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Grain loading standards for seagoing bulk carriers - Limitations involved

Grain is the collective name for the edible seeds of various plants. Many of them are also called cereals, e.g. wheat, barley, although products like maize and rice are also considered under this heading. Most grain, especially wheat and maize (corn), is carried in bulk.

Wheat flour is a powder made from the grinding of wheat used for human consumption. More wheat flour is produced than any other flour. Wheat varieties are called "clean," "white," or "brown" if they have high gluten content, and they are called "soft" or "weak" flour if gluten content is low. Hard flour, or bread flour, is high in gluten, with 12% to 14% gluten content, and has elastic toughness that holds its shape well once baked. Soft flour is comparatively low in gluten and so results in a finer or crumbly texture.[1] Soft flour is usually divided into cake flour, which is the lowest in gluten, and pastry flour, which has slightly more gluten than cake flour.

grain clean cargo hold
Fig: Bulk carrier cargo hold cleaned for loading grain


Contaminants are defined individually in these Standards and consist of the following:
  1. Bread wheat (in durum deliveries only)
  2. Cereal Ergot
  3. Chemicals not Approved for Wheat
  4. Chemicals in excess of the MRL
  5. Earcockle
  6. Earth
  7. Foreign Seeds
  8. Insects – Large
  9. Insects – Small
  10. Loose Smut
  11. Objectionable Material
  12. Other Non-Objectionable Material
  13. Pickling Compounds
  14. Ryegrass Ergot
  15. Sand
  16. Snails
  17. Stored Grain Insects and Pea Weevil – Live

Contaminants may be referred to as foreign material, being all material other than whole or broken seeds or hulls of the wheat being assessed.

Defective Grains

Defective grains refer to wheat that has been damaged to some degree, as outlined in these Standards. They include the following:
  1. Dry Green or Sappy
  2. Field Fungi
  3. Frost Damaged
  4. Heat Damaged, Bin Burnt, Storage Mould Affected or Rotted
  5. Insect Damaged
  6. Non vitreous kernels (Durum only)
  7. Over-Dried Damaged
  8. Pink Stained
  9. Smut
  10. Sprouted
  11. Stained
  12. Takeall Affected

Bulk grain loading
Fig: Bulk grain loading

Grain Loading

The ship should be kept upright during loading of this cargo. This cargo shall be so trimmed to the boundaries of the cargo space that the angle of the surface of the cargo with horizontal plane does not exceed 25 deg. This cargo shall be kept as dry as practicable. This cargo shall not be handled during precipitation. During handling of this cargo, all non working hatches of the cargo spaces into which the cargo is loaded or to be loaded shall be closed

Trimming of Bulk Grain

Under Part A of the IGC "All necessary and reasonable trimming shall be performed to level all free grain surfaces and to minimise the effect of grain shifting" and "In any filled compartment, trimmed, the bulk grain shall be trimmed so as to fill all spaces under the decks and hatch covers to the maximum extent possible."

However, in any filled untrimmed compartment the hatch opening shall be filled with bulk grain to the maximum extent possible but lie at its natural angle of repose outside the periphery of the hatch opening. This is subject to the administration issuing the document of authorisation (as specified in the IGC) granting a dispensation from trimming, or the compartment being specially suitable (as defined in the IGC) and a dispensation being granted from trimming the ends of that compartment. This allows the hatch opening to effectively be used as a feeder to the unfilled ends. However, should neither of the above conditions be met, trimming into the ends of the hold will be required. Similarly, if calculations show that the stability with such loading will be insufficient for the proposed voyage, then trimming into the ends of the hold will be required.

Part B of the IGC provides general assumptions in respect of stability calculations for untrimmed compartments and assumed volumetric heeling moments of a filled compartment (trimmed and untrimmed) together with similar assumptions for trunks and a partly filled compartment.

If trimming into the ends is required it may be possible to utilise spout extensions or scoops to achieve the filling of the ends without machine trimming but this will depend on the particular design and capability of the grain elevator. However, most modern bulk carriers are deemed specially suitable and trimming is not required.

To meet charter party provisions regarding cargo quantity and trim it may be necessary to leave one hold (or more) slack which will obviously have an adverse effect on the ship's stability. Should calculations show that the stability of the ship is consequently not sufficient, it will be necessary to secure the free surface of the grain. The approved methods of securing are specified in the IGC to which reference should be made for the most appropriate in a particular situation.


Grains may settle by up to five or six percent while on passage. While this could have an adverse effect on the stability, it should not be a problem as long as the cargo is trimmed properly or, alternatively, the hatch opening is completely filled as described above.


As an objective of the IGC is to ensure that there is no empty space at the top of a grain cargo, it is apparent that surface ventilation is either difficult or impossible. Thus, the advice of one of the major P&I clubs is that any attempt at ventilation of a grain cargo is likely to be ineffective and it is acceptable for it to be left unventilated.

Bagged grain

While bagged grain may still be carried in a general cargo ship, it is not unknown for a bulk carrier to be loaded with cargo that arrives on board in bags that are then cut open and bled into the holds. This is an operation that is not only slow but may lead to other problems including debris in the cargo (e.g. sacking material, stones, pieces of wood) and claims for short delivery. The latter may arise through the weight of cargo loaded being calculated by deducting the weight of empty bags from the weighbridge weight of full bags arriving for shipment. Additionally, the removal of debris from the cargo will also affect the final weight of cargo shipped.


Appropriate precautions should be taken to protect machinery and accommodation spaces from the dust of the cargo. Bilge wells of the cargo spaces shall be protected from ingress of the cargo. Person who may be exposed the dust of the cargo shall wear protective clothing, goggles or other equivalent dust eye protection and dust filter masks, as necessary. Bilge wells shall be clean. Dry and covered as appropriate, to prevent ingress of the cargo.


After completion of loading of this cargo, the hatches of the cargo spaces shall be sealed as necessary. All vents and access ways to the cargo spaces shall shut during the voyage. Bilges in the cargo spaces carrying this cargo shall not be pumped unless special precautions are taken.


Grain can germinate during a voyage so it is essential that the cargo is loaded in a completely dry condition. It follows that grain must not be loaded and holds should be covered during periods of precipitation.

Clean up

In the case that the residues of this cargo are to be washed out, the cargo spaces and the other structures and equipment which may have been in contact with this cargo or its dust shall be thoroughly swept prior to washing out. Particular attention shall be paid to bilge wells and framework in the cargo spaces. The fixed bilge pumps shall not be used to pump the cargo spaces, because this cargo may make the bilge system inoperative.

Risk of claims

There is a strong risk of spurious cargo claims being made on grain cargoes in Iraq. During the discharge of an Argentinean wheat cargo at Umm Qasr, the Iraqi receivers claimed that cargo in one hold was contaminated with e-coli bacteria. The cargo was analyzed three times by a local health authority laboratory and on each occasion the tests were positive. The Member had a cargo sample analyzed by Solomon and Seaber in the UK and the result was negative.

Grain handling more guidelines
  1. Hazards and safety precautions for grain cargo
  2. Grain loading preparation
  3. Presence of contaminants & handling other defective grain
  4. Grain terminology from IMO grain code
  5. What is international grain code and why it is used in bulk carriers ?

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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 Contact us

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