Self-unloaders cargo loading sequence & other related considerations

There are many things to consider before loading a bulk cargo, and foremost in these considerations are the safety of personnel, and the safety of the vessel. As much information as possible is to be gathered about the cargo to be loaded. Even though the vessel may be carrying the same standard cargo e.g. gypsum, the condition of the cargo may differ every other voyage, and thus its stowage factor. The ratio of rock to fines will vary, and the exposure of the pile to weather conditions, will affect its flow ability.



It is the Master’s responsibility to consult all the appropriate publications and information concerning the cargo as possible, and to make himself aware of the associated dangers, precautions, and peculiarities. Past records are to be consulted, to ascertain if any problems have been experienced. If any doubt exists, the Master is to contact the relevant Management Office who will assist in any possible way.

self unloader belt
Fig:Self unloader belt operation

When declaring the amount which can be loaded, due attention is to be paid to limitations and draft restrictions imposed in the loading and discharging ports, seasonal draft restrictions, bunkers to be taken, the expected stowage factor of the cargo and, the Charter Party requirement. The Salt Water Arrival Draft, or Fresh Water Arrival Draft at the discharge port will be stated in the immediate voyage instructions issued by the Owners, or their Representatives. If the voyage instructions do not state the required arrival draft at the disport, the Master must obtain this from the Owners or their Representatives before loading.

The water level in rivers is affected by sustained winds in the same direction, and may be more or less than that stated in the voyage instructions. The Master, however, must ensure that the vessel’s arrival draft at the discharge port is as per the requirement of the immediate voyage instructions. The Master must, on departure load port, declare his sailing draft and the calculated arrival draft (at disport) to all parties. The Master is to refer to latest nautical publications and notices to ensure that the draft stated in the voyage instructions closely matches, and allows for the underkeel clearance. The passage of the vessels in shallow waters is subject to the effects of squat etc, and this in turn affects its manoeuvrability.

A preliminary loading plan for the sequence and stowage of cargo, for the amount of uplift calculated based on; the loading rates, deballasting rates, and within the permissible stresses at each sequence, is to be drawn up by the Chief Officer and presented to the Master for approval.

The priority must always be to ensure that the proposed cargo can be safely loaded, and ensuring that the vessel has adequate stability for all stages of the intended voyage, and in the event of multiple discharge ports. This is particularly important for grain cargoes, to ensure that grain moments are within acceptable limits when proceeding between ports with partially filled cargo compartments. The distribution of cargo must always be such, that the vessels bending limits are never exceeded as defined in the builders manual for dynamic seaway conditions. The in port static vessel loading, and deballasting sequences must be within the prescribed limits at all times.

A copy of the loading plan must be handed to and discussed with shore/terminal representatives when completing the ‘Ship/Shore Readiness Checklist’. The shore loader must adhere to the loading plan and sequences therein. Caution must also be exercised when loading in a manner which requires any hold or holds to remain empty, or when loading different grades where a hold-wise pattern of loading may be insisted upon. If there is any doubt that the vessel may be over stressed in any way during loading or discharging, the operations must be ceased immediately, and not recommenced until such a time as the situation has been re-checked and you are satisfied that the operations can continue without harm to the vessel. The times of high and low water at berth are to be calculated by the navigating Officer, and are to be written on the Loading Plan.


OTHER LOADING CONSIDERATIONS

It has sometimes been customary to use the shore loaders counter figures for the Bill of Lading. These belt counters, or weight sensors are not always accurate, and if the difference between the draft survey figures and those obtained from the shore weight counter is substantial, a Protest of Difference is to be issued and the facts documented. The Company and the Owners must however be informed prior to such a letter being issued.

Before loading the cargo, the Master must satisfy himself that the vessel has the capability to maintain the condition of the cargo in the same condition as that when it was loaded, taking into account the type and amount of ventilation required, the instruments required for monitoring are on board and their calibration valid and any segregation/separation requirements. If any doubt exists, the relevant Management Office must be contacted immediately in order to make arrangements in advance for any remedial action required, and avoid unnecessary delays to the vessel.


SEGREGATION OF VARIOUS GRADES (LOADING)

The planning and segregation of grades is very important for the avoidance of cargo claims.

The sequence of loading of the various grades must be agreed with shippers and shore personnel. The planned sequence of the ‘Loading Plan’ must be accepted and approved by the Shore Terminal. All means of communications between ship and shore are to be tested. Clear information and instructions must be provided by the shore personnel at completion and change of grade.

The Duty Officer is required to visibly ensure that the shore loading/conveyor system is absolutely clear of the previous grade and to request the shore to verbally confirm the same. If, when inspecting the cargo loaded in the holds, any contamination or non uniformity in the cargo is observed, this must be immediately brought to the notice of the Shore Foreman or authorised person. If the doubt persists the Company must be informed.




Reference publications

  • International Code for the Safe Carriage of Grain in Bulk
  • Code of Safe Practice for Solid Bulk Cargoes (IMSBC Code)
  • Thomas Stowage: The Properties of Stowage of Cargoes
  • IMDG Code + Supplement to the Code





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

Copyright © 2010 www.bulkcarrierguide.com All rights reserved.

Although every effort have been taken to improve the accuracy of content provided the publisher of this website cannot take responsibility for errors. Disclaimer Privacy policy Home page


A Bulk carrier underway
"A ship which is intended primarily to carry dry cargo in bulk, including such types as ore carriers and combination carriers"


Related information

  1. Self unloader components

  2. Function of loop & bucket belt elevators

  3. Self unloaders various cargo handling gears

  4. Various type boom conveyor belts - How the belt sytem practically works ?

  5. Dealing with self unloaders stalled lift belt

  6. Conveyor belt construction & troubleshoot guide

  7. Conveyor belt installation guide

  8. Conveyor belt repair & maintenence guide

  9. Safe working practice onboard self unloading bulk carriers

  10. Preventing conveyor belt fire onboard self unloading bulk carriers

  11. Cargo work safety precautions

  12. Various bulk cargoes - free flow ability

  13. Various bulk cargoes & dealing with cargo hang ups

  14. Navigation in Ice & safety precautions

  15. Dust suppression procedure & environment protection

  16. Preparations for cargo planning, handling & stowage

  17. Maintaining safe stability onboard self-unloading bulk carriers

  18. Procedure for bulk cargo handling prior to and during loading

  19. Loading operations - voyage orders, draft restrictions, various grades and rates

  20. Preparations for discharging & related guideline

  21. Self unloaders discharging operation

  22. Safety precautions for boom operation

  23. Directing gate operation, gate problems & crew duties

  24. Cargo holds/ tunnels cleaning, maintenance and check items

  25. Procedure for transporting coal on self- unloading bulk carriers