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Container ship cargo stowage and planning procedures

Cargo stowage consideration:
The aim of shipís officers and crewmembers on board should be to prevent damage or deterioration whilst the cargo is under their care and to deliver it, as far as possible, in as good condition and order as it was when received aboard. If unacquainted with a certain type of cargo you should ascertain as to its nature and any necessary precautions. Therefore, the Master and officers of all vessels require a good working knowledge of the various kinds of cargo they are likely to carry: their peculiar characteristics, liability to damage, decay, or deterioration, their measurement, and the usual methods of packing, loading and discharging, stowage, dunnaging, etc., as the Master is responsible for the safe loading of his vessel and the proper stowage of the cargo.

lashing-bridge-at-containership
Fig: Lashing bridge at containership

The actual handling of the cargo in loading and discharging is done by stevedores, who are experienced men appointed for this purpose when a vessel arrives at a port. This does not release the Master from the responsibility for the safety of the ship and cargo, and he must supervise the work of the stevedores for general safety.

Therefore, during stowage the first consideration must be given to safety, i.e. the cargo must be stowed so that the ship will be stable and seaworthy, and it must be secured in such a manner that it cannot shift if the vessel encounters bad weather. The type of vessel, the cubic capacity of her compartments destined for the cargo and the appliances on board or on shore for loading or discharging, as well as the nature of the cargo, affect the question of how to stow the cargo in the best possible manner. The ship must be made neither stiff nor too tender. The next consideration is for the safety of the cargo itself: it must not be damaged by shifting; certain commodities become easily tainted by others, water might find its way into the hold and condensation or sweating must be prevented. Valuable cargo may be stolen or broached.

Finally, the Chief Officer must bear in mind the various destinations of the goods the ship carries, and arrange things, as far as he can, to see that the cargo for a certain place can be lifted out without disturbing the other cargo. The Chief Officer must watch closely the ship's stability (i.e. what the ship's trim is or how she is sitting).

Since a ship is supported by fluid pressure she will incline in any direction according to the position of the weights placed on her. The trim, therefore, is the angle that a ship is making, fore and aft, with the water.

The levels are read by numbers painted on the ship's stem and stem. These are called draught marks. Another word is heel. This means a list or inclination from one side to another, caused by loading. The Chief Officer must watch the load lines. They are welded or punched on and then painted. Working stowage plans are drawn up to assist in advance planning. Master plans definitively document the positioning of containers on board.

Fore and aft stowage

Load stowed along the length of the container or the ship. Contrast athwartships stowage. In the context of load securing, it is of utmost importance whether a container is stowed fore and aft or athwartships on a ship. In the case of athwartships stowage, the greatest acceleration forces act on the actual container longitudinally rather than transversely. Load securing measures must then be taken with this in mind.

Container Stowage (DOORS AFT) Containers are whenever possible to be stowed with the doors facing aft. However, reefer containers can be stowed doors facing forward as per plug socket arrangements on a case by case basis.

Container Stowage (OPEN TOPS) Whenever possible, open top containers on deck are to be stowed in such a position that for all sea passages a standard container is able to be stowed on top of them. If this is not possible, due to overheights, etc, consideration is to be given to stowing them with the maximum shelter and all tarpaulin lashings checked and tightened by the stevedores. Bay-tier-row system

Numbering system for the arrangement of containers on a vessel. In this numbering system, the bay is specified first, then the tier (vertical layer) and finally the container row, which runs the length of the ship. According to this principle, bays are the container blocks in the transverse direction, rows are the lengthwise rows and tiers are the vertical layers.

Cargo information

Goods can be rendered fit for container transport by taking account of the individual transport information relating to loss prevention. Fitness for container transport may depend on the season or the route the cargo will take over land or sea. It must be adapted to the conditions of the transport route. The cargo information may also be helpful when considering how best to utilize a standard container or the possible use of other container types.


containers at sea

Transport requirement

Individual packages are known as general cargo, which may be divided, depending on atmosphere requirements (natural, partially air-conditioned or temperature-controlled atmosphere), into general cargo, general cargo requiring ventilation and refrigerated cargo, which place corresponding requirements on containers (general purpose container, ventilated container, refrigerated container), or indeed into further sub-categories .


Compatibility characteristics

If goods are to be stowed together when packing a container, the interrelationships between the transport properties of products must be taken into account, since disregarding them may result in quality degradation and damage. Goods may react with one another and possibly with their environment.

principles of stowage

When stowing and securing containers, the following points should be borne in mind:
  1. a deck stack of containers is only as strong as the weakest component in that stack. Premature failure of a component can cause loss of an entire stack. During loading, containers should be inspected for damage and, if damaged, they should be rejected


  2. twistlocks limit vertical and transverse movement. Diagonal crossed lashing rods, placed at the ends of a container, can withstand large tensile loads


  3. outside lashings are sometimes used. These are lashings that lead away from a container. However, although this arrangement provides a more rigid stow than a combination of crossed lashings and twistlocks, it is less common


  4. containers exposed to wind loading need additional or stronger lashings. When carried in block stowage, it is the outer stacks that are exposed to wind loading. However, when carried on a partially loaded deck, isolated stacks and inboard containers can also be exposed to wind, in which case, additional lashings need to be applied


  5. if containers of non-standard length, that is, 45, 48 or 53 feet are carried, the ship arrangement will need to be specially adapted


  6. 45-foot containers fitted with additional corner posts at 40-foot spacing can be stowed on top of 40-foot containers. Lashings can be applied in the normal way. It should be noted, however, that the additional corner posts may not be suitable for carrying the required loads, either from the container itself or from those stowed above. Lashings should not be applied to the overhang. The container specification and the Cargo Securing Manual should be consulted


  7. 40-foot containers may be stowed on top of 45-foot containers. However, this arrangement of stowage will present difficulties in fastening/unfastening twistlocks, and it will not be possible to apply lashings to the 40-foot containers


  8. when carrying over-width containers, for example 45-foot or 53-foot containers with width 8'-6", adaptor platforms may be used. These must be certified by a class society or an appropriate recognised body. The arrangement must be defined and approved in the shipís Cargo Securing Manual


  9. twistlocks should always be locked, even when the ship is at anchor, except during container loading and unloading. Lashing rods should be kept taut and, where possible, have even tension. Lashing rods should never be loose nor should they be overtightened. Turnbuckle locking nuts should be fully tightened


  10. as a ship rolls, pitches and heaves in a seaway, tension, compression and racking forces are transmitted through the container frames, lashings and twistlocks to the shipís structure. However, clearances between securing components and the elasticity of the container frame and lashing equipment produce a securing system that forms a flexible structure. Thus, a deck stow of containers will move


  11. containers can be held by only twistlocks when two or three tiers are carried on deck, depending upon container weights


  12. arrangements with automatic and semi-automatic twistlocks are used to reduce time spent securing the stow and to eliminate the need for lashers to climb the stacks

Checks and tests during discharge and loading
  1. regularly examine lashing components, looking for wear and tear, damage or distortion. Check that left-hand and right-hand locking twistlocks are not being mixed in the same storage bin. Remove from the ship any lashing component found to be worn, damaged or distorted


  2. make arrangements for some damaged or distorted lashing components to be sent for non-destructive testing. This will determine their strength and help to establish replacement criteria


  3. carefully check twistlocks that stevedores return to the ship as the locks might not originate from your ship, that is, their strength and locking direction could differ


  4. discourage stevedores from treating lashing equipment roughly as this can induce weakness


  5. examine dovetail foundations, D rings and pad-eyes for damage. Repair if damage is found


  6. observe the loading of containers to determine if stowage is in accordance with the stowage plan and that best practice is always followed


  7. observe the application of lashings to make sure that they are correctly applied in accordance with the requirements set out in the Cargo Securing Manual

containership-mounted-with-deck-crane
Containership mounted with deck crane

Checks and tests at sea
  1. 24 hours after sailing, examine, check and tighten turnbuckles. Check that lashings are applied in accordance with the Cargo Securing Manual and that twistlocks have been locked


  2. examine lashings daily. Check that they have not become loose and tighten turnbuckles as necessary


  3. before the onset of bad weather, examine lashings thoroughly and tighten turnbuckles, being careful to keep an equal tension in individual lashing rods. If necessary, apply additional lashing rods to the outboard stacks and to stacks with 20-foot containers in 40-foot bays


  4. re-check lashings after passing through bad weather


  5. make sure that lashing equipment that is not in use is correctly stored in baskets or racks


  6. make an inventory of lashing equipment and order spares before they are needed


  7. check that refrigerated boxes remain connected to the shipís power supply




Additional guideline while planning a container cargo stowage plan:


Cargo cranes operation, maintenance & safety matters

Stacking Weights Restrictions

Lashing strength calculation

Dangerous goods stowage and segregation

Reefer Container Stowage

Out of Gauge Container Stowage

Special Container Stowage

20 or 40 or 45 feet Compulsory Stowage Locations

Irregular Stowage of Containers

Over-stow of Containers

Hatch Cover Clearance (High cube containers Under Deck )

Other matters regarding cargo stowage as necessary



Related Information:


How to load maximum number 20 feet container on deck ?

What are the extra precaution should be taken prior loading a 45 feet container on deck ?

Container damage in ''2 in 1'' cargo Operation

Modern containership & loading of various container types

How to load containers coming in different forms/sizes

Cargo cranes operation, maintenance & safety matters



Our additional pages contain somewhat larger lists of resources where you can find useful informations


Container handling more info pages:

  1. Definition of various containers in containership
    The exterior dimensions of all containers conforming to ISO standards are 20 feet long x 8 feet wide x 8 feet 6 inches high or 9 feet 6 inches high for high cube containers. Some of the most commonly used types are:Read more......


  2. Dimensions of various containers
  3. Containers are standardized cargo units. They are manufactured in a large variety of sizes and types, each designed to meet specific cargo and transportation requirements. Their length is usually 20 or 40 feet, although longer containers are used, principally in the US trade; these containers are 45, 48 and 53 feet long.
    Read more......

  4. Containership advantages : In principle they are boxes or containers within a box. These boxes or containers have dimensions of 2.60 x 2.45 m with lengths of 6.10, 9.15 and 12.20 m. Containers are made in steel, aluminium or GRP. They are also of refrigerated design, thus advantageous for long voyages between Australia or New Zealand and the UK. Read more......


  5. Containership cargo stowage and planning : When considering acceptability of a container cargo stowage plan, the following procedures / guidelines concerning cargo stowage shall be taken into account: Stacking Weights Restrictions, Lashing strength calculation, Dangerous goods stowage and segregation, Reefer Container Stowage , Out of Gauge Container Stowage , ....Read more......


  6. DG cargo handling - IMDG code guideline :The general provisions for segregation between the various classes of dangerous goods are shown in "Segregation table" (IMDG Code Chapter 7.2.1.16). In addition to the general provisions, there may be a need to segregate a particular substance, material or article from other goods which could contribute to its hazard. Read more......


  7. How to avoid irregular stowage of containers ? Stowage plan must be checked for any irregular stowage like those mentioned here : Stacking Weights, Lashing Strength, Special Container Stowage, Over-stow of Containers, Dangerous Cargo Stowage & Segregation, 20 or 40 or 45 feet Compulsory Stowage Locations, Hatch Cover Clearance (High cube containers Under Deck ), Out of Gauge Container Stowage etc.Read more......


  8. Measures against lashing failure : Lashing strength of deck cargo shall be ascertained by using the appropriate lashing strength calculation software where provided. All resulting values for lashing strength must be within the tolerance limits prescribed by vessels classification society.Read more......


  9. Reefer container stowage guideline : Reefer containers proposed for stowage must be accompanied by a reefer manifest. This reefer manifest should contain information regarding Container No., Stow position, Commodity, Temperature and Ventilation status. Read more......


  10. Care of Reefer container during sea passage :Reefer containers require special care after they are loaded on board ship. These containers need to be supplied with power, monitored closely for proper function and repaired as required in case of malfunction. Read more......


  11. Container ships procedures for securing for sea :All movable items on deck, inside accommodation and in E/R spaces, including under-deck passages and steering flat are firmly secured. Any unsecured items, in heavy weather, risk not only being damaged themselves, but could also pose a danger to vessel safety by violent contact with sensitive equipment or fittings.Read more......


  12. Deployment and monitoring of moorings and safety of crew :The Companyís Risk Assessment procedure shall be utilized to ensure that during all anticipated mooring arrangements and equipment use, the safety of crew is ensured. Read more......


  13. Cargo securing procedure for container ship :Securing equipment will vary depending on the type of ship but is likely to include; Twistlocks Lashing bars Turnbuckles Extension hooks Stacking cones (single and double) Twist Stackers Lashing D rings Shoes/Sockets for base twistlocks ...Read more......


  14. Containership operation -Check items upon completion of repair works : As the nature of container ship operation, itís tread to be lack of stability, due to Top Heavy Load, the Master shall always take special attention for her stability. Also the Master should remind factors to cause reducing stability more such as Alternating course with Big angle of Rudder, Towing by tugs at the scene of Berthing / Un-berthing, etc. Read more......


  15. Containership operation -Cargo ventilation requirement : Cargo holds of container ships are fitted with two basic types of ventilation systems, namely natural and mechanical. Mechanical ventilation could be of either the supply or the exhaust type. Read more......


  16. Containership operation -How to avoid wet damage ? :Water entered into vessel cargo holds may cause wet damage to the cargo inside containers especially stowed on the bottom, unless the bilge water is drained in a proper and swift manner. Read more......







Other info pages !

Ships Charterparties Related terms & guideline
Stevedores injury How to prevent injury onboard
Environmental issues How to prevent marine pollution
Cargo & Ballast Handling Safety Guideline
Reefer cargo handling Troubleshoot and countermeasures
DG cargo handling Procedures & Guidelines
Safety in engine room Standard procedures
Questions from user and feedback Read our knowledgebase
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