Stowage of Containers

Safe stowage and carriage of containers on cargo ships

System of work for containerized cargo

All cargoes should be stowed and secured in a manner that will avoid exposing the ship and persons on board to unnecessary risk. The safe stowage and securing of cargo depends upon proper planning, execution and supervision by properly qualified and experienced personnel. Advance planning, exchange of information, and continuous ship to shore communication are all critical.

Containers are simply packages of pre-stowed cargo . The equipment used for lifting a container should be suitable for the load, and safely attached to the container. The container should be free to be lifted and should be lifted slowly to guard against the possibility of the container swinging or some part of the lifting appliances failing, should the contents be poorly secured, unevenly loaded and poorly distributed or weight of contents incorrectly declared.

The process of loading and securing of goods into a container should follow the IMO/ILO/UN/ECE Guidelines for Packing of Cargo Transport Units (CTUs). Special care should be taken when lifting a container the centre of gravity of which is mobile, e.g. a tank container, bulk container or a container with contents which are hanging.

Safe means of access to the top of a container should be provided to release lifting gear, and to fix lashings, and personnel so engaged should, where appropriate, be protected from falling by use of a properly secured safety harness or other suitable means. Where containers are stacked account should be taken of the appropriate strength features and stacking induced stress. Containers should be lashed individually.

On ships not specially constructed or adapted for their carriage, containers should, wherever possible, be stowed fore and aft, and should be securely lashed. Containers should not be stowed on decks or hatches unless it is known that the decks or hatches are of adequate overall and point load-bearing strength. Adequate dunnage should be used.

The system of work should be such as to limit the needs to work on container tops. Where the design for securing of containers and the checking of lashing makes access onto the container tops necessary, it should be achieved by means of the ship's superstructure or by a purpose- designed access platform or personnel cages using a suitable adapted lifting appliance. If this is not possible, an alternative safe system of work should be in place.

To allow access to the tops of over-height, soft top or tank containers where necessary for securing or cargo handling operations, solid top or "closed containers" should be stowed between them whenever practicable.

Where the ship's electrical supply is used for refrigerated containers, the supply cables should be provided with proper connections for the power circuits and for earthing the container. Before use the supply cables and connections should be inspected and any defects repaired and tested by a competent person.

Supply cables should only be handled when the power is switched off. Where there is a need to monitor and repair refrigeration units during the voyage, account should be taken of the need to provide safe access in a seaway when stowing these containers.

Personnel should be aware that containers may have been fumigated at other points in the transport chain, and there may be a residual hazard from the substances used.

It is important to plan in advance, both at the shore terminal and offshore to aid effective cargo securing. The objective of pre-planning is the safe and practical restraint of cargo carried on the deck of offshore support vessels so that personnel, ship and cargo may be reasonably protected at all stages of carriage, and during cargo operations offshore.

The master and the Offshore Liaison Manager or their representatives must establish liaison prior to unloading or backloading of cargo.

The order of loading/discharging and stowage arrangements should be pre-planned in order to avoid wherever possible the "slotting-in" of containers and the necessity for any person to climb on top of the cargo.

The master should ensure he is provided with details of any unusual items of cargo, including dangerous goods, cargoes requiring special sea-fastening arrangements, or heavy lifts before loading




Container types


The standard terms of measurement for refrigerated containers are the "20 foot equivalent unit" (TEU) and the "40 foot equivalent unit" (FEU). These terms do not distinguish between containers of differing heights. Two principal types of reefer container are in use today:


  • Insulated containers requiring an external refrigeration source. These units are often referred to as being of "port hole" or "Con-air" design. It is expected that they will be gradually phased out.
  • The second, and by far the largest group, consists of insulated containers each fitted with an integral reefer machinery unit, often known as "integrals" or "reefers".


Prior to delivery to a shipper, an integral unit container must be subjected to a Pre-Trip Inspection (PTI) arranged by the carrier or his local agent, which involves the refrigeration machinery being run and tested by a specialist engineer, usually within the port area. During a PTI the machinery is checked, faulty parts are repaired or replaced, and thermostatic temperature recorders (if fitted) are wound up and calibrated (normally at 0ºC).

If the cargo is to be carried under controlled atmosphere (CA) conditions, gas controllers must be correctly set and fresh air vents must be closed. Instructions should be issued regarding the steps to be taken in the event of gas control failure, which may include opening fresh air vents when switching off the CA system.

In tropical or sub-tropical regions, it is preferable that containers are loaded in a temperature controlled environment (eg chilled warehouse). However, if loading in ambient conditions, containers should not be pre-cooled before stuffing except in exceptional circumstances as this may lead to the development of excessive condensation on the inner surfaces of the container.

Refrigeration machinery should always be switched off when the container doors are open to minimise the accumulation of moisture on the evaporator coil, the only exception being loading or devanning using a cold store tunnel.



In CFS operations, the carrier's seal is attached immediately stuffing has been completed, recording the serial number on all shipping documents. In shipper-stuffed units, it is not normally possible for the container to be sealed by the carrier or his representative until the container has been returned to the container yard for shipping out. On receipt, a seal should be affixed without delay and the details again noted on all documents.

It is particularly important where veterinary seals are attached to containers that all details are noted and the seals checked for signs of interference on arrival at the container yard. Imports to the EU, USA and Japan will only be permitted if veterinary seals are intact on arrival, thus confirming the cargo has not been tampered with in any way during the transit. At intermediate ports, the vessel or her agents must reconfirm the security of all such seals and this fact must be noted on the accompanying documentation.

For cargoes classified and labelled as "Quick Frozen", there are special EU importation requirements which demand correct temperature maintenance from the point of production, which may be prior to receipt by the carrier. In such cases, the carrier needs to have evidence of previous temperature maintenance.