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Procedure for 20',40' or 45' container stowage

The evolution of containerization was a giant step forward in carrying most general cargo at sea. At the time, it was predicted that unit prices would fall, and cargo damage become a thing of the past.
In the early days of containerized transport, ships carried containers stowed on hatch covers, three or four high. A variety of lashing systems were in use. However, the most reliable system consisted of stacking cones, twistlocks, lashing rods and turnbuckles (bottle screws). These systems were effective in lashing containers carried on deck to the third tier.

Today, ships are bigger, and a post-Panamax container ship will carry containers on deck stacked up to nine tiers high. However, while the ships can carry containers stacked higher, the lashing systems are only capable of lashing to the bottom of the third tier containers or the bottom of the fourth or fifth tier containers when a lashing bridge is fitted. Ship design has developed, but methods to secure containers have not.

containerships operational matters
Oil Tanker Safety Guide
A classification society will approve a ship for the carriage of containers. Regulations stipulate that the ship must carry a Cargo Securing Manual. It contains instructions as to how cargo should be secured. However, approval of the arrangements in the manual will not necessarily mean that cargo securing arrangements will withstand foul weather.

45 feet container stowage

20 feet,40 feet or 45 feet Compulsory Stowage Locations for Container ships cargo planning:

Most cargo securing manual provide a guideline for different container types. These stow positions of 20 feet,40 feet, or 45 feet are also incorporated in a ship-specific stowage planning software and highlight errors if any violations occur. Do not override the stowage planning software manually to accommodate any inappropriate stow suggested by the terminal. When stowing boxes Under Deck, Hatch cover clearance must be considered. Depending on the vessel's construction, a slot may need to be kept vacant if necessary.

45ft Container Clearance Requirement :

The stowage of 45-foot containers is generally restricted by lashing requirements, lashing bridges, Reefer monitoring platforms, or other obstructions. Allowable positions for loading 45 feet containers must be carefully checked before loading. For most vessel, proportionately space between the bays need to maintain enough clearance, which can load 45ft container at fore and aft of the cross deck. When it is three or more high containers, 45ft boxes can be loaded into every bay location. In some vessels, the loading of 45ft containers may not be able to be performed because of the clearance; therefore, cautions are required in stowage.

45 feet container
Do not lash to the overhanging end of
a 45 feet container

Container Damage Prevention

Specific actions should always be taken to prevent containers from being damaged or lost overboard. The following steps are considered best practice. Points to remember:
  1. check stack weights before stowage. It is important not to exceed the allowable stack weights; otherwise failure of the corner posts of the containers stowed at the bottom of the stack is possible. If the stow is too heavy, the lashings may have insufficient strength to hold the containers in place if bad weather is encountered
  2. never deviate from the approved lashing arrangements shown in the Cargo Securing Manual, except to add additional lashings. Calculate forces using the approved loading computer
  3. discuss the proposed loading with stevedores to ensure that the proposed loading does not compromise the ship's lashing system, loading requirements or stability
  4. consult the Cargo Securing Manual before applying lashings
  5. if stack weights are high and bad weather is expected, then fit additional lashings
  6. try to avoid isolated stacks of containers in holds or on deck. Where possible, load containers so they are evenly distributed
  7. avoid heavy loading containers above light containers and at the top of a stack, unless the stowage arrangement is shown in the Cargo Securing Manual, and the stowage is found satisfactory when checked using the approved loading computer
  8. avoid carrying open frame containers in cargo holds unless specifically permitted in the Cargo Securing Manual
  9. keep your system of lashing simple, using the highest rated components
  10. to assist the shore lashing gang, give them precise instructions as to how containers should be secured
  11. examine containers for visible defects – check the corner posts carefully. The corner posts have to withstand high compression forces as a result of static weights from containers stowed on top and from dynamic forces that transpire when the ship rolls, heaves and pitches. Containers with disparaged corner posts placed in the bottom of a stow are likely to collapse. Reject damaged containers
  12. check that all cell guides are clear of obstacles are straight and are not buckled
  13. check that turnbuckles are fully tightened. Loose lashings will be ineffective
  14. avoid using left-hand and right-hand twist locks on the same ship
  15. regularly examine lashing components, including ship fittings, for wear and defects. Replace worn or damaged lashing components—repair worn-out or damaged ship fittings. Check all equipment, not just equipment in regular use. Keep turnbuckles, and twist locks clean and well greased
  16. consider additional lashings if bad weather is expected
  17. it isn't easy to know when lashing components should be replaced. Few organizations are confident to issue 'criteria for replacement,' which means that the ship's owner or individual master will need to exercise judgment. If in doubt, replace the equipment. Give special attention to dovetail or sliding socket foundations
  18. remember that forces on container corner posts can be up to three times greater than the upward compression force during ship rolling. The weather route is an attempt to avoid the worst of the meteorological systems or areas where high seas in winter are frequent. Check the specified limits of metacentric height (GM) in the Cargo Securing Manual and make sure this is not exceeded. If navigating in bad weather, reduce speed, avoid beam seas and proceed with caution until the storm has passed
  19. try to avoid loading 'high cube' containers on deck in the first or second tier. Lashing rods are more difficult to fit, and special rods with extension pieces are often needed. Before loading, identify where these containers are to be stowed. It may be necessary to reposition them
  20. always consider personal safety when accessing lashing positions and working with lashing equipment. It applies equally in port and at sea.

Related topics

2 in 1 container operation in cargo hold

How to load 45 feet containers

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

Other factors should be taken into account before accepting a containership cargo stowage plan :

Stacking Weights

Lashing strength

Dangerous goods stowage and segregation

Reefer Container Stowage

Out of Gauge Container Stowage

Special Container Stowage

Irregular Stowage of Containers

Over-stow of Containers

Hatch Cover Clearance (High cube containers Under Deck )

Other matters regarding cargo stowage as necessary

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 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 Company’s 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, it’s 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......

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