Informative Material 3 - Cargo Transport Unit (CTU) types

 This informative material provides detailed information on the types of CTU available with the aim of providing packers and shippers with the best possible independent advice.

1 ISO Containers

1.1 Containers – General

1.1.1 A container^footnote (freight container) is an article of transport equipment which is:

• .1 of a permanent character and accordingly strong enough to be suitable for repeated use;

• .2 specially designed to facilitate the carriage of goods by one or more modes of transport, without intermediate reloading;

• .3 fitted with devices permitting its ready handling, particularly its transfer from one mode of transport to another;

• .4 so designed as to be easy to pack and unpack; and

• .5 having an internal volume of at least 1 m³ (35.3 ft³).

1.1.2 A container is further defined by the CSC^footnote:

• .1 designed to be secured and / or readily handled, having corner fittings for these purposes; and

• .2 of a size such that the area enclosed by the four outer bottom corners is either:

  • .1 at least 14 m² (150 ft²); or

  • .2 at least 7 m² (75 ft²), if it is fitted with top corner fittings.

1.1.3 ISO container dimensions:

1.1.4 In addition to the standard lengths there are regional / domestic variations, which include 48–foot, 53–foot and longer.

1.1.5 The standard width is 8 ft (2,438 mm), with regional variations of 8ft 6in (United States) and 2.5 m (Europe).

1.1.6 The ISO standard heights are half height (4 ft 3 in / 1,295 mm), 8 ft (2,438 mm), 8 ft 6 in (2,591 mm) and 9 ft 6 in (2,896 mm).

1.1.6.1 There are very few 8–foot high containers left in circulation.

1.1.6.2 Practically all 20–foot long containers are 8 ft 6 in high.

1.1.6.3 Practically all 45–foot long containers are 9 ft 6 in high.

1.1.6.4 Regional heights of 9 ft, 10 ft and 3 m can be found for specific cargoes.

1.1.7 Carrying capacity of containers

1.1.7.1 When considering the carrying capacity of containers in terms of mass, three values should be considered:

• .1 Rating (R) or maximum gross mass (MGM). These values refer to the maximum permissible gross mass of the container for which it is designed;

• .2 Tare mass (T) refers to the mass of the container in an empty condition; and

• .3 Maximum payload (P) can be calculated by subtracting the tare from the rating / maximum gross mass (P = R – T) and refers to the maximum permissible mass of the cargo carried in the container including the mass of all securing materials and dunnage.

1.1.7.2 Under ISO standards^footnote all container types and lengths except 10-foot have a maximum rating of 30,480 kg. However, 20-foot, 40-foot and 45-foot long box type containers may be rated at 32,500 kg or 34,000 kg. Platform based containers, including flatracks may be rated up to 55,500 kg. Special containers or those manufactured to previous versions of the standard may have a lesser rating.

1.1.7.3 When planning, the packer may know only the mass of all packages and cargo items. An estimate of the mass of securing materials and dunnage should be made. These values should be added to the tare of the container, which varies from 2,200 kg for a 20-foot general purpose containers to 5,300 kg for a 40–foot folding flatrack. The sum of these three elements produces an estimated gross mass for the container. If this value exceeds 30,480 kg then the packer should contact the CTU operator to see if there are containers with higher ratings available. This estimated gross mass should not be used when providing the verified gross mass of the CTU after packing. For more information concerning verification of the gross mass of containers in international transport, including sea voyage see the Guidelines regarding the verified gross mass of a container carrying cargo (MSC.1/Circ.1475).

1.1.7.4 Consideration should be given to local or national road and rail regulations which may limit the permissible gross mass of the packed container.

1.1.8 Floor strengths

1.1.8.1 Floors on freight containers according to the CSC are required to withstand an axle load of 5,460 kg or 2,730 kg per wheel. This value depends on the diameter and width of the wheel and the length of the axle. To achieve this value the wheels are arranged so that all points of contact between each wheel and a flat continuous surface lie within a rectangular envelope measuring 185 mm (in a direction parallel to the axle of the wheel) by 100 mm and that each wheel makes physical contact over an area within this envelope of not more than 142 cm². The wheel width should be nominally 180 mm and the wheel centres should be nominally 760 mm. Using a counterbalance fork lift truck with a front axle in line with these dimensions will permit the movement of 2,000 to 2,500 kg packages.

1.1.8.2 Axle loads may be increased if the wheel diameter or width is increased and the contact area is greater than 142 cm². Conversely, fork trucks with smaller diameter wheels will not be able to move similar mass packages. The CTU operator may be able to provide more precise information.

1.1.9 Fork-lift pockets:

• .1 may be provided on 10-foot and 20-foot containers, but are not generally fitted on 30-foot and longer containers;

• .2 twenty-foot containers are generally fitted with fork-lift pockets with centres of 2,050 mm ±50 mm, which may be used for lifting full containers. Some 20-foot containers may have a second set at 900 mm centres, which should only be used for lifting containers when they are empty. However, this design feature is now almost extinct;

• .3 according to the ISO standard fork lift pockets may not be fitted on tank containers; and

• .4 when fitted on 30–foot and longer containers, fork-lift pockets should only be used for the lifting of empty containers.

1.2 General cargo containers for general purpose (standard ISO 1496, part 1)

Containers built to this international standard include:

• .1 dry freight (box);

• .2 dry freight with bulk capabilities;

• .3 ventilated;

• .4 open top;

• .5 open side; and

• .6 named cargo.

1.2.1 Dry freight containers

1.2.1.1 A general purpose container (also known as a GP or dry van) is a container which is totally enclosed and weather–proof. It generally will have a corten steel frame with a rigid roof, rigid side walls, rigid end walls at least one of which is equipped with doors, and a floor. It is intended to be suitable for the transport of cargo in the greatest possible variety.

1.2.1.2 It is not intended for the carriage of a particular category of cargo, such as cargo requiring temperature control, a liquid or gas cargo, dry solids in bulk, cars or livestock or for use in air mode transport.

1.2.1.3 The GP container is by far the largest container type in the intermodal fleet comprising about 90% of the ISO series I (maritime) fleet. The 20ft x 8ft 6in GP container is the largest single container type forming just under half of the GP fleet and about 40% of all container types and sizes.

1.2.1.4 Dimensions and volume:

• .1 there are very few 20-foot long x 9ft 6in high GP containers;

• .2 there are very few 30-foot long GP containers, this length can be considered as obsolete and not available; and

• .3 there are very few 45-foot long GP container that are not 9ft 6in high. GP containers with lower heights can be considered as unavailable.

• .4 minimum internal dimensions and volume:

• Figure 3.5 – Table of internal dimensions

• .5 minimum door openings:

  • – 9 ft 6 in high – 2,566 mm high x 2,286 mm wide;

  • – 8 ft 6 in high – 2,261 mm high x 2,286 mm wide; and

  • – 8 ft high – 2,134 x 2,286 mm wide.

• .6 load distribution and planning guide:

  Loads should be evenly distributed across the flooring (see table below). Where the mass of the cargo exceeds either the mass per linear m or per m², the packer should contact the CTU operator for additional advice on concentrated loads.

1.2.1.5 Strengths:

• .1 wall strengths:

  • - side walls – 0.6P evenly distributed over the entire side wall; and

  • - front and rear walls – 0.4P evenly distributed over the entire wall.

  • where P = payload of container; and

  • Payload is defined as maximum gross mass minus tare mass.

• Walls are tested to withstand the above load so that there is no or limited plastic (permanent) deformation. Walls that are tested and found to have a greater plastic deformation will be down rated and this will be marked on the CSC Safety Approval Plate (for more information see the CTU Code, annex 4). Line 7 and/or 8 will be marked with end wall and side wall strength respectively, if it is lesser or greater than the standard load.

• .2 cargo securing systems (if provided):

  • - anchor points are securing devices located in the base structure of the container;

  • - lashing points are securing devices located in any part of the container other than their base structure;

  • - they are either fixed, hinged or sliding eyes, rings or bars;

    Figure 3.7 – Table of lashings in ISO container

  • - each anchor point should be designed and installed to provide a minimum rated load of 1,000 kg applied in any direction. Many containers have anchor points with a rating of 2,000 kg; and

  • - each lashing point should be designed and installed to provide a minimum rated load of 500 kg applied in any direction.

1.2.1.6 Typical cargoes:

• .1 the 20–foot long GP container provides the most flexible of all the container types and sizes as it is capable of carrying denser materials and is often used to carry granite, slate and marble blocks;

• .2 the GP container is used for such cargoes as dairy and other "clean" products which require the interior to be "as new" without corrosion and flaking paint. At the other end of the spectrum, the GP container may be used for corrosive materials, such as wet salted hides. It is important that consignors advise the container supplier of the cargo prior to its delivery so that the correct standard of container can be delivered;

• .3 packages can be loaded by hand and stacked across the container, lifted in using a counterbalance or pallet truck, or slid in on skids or slip sheets. When loading using a counterbalance truck, it is important that the axle loads do not exceed the maximum permitted and that the cargo is distributed evenly;

• Figure 3.8 – Hand stacking

  Figure 3.9 – Using fork truck

  Figure 3.10 – Unit load packing

• .4 GP containers are also used to transport cars and small vans either driven and secured to the floor, or secured to specialist racking that can be fitted and removed from the container without any modifications; and

• Figure 3.11 – Individual cars

  Figure 3.12 – Car racks

  Figure 3.13 – Solid bulk

  Figure 3.14 – Bulk liquid

• .5 the GP container is also becoming a major transporter of bulk powders, granules and liquids, within dry liner bags or flexitanks.

1.2.1.7 Variations:

• .1 there are a few variations to the basic GP container, some 40-foot GP containers are built with a door at each end. The example shown in figure 3.15 shows the doors above the gooseneck tunnel and fork pockets for handling when empty; and

• Figure 3.15 – 40–foot 8ft 6in high double ended container

  Figure 3.16 – With doors open

• .2 another variant to the general purpose container is the pallet–wide container. These units have end frames that comply with the requirements of the series-1 ISO freight container, but can accommodate two 1,200 mm wide pallets across the width of the container. This is achieved through a design where the side walls are thinner and moved outside of the ISO envelope.

  Pallet-wide containers may not be fitted with anchor points and only have a limited number of lashing points.

1.2.2 Dry freight with bulk capabilities (see also paragraph 1.5.4)

1.2.2.1 These are dry freight containers fitted with loading hatches in the roof and/or discharge hatches in the end walls.

1.2.2.2 They have the same physical and strength characteristics of the dry freight container.

1.2.2.3 The lashing points along the roof may be fitted with hooks that may only be used to support the bulk liner bag.

1.2.3 Closed vented and ventilated containers

1.2.3.1 A ventilated container is a closed type of container similar to a general purpose container, but designed to allow air exchange between its interior and the outside atmosphere. It will be totally enclosed and weatherproof, having a rigid roof, rigid side walls, rigid end walls and a floor, at least one of its end walls equipped with doors and that has devices for ventilation, either natural or mechanical (forced).

1.2.3.2 Vented containers are containers that have passive vents at the upper part of their cargo space. While most containers built now are fitted with two or more vents fitted in the front or side walls, ventilated containers are containers which have a ventilating system designed to accelerate and increase the natural convection of the atmosphere within the container as uniformly as possible, either by non-mechanical vents at both the upper and lower parts of their cargo space, or by internal or external mechanical means.

1.2.3.3 Dimensions and volume

All ventilated containers are 20-foot long and 8 ft 6 in high.

1.2.3.4 Minimum internal dimensions and volume

Similar to the 20-foot GP Container.

1.2.3.5 Minimum door openings

Similar to the 8 ft 6 in high GP containers.

1.2.3.6 load distribution and planning guide

As GP container.

1.2.3.7 Strengths

Similar to the GP container.

1.2.3.8 Typical cargoes

Ventilated containers were developed to carry green coffee beans and other agricultural products. Produce such as melons, oranges, potatoes, sweet potatoes, yams and onions are sometimes carried in ventilated containers.

1.2.3.9 Variations

Most ventilated containers have ventilation grills built into the top and bottom side rails and the front top rail and bottom sill. To further improve the movement of air through the container an electrical fan can be mounted in the door end and connected up to shore and ships' supply. After the cargo has been delivered the fan can be removed and the fan hatch closed so that the container can be used as a GP container. These units are referred to as Fantainers.

1.2.4 Open top containers

1.2.4.1 An open top container is similar to a general purpose container in all respects except that it has no permanent rigid roof. It may have a flexible and movable or removable cover, e.g. of canvas, plastic or reinforced plastic material often referred to as a Tarpaulin, "tarp" or "Tilt". The cover is normally supported on movable or removable roof bows. In some cases the removable roof is fabricated from steel that can be fitted to lift off from the top of the container. Containers thus built are known as 'solid top' containers.

1.2.4.2 The open top container is designed to operate with the tarpaulin or hard top fitted or not fitted, therefore to withstand the loads exerted onto the side walls the top side rails are substantially larger than those of a GP container. For the traditional open top container, the top side rail also has to accommodate receptacles for the roof bows and loops for attaching the tarpaulin. It is essential that the tarpaulin is the correct design and the eyelets on the tarpaulin match the eyes on the top side rail, front and back rails and around the corner fittings to ensure the best weather tightness and to permit the TIR wire to be threaded through all of them to maximize security.

1.2.4.3 The open top container was designed for two categories of cargo, those that are too heavy or difficult to load by conventional methods through the doors, or that are too tall for a standard GP container. The hard top, open top container caters for the former but due to the rigid roof, transporting tall cargoes may present problems with moving the roof to the destination.

1.2.4.4 The other feature of the open top container is the ability to pack tall items into the container through the doors, as the header (transverse top rail above the doors) is generally movable or removable (known as ‘swing header’). The swinging header either forms a trough into which the tarpaulin is attached or the tarpaulin folds over the front face of the header to prevent water runoff from entering the container. The header is held in place by hinges at each end adjacent to the corner fittings, and each hinge has a removable pin so that the header can be swung out of the way. However, it is advisable to remove both pins and lift the header down using a fork truck rather than leaving the header unsupported at one end.

1.2.4.5 Open tops are generally 20–foot or 40–foot long and 8ft 6in high. There are a few 9 ft 6 in high to cater for some cargoes and which will enable standard tarpaulins or hard tops to be used.

1.2.4.6 Dimensions and volume

With the exception of the removable tarpaulin, roof, the dimensions are generally in line with the GP container.

1.2.4.7 Minimum internal dimensions and volume

Similar to the GP Container.

1.2.4.8 Minimum door openings

Similar to the 8 ft 6 in high GP containers.

1.2.4.9 Load distribution and planning guide

As GP container.

1.2.4.10 Strengths

Similar to the GP container.

1.2.4.11 Typical cargoes

Open top containers carry a variety of tall and heavy, generally project type cargo. Regular cargoes include glass sheets mounted on special A frames often lifted in through the roof and covered using an over height tarpaulin, large diameter tyres for mine vehicles and scrap steel.

1.2.4.12 Variations

There are a few variations from the standard tarpaulin covered open top container. Many designs have been developed to ease the fitting and removal of the tarpaulin roof and roof bows. These include sliding tarpaulins which fold towards the front of the container and captive roof bows that lift out on one side and hang from a bar on the other, thus reducing the risk of loss when an over height cargo is carried.

Hard open top containers have been adapted to carry large steel coils or long bars^footnote. These specialist open top containers may have higher maximum gross mass values.

1.2.5 Open side containers

1.2.5.1 The open side container was introduced into the maritime fleet as a GP container variation and as an alternative to the standard curtain sided trailer used in road transport. Original designs had a curtain on one or both sides, a rigid roof and rear doors. Without side walls the base structure had to be self-supporting; therefore required to be more substantial than the GP floor to achieve the same floor strength and load carrying capabilities. In this form the open side container took on some of the characteristics of the platform based container with complete superstructure^footnote. As a consequence of the self-supporting floor the tare generally increased.

1.2.5.2 To improve security some manufacturers offer solid doors in place of the curtains offering doors to one or both sides, with no rear doors, with doors at the rear of the container and with door at the front of the container, offering one, two, three and four side access.

1.2.5.3 The open side container is a specialist item of transport equipment, although the 45-foot long and 2.5 m wide pallet-wide curtain side variation is becoming more popular in Europe. However, the full length side door 20-foot long unit is also becoming popular as a regional variation in other parts of the world.

1.2.5.4 Dimensions

As GP container.

1.2.5.5 Minimum internal dimensions and volume

Similar to the GP Container although the internal height is reduced to approximately 2.4 m.

1.2.5.6 Minimum door openings

Reduced height to match the reduction of internal height.

1.2.5.7 load distribution and planning guide

Approximately 10% lower than GP container.

1.2.5.8 Strengths

• .1 Wall strengths

  • - side walls – Refer to CSC safety approval plate. Open side containers with tarpaulin sides may have little (0.3P) or no strength; however, some are fitted with removable gates or rigid side doors, which may achieve full side wall strength (0.6P);

  • - front and rear walls – 0.4P evenly distributed over the entire wall.

• .2 Cargo securing systems

  • - Anchor points may be recessed onto the floor but may be rated lower than standard GP containers. Please check with CTU operator.

1.2.5.9 Typical cargoes

Open side containers are designed to carry packages that can be loaded using a fork truck, typically pallets and long packages.

1.2.5.10 Variations

Variations are available for specific trades, such as an open side container with a built in half height deck.

Other variations include internal full length or partial length central walls to provide support to the base structure and assist with pallet placement.

1.2.6 Named cargo containers

1.2.6.1 Named cargo types of containers are containers built in general accordance with ISO standards either solely or principally for the carriage of named cargo such as cars or livestock.

1.2.6.2 One particular container type is the Power Pack, which can be used to supply 3 phase electricity to reefer containers when carried by rail, to supplement or provide power on board during sea transport or to supplement or provide power in terminals.

1.2.6.3 A power pack would typically consist of a diesel generator set (250kW-00kW) with up to 64 sockets. They can include built in fuel tanks for the generator or use a 20-foot tank container carried in an adjacent slot.

1.2.6.4 Externally it will be the same as a 20–foot GP container.

1.3 Thermal containers (ISO 1496, part 2)

1.3.1 A thermal container is a container that has insulating walls, doors, floor and roof. Over the years the thermal container has evolved from a simple insulated container with no device for cooling and/or heating to a refrigerated and insulated container cooled using expendable refrigerants such as ice, "dry ice" (solid carbon dioxide), or liquefied gasses, but again with no external power or fuel supply.

1.3.2 A variation of this design is the porthole container, which is refrigerated by cold air from an external source introduced through a porthole. This design is being phased out.

1.3.3 The most common variant of the thermal container is the integrated refrigerated container, often referred to as the "Reefer". The internal temperature is controlled by a refrigerating appliance such as a mechanical compressor unit or an absorption unit. The Reefer consists of a container body with insulated walls, sides and roof plus insulated doors at the rear. The front of the container body is left open for mounting the refrigeration machinery.

1.3.4 Refrigeration machinery is generally powered by 3–phase electricity supplied by a trailing lead that can be connected to sockets on board ship or in the terminal. Where there is insufficient power capacity freestanding "power packs" can be used. Power packs can also be used to supply power to a number of Reefers being carried by rail. When the Reefer is to be carried by road, unless the journey is relatively short, most cargo owners will require the reefer to be running and for this nose mounted or trailer mounted generator sets are available.

1.3.5 There are some refrigerated containers fitted with integrated power packs, fitted with a diesel generator negating the need for a standalone generator. However, the volume of diesel that these containers can carry is limited and needs to be monitored regularly. These are very specialist pieces of equipment and used on closed loop trades, and are not generally available.

1.3.6 Where Reefers are used to transport chilled or frozen cargo by road, some owners have integral refrigerated containers with the machinery including a diesel generator.

1.3.7 The refrigeration machinery works by passing air through the container from top to bottom. In general, the "warm" air is drawn off from the inside of the container, cooled in the refrigeration unit and then blown back in the container as cold air along the "T" floor grating.

1.3.8 To ensure adequate circulation of the cold air, the floor is provided with "T" section gratings. Pallets form an additional space between container floor and cargo, so also forming a satisfactory air flow channel.

1.3.9 The last form of thermal containers are those that can operate within areas with low or very low ambient temperatures, often servicing areas of extreme cold such as Alaska. The design of these can be based on a thermal as described above except with a heating device, or by the use of a general purpose container fitted with internal insulation and heating filaments.

1.3.10 The mix of Reefer units has changed over the last few years, new purchases of 20-foot and 40-foot long 8ft 6in high Reefer containers has not matched the number of sales of old units, therefore, the fleet size is shrinking. On the other hand the 40-foot 9ft 6in high Reefers have been growing.

1.3.11 Dimensions and volume

Externally the same as 20-foot, 40-foot and 45-foot GP containers.

1.3.12 Typical internal dimensions

The dimensions shown above are typical for a steel reefer unit, however, packers are advised to contact the CTU operator for exact internal dimensions.

1.3.13 Door openings

Each thermal container should be provided with a door opening at least at one end.

All door openings and end openings should be as large as possible.

The usable width should correspond with the appropriate minimum internal dimension given in figure 3.35.

The usable height should be as close as practicable to the appropriate minimum internal dimension given in figure 3.35.

1.3.14 Load distribution and planning guide

1.3.14.1 Strengths

• .1 Wall strengths

  • - side walls – 0.6P evenly distributed over the entire side wall; and

  • - front and rear walls – 0.4P evenly distributed over the entire wall.

  • Walls are tested to withstand the above load so that there is no or limited plastic (permanent) deformation. Walls that are tested and found to have a greater plastic deformation will be down rated and this will be marked on the CSC safety approval plate. Line 7 and/or 8 will be marked with end wall and side wall strength, respectively, if it is lesser or greater than the standard load.

• .2 Floor

  • - mechanical handling equipment with narrow wheels may damage the "T" section flooring, and wherever possible the width of the wheels should be greater than twice the distance between centre lines of "T" sections.

• .3 Cargo securing systems

  • - there is no requirement for either anchor or lashing points within the ISO standard and very few thermal containers will be fitted with them.

1.3.15 Typical cargoes

1.3.15.1 Reefer containers were developed to transport perishable cargoes. A "perishable" may be described as something that is easily damaged or destroyed. Without careful treatment, the time taken to deteriorate to a condition which will either reduce the value or render it unsaleable (shelf life) may become unacceptably short.

1.3.15.2 Careful consideration of the factors affecting the "shelf life" of perishables should be made and applied during their transport.

1.3.15.3 Perishables include frozen produce, meats, seafood, dairy products, fruit and vegetables, horticultural products such as flowering bulbs and fresh flowers plus chemical compounds and photographic materials.

1.3.16 Variations

1.3.16.1 Reefers can be fitted with a number of refrigeration units from different suppliers and those can also provide controlled atmosphere provisions.

1.3.16.2 Structurally, special designs have been produced for rail based equipment, 48, 53 and 58-foot long and over wide units (2.6 m).

1.4 Tank containers for liquids, gases and pressurized dry bulk (ISO 1496 part 3).

1.4.1 A tank container comprises two basic elements, the tank (barrel) or tanks and the framework and complies with the requirements of ISO 1496-3.^footnote

1.4.2 In the freight container industry, the term "tank" or "tank container" usually refers to a 20-foot tank container consisting of a stainless steel pressure vessel supported and protected within a steel frame.

1.4.3 The tank container industry has developed a number of containment designs that carry all sorts of bulk liquids, powders, granules and liquefied gases; however, it is important to differentiate bulk liquid and pressurized dry bulk tank containers from non-pressured dry bulk containers that may look very similar to a tank container.

1.4.4 The majority of the maritime tank container fleet is 20-foot long and 8ft 6in high. The split between the major tank designs is not known although the most current production is generally collar tanks. All the tank designs fulfil the requirements of the ISO standards.

1.4.5 Designs

There are three main structural types of tank container used in the international transport of bulk liquids and liquefied gases – beam, frame and collar. All designs have been manufactured since the 1970s.

All designs can be top lifted, must be stackable and the pressure vessel/barrel as well as all valves and other service equipment must remain within the ISO envelope, i.e. no part can protrude past the outer faces of the corner fittings.

1.4.5.1 Frame Tanks

1.4.5.1.1 This design consists of two end frames separated by two main beams at low level forming a support frame. Since there is more material in the support frame than with other designs the tare is relatively high. Often the lower beams are "castellated" a method of lightening the main beams by cutting holes to reduce the tare and therefore to increase the payload. Top rails are often light weight, play little part in the overall structural strength and often there to support the walkway. Top rails in these cases are not usually attached to the pressure vessel. In some designs these rails can be attached using mechanical fasteners (nuts and bolts) but are more often welded in place.

1.4.5.1.2 The pressure vessel is supported from the main beams generally on saddle supports which are in the form of bolted clamps or welded interface supports.

1.4.5.1.3 The two pictures above show a 20,000 litre (Figure 3.36) and a 25,000 litre design (Figure 3.37). Both are insulated.

1.4.5.2 Beam Tanks

1.4.5.2.1 A beam tank is supported by a series of bearers attached to the end frames which interface with the pressure vessel at various locations on the periphery of the barrel. The interface consists of plates that are welded to the pressure vessel and the bearers to ensure load sharing and a "barrier" between carbon steel and stainless steel components.

1.4.5.2.2 The example shown in Figure 3.38 is a typical beam tank with no top or bottom side rails. The tank is attached using four beams that connect at the four corner fittings of each end frame. The walkway is supported using brackets attached to the pressure vessel.

1.4.5.2.3 Figure 3.39 shows a different design where the attachment of the pressure vessel is made using fabricated brackets attached to the corner posts and the end frame corner braces. Top side rails are fitted to the top corner fittings.

1.4.5.2.4 The tank container is also uninsulated. Both examples show 17,500 litre low volume pressure vessels.

1.4.5.2.5 Figure 3.40 shows four 10-foot ISO International beam tanks, being carried as two 20-foot units. In this example, two 10-foot units are connected using approved horizontal interbox connectors and the design tested in that configuration. They can then be loaded, handled and stowed in the same way as any 20-foot ISO tank container.

1.4.5.3 Collar Tanks

1.4.5.3.1 The collar tank is probably the simplest of all the tank designs with a minimum of differing materials in contact with the pressure vessel. Attachment of the pressure vessel to the end frames is by means of a stainless steel collar, which is welded to the pressure vessel end dome at the edge (out–set) or to the crown of the domed ends of the pressure vessel (inset). The collar connects with the side posts, top and bottom rails and the diagonal braces via interface flanges.

1.4.5.3.2 The collar is continuous at the front/non-discharge end. At the rear of the tank container some collar tank designs have a break in the collar where the discharge valve is located.

1.4.5.3.3 Figure 3.41 shows an insulated 25,000 litre collar tank. Once insulated it is virtually impossible to distinguish between the inset and outset collar design.

1.4.6 Dimensions and volume

Practically all maritime tank containers are 20-foot long and 8ft 6in high although there are 30-foot and 40-foot versions.

1.4.7 Minimum internal dimensions and volume

Volumes vary from 9,000 to 27,000 litres.

1.4.8 Minimum door openings

No doors fitted.

1.4.9 Load distribution and planning guide

Tank containers should be filled to minimum of 80% of the total volume. The choice of tank capacity should be taken to achieve this. To accommodate most liquids the maximum gross mass for tank containers varies but is generally 34,000 kg or greater.

1.4.10 Typical cargoes

Tank containers can carry practically all liquids, non-regulated, i.e. orange juice, to dangerous goods.

1.4.11 Variations

Tank containers can be supplied uninsulated or insulated, with steam heating, with electrical heating, with refrigerant plants attached, with cooling tubes.

Additionally the tank can be partitioned into two or more discrete compartments or divided with baffle / surge plates.

1.5 Non-pressurized containers for dry bulk (ISO 1496 part 4)

1.5.1 Within this type of container, there are a number of variations available. The definition of a non–pressurized dry bulk container is:

• "Container for the transport of dry solids, capable of withstanding the loads resulting from filling, transport motions and discharging of non–packaged dry bulk solids, having filling and discharge apertures and fittings and complying with ISO 1496, part 4^footnote."

1.5.2 Within that standard two sub types are described:

• "Box type – dry bulk non-pressurized container for tipping discharge having a parallelepiped^footnotecargo space and a door opening at least at one end, which therefore may be used as a general purpose freight container."

• "Hopper type – dry bulk non-pressurized container for horizontal discharge having no door opening, which therefore may not be used as a general purpose freight container."

1.5.3 These are specialized items of equipment and are generally located near companies that are actively involved with the transport of bulk materials. There are a number of specialist companies who provide complete logistics services for bulk dry materials.

1.5.4 Box type

1.5.4.1 Box type bulk containers have the outwards appearance of the GP container with loading and or discharge hatches.

1.5.4.2 Loading hatches are generally round, 600 mm in diameter varying in number from one centrally up to six along the centre line.

1.5.4.3 Discharge hatches come in a number of forms:

• .1 Full width "letterbox" type either in the front wall or in the rear as part of the door structure or "cat flap" type hatches fitted into the rear doors;

• .2 In some box type dry bulk containers with full width discharge hatches in the rear (door) end, the hatch can be incorporated into the left hand door, as shown in Figure 3.42, or as shown in Figure 3.44, access is gained to the interior by a smaller right hand door only. Box type bulk containers with this design feature are not available for use as general purpose containers when not being used as bulk containers.

1.5.4.4 New type code designations are being introduced for all categories of dry bulk containers.

1.5.4.5 Dimensions and volume

The majority of bulk containers in Europe are 30-foot long and often 2.5 m wide and therefore should be considered as a swap body; however, they have the appearance of an ISO container and are often confused with them.

In other parts of the world the majority of bulk containers are 20-foot long although 40-foot and 45–foot containers have been built for transporting dry bulk materials and cellular friendly pallet–wide containers are also built to the standard ISO 1496, part 4, to increase the internal volume.

1.5.4.6 Minimum internal dimensions and volume

• - similar to the GP Container;

• - cellular friendly – 2,400 mm internal width.

1.5.4.7 Minimum door openings

For those units with doors, they are broadly similar to 8ft 6in and 9ft 6in high GP containers.

1.5.4.8 Load distribution and planning guide

Dry bulk containers are often built to meet the particular transport requirements of a customer or product. Maximum gross mass can be as high as 38 tonnes which requires specialist road vehicles and handling equipment, but generally the maximum gross mass is higher than for a similar sized GP container.

Thirty-foot dry bulk containers in use in Europe may also be manufactured with reduced stacking capabilities; therefore, are not suitable for stacking more than one fully laden container above it.

1.5.4.9 Strength and rating

• .1 Wall strengths

  • - side walls – 0.6P evenly distributed over the entire side wall

  • - front and rear walls:

  • 40-foot and 30-foot – 0.4P evenly distributed over the entire wall.

  • 20-foot and 10-foot – 0.6P evenly distributed over the entire wall.

• .2 Cargo securing systems

  • - there is no requirement for either anchor or lashing points within the ISO standard;

  • - containers without two opening doors and pallet-wide containers may not have anchor points and may only be fitted with liner support hooks.

1.5.4.10 Typical cargoes

These containers are suitable for all types of dry powder, granules and aggregate generally which are free flowing.

1.5.4.11 Variations

Dry bulk containers for aggregate are generally built with larger loading and/or discharge hatches. They may also be built without a solid top, so blending the dry bulk container with the open top container.

1.5.5 Hopper Type

1.5.5.1 Hopper type dry bulk containers are very specialist items of equipment and are generally built to meet the specific requirements of the cargo to be carried. An example of such a specialist item, shown in figure 3.46, is a 30-foot five compartment silo container with each compartment capable of handling about 6 m³ of product. When designing silo containers a number of characteristics need to be considered. Firstly the length; 30-foot is associated with European transport and is ideally suited to medium density powders and granules. For higher density cargoes and for deep sea trades, the 20-foot units would be appropriate. For low density cargoes the new internationally approved length of 45-foot is becoming popular. The material, shape and volume of the hopper and discharge will be dictated by the dry cargo being carried and its flowability. Lastly the loading and discharge capabilities will need to be designed to interface with the facilities at origin and destination.

1.5.5.2 In the example shown in figure 3.46, loading is achieved through the top loading hatches and the separate compartments ensure that the container can be evenly loaded and the cargo kept stable from longitudinal movement. Unloading can be either vertical discharge where the container is positioned above receiving hoppers set below the road surface/rail bed or from the rear by horizontal discharge to the rear mounted discharge pipe via an internal conveyor / screw. This type of container would not be tipped.

1.5.5.3 If the cargo is to be discharged vertically by gravity into ground level receiver hoppers then the freight container can either be lifted onto the discharge area or must be mounted on a special trailer/chassis that permits such discharge.

1.6 Platform and platform based containers (ISO 1496, part 5)

1.6.1 Platform based containers are specific–purpose containers that have no side walls, but have a base structure. The simplest version is the platform container which has no superstructure whatsoever but is the same length, width, strength requirement and handling and securing features as required for interchange of its size within the ISO series of containers. There are approximately 16,300 platform containers in the maritime fleet.

1.6.2 Since the platform container has no vertical superstructure, it is impossible to load one or more packages on it and then stack another container above it. To do this a platform based container with incomplete superstructure with vertical ends is required. The end structure can consist of posts, posts with transverse rails or complete end walls. The original designs for these were fitted with fixed end walls and were called flatracks.

1.6.3 The next design innovation was to build a platform based container with folding ends which could act as a platform when the end walls/posts were folded down or as a flatrack with the end walls erected.

1.6.4 Folding flatracks are now the major project transport equipment with about 151,000 containers in service in the maritime fleet. They can be readily sourced in most locations, although there are areas where concentrations are greater to meet local on-going demand.

1.6.5 Dimensions and volume

1.6.5.1 Platforms and fixed end flatracks are available in 20-foot and 40-foot lengths whereas folding flatracks are available in these two lengths plus a very limited number of 45-foot long containers.

1.6.5.2 Folded flatracks can be stacked using the integral interconnectors for empty transport, forming an 8ft 6in high pile. 20-foot folded flatracks are stacked in groups of 7 and 40-foot in stacks of 4.

1.6.6 Minimum internal dimensions and volume

1.6.6.1 Flatracks with end walls erected will have internal volume similar to the GP container, although the size of the corner posts will restrict the width at the ends. However, most flatracks are built with end walls that create an 8ft 6in high container so that the distance between the deck and the top of the posts are approximately 1,953 mm (6ft 5in).

1.6.6.2 Owners desiring to fit more or taller cargo "inside" the height of the flatrack walls have started to build some flatracks with higher end walls thus forming a 9ft 6in high container.

1.6.6.3 A progression from that is the flatrack with extendable posts that takes the overall height to 13 ft 6 in high.

1.6.7 Minimum door openings

No doors fitted.

1.6.8 Rating and load distribution

Flatrack maximum gross mass values have increased over the past years, rising from 30,480 kg to 45,000 kg and most 40-foot flatracks are now built to this rating. This means that payloads of approximately 40 tonnes evenly distributed over the deck and supported by the side rails can be lifted and transported by suitable modes. For concentrated loads contact the CTU operator.

1.6.9 Strength and rating

• .1 Wall strengths:

  • - side walls – There is no test for side walls; and

  • - front and rear walls: Where there is a solid end wall, it must be tested for 0.4P evenly distributed over the entire wall.

• .2 Floor strength:

  • - the flooring material is different from other ISO containers, however, the majority of the load is borne by the main side beams and not the flooring; and

  • - refer to the CTU operator for more information.

• .3 Cargo securing systems

  • - Anchor points are securing devices located in the base structure of the container.

  • - Lashing points are securing devices located in any part of the container other than their base structure.

  • Figure 3.53 – Table for lashings on a flatrack

  • - Each unit should be fitted with cargo–securing devices complying with the following requirements:

    • - The anchor points should be designed and installed along the perimeter of the container base structure in such a way as to provide a total minimum securing capability at least equivalent to:

      • - 0.6P transversally; and

      • - 0.4P longitudinal (for those containers having no end walls or end walls that are not capable of withstanding the full end wall test.

    • - Such securing capability can be reached either:

      • - by a combination of a minimum number of anchor points rated to an appropriate load; or

      • - a combination of a higher number of anchor points having a lower individual rated load.

    • - Each anchor point should be designed and installed to provide a minimum rated load of 3,000 kg applied in any direction.

    • - Each lashing point should be designed and installed to provide a minimum rated load of 1,000 kg applied in any direction.

1.6.10 Typical cargoes

The platform container and flatrack are used to transport out of gauge packages and items that need special handling. One of the most readily identifiable cargoes carried are road, farm and construction vehicles carried on flatracks or platforms because they are often over-height or width.

1.6.11 Variations

There are a number of variations available from specialist flatrack suppliers, when carrying, for example pipes, coil materials or cars. However, these are generally held for specific trades and are few in number.

2 European Swap Body

2.1 General

2.1.1 An item of transport equipment having a mechanical strength designed only for rail and road vehicle transport by land or by ferry within Europe and, therefore, not needing to fulfil the same requirements as series 1 ISO containers; having a width and/or a length exceeding those of series 1 ISO containers of equivalent basic size, for better utilisation of the dimensions specified for road traffic.

2.1.2 Swap bodies are generally 2.5 m or 2.55 m wide although thermal swap bodies can be up to 2.6 m wide.

2.1.3 Swap bodies generally fall into three length categories:

Class A: 12.19 (40 ft), 12.5, 13.6 or 13.712 m (45 ft) long

Class B: 30–foot long

Class C: 7.15, 7.45 or 7.8 m long. The most commonly used length in this class is 7.45 m.

2.1.4 Swap bodies are fixed and secured to the vehicles with the same devices as those of series 1 ISO containers: for this reason, such devices are fixed as specified in ISO 668 and ISO 1161, but owing to the size difference are not always located at the swap body corners.

2.1.5 Most swap bodies were originally designed for road and rail transport without the need for stacking and lifting achieved using grapple arms or lowering the swap body onto their own legs (Class C). Class A and B outwardly have the appearance of the ISO container and all sizes are now produced with the ability to top lift and to have limited stacking capability.

2.1.6 Stacking

2.1.6.1 All classes of swap body may be stacked if the design permits it and has been subjected to appropriate tests. Such swap bodies will be fitted top fittings. The external faces will be 2.438 m (8 ft) when measured across the unit and 2.259 m between aperture centres.

2.1.6.2 The placing of the top corner fittings is such that the swap body can be handled using standard ISO container handling equipment.

2.1.6.3 The stacking capability is generally well below that of the ISO container. Before stacking the swap body, the handler must check the stacking strength shown on the Safety Approval Plate (if fitted) or marks on the swap body to indicate its stacking capability, for example "2 high stacking only".

2.1.6.4 The top fittings will be placed as follows:

• - Class A swap bodies will have top fittings at the central 40–foot positions and at the corners;

• - Class B will have corner fittings only; and

• - Class C box type swap bodies will have corner fittings only. Swap tanks will have the top fittings directly above the lower (at 20–foot positions).

2.2 Dimensions and rating

2.2.1 Swap bodies of Class A (EN 452 and CEN / TS 14993)

2.2.2 Swap bodies – non stackable swap bodies of Class C

Figure 3.61 – Swap body Class C rating

2.3 Cargo securing devices

Cargo securing devices may be provided in swap bodies as optional features; however, for curtain sider swapbodies, cargo securing devices are mandatory.

Where fitted, cargo securing devices should meet the requirements of EN 12640 (Securing of cargo on road vehicles – Lashing points on commercial vehicles for goods transportation – minimum requirements and testing) 2.3.1 Lashing points should be designed so that they transmit the forces they receive into the structural elements of the vehicle. They should be fixed in the loading platform and in the vertical front end wall. In their position of rest they should not project above the horizontal level of the loading platform nor beyond the vertical surface of the front end wall into the loading space.

NOTE: The recesses in the loading platform required to accommodate the lashing points should be as small as possible.

2.3.1 Lashing points should be designed to accommodate lashing forces applied from any direction within the conical area determined as follows:

• .1 angle of inclination ß from 0° to 60°;

• .2 angle of rotation (α) from 0° to 180° for lashing points with a transverse distance from the side wall and the lashing points ≤ 50 mm; and

• .3 angle of rotation (α) from 0° to 360° for lashing points within a transverse distance from the side wall and the lashing points ≥ 50 mm but ≤ 250 mm.

2.3.2 Number and layout of the lashing points

2.3.2.1 Lashing points on the floor

The number of lashing points should be determined by the highest result of the following:

• .1 length of the loading platform;

• .2 maximum distance between lashing points; and

• .3 permissible tensile load.

2.3.2.2 Length of the loading platform

For vehicles with an effective cargo loading length greater than 2 200 mm there should be at least 6 lashing points, at least 3 on each side.

2.3.2.3 Maximum distance between lashing points

• .1 The lashing points are to be arranged in such a way that:
  • - with the exception of the area above the rear axle, the distance between two adjacent lashing points on one side should be not more than 1,200 mm. In the area above the rear axle the distance between two adjacent lashing points should be as close to 1,200 mm as practicable but in any case should not be more than 1,500 mm;

  • - the distance from front or rear end wall should not be greater than 500 mm;

  • - the distance from the side walls of the loading area should be as small as possible and in any case should not be greater than 250 mm.

  • Loading length (mm)	Number of pairs
    7,450	7
    7,820	7
    9,150 (30 ft)	8
    12,190	11
    12,500	11
    13,600	12
    13,719	12

    Figure 3.62 Number of lashings based on length

• .2 For vehicles with a maximum authorized total mass greater than 12 tonnes, the number of lashing points n should be calculated by use of the formula:
  • 

  • Where p is the inertial force in KN resulting from the maximum payload

  • Payload (kg)	Number of lashing points
    16,000	12
    32,500	24
    34,000	25

    Figure 3.63 – Number of lashing based on maximum net mass

2.3.2.4 Permissible tensile load

Permissible tensile load for lashing points – 20kN.

2.4 Strengths

2.4.1 End walls

For all designs – 0.4P.

2.4.2 Side walls

2.4.3 Floor strength

2.5 Swap body types

2.5.1 Box type swap body

The standard box type swap body will have a rigid roof, side walls and end walls, and a floor and with at least one of its end walls or side walls equipped with doors. There are a number of variations to the basic design that can include units fitted with roller shutter rear door, hinged or roller shutter side doors to one or both sides and garment carriers which are box type swap bodies with single or multiple vertical or horizontal tracks for holding transverse garment rails.

2.5.2 Open side swap body

The open side swap body has a number of different variations all designed to provide similar access to that of standard trailer bodies. Each variation will be an enclosed structure with rigid roof and end walls and a floor. The end walls may be fitted with doors.

• .1 Curtain side unit: swap body with movable or removable canvas or plastic material side walls normally supported on movable or removable roof bows.

• .2 Drop side swap bodies: swap bodies with folding or removable partial height side walls and movable or removable canvas or plastic material side walls above normally supported on movable or removable roof bows.

• .3 Tautliner: swap body with flexible, movable side walls (e.g. made of canvas or plastic material normally supported on movable webbing).

• .4 Gated tautliner – swap body fitted with a swinging gate at either end to provide top lift or stacking capability at the 20 or 40-foot positions. A flexible, movable side wall may be fitted between the gates or over the full length of the swap body.

• .5 Full length side door: swap body with full length folding doors to one or both sides.

2.5.3 Thermal swap body

A thermal swap body is a swap body that has insulating walls, doors, floor and roof. Thermal swap bodies may be: insulated – with no device for cooling and/or heating, refrigerated – using expendable refrigerants such as ice, "dry ice" (solid carbon dioxide), or liquefied gasses, and with no external power or fuel supply. Like the ISO container there are variants to this basic design such as the mechanically refrigerated swap reefer.

2.5.4 Tank Swap Bodies (Swap Tanks)

2.5.4.1 There are fewer design variations of swap tanks than for ISO tanks. The most important difference relates to their length, handling and stacking capabilities. All swap tanks have bottom fittings at the ISO 20-foot or 40-foot locations. Generally, the bottom fittings are wider than their ISO counterparts, this is so that the bottom aperture is in the correct ISO position/width while the outer face of the bottom fitting extends to the full width of the unit.

2.5.4.2 Approximately 85% of all swap tanks can be stacked and top lifted. However, the majority of filling and emptying facilities for tanks will leave the tank on its transport equipment thus negating the need for the stacking / lifting capability.

2.5.4.3 The swap tank should never be lifted from the side when loaded.

2.5.4.4 There are swap tanks which are not stackable or capable of being lifted using traditional spreaders. The design of these earlier models was similar to the frame tank with the pressure vessel being supported from the bottom side beams. Some non-stackable swap tanks are still built today to meet the particular needs of the industry, particularly intra-European.

2.5.4.5 A swap tank is a swap body that includes two basic elements, the tank or tanks, and the framework. Unlike the ISO tank container the tank barrel is not always fully enclosed by the frame work which may present a risk of damage.

2.5.5 Swap bulker

A swap bulker is a swap body that consists of a cargo carrying structure for the carriage of dry solids in bulk without packaging. It may be fitted with one or more round or rectangular loading hatches in the roof and "cat flap" or "letter box" discharge hatches in the rear and/or front ends. Identical in most ways to the ISO bulk container except that it may have reduced stacking capability. Often 30–foot long.

3 REGIONAL, DOMESTIC OR OFFSHORE CONTAINERS

3.1 Regional containers are intended for use within an economic or geographical region and where there are no international maritime legs or where the regional container is not expected to be lifted using standard container handling equipment.

3.2 Domestic or national containers are intended for use within the borders of a nation but may be transported on maritime legs between ports within the national borders.

3.3 Regional or domestic containers may appear to be similar to the ISO container, however, they may:

• .1 have a mechanical strength designed only for rail and road vehicle transport by land or by ferry, and therefore not needing to fulfil the same requirements as series 1 ISO containers;

• .2 can be of any width and/or length to suit national legislation for better utilisation of the dimensions specified for road traffic. In general they will be 2.5 or 2.6 m or 8 ft 6 in wide;

• .3 may have castings at least at each corner and suitable for top lifting;

• .4 may have corner castings that are the same width as the width of the container when measured across the unit to the external faces of the castings;

• .5 may be stacked; and

• .6 Domestic containers may be general cargo containers or specific cargo containers.

3.4 Offshore containers

3.4.1 Offshore containers are intended for use in the transport of goods or equipment handled in open seas to, from and between fixed and/or floating installations and ships. Offshore containers should comply with the provisions of the Guidelines for the approval of offshore containers handled in open seas (MSC/Circ.860), as may be amended.

3.4.2 The CSC does not necessarily apply to offshore containers that are handled in open seas. Offshore containers are subject to different design, handling and testing parameters as determined by the Administration. Nonetheless, offshore containers may be approved under the provisions of CSC provided the containers meet all the applicable provisions and requirements of the Convention, in order to undertake international maritime transport.

4 Roll Trailers

4.1 Roll trailers are exclusively used for the transport of goods in RO/RO ships and are loaded or unloaded and moved in port areas only. They present a rigid platform with strong securing points at the sides, and occasionally brackets for the attachment of cargo stanchions. The trailer rests on one or two sets of low solid rubber tyres at about one third of the length and on a solid socket at the other end. This end contains a recess for attaching a heavy adapter, the so–called gooseneck. This adapter has the kingpin for coupling the trailer to the fifth wheel of an articulated truck.

4.2 The packing of a roll trailer with cargo or cargo units must be planned and conducted under the conception that the cargo must be secured entirely by lashings (see CTU Code, annex 7, paragraph 4.3.2). However, roll trailers are available equipped with standardized locking devices for the securing of ISO containers and swap bodies.

5 Road Vehicles

5.1 Introduction

5.1.1 Vehicles with closed superstructures are the primary choice for cargo that is sensitive to rain, snow, dust, sunlight, theft and other consequences of easy access. Such closed superstructure may consist of a solid van body or a canvas covered framework of roof stanchions and longitudinal battens, occasionally reinforced by side and stern boards of moderate height. In nearly all cases these vehicles have a strong front wall integrated into the closed superstructure. Closed superstructures of road vehicles may be provided with arrangements for applying approved seals.

5.2 Road vehicle types

5.2.1 Flatbed – used for almost any kind of cargo, but goods need to be protected from the elements and theft.

5.2.2 Drop side – like a flatbed but with fold down partial height side and rear panels.

5.2.3 Tilt – like a flatbed, but with a removable PVC canopy.

5.2.4 Curtain-sider – this has a rigid roof and rear doors. The sides are fabric curtains that can be opened for easy loading.

5.2.5 Open top – similar to the box but with a removable canvas or netting top cover generally used for bulk cargoes. Canvas covered vehicles may be packed or unpacked through the rear doors as well as from the side(s). The side operation is accomplished by forklift trucks operating at the ground level. The option of loading or unloading via the top is limited to vehicles where the canvas structure can be shifted to one or both ends of the vehicle.

5.2.6 Box – a secure option for valuable goods. Solid van superstructures generally have two door wings at the end and will be packed or unpacked by forklift trucks suitable for moving packages inside a CTU.

5.2.7 Road train – a rigid vehicle at the front, which pulls a trailer behind it.

5.2.8 Low-loaders – often used for transporting heavy machinery and other outsize goods. Set low to the ground for easy loading.

5.2.9 Vans are frequently used to transport smaller cargoes shorter distances.

5.2.10 Semi-trailers suitable for combined road/rail transport may be equipped with standardized recesses for being lifted by suitable cranes, stackers or forklift trucks. This makes a lifting transfer from road to rail or vice versa feasible.

5.3 In addition to the road specific vehicles that are shown above, there are also road vehicles that carry other CTUs:

5.3.1 Container carriers – flatbed, extendable or skeletal trailers designed to carry one or two 20-foot long, or one 30-foot and longer containers.

5.3.2 Swap body system – built to accommodate European swap body units. Allows containers to be swiftly transferred during intermodal transport.

5.4 Road vehicle capacity and dimensions

5.4.1 Road vehicles are allocated a specific maximum payload. For road trucks and full trailers the maximum payload is a constant value for a given vehicle and should be documented in the registration papers. However, the maximum allowed gross mass of a semi-trailer may vary to some extent with the carrying capacity of the employed articulated truck as well as in which country it is operating. The total gross combination mass, documented with the articulated truck, should not be exceeded.

5.4.2 The actual permissible payload of any road vehicle depends distinctly on the longitudinal position of the centre of gravity of the cargo carried. In general, the actual payload must be reduced if the centre of gravity of the cargo is conspicuously off the centre of the loading area. The reduction should be determined from the vehicle specific load distribution diagram. Applicable national regulations on this matter should be observed. In particular ISO box containers transported on semi-trailers with the doors at the rear of the vehicle quite often tend to have their centre of gravity forward of the central position. This may lead to an overloading of the articulated truck if the container is loaded toward its full payload.

5.4.3 The boundaries of the loading platform of road vehicles may be designed and made available in a strength that would be sufficient – together with adequate friction – to retain the cargo under the specified external loads of the intended mode of transport. Such advanced boundaries may be specified by national or regional industry standards. However, a large number of road vehicles are equipped with boundaries of less resistivity in longitudinal and transverse direction, so that any loaded cargo should be additionally secured by lashings and/or friction increasing material. The rating of the confinement capacity of such weak boundaries may be improved if the resistance capacity is marked and certified for the distinguished boundary elements of the vehicle.

5.4.4 Road vehicles are generally equipped with securing points along both sides of the loading platform. These points may consist of flush arranged clamps, securing rails or insertable brackets and should be designed for attaching the hooks of web lashings and chains. The lashing capacity of securing points varies with the maximum gross mass of the vehicle. The majority of vehicles is fitted with points of a lashing capacity (LC) or maximum securing load (MSL) of 20 kN. Another type of variable securing device is pluck-in posts, which may be inserted into pockets at certain locations for providing intermediate barriers to the cargo. The rating of the lashing capacity of the securing points may be improved if their capacity is marked and certified.

5.4.5 In Europe, the maximum individual truck length is 12 m, articulated truck and trailer length is 16.5 m and road trains are allowed up to 18.75 m. The maximum width for all is 2.55 m. If a vehicle has an overall height of 3 m or above, a notice is required to be displayed in the cab showing its full height.

5.4.6 Other countries set different overall lengths and maximum vehicle masses.

5.4.7 Within Europe trials are currently being undertaken to examine longer and heavier trucks, up to 25 m in the length and 60 tonnes overall gross mass. These sizes may be permitted within regions or areas within Europe.

5.4.8 Within the United States National Highway network, the gross vehicle mass is generally limited to 80,000 lb (36,290 kg) with a maximum overall length varying from 48 ft (14.63 m) to 59 ft 6 in (18.14 m) depending on the state. However, longer combinations vehicles are permitted on specific road routes (corridors).

6 Railway Wagons

6.1 General

6.1.1 In intermodal transport, railway wagons are used for two different purposes: First, they may be used as carrier units to transport other CTUs such as containers, swap bodies or semi-trailers. Second, they may be used as CTUs themselves which are packed or loaded with cargo and run by rail or by sea on railway ferries.

6.1.2 The first mentioned purpose is exclusively served by open wagons, which are specifically fitted with locking devices for securing ISO containers, inland containers and swap bodies or have dedicated bedding devices for accommodating road vehicles, in particular semi-trailers. The second mentioned purpose is served by multifunctional closed or open wagons, or wagons which have special equipment for certain cargoes, e.g. coil hutches, pipe stakes or strong lashing points.

6.1.3 On board ferries the shunting twin hooks are normally used for securing the wagon to the ships deck. These twin hooks have a limited strength and some wagons are equipped with additional stronger ferry eyes. These external lashing points should never be used for securing cargo to the wagon.

6.1.4 The maximum payload and concentrated loading marks are described in the CTU Code.

6.1.5 Closed railway wagons are designed for the compact stowage of cargo. The securing of cargo should be accomplished by tight packing or blocking to the boundaries of the wagon. However, wagons equipped with sliding doors should be packed in a way that doors remain operable.

6.1.6 When a railway ferry is operating between railway systems of different gauges, wagons which are capable of changing their wheel sets over from standard gauge to broad gauge or vice versa are employed. Such wagons are identified by the first two figures of the wagon number code.

6.2 Intermodal Trains

6.2.1 Intermodal trains come in two forms, unaccompanied and accompanied CTUs.

6.2.2 Unaccompanied CTUs (trailers, containers and swap bodies as illustrated in figure 3.86) are lifted on and off rail wagons at terminals using top lift reach stackers or overhead gantries.

6.2.2.1 The recent trend in container handling equipment being used has been directed towards adjustable spreaders utilising the top lift capabilities of the container and swap body (shown figure 3.88).

6.2.2.2 The introduction of the rolling motorway (RoMo) and trailer on flat car (ToFC) has reinvigorated the used of the grappler arm (shown figure 3.87) originally designed for the swap body.

6.2.3 Accompanied CTUs are generally rigid or tractor and trailer units which are driven onto the train wagon. These trains are often point to point services.

6.2.3.1 Accompanied CTU trains will normally have a coach included in the train for the drivers who are accompanying the CTUs.

6.3 Wagon Types

6.3.1 The wagons in Europe are divided into thirteen main classes:

6.3.1.1 Open wagons

• - Class "E" – Normal open wagon;

• - Class "K" – 2 axle flat wagon;

• - Class "L" – 2 axle special flat wagon;

• - Class "O" – 2 axle flat wagon with sideboards;

• - Class "R" – 4 axle flat wagon.

6.3.1.2 Closed wagons

• - Class "G" – Closed wagon;

• - Class "H" – Special closed wagon.

6.3.1.3 Special wagons

• - Class "F" – Special open wagon;

• - Class "I" – Isolated/Refrigerator wagon;

• - Class "S" – 4+ axle special flat wagon;

• - Class "T" – Wagon with opening roof;

• - Class "U" – Special wagon;

• - Class "Z" – Tank wagon.

6.3.1.4 Payload limits are often about 25 to 30 tonnes for two axle wagons or 50 tonnes and above for multi axle wagons.

6.3.1.5 The strength requirements according to UIC are described in this chapter for "Covered wagons with fixed or movable roofs and sides conforming to UIC 571–1 and 571–3 and class T wagons" and "High-sided open wagons conforming to UIC 571–1 and 571–2". "Wagons with a fully opening roof complying with UIC 571–3 and wagons with folding roofs" are not described.

6.3.2 Wagon types in North America

6.3.2.1 These wagons are divided into nine main classes:

• - Class "X" – Box Car Types;

• - Class "R" – Refrigerator Car Types;

• - Class "V" – Ventilator Car types;

• - Class "S" – Stock Car types;

• - Class "H" – Hopper Car Types;

• - Class "F" – Flat Car types;

• - Class "L" – Special Car types;

• - Class "T" – Tank Car types;

• - Class "G" – Gondola Car types.

6.3.2.2 In each class the wagons are subdivided depending on payload. The three most common payloads are 50 tonnes, 70 tonnes and 100 tonnes.

6.4 Wagon strength guide

This chapter describes the strength of the Box car types and some of the Flat car types. The recommended practices for design and construction also have rules for Hopper Cars and Gondola cars, but it is only the Box car types and Flat car types that are used for general cargo.

6.4.1 European Railways

6.4.1.1 Covered wagons

• .1 sides with body pillars should be able to withstand a transverse force of 8kN (800 kg) acting at a height of one metre above the wagon floor on a pair of opposite body pillars. A residual deformation of maximum 2 mm is acceptable;

• .2 sides with metal construction should be able to withstand a transverse force of 10kN (1,000 kg) acting at a height of one metre above the wagon floor on the body side at a point located below the end loading hole (or ventilation hole) and in the centre-line of this hole. A residual deformation of maximum 3 mm is acceptable. A 100×100 mm hardwood rod should be used when applying the force.

6.4.1.2 High-sided open wagons

Sides should be able to withstand a transverse force of 100 kN (10 t) acting at a height of one and a half metre above the wagon floor applied to the four centre pillars. A residual deformation of maximum 1 mm is acceptable.

6.4.2 American Railways

6.4.2.1 For Box car side walls there are no maximum force requirements mentioned in the AAR regulations. There is, however, a maximum force requirement when designing adjustable or fixed side wall fillers in Box cars. Box cars equipped with adjustable side wall fillers at diagonally opposite sides of car, for filling void space crosswise of car, may be used provided such space does not exceed 38 cm. Box cars equipped with full side wall fillers at both sides in both ends of car, for filling void space crosswise of car, may be used provided such space does not exceed 15 cm from each side of car. The wall fillers should be designed to withstand a lateral force equivalent to 25% of the weight of cargo, (= 0.25 g). The force should be uniformly distributed over the entire face of the wall filler.

6.4.2.2 Lateral pressure of granular, lump or pulverized bulk material should be considered in the design of wagons in which such pressure may be active. If the weight of the cargo is 4.8 tonnes per metre of length the lateral force from the cargo in a typical closed top 70 tonnes Box car is 10 tonnes per metre of length. The lateral force should be distributed vertically so that it is a maximum at the floor line decreasing uniformly to zero at the top surface of the cargo.