Cargo and Packaging

UNESCAP Training Module

Introduction

he two principle challenges facing shippers are to satisfy both the customer and the shipper. The customer requires

a secure and reliable method of carriage whilst the shipper requires that the space on his vehicle of carriage is fully utilised in order to receive maximum freight.

T TTo achieve compatibility between cargo owners and the owners of the means of transport requires knowledge of the cargo-handling procedures in transport. These procedures are described with reference to major characteristics of commodities and cargoes.

The methods of cargo carriage and packaging must be considered at the very outset of the shipping process. The size and quality of packages must be compatible with the transport technology contemplated, e.g. utilisation of containers depends on positioning packages to avoid empty space. Hence, the considered transformation of commodity to cargo carries significant commercial, operational and economic impact. Space with a container is not just loss of revenue but poses the danger of goods shifting during transit and so sustaining damage.

Basically, packaging performs the following three basic functions, which we may call the three P’s of packaging, namely: protection, preservation and presentation.

A package should protect and preserve the contents during storage and transit from the harvesting (for agricultural products), manufacturing (for manufactured goods) or mining (for ore or other mineral products), to the consuming centre. Protection is required not only against loss, damage and pilferage, but also, depending on the nature of the contents, against moisture entering or leaving the package, high or low temperatures, light, gases, insect infestation, contamination and other natural hazards.

In this chapter, we shall look at the transformation from commodity to cargo and the packaging requirements for the various types of cargo, including its implications on shippers of unitised cargo. Chapter objectives

On completion of this chapter, you should be able to:

Understand the transformation from cargo to commodity.

Describe the packaging requirement of the different types of cargo.

List the guidelines on the choice of packaging.

Know the principles of packing cargo in container.

From commodity to cargo

Commodities and cargoes may be in solid dry form, or they may be liquids or gases. The physical state has clear implications for storing, handling and movement of commodities. Different forms require different transport modes, means and packaging.

Gases and liquids have to be contained in some form. They may be packed into containers or flasks, or alternatively be moved without packaging in pipelines and special carriers. When gas is moved in tanks onboard ships, it is often liquefied by low temperature. This is a highly specialised form of transport requiring not only expensive, purpose built carriers, but also special terminals and handling equipment. There are two forms of gas which are shipped by sea, liquefied natural gas (LNG) and liquefied petroleum gas (LPG). The advantages of cooling gases can be evidenced in the simple arithmetic that liquid gasses can be reduced by about 600%.

A Typical LNG Vessel

The traditional liquid cargoes are mainly crude oil and its refined products, vegetable oils, wines, latex, various chemicals and even water. In bigger lots liquid cargoes are carried loose in ships, i.e. they are pumped from tanks on shore through pipelines to tanks onboard the ship and vice versa. This is the practice for very large crude carriers (VLCC).

A Typical VLCC Vessel

In smaller lots liquids and gases are stored and moved in containers or flasks. When packed in this way, the commodities may be regarded as dry cargo from a transport point of view.

The dry cargoes embrace raw materials, semi-finished or finished goods. They do not require the same containment as gases and liquids. The number of dry cargo types is almost endless. The type of commodity, the level of finishing, and the transport method will determine the need for packaging and storage requirements. Detailed recommendations of methods of cargo carriage, cargo handling, and transport requirements for various types of goods are found in many literatures1.

Storage requirements will tend to determine the choice of transport method. Some commodities have to be kept frozen (e.g. meat) while others need refrigeration (e.g. fruit). Flowers need to reach the customers

quickly, while other cargoes need adequate ventilation to avoid combustion (e.g. grain, coal and copra). The shipper must choose a transport method which secures proper storage and speed of delivery. There are several international conventions as well as common practices shipowners will have to follow to secure proper handling of different cargoes onboard a ships.

Loading of dry bulk cargo at dedicated bulk terminal.

Packaging will also have to be considered relative to the transport method chosen. Some raw materials, like ores, need not be packaged at all. If finished goods are moved in containers, the packaging required is much less than if the goods are transported in individual cases.

Methods of cargo carriage2

In general, commodities are either moved in bulk or as general cargo. Bulk and general cargoes are defined relative to their means of transport and the cargo mix onboard. If, for example, a ship carries a homogeneous cargo lot which is not packed in any form, this is a bulk cargo: oil carried directly in tanks, grain carried directly in holds or pig iron loaded directly, in holds.

When cargoes are packed and mixed onboard, it is referred to as general cargo. Most finished goods are shipped as general cargo, while raw materials in bigger lots are usually bulk cargoes.

1 Example: Branch, A.E., Elements of Shipping, Chapman and Hall Ltd., London and New York, 1996.

2 Use of Maritime Transport. A Guide for Shippers, Freight Forwarders and Ship Operators, Volume 1, United Nations Economic and Social Commission for Asia and the Pacific, ST/ESCAP/516, p. 50-51.

The distinction between bulk cargoes and general cargoes is not strict. There are examples of more than one bulk cargo being carried onboard the same ship, in different holds or sections. Similarly, there are general cargoes which fill up the whole carrier, e.g. shiploads of sugar in bags. This is referred to as unit loads of general cargoes (which does not necessarily involve pallets or containers). The opposite, where the ship carries different cargoes packed differently is referred to as general break bulk cargoes. Such cargoes may consist of pallets, unpacked machinery, drums, crates and so on.

The table below clarifies the difference between the physical form of a cargo and the way it is shipped. Commodities, dry as well as liquid, may be shipped in unit loads, in break bulk or as bulk cargo. It should be noted that terminology with regard to the above is not fully consequent, and that additional terms are in use. The term "parcel bulk" in chemical carriers is one example of this; up to 30 different chemicals may be transported simultaneously onboard the same ship.

Table 2.1: Cargo physical forms and ways shipped

The ways Dry cargo is shipped

Physical form Unit load Break bulk Bulk cargo Dry cargoes e.g. bagged rice in

whole load e.g. machinery parts in crates and boxes

e.g. loose grain in holds

Liquid cargoes e.g. whole load of oil in drums

e.g. part loads of e.g. crude oil in wine in cases tank vessels

There exists a third; “hybrid” form of moving cargoes, involving slurry techniques. Dry bulk cargoes may be transformed into slurries and moved in a form similar to that of liquid bulk. This has been applied to coal and iron ores, where the ores or the coal are mixed with water and transported by means of pipelines.

On a world wide basis, almost all the liquid commodities, measured in tons, are moved in bulk. Important dry goods, like grain, coal, ores, tapioca,

copra and salt are similarly moved in homogeneous unpackaged lots. Such bulk cargoes can be handled in many different ways. Liquids are moved in pipelines, grain are mostly loaded by conveyors or chutes and unloaded pneumatically, while ores and coal are mostly moved with conveyors or grabs.

Bulk coal loader incorporating centralised dust control system

The cargo characteristics will influence the choice of ship needed for a specific job. Different ships are constructed to carry different bulk cargoes.

Similarly, the cargo access equipment have been constructed to cater for different commodities. The equipment available for cargo handling at the intended ports of

loading and discharge will also be reflected in the type of ship needed for a specific job. If, for example, no cranes are available in the discharging port, a ship equipped with cranes will have to be chosen for the transport task.

Cargo in its different forms

General Cargo

General cargo is a term that covers a great variety of goods. In regard to modern cargo handling it refers to loose cargo that has not been consolidated for handling with mechanical means such as unitised or containerised cargo. It refers to individual items of any type of cargo, bagged or baled items, cases or crates, individual drums or barrels pieces of machinery or small items of steel construction.

If general cargo is to be loaded on a ship in general stow it is usually man handled into place. Hence the reason why general cargo is rarely seen in developed countries today, the cost of handling such items is prohibitive and the time taken is unacceptable for most maritime operations.

In stow, general cargo is susceptible to crushing damage from other items of cargo or damage from the ship's steel work, general handling damage, sweat damage and from pilferage. Hence cargo stowed in this state must be protected with suitable dunnage depending on the type of cargo and the risk of such cargo in stow. For example, bagged cargo if susceptible to moisture damage should never be stowed against the steel in the cargo compartment, some type of dunnage or cargo battens must be placed between the cargo and the steel work.

Cargo susceptible to crushing

General cargo must be appropriately labelled. Usually with the port of destination and

Sling here Fragile – handle with care

Do not use hooks This way up

Keep away from heat Centre of Gravity

The International Marking Symbols

must be placed in top stow. Food stuff can often taint other cargoes so must be stowed apart. Some cargoes need ventilation and must be stowed accordingly. Cargo that has a value to any individual must be protected from pilferage, examples of this are shoes and clothing, beer and spirits, grocery items and electrical goods.

the consignee's identification, this is called the ‘cargo mark’. And it is this mark that is also shown on the Bill of Lading and the Cargo Manifest.

It is the responsibility of the shipper to ensure that general cargo is presented for shipment suitably packaged to prevent damage in handling. If there is any risk in handling damage then the items should be clearly marked with the international symbols as shown above.

Due to the numerous small parcels making up general cargo, it is usual to tally such cargo onto the vessel while loading and in some

instances discharge tallies are also conducted. Cargo quantity on board is confirmed by the ship's officers signing a Mate's Receipt, details from the Mate's Receipt then make up the information on the Bill of Lading.

Cargo handling operations at a conventional cargo berth.

Tallies, Mates Receipts and thence Bill of Ladings must accurately record the quantity and condition of the cargo. The ship is then obliged to discharge the cargo at its destination in the same quantity and condition as stated on the Bill of Lading. If it does not then the carrier (the shipowner) is liable.

It is important therefore, that any defects, damage, lack of suitable packaging, or any deterioration whatsoever to general cargo sighted by the ship during or prior to loading is outlined on the Mates Receipt. The Bill of Lading must then be suitably claused prior to signing by the ship's Master or his agent.

Obviously the usual type of ship carrying general cargo are general cargo vessels, although it is not unusual for bulk carriers to carry certain types of general cargo such as forest or steel products. In addition it is fairly common for bulk carriers to also carry large quantities of bagged cargo, although this is often referred to a specialised or particular bulk cargo.

Further knowledge of general cargo, types, characteristics, stowage factors and usual packaging can be gleaned from the publication by THOMAS et al entitled “Thomas' stowage : The properties and stowage of cargoes” 4th ed. Glasgow (UK), Brown, Son & Ferguson, 2002.

(ISBN 0-85714-694-2) this is the only comprehensive text book written on the subject and also includes text on operational matters of working a general cargo vessel.

Containerised Cargo

General cargo moving between developed countries today is usually containerised and carried on cellular container or Ro/Ro vessels. So just what is the difference when we refer to containerised cargo?

Almost any commodity can be containerised. The great advantages to the industry with containerisation is that the cargo is not man handled on and off the ship, instead the container is handled with fast and sophisticated handing equipment. Naturally in

developed countries where labour is expensive significant savings can be made, less so initially for developing countries but over time as they become developed this will change.

The cargo itself therefore needs less protective packaging. The cargo can be stowed in the container away from the wharf, often by the shipper himself. The containers fit into predetermined positions on board ship, complicated stowage planning is not necessary. Documentation and identification of cargo is simplified as the container number replaces the cargo mark. Computers and electronic data interchange now play a large part in

ensuring the correct cargo movement, there is no need to tally the cargo.

A general purpose container.

The containers themselves are owned or leased by the shipping companies and are responsible in ensuring that sufficient empty units are available for shippers at the load ports. To achieve this often large quantities of empty units are carried at the shipowners expense to high demand areas. A refrigerated (reefer) container.

The containers themselves were originally designed to fit international standards of specific sizes. However, ship owners have pushed the actual dimensions of the units to their absolute limits, consequently there are a variety of heights, widths and even lengths of units in the system today.

There are of course many specialised, or special purpose containers in use. The full list is endless but some of the more common are listed below:

Type Typical Cargo

Insulated Used for frozen or cool cargo containers

Half height units Steel or other heavy items

Flat racks Timber, vehicles and odd shapes

Open top Over height items containers

Bulk boxes Bulk cargo such as grain or fertilisers

Open sided Ventilated cargo such as onions

Tank containers Liquids and chemicals in bulk

A typical dry box was 20 x 8 x 8 feet (L x B x H) but it is not unusual to find units in the system today measuring 20' x 8' x 8' - 9' 6". Forty foot (40’) units, were, until recently the maximum length of containers but 44' and 48' units have been introduced on the American coast and many are now finding their way into international trades. Forty-five foot (45’) units have also gained worldwide acceptance today.

Compared with general cargo carried break bulk, cargo damage in containers is considerably reduced, however, it still exists. Some of the more common forms of damage are explained below.

Cargo not properly secured or trimmed-off within the container will damage either due to heavy rolling of the ship or from shunting if transported by rail. The further a container is stowed away from the ship's centre of motion the greater will be the acceleration forces on the cargo and therefore the greater risk of damage in heavy weather.

Water damage can be expected if the container has a leaking roof, although the majority of water damage sustained by a substandard box is caused at the terminal while the container is waiting in the stacks. Water damage on board is usually caused by a flooded hold due to blocked bilges or a leaking ballast tank. Another source of water damage is often caused when a container is stowed outside on deck where the seas can reach the underside of the unit.

Refrigerated cargo damage can occur due to a malfunction of refrigeration machinery, or through a hot spot within the container due to insufficient cold air circulation in the stow caused by poor packing or lack of adequate separation through the stow.

Container and cargo within the container can be damaged due to inappropriate or inadequate securing arrangements when containers are stowed on deck.

Despite cargo being stowed in containers it is still possible for some products to taint due to being stowed in close proximity of badly smelling cargoes. Foodstuff stowed close to wet salted hides is a classic example.

Some cargoes can spoil in the close confines of a container due to lack of ventilation. Sweat damage is as much of a problem with some containerised cargoes as it is with some general cargoes in an open hold.

To prevent damage to container roof top, accurate positioning of quay crane’s spreader is very important.

Pilferage can still take place with containerised cargo. Despite the fact that the door leaves are sealed it is still possible for the doors to be sprung open with the use of heavy machinery, individual items within the container can then be stolen and the doors sprung shut without the door seal being broken. Although in most

cases of container pilferage the entire container is hijacked and box and contents disappear without a trace!

Before packing a container

Packing a container should always be done on level plane either on the ground, on a railcar, or on a trailer. In the case of a trailer, care should be taken to ensure the trailer cannot tip whilst being packed especially if a forklift truck is being used. If necessary the trailer should be propped. Brakes should be securely applied and wheels choked.

Stowage should be planned before packing is commenced. This should make it possible to produce either a tight or a secured stow, in which the compatibility of all items of cargo and the nature i.e. Type and strength of any packages or packaging involved are taken into account. The possibility of cross-contamination by odour or dust as well as physical or chemical compatibility should be considered.

The planned load should not weight more than the payload of the container which is marked upon it. This ensures that the permitted maximum gross weight of the container on the CSC Safety Approval Plate (which includes the payload) will never be exceeded. A picture of the rear end of a typical container is shown below:

A Rear View of a Container

Notwithstanding the load limitations on a container mentioned above, any limitation along the projected route that may be dictated by regulations or other circumstances (such as lifting and handling equipment or road restrictions on height and weight) should be complied with. Such limit may be considerably less that the permitted gross weight already referred to. In case of doubt, the container operator should be consulted.

Stowage planning should take account of the fact that containers are generally designed assuming the load to be evenly distributed over the entire floor area. Where substantial deviations from uniform packing could occur, specialist advice should be sought.

When a heavy indivisible load is to be shipped in a container or vehicle, due regard should be given to the localised weight bearing capability of the container. If necessary, the weight should be spread over a larger area than the actual bearing surface of the load, for example, by use of timber bulks.

In such a case the method of securing the load should be planned before packing occurs and any necessary preparations made.

If the planned load of an open-topped or open-sided container is to project beyond the container overall dimensions, special arrangements should be made.

When heavy cargo is to be shipped, if it is impracticable to place the centre of gravity in or near the centre of the horizontal plane of the container, or if it will be above the half height, the container operator should be consulted.

When planning the packing of a container, consideration should be given to potential problems which may be created for those who will unpack it.

Packing and Securing

It is essential to make the cargo in a container or vehicle secure against any reasonably foreseeable movement. At the same time, the method of securing the cargo should not itself cause damage or deterioration either to the cargo or the container or vehicle.

Where goods of regular shape and size are concerned, a tight stow from wall to wall should be sought. However, in many instances some void spaces will occur. These can be tolerated if security is obtained by the frictional effect between adjacent packages. If there is an insufficient frictional effect, or if the spaces between the packages are tool large, then the stow should be completed by using dunnage, folded cardboard, air bags or other suitable means.

If airbags are used, the manufacturer's instructions as to filling pressure should be scrupulously observed. Allowance should be made for the possibility of a considerable rise in the internal temperature of the container above the temperature at the time of packing which might cause the bags to expand and burst, thereby making them ineffectual as a means of securing the cargo. Air bags should be not be used as a means of filing space at the doorway unless precautions are taken to ensure that they cannot cause the door to open violently when the locking bars are released.

The cargo weight should be evenly distributed over the floor of a container or vehicle. Where cargo items of a varying weight are to be packed into a container or vehicle or where a container or vehicle will not be full (either because of insufficient cargo or because the maximum weight allowed will be reached before the container or vehicle is full), the stow should be so arranged and secured that the approximate centre of the weight of the cargo is close to the mid-length of the container or vehicle. In no case

should more than 60 per cent of the load be concentrated in less than half of the length of a container measured from one end.

Heavy goods should not be placed on top of lighter goods and liquids should not be placed on top of solids. The centre of gravity should be below the half height of a container.

In order to avoid cargo damage from moisture, wet cargoes, moisture inherent cargoes or cargoes liable to leak should not be packed with goods susceptible to damage by moisture. Wet dunnage, pallets or packaging should not be used. In

certain cases, damage to equipment and cargo can be prevented by the use of protective material such as polythene sheeting.

Damaged packages should not be packed into container or vehicle unless precautions have been taken against harm from spillage or leakage.

Permanent securing equipment incorporated in the design of a container should be used wherever necessary to prevent cargo movement.

Where open-sided vehicles are concerned, particular care should be taken to secure cargo the forces likely to arise from the rolling of the ship. In order words, a check should be made to ensure that all side battens are fitted or other adequate precautions are taken.

Special packing instructions shown on packages or otherwise available, should be followed. E.g.:

Goods marked "protect from frost" should be packed away from the walls of a container;

Goods marked "this way up" should be packed accordingly.

On completion of packing a container

During the final stages of packing a container, care should be taken, so far as practicable, to build a secure face of the cargo so as to prevent "fall out" when the doors are opened. Where there is any doubt as to the security of the cargo, further steps should be taken to ensure security by weaving strapping between securing points or placing timber between the rear posts. Two factors should be borne in mind:

that a container on a trailer usually inclines towards the door;

that a cargo may move against the doors due to jolts etc. during the transit.

If a container is destined for a country with wood treatment quarantine regulations, care should be taken that all wood in the container, packaging and cargo complies with the regulations. It is useful to place a copy of the wood treatment certificate in a conspicuous place in the container.

After closing the doors, ensure that all closures are properly engaged and secure. Usually a seal should be applied. Care should be taken that sealing procedures are carried out properly and transport documents/receipts bear the correct seal number before the container leaves the premise.

When a container, or its contents, has been fumigated and is to be shipped under fumigation, then a warning label should be placed on the outside of the doors so that it is clearly visible to any person operating the doors. The label should state the method of fumigation employed and the date and time on which it took place.

As containers offered for shipment under fumigation may require special precautions, they should only be accepted with the agreement of the carrier and they should be identified to him prior to loading. Note: point 4 and 5 do not apply to containers which have been fumigated, ventilated thereafter and certified as safe.

Dry bulk cargo

The loading, carriage and finally the discharge of dry bulk cargo is not as simple or straight forward as most people would imagine. Many bulk cargoes have hazardous properties, or can change their properties on passage. The ship can be easily damaged by incorrect loading e.g. loading a forward hold to it maximum can cause the ship to bend. This ‘stress’ can have life threatening results at sea in rough weather. Residues from previous cargoes can also seriously effect latter cargoes. Water damage can also have devastating effect on some bulk cargoes e.g. cement power. It is not easy to verify true weights or quantities of cargoes loaded or discharged. All these factors have a serious consequence on the methods of operation for the safe carriage of bulk cargoes.

Discharging bulk cargo using “grab”

Consider some of the more common bulk cargoes and their properties:

Coal – Coal is transported on all types of bulk carriers from handy size to VLCBs. However, it is not an easy or straight forward cargo to handle. It can emit methane gas and it is self-heating. In addition coal contains sulphur which causes severe corrosion when in contact with the ship's steelwork. In most ports the cargo is loaded wet to reduce dust. Much of this moisture settles on passage and is pumped out through the ship's hold bilges which means that less weight is discharged than is loaded.

Iron Ore - This cargo is loaded very fast, 10,000 tonnes an hour is not unusual. The loading and de-ballasting of the ship must be meticulously planned to ensure that the vessel is not overstressed. There is very little chance of damaging the cargo but the ship can receive extensive damage during the discharge operation from the equipment used.

Mineral Concentrates - Many different types of concentrates are handled in various parts of the world and in varying quantities. Most of these cargoes are extremely heavy and have a low transportable moisture limit (TML). This means that if the

moisture content of the cargo become greater than the TML the cargo can liquefy and turn into a slurry. When this happens on board, the cargo moves from side to side as the ship rolls which reduces the ship's righting lever. It does not require much cargo weight to capsize the vessel when this happens, it a loss of stability due to free surface effect. Some of the most dangerous cargoes where this can happen are copper, lead or zinc concentrates, magnetite, limonite and most pyrites.

Grain - One of the most difficult and dangerous cargoes to carry in bulk are grain cargoes. Most grains have an angle of repose (slip angle) of about 20° from the horizontal, which means that if the ship rolls more than 20° the cargo will shift. Then this happens the ship will develop a large list, lying on her side and still rolling will obviously cause a greater shift of cargo which in turn will capsize the vessel. Most authorities therefore request that the master proves that his ship is capable of remaining stable even if the grain cargo shifts. This is done by the compiling of the Grain Loading Form which fully outlines the ships stability at the worse condition on passage.

Naturally grain cargoes, like any foodstuff, are susceptible to claims with contamination from a previous cargo and in addition can easily be damaged by water.

Loading of grain using movable loader fitted with “chute”

Vermin can also be a problem. Cargo holds must be clean and dry prior to the loading of any grain cargo and most grain charters demand a survey of the ship's hold prior to loading for this reason.

Cement - Obviously any moisture is going to ruin a cargo of cement but probably a greater danger to the vessel is the dust that can be produced during the loading and discharge of the cargo. If it is not removed promptly or gets into the ship's air intakes it can cause some long term problems to the vessel.

Salt- Salt, strangely enough, is not damaged from water, in fact the cargo can be loaded slightly moist. However, it can get rust stained from the ship's steelwork, therefore the ship must cover all the steel within the cargo hold with a lime wash solution thereby keeping the salt off the steelwork.

Woodchips - Again a supposedly harmless cargo that does have some hidden dangers. Some shipments many be subject to oxidation leading to depletion of oxygen and an increase of carbon dioxide in the cargo hold and adjacent spaces. In addition, woodchips can be easily ignited by external sources, it is readily combustible and can also ignite by friction. The stowage factor can vary greatly with this cargo depending on the wood type, the moisture content and the type of loading head used. Even different loading operators can achieve varying stowage factors with the same cargo.

Liquid cargo

Even liquid cargoes have their difficulties. Outlined below are some problems associated with various cargo systems found in tankers.

There is a high risk of contamination when a common pump is used for several cargo tanks, if the system is not properly drained between different cargoes. Modern tankers are often equipped with individual submersible cargo pumps but if these are connected to common or shared lines there is still a risk of contamination. There will normally be a drain cock near or on the cargo pump itself, this drain cock should be opened to verify that the line has been properly drained before pumping a different cargo. In addition most of these pumps are hydraulically driven, damage oil seals can lead to hydraulic oil leakage into the cargo tank contaminating sensitive cargoes.

Connecting shore loading arm to the ship’s manifold onboard a tanker.

On oil tankers it is normal to have a common cargo tank ventilation system. The vapours from one cargo tanks can easily enter a different tank in the system. This may result in cargo contamination or change the flash point of the product. Petroleum products are classified into volatile and non-volatile cargoes. A cargo with a flash point below 60°C is a volatile product and a cargo with a flash point above 60°C is a non-volatile cargo (different rules apply to the handling of volatile and non-volatile cargoes). Diesel oil has a flash point of around 63°C and vapours from a volatile cargo can easily change the flash point to below 60°C, causing the cargo to be re-classified.

Many lube oils and lube additives are heated during transport. Steam coils are normally used for this purpose. A leaking heating coil can lead to water entering the cargo tank and consequently contaminating the cargo. Laboratory tests should be carried out on cargoes contaminated by water. It should be established whether the water is fresh or salt water. Contamination caused by fresh water is most likely to be caused by a leaking heating coil whereas salt water contamination would probably be caused by a leaking tank hatch, in which case the hatch packing should be checked.

Chemical tankers are normally constructed with completely independent cargo systems. Each cargo tank will have an independent pumping and venting system. Cargo contamination in chemical tankers are often caused by poor cleaning of cargo tanks or pipe lines. Unfortunately many chemicals are extremely sensitive to contamination, just a few parts per million of a previous cargo can contaminate an entire shipment. Many

cargo samples are taken during the loading of chemicals. When a cargo is contaminated it must be established whether the cargo was effected prior to loading; or during its transportation on board. Cargo transfer hoses may also contribute to

A typical chemical tanker.

cargo contamination, therefore hoses should be properly cleaned in between different cargoes.

Cargo Handling

The techniques of cargo handling have, at least in ocean transport, developed considerably over the last decades. This is particularly due to:

(a) Technological advances in ship design and lifting equipment

(b) Rapid development and increase in the tonnages of bulk cargo

(c) The impact of unitisation, and

(d) The new and modern techniques of refrigeration, particularly with container carriage.

It is shippers, as a group, which have been influencing these developments. The requirements for efficient transport have led the transport industry, port authorities, shipowners etc., to develop new concepts for ship technology and cargo handling. It is up to the individual shipper to utilise the available methods of transport and cargo handling, in order to be competitive in the international markets. As a minimum, requirements must be properly defined by shippers so that the most appropriate services may be made available by the carrier.

The shipper will have to prepare consignments for transport. The handling and storage of cargo is not his immediate responsibility, but as it will influence the total transport cost and quality, shippers' will have to ascertain that the best available methods are provided and used. While in transit, commodities are represented by documents. It is in the shipper's interest to see to that the paper work is handled efficiently.

Cargo preparations

Some sort of packaging will normally be a prerequisite for carrying commodities as general cargo, especially in break bulk. Packaging has at least three functions:

(a) To protect the goods;

(b) To keep a consignment together;

(c) To prevent the goods from damaging the environment.

Transport usually subjects the cargo to mechanical forces (shocks, vibrations, pressures) and/or climatical forces (temperature, moisture). At least for a conventional shipment, the packaging needs to be strong enough to withstand the rigours of stowage and multiple handling. Goods which are not packed properly may damage other goods in the same transport. In such cases the shipper may be liable. Paper and carton are traditionally mostly used in local transport, where the risk of damage is usually smaller. Plastic and especially jute are used to produce bags. Bags are commonly used to pack traditional bulk commodities in small quantities, like cement,

sugar or grain. Wood is still common to make cases or crates. Drums and barrels are made of metal or plastics and are used for transport of liquids in small lots.

The shipper has to follow procedures laid down by public authorities as well as commercial practice with regard to packaging, marking and declarations of contents.

Unstuffing bagged rice from a container. The marking should embrace at least the following:

(a) Destination: Address of the end receiver, transhipment, order-number.

(b) Handling instructions: Especially with fragile commodities it is important to mark the package with handling directions to avoid breakage and other damages. To avoid language difficulties a set of internationally recognised signs are developed for cargo marking.

(c) Dangerous goods: Some goods are classified as dangerous. In general, goods are regarded as dangerous if they have chemical or physical properties which can damage other goods, materials or the environment. Examples are explosives, flammable liquids or gases and poisons.

IMO, the International Maritime Organisation, has worked out rules for the handling of dangerous goods at sea in conventions which have been ratified by most member countries. These rules contain regulations regarding packaging, marking and labelling, stowage requirements, etc. for various types of explosives, gases, and various types of inflammable materials. This is discussed later in detail.

Cargo loading and discharging

The use of quay cranes in modern container terminal help in reducing vessel’s turn around time.

The rate at which cargo is loaded aboard or discharged from a ship has a significant bearing upon the overall cost of transport. Excessive time in port deprives consignees of the use of their goods, and ship operators of the use of their vessels. Therefore, the improvement of cargo handling methods has been a constant aim of many of those concerned in the operation of ships.

Every cargo handling or transfer system consists of a number of identifiable elements. Goods are moved from one place to another, such as a quayside storage area and a ship's hold. Then there is the commodity itself, which may take many forms, as already described. Finally, there is the medium by which the cargo is transferred, which may be manual labour, specially designed equipment or some combination of

the two. In an efficient system, these four elements must be properly matched. This implies a certain cooperation between the port authority, the shipowner, the shipper, and the possible stevedoring company engaging the port labour.

The earliest efforts to increase cargo handling rates were concentrated mainly on the transfer medium, and led to the development of a wide range of mechanical equipment, such as cranes, conveyors etc., which has substantially improved loading and discharging rates, especially for bulk cargoes.

General cargo handling has, however, not benefited to such a great extent from such developments. In liner shipping, the principal restriction to high handling rates has always been the large variety of packagings used for general cargo, so that significant improvements have only become possible by reducing the number of different forms in which goods are presented for shipment.

The use of modern handling equipment in bulk handling operations such as mobile unloader connected to a conveyor system shown here will facilitate the smooth movement of cargo at the port interface.

Thus it is only with the adoption of unitisation that general cargo carriers have achieved high transfer rates and been able to take advantage of handling techniques similar to those which have been developed for homogeneous cargoes.

It is customary to distinguish between vertical and horizontal loading of ships as well as other means of transport. With vertical loading, the cargo must pass over the rail of

the ship and into holds through hatches in the deck. Derricks, cranes and conveyor belts are commonly used for the transfer of dry commodities. Liquids and gases are moved through pipelines. This traditional method is very useful for the handling of bulk cargoes.

Horizontal loading of cargo is done through openings in the bow, side or stern of a ship. These ships are commonly referred to as roll-on/roll-off (Ro/Ro) ships as the cargo can be accepted on wheeled vehicles.

Flexibility and fast port turnarounds are the essential feature of Ro-Ro operations, and cargo handling rates can be significantly increased.

Discharging of a train coach via the stern door of a Ro/Ro ship.

Not all horizontal loading ships are strictly Ro-Ro ships. Pallet carriers may, for example, have side doors only and the cargo is loaded or discharged by fork-lift trucks operating on the quayside.

Cargo stowage

The shipowner is generally responsible for the stowage of cargo onboard the vessel. In the handling of stowage and carriage of cargo, the following general principles will apply:

Systematic and efficient stowage of cargo will help prevent cargo damage and ensure maximum utilisation of hold space.

The safety of ship and crew

The safety of the cargo

The highest possible port speed

The most efficient use of space

When loading a general cargo at a variety of ports for a variety of ports, the problem of where to place the individual cargoes must be solved to secure minimum time in port. The cargo must be stowed in reverse order of the intended discharge to avoid rearrangements of the consignments. At the same time the amount of unused space should be kept as low as possible to obtain the best economical use of the vessel.

It is common to distinguish between horizontal and vertical stowage of general cargo in a ship. With horizontal stowage the cargo is spread over a relatively large area, while in vertical loading the consignments are stacked on top of each other so that space can be better utilised. Bulk cargoes present little difficulty in stowage, as they can fill up the holds as appropriate. In some cases the cargo needs to be trimmed, i.e. shovelled by hand from high piles in the centre of the hold to the perimeter so that the vessel can be filled up and best utilised.

The given stowage factor of a particular cargo will normally take what is called broken stowage into account. Broken stowage is space lost because of the shape of the cargo and/or particular requirements in regard to stowing it in the cargo holds. For example, there may be limitations on how many units or consignments which may be placed on top of each other. For homogeneous bulk commodities, broken stowage is usually small. For irregular packages, as often found in typical general cargo lot, it may be substantial.

Rolls of Newsprint paper stowed on its end

Plan view of the cargo hold (cargo compartment)

Broken stowage

A simple sketch showing the concept of Broken Stowage.

The stowage factor of any cargo is the volume which a certain amount in weight of that cargo occupies. It is usually measures in cubic feet per long ton or alternatively in cubic metres per metric ton. If the stowage factor is 20, it indicates a heavy cargo. If it is 100, it indicates that the cargo is light.

The stowage factor is important for the loading of cargo in the various means of transport, as it indicates the amount of the cargo which can go into the holds. Either the volume or the weight will be the limiting factor. The stowage factors of various products are given in published stowage tables.

While stowage of goods is important for the utilisation of space in containers and holds, packaging and stowage must also be carefully considered in relation to marketing and the needs and specifications of the customers as well as in relation to minimising damage.

Cargo documents

Goods are carried by sea under a contract of carriage between the shipper and the shipowner. The shipper may employ a forwarding agent to arrange the transport, while the Shipowner may employ a loading broker to control the allocation of space and advertise the service, and to make the loading arrangements and prepare documents on the shipowner's behalf .

When a shipper wants to send a particular cargo with a particular ship on a scheduled service, a "shipping

note" for the consignment is completed by the shipper and forwarded to the shipowner or his agent. This note will have to contain a brief description of the commodity. The loading broker then compiles a list of the consignments intended for shipment, the booking list. This is sent to the ship to enable the Master to plan the stow and to the stevedore to arrange the loading. The shipper may receive a "booking note", which specifies that the carrier reserves space for a specified volume and kind of cargo in a named vessel between named ports. The broker may also issue a "calling forward notice" to the shipper, advising him of the time and place at which he is to deliver the goods.

When the cargo is delivered to the warehouse or to the ship, a receipt for that cargo must be obtained by the shipper. When the cargo is placed onboard, this is called a "mate's receipt". This receipt acknowledges that the goods ha ve been loaded and have been properly and carefully handled, loaded and stowed. If there are any damages to the goods before loading, this will be recorded on the receipt, and it is no longer "clean".

In some trades, it is customary for the shippers to have a "boat note" following the cargo. When the "boat note" is signed by the cargo officer aboard the ship, it becomes a "mate's receipt". With many shipping companies it is the practice to give an official "mate's receipt" irrespective of the fact that a boat note may be provided by the shipper. Modern practice is to present a copy of the shipping note as the boat note, which when endorsed, become the "mate's receipt".

Special tally companies are engaged by the shipowner to check or keep record of all cargo loaded into and discharged from a vessel. This is an essential part of cargo work in order to prevent claims upon the ship for so-called "short" discharge, i.e. when some of the cargo is missing. It is sometimes customary for the shipper or consignee to provide his own tally clerks, particularly with cargoes of a straight nature, such as bags, bales etc.

A copy of the "mate's receipt" will be returned to the shipowner, so that a "bill of lading" can be issued to the shipper. The "bill of lading" acknowledges that the goods have been "shipped in apparent good order and condition" if the "mate's receipt" is clean. Otherwise, comments are transferred to the "bill of lading". This document is issued under all forms of shipping, scheduled or not. The complete list of cargo loaded, as compiled from the "bills of lading" form the "manifest" of the ship. Customs regulations at most ports require at least one copy of the manifest and copies are also required for stevedores at discharging ports.

While cargoes are in transit, they may be sold so that the goods change ownership. Such a sale will be represented by the "bill of lading" changing hands. At the port of discharge, the consignment will be handed over to the party presenting the original "bill of lading".

Packaging of Cargo

As mentioned earlier, packaging perform the following three basic functions, which we may call the three P’s of packaging, namely: protection, preservation and presentation.

Guidelines on the choice of packaging

Some broad guidelines to be followed in the choice of packaging technique include the considerations which follow.

Goods should be well stowed within the package, evenly distributed and properly secured. Items completely filling the case or carton contribute to the strength of the whole package. Items which do not completely fill the package must be cushioned against shock or vibration. There must be adequate internal bracing or securing using battens (bars of wood) or dunnage (mats, wood shavings, etc.).

Where the consignment consists of a number of small packages, it is preferable to consolidate them into one load by strapping and securing them to a wooden pallet base (a portable platform for storing loads). The assembly of cargo into the largest practical unit consistent with the handling, weight and dimension requirements reduces the danger of theft to a minimum. There is also the advantage of reduced handling stresses, as larger units require the use of mechanical handling equipment rather than crude manual techniques.

Pallet packing is quite suitable for goods carried in containers although they may also be carried by conventional methods. In this case, however, there is the risk of breakage during transfer, or on forwarding and handling operations.

In selecting the appropriate type of package, account should be taken of the probability of cargo being "overstowed" by other packages in warehouses and cargo holds.

Appropriate strapping and banding techniques should be used for all packages.

The regulations of the destination country as well as those of any transit countries should be checked in order to ensure that they do not prohibit certain types of packing material, particularly material which is harmful to the environment.

The re-use of second-hand cartons or cases should be avoided as they are more liable to collapse or and may invite pilferage (stealing in small quantities) if the contents become exposed.

To improve the handling of bigger volumes of cargo, the design of the package should match the dimensions of the product so as to save packaging and freight costs. From the shipper's point of view, it is desirable that the following considerations should be borne in mind in order to minimize the cost of freight:

in respect of measurement of the cargo, the package should be of minimum dimension;

there should be optimum utilization of space within the package; and

goods attracting different freight rates should not be packed together in one package, in case the carrier charges freight for the whole package at the rate applicable to the highest-rated commodity.

It is essential that waterproof wrapping for the contents and waterproof lining for packages should be provided, particularly when the packages are likely to remain in an unprotected area, such as the customs area.

Over-packaging in the name of protective packaging should be avoided, in order to make optimum use of the carrying capacity. This is particularly important in air transport where packages are consolidated into pallets, igloos

An aircraft “igloo”

3 or containers.

Powdered or granular material should be packed preferably in flexible multiwall bags which are adapted to the requirements of the material, taking into account its chemical and physical

3 Igloo: An open front, bottomless, rigid shell made of fiberglass, metal or other suitable materials. The slope conforms to the contours of the cargo aircraft envelope, i.e. the interior cabin cross-section.

characteristics.

In the case of pressed bales (canvas packages of merchandise), it is advisable to use an inner wrap of waterproof paper below an outer or primary cover of fiberboard material, over which heavy jute or a similar cover can be provided before strapping.

In designing or choosing a suitable package, it may be useful to consult, wherever possible, the consignee and obtain reports from his end about the packaging of specific products moving on specific routes. It would also be advisable to ascertain from consignees to what extent handling gear, port equipment, etc., are available at the port of destination, what inland transportation facilities are available and if the goods have to be moved to inland centres.

In export packing, consideration should be given to the "presentation" aspect of the package: the design; colour, embellishment of the packages, which could produce a favourable reaction in the export market and improve the competitiveness of the product.

Information required for packaging

The type of packaging required depends on the:

Nature and type of goods

Volume

Weight

Number of packages

Types of packages

Mode of transport

Final destination

Types of packaging for break bulk cargo

The exporter or seller is usually responsible for packing the goods for break bulk cargo, whereby a consolidated consignment is broken down on delivery for distribution to individual consignees. The type of packaging required for any product varies with the nature and volume of the product as well as the method of transport it is carried over. Generally the following types of packaging are used:

Bagged cargo

The commodity itself has to be robust to withstand outside pressure and compression, for the bags will only hold the contents in one place and will not provide protection against external damage. Such commodities might typically be fertilizers, grain (rice, maize, wheat, etc.), seeds, dried fruit, sugar, coconut, coffee, fresh vegetables, frozen offal (meat

from carcasses), flour, copra, small items such as shells, raisins, etc., mail, salt, mineral sands and ores, meal (fish, seed, copra, etc.), dried blood, dried milk etc..

Fibreboard boxes and cartons

Fibreboard boxes and cartons are very widely used for the sake of economy and efficiency. Although comparatively cheap, they are able to withstand normal transport hazards and protect the contents against loss or damage. They may be particularly suitable in the case of goods carried in containers from the point of origin to the destination provided the goods are not fragile. But if the containers have to be unloaded at the port of discharge for further transport to their final destination, they may have to be placed on pallets and securely strapped in order to protect them from pilferage and damage. Depending upon the nature of the commodities, cartons of the right type of suitable strength and sizes should be used.

Wooden cases

These have stood the test of time and their main advantage is that they have the wall strength to support superimposed loads. They are more expensive than the carton-type packing due to the cost of wood. Wooden cases are particularly suitable when the goods are carried by conventional methods and, when they are sensitive to heat, dampness, etc. The goods may require protection by way of packing with layers of insulating material, tar paper, sealed plastic covering etc. There are different types of wooden cases,

including those made of plywood, which are being increasingly used by exporters.

Wooden crates

These are suitable for wooden packages built like a skeleton. The open crate can be used when the contents are sufficiently resilient to require a minimal form of packing to facilitate handling and stowage. Sometimes, it is used as an outer package to consolidate fibreboard boxes or give cartons extra protection. The skeleton crate is often used for the carriage of large pieces of machinery.

Bales

For certain trades, the use of hessian-wrapped bales is suitable, particularly when the product permits pressure baling or compression by banding. It is, however, vulnerable to pilferage, damage by handling using looks, etc..

Drums, barrels, casks

These are generally used for liquids such as latex, chemicals, whisky, detergents, oil, molasses, casings, paints, powders, granules and other solids such as chemicals, cement, some ores and scrap metal.

Shrink wrapping

Dry chemicals, granular and powdered substances in bags cannot be easily strapped on to a pallet. When these items have to be unitised, bags are stowed on the pallet and interlocked; a polythene sheet of suitable gauge is then draped over the bags. This unit is then passed through a tunnel oven where polythene is heat-sealed tight, binding the bags to the pallet to form a good unit load.

Lift vans

When household goods such as tables, chairs, cupboards, glassware, brassware, etc., have to be moved, especially from one country to another, they have to be packed in "lift vans" which are unit loads specially built for the purpose. They are generally made of wood, lined with waterproof material on all sides and additional metallic proofing on the roof to prevent damage by rain and sun. These units are made to be handled by forklift trucks and packed in ISO 20 foot containers.

Preservation against corrosion

Machinery when being packed for export by sea has to be preserved against humidity and corrosion. All the open parts are chemically treated and sometimes greased. The best preservation is to vacuum-seal the machine. The machine is covered by high density polythene which is draped aver the unit and heat-sealed. A vacuum pump then draws the air out of the polythene and the machine is preserved for as long as one year under vacuum. In lift vans and other packaging, silica gel in sufficient quantity is used, depending on the volume of the package.

Special cargo

There are also various other types of packages designed for special commodities moving by different forms of transport. For example, there are special types of packages for air shipments of commodities like fresh vegetables, meat etc. Again the unit load device (ULD) system adopted for air transport includes containers of metal and fibre-glass as well as lightweight pallets. In regard to shipments of ready-made clothes, the latest development, garments on hangers (GOH), is that

they are carried on hangers inside containers for delivery in the same condition as they left to the consignees' premises or to the department stores at their destination.

Special cargoes fall into the following categories:

(a) Bulk commodities - heavy equipment, machinery, etc.

Bulk commodities like ore and food grains, heavy equipment and machinery, locomotives and structures, do not require packing. They require suitable vessels with suitable handling gear and the like.

(b) Goods of high value

Goods of high value such as gold and platinum in all forms, coins, jewellery, live animals, legal banknotes, securities, at present are mostly moved by air. They need special care and protection. Direct delivery to the vessel and direct collection upon arrival of the vessel is advisable.

(c) Perishables and refrigerated cargo

Perishables and refrigerated cargo like fruits, fresh vegetables, cheese and meat, are usually carried in suitable ventilated packages in temperature-controlled holds or in thermal containers. Loading or unloading operations in respect of such cargoes have to be carried out quickly or on a priority basis when the vessel calls at the port, and this is an aspect to which freight forwarders need to pay special attention.

(d) Live animals

The carriage of live animals requires special arrangements, such as the erection of cages, the provision of necessary attendants as well as the right type and amount of animal food. Possible quarantine regulations in the countries of origin and destination must be taken into consideration.

(e) Dangerous/Hazardous cargo

This kind of cargo requires special packing, marking and labelling, which is a task undertaken by the shippers themselves. There is a separate section on the carriage of dangerous goods later in this manual.

Packing principles relating to cargo in containers

The principles below are applicable to cargo stowage in containers carried by sea, air, road or rail. This topic will be further discussed and illustrated in the relevant modules on the carriage of goods by sea, by air and by road and rail.

There are a number of basic principles applicable to the stowage of ALL cargo into containers. The maxim which summarises this set of principles is: safe container transport depends chiefly on a correct and immovable stow and an even weight distribution.

Either the container must be stowed tightly so that lateral and longitudinal movement of the cargo within it is impossible;

or else the cargo must be effectively restrained.

Tight stowage

This can be achieved by making the shape and the dimensions of the package an optimum module of the container or making the base of a unit load a module of the container.

Restraint

It is always necessary to restrain the cargo for one or more of the following reasons:

To prevent. collapse of the stow while packing, unpacking, or during transit (e.g., rolls of linoleum on end);

To stop any movement during transit of part-loads or of single heavy items (e.g., large pieces of machinery) - the heavier the item the more damage it will do if allowed to move; and

To prevent the "face" of the stow collapsing and leaning against the container doors to fall out when the doors are opened at the final destination or for customs inspection.

Cartons strapped on pallet

Methods of securing cargo

The more common methods of securing cargo are:

Shoring - bars, struts and spars located in the cargo voids to keep the cargo pressed against the walls or other cargo.

Lashing - ropes, wire, chains, strapping or netting secured to proper anchoring points and tensioned against the cargo.

Wedging - wooden distance pieces, pads of synthetic material, inflatable dunnage to fill voids in the cargo and keep it immobile against the container walls.

Locking - cargo built up to give a three-dimensional brick wall effect.

Aids to good securing

There is no simple formula to follow when securing cargo. Each stow must be treated on its own merits - the type of cargo, the way it is stowed, the equipment available, or the permanent fittings in the container. But the following points should be borne in mind when applying restraint:

Always use the built-in securing points which are provided. For obvious reasons comply with the safe loading limitation on the securing points.

Any timber used - i.e., dunnage or filler pieces - should be dry. It may also have to comply with certain quarantine regulations in force.

If nails have to be used to secure cargo to a wooden floor, they should only penetrate about two-thirds the thickness of the floor to achieve adequate grip without total penetration. Holes must not be drilled in walls or floor. Never use nails in a reefer container (a refrigerated container).

Any shoring which presses against the container wall should have extra timber laid longitudinally between the wall and point of support to spread the weight over two or more side posts.

Useful filler pieces for wedging or preventing rubbing, sometimes called chafe, are old tyres, paper pads softened by soaking (macerated) or, for light packages, rolled-up cardboard.

Unless an identical stow is anticipated on the return journey (known as a closed circuit operation) it is best if, when the lashing equipment is chosen, it is considered re-usable.

How to restrain certain types of cargo

Top-heavy articles should be wedged, shored and lashed to prevent toppling.

Heavy weights should be secured to stout ring-bolts (sited in the container floor and side walls) and/or be shored with timber. They should be chained or wired with bottle-screws (e.g., 1/2 in chain; 11/4 inch bottle-screws; three ton “D” shackles are adequate for lashing cargo up to 18 tons in weight).

Resilient loads can cause lashings to slacken - this may sometimes be overcome by introducing elasticity (e.g. rubber rope) into the lashing pattern.

No securing of pallets is necessary (provided the load is properly secured to the pallet) if the distance between pallets and container walls is 4in (100mm) or less. Pallets must not be allowed any longitudinal movement. If it is necessary to secure them, stow the pallets against the container walls and wedge wood blocks between the pallets. It may be necessary to insert sheets of board between the pallet loads to protect them against chafing and prevent bags, cartons; etc., interweaving and jamming the stowage.

Stowage precautions

In the majority of cases, there is a space (1" to 24") left between the face of the cargo and the container doors. It is important that the cargo does not collapse into this space. It can be prevented in a variety of ways, such as:

(a) Using suitably positioned lashing points with wire, rope, strapping, etc., woven across

(b) Inserting a simple wooden gate for the wider gaps and heavier cargo

(c) Providing filler pieces i.e., macerated (water-softened) paper pads, wood-wool pads made of fine shavings and used for packing, etc., for narrower gaps and lighter cargoes (like cartons of biscuits).

It is also important to ensure that the cargo does not fall out when the container doors are opened. This is particularly relevant to a container which has been completely packed (as with cartons or sacks). Although this can sometimes be achieved by interlocking tiers of packages, it is better to use the fixing points located in the door posts of general cargo container. Nylon strapping in polypropylene cord or wire (1/4" diameter or less) threaded through these points forms an effective barrier.

Other stowage precautions to be taken are:

Securing the goods in their packages and making the pack itself as full as possible so as to resist external pressures.

Making packages sufficiently rigid to withstand the weight imposed upon them when stacked to a minimum height of 8ft.

Making sure, if more than one type of cargo is stowed in a container, that they are compatible and cannot cause contamination or become contaminated.

Placing heavy items and liquids at the bottom, with light and dry items on the top.

Within practical physical limitations of handling, the unit package should be as large as possible, since this can reduce costs by up to 20 percent and increase the efficiency in volume by up to 10 percent.

Where relevant, stowing should be carried out in a sequence which will permit rapid checking and storage operations during and after unloading. Should the consignment include cargo subject to customs pre-entry procedures, customs examination would be made easier and unloading avoided if the cargo were stowed at the end of the container by the door.

One should try to arrange for any unavoidable gap in the stowage to be along the centre line of the container and not at the sides. It is much easier and cheaper to restrain the shifting of cargo in this way.

A lighted cigarette end can destroy the contents of a container and even endanger the ship. When stowing a container the rule should therefore be NO SMOKING.

Load factors

Heavy loads must be assessed according to their shape, dimension and weight. How-ever, as a guide, the weight or loads should be distributed over the container floor by means of suitable bearers or dunnage as follows:

(a) Width: distribution should be over the entire width of the container;

(b) Length: each ton weight of cargo should be spread over at least two floor members, which run transversely under the container floor at 1 foot centres (e.g., a 13 ton integral load would require to be distributed over 14 floor members i.e., 14 foot run of container floor).

The total load should be distributed as evenly as possible, but in certain circumstances the closed end half of the container can carry more than 65 per cent, or conversely the door end half more than 60 per cent, of the total load.