to grain clean on completion of discharge. The guideline here is aimed at the majority of bulk carriers engaged in the carriage of usual bulk cargoes in conventional ships, which are cleaned to a grain clean standard. As noted above, there are certain cargoes, such as kaolin, which require the higher standard of cleanliness or hospital clean.
What is loose scale?
It is important to differentiate such scale from oxidation rust (i.e. light atmospheric rusting). Loose scale will break away when struck with a fist or when light pressure is applied with a knife blade or scraper under the edge of the scale. Oxidation rust will typically form on bare metal surfaces but will not flake off when struck or when light pressure from a knife is applied. Generally, the presence of hard-adhering scale within a hold is acceptable in a grain clean hold. The scale should not fall during the voyage or during normal cargo operations.
Countries apply different standards to what constitutes an acceptable amount of loose scale or loose paint. While in some countries, no such material is permitted, the United States Department of Agriculture permits a single area of loose paint or loose scale of 2.32 sq m, or several patches that in total do not exceed 9.26 sq m, before a hold is deemed to be unfit. In practice, the hold should be free of loose scale as each surveyors interpretation of the required standard may vary.
The industry accepted definition of grain clean is provided by the National Cargo Bureau (NCB).
Compartments are to be completely clean, dry, odour-free, and gas-free. All loose scale is to be removed. The definition is clear:
- all past cargo residues and any lashing materials are to be removed from the hold
- any loose paint or rust scale must be removed
- if it is necessary to wash the hold, as it generally will be, the holds must be dried after washing
- the hold must be well ventilated to ensure that it is odour-free and gas-free
Points to consider
- management must take a close interest in hold cleaning
- take photographs
- officers must fully understand what level of cleanliness is required for various cargoes
- an independent survey can be useful to confirm if the ship is ready to load particularly if there is a long waiting time before loading
Grain handling more guidelines
Hazards and safety precautions for grain cargo
Grain loading preparation
Presence of contaminants & handling other defective grain
Grain terminology from IMO grain code
What is international grain code and why it is used in bulk carriers ?
Cargo hold cleaning problem and related guideline
Cargo hold maintenance guideline
Hold preparation checklist -Cleanliness/preparation, additional measures
Cargo holds readinesss, maintenance requirement, preventing stevedore damages & safety aspects
Cargo hold inspection -Reasons for failing hold inspections
Chief officers final inspection prior cargo hold survey
Maintenance procedure for mechanical steel hatch covers
- Garbage management plan for bulk carriers
- Classification of various dry bulk commodities
- Cargo hold cleaning recommended chemicals
- Various Cargo Hold Cleaning Kits & chemical washing technics
- Cargo hold Swept cleaning, Washing down, Use of chemicals, Limewashing & Drying holds technics
- Cargo hold cleaning problem and related guideline
- Hold cleaning in bulk carriers- Preparation for grain loading
- Methods of cargo hold cleaning
- Cargo hold maintenance guideline
- Hold preparation checklist -Cleanliness/preparation, additional measures
- Cargo holds readinesss, maintenance requirement, preventing stevedore damages & safety aspects
- Cargo hold inspection -Reasons for failing hold inspections
- Chief officers final inspection prior cargo hold survey
- Maintenance procedure for mechanical steel hatch covers
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