Note: Definitions are given in chapter 2.
6.1 Introduction
6.1.1 When planning a consignment for transport the shipper should ensure that the
CTU best suited for the cargo and the probable route is selected. If the shipper is
uncertain about which CTU to select, further information can be obtained by
contacting the CTU operator.
6.1.2 Packers should acquaint themselves with the characteristics of the CTU with
particular reference to:
6.2 Freight containers
6.2.1 The external and internal dimensions of most freight containers are
standardized by ISO.
6.2.2 The maximum gross mass and the permitted payload of a freight
container depend on standardized design parameters. The
International Convention for Safe Containers requires each freight
container to carry a CSC safety approval plate, where the maximum permitted gross
mass is specified (see subsection 8.2.1 and annex 4, section 1). Additionally, the
tare mass and the payload are marked in painted letters on the door or on the rear
end of the freight container.
6.2.3 With the exception of platforms (a container deck without walls), packed
freight containers are capable of being stacked. This feature is mainly used in
land-based storage areas and on ships during a sea passage. The permissible stacking
mass is displayed on the approval plate. Freight containers with a stacking mass
equal to or greater than 192,000 kg may be transported without restriction. However,
freight containers with a stacking mass value less than 192,000 kg do also exist and
require special attention when used for intermodal transport, in particular for the
stowage in stacks on seagoing vessels (see subsections 7.3.1 and 8.2.1).
6.2.4 General purpose freight containers are available as closed freight containers,
ventilated containers and open top containers. The side walls are capable of
withstanding a uniform load equal to 60% of the permitted payload. The front wall
and the door end are capable of withstanding 40% of the permitted payload. These
limitations are applicable for a homogenous load on the relevant wall area and do
not exclude the capability of absorbing higher forces by the framework of the
freight container. The container floor is primarily designed to sustain the total
payload homogeneously distributed over the bottom structure. This results in
limitations for concentrated loads (see annex 7, section 3).
6.2.5 Most general purpose freight containers have a limited number of lashing rings
or bars. When lashing rings are fitted, the anchor points at the bottom have a
maximum securing load (MSL) of at least 10 kN in any direction. Recently built
freight containers have, in many cases, anchor points with a MSL of 20 kN. The
lashing points at the top side rails have a MSL of at least 5 kNfootnote.
6.2.6 Floors on freight containers covered by the CSC are only required to withstand
an axle load of 5,460 kg or 2,730 kg per wheelfootnote although they may be built to withstand a greater axle
load. The CTU operator can provide more precise information.
6.2.7 Closed freight containers generally have labyrinth protected openings for
venting (pressure compensation), but these openings do not measurably support air
exchange with the ambient atmosphere. Special type "ventilated containers" have
weatherproof ventilation grills built into the top and bottom side rails and the
front top rail and bottom sill, through which the natural convection inside the
freight container is intensified and a limited exchange of air and humidity with the
ambient atmosphere is established.
6.2.8 An open top container is similar to a closed freight 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. The cover
is normally supported by movable or removable roof bows. In some cases the removable
roof is a compact steel construction suitable to be lifted off in one piece. The
header (transverse top rail above the doors) is generally movable or removable
(known as swinging headers). The headers are part of the container strength and
should be fitted to have full strength of the freight container.
6.2.9 Open side containers have a curtain or canvas on one or both sides, a rigid
roof and rear doors. While the strength of the end walls is similar to that of
closed freight containers, the side curtain provides limited or no restraint
capability. Open side containers are not covered by ISO standards.
6.2.10 Platforms and platform based containers are characterized by having no side
superstructure except either fixed or collapsible end walls (flatracks) or are
designed without any superstructure (platforms). The benefit of collapsible end
walls is that the flatrack may be efficiently stacked when transported in empty
condition for repositioning.
6.2.11 Flatracks and platforms have a bottom structure consisting of at least two
strong longitudinal H-beam girders, connected by transverse stiffeners and lined by
solid wooden boards. For securing of cargo units, strong lashing brackets are welded
to the outer sides of the longitudinal bottom girders with a MSL of at least 30 kN
according to the standard. In many cases the lashing points have a MSL of 50 kN.
Cargo may also be secured in longitudinal direction by shoring to the end walls of
flatracks. These end walls may be additionally equipped with lashing points of at
least 10 kN MSL.
6.2.12 Thermal containers, commonly referred to as reefer containers, are designed
for the transport of cargo under temperature control. Such cargo is generally
homogeneously packed and tightly stowed from wall to wall. Therefore, the side and
end wall strength is similar to that of general purpose freight containers. However,
thermal containers are generally not equipped with anchor and lashing points. When a
cargo needs to be secured by lashings, specific fittings may be affixed to the "T"
section gratings, thus providing the required anchor points.
6.2.13 A tank container comprises two basic elements, the tank shell (or shells in
case of a multiple-compartment tank container) and the framework. The framework is
equipped with corner fittings and renders the tank suitable for intermodal
transport. The frame should comply with the requirements of the CSC. If dangerous
goods are intended to be carried in the tank, the shell and all fittings such as
valves and pressure relief devices should comply with the applicable dangerous goods
regulations.
6.2.14 A non-pressurized dry bulk container is a container especially designed 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 discharging apertures and fittings. There are freight containers for
tipping discharge, having filling and discharge openings and also a door. A variant
is the hopper type for horizontal discharge, having filling and discharge openings
but no doors. The front and rear end walls of solid bulk containers are reinforced
and so constructed to bear a load equal to 60% of the payload. The strength of the
side walls is similar to that of general purpose freight containers.
6.3 Regional and domestic containers
Regional and domestic containers are designed and manufactured to meet the needs of
local transport operations. They may have the appearance of a freight container, but
unless fitted with valid CSC safety approval plates they should not be used in
international transport.
6.4 Swap bodies
6.4.1 A swap body is a regional transport containment of a permanent character
designed for road and rail transport within Europe and complying with European
standards. Swap bodies are generally 2.5 m or 2.55 m wide and are subdivided into
three length categories:
6.4.2 Swap bodies are fixed and secured to the vehicles with the same devices as
freight containers, but owing to the size difference, these fittings are not always
located at the swap body corners.
6.4.3 Stackable swap bodies have top fittings enabling the handling with standard
freight container handling equipment. Alternatively, the swap body may be handled
using grappler arms, inserted into the four recesses in the bottom structure. Swap
bodies not suitable for stacking can only be handled with grappler arms. Class C
swap bodies can be transferred from the road vehicle to their supporting legs and
returned to the vehicle by lowering or raising the carrier vehicle on its wheels.
6.4.4 The standard box type swap body has a roof, side walls and end walls, and a
floor and has at least one of its end walls or side walls equipped with doors. Class
C swap bodies complying with standard EN 283 have a defined boundary strength: the
front and the rear end are capable to withstand a load equal to 40% of the permitted
payload, the sides are capable to withstand 30% of the permitted payload. For a
cover-stake body the drop sides are designed to withstand a force equal to 24% of
the maximum permitted payload and the remaining part of the side is designed to
withstand 6% of the maximum permitted payload. The sides in a curtain sided swap
body may not be used for cargo securing unless purposely designed to do so.
6.4.5 Floors of swap bodies are built to withstand corresponding axle loads of 4,400
kg and wheel loads of 2,200 kg (reference: EN 283). Such axle loads are typical for
forklift trucks with a lifting capacity of 2.5 tons.
6.4.6 The curtain-sided swap body is designed similarly to a standard curtain side
semi-trailer. It has an enclosed structure with rigid roof and end walls and a
floor. The sides consist of removable canvas or plastic material. The side boundary
may be enforced by battens.
6.4.7 A thermal swap body is a swap body that has insulating walls, doors, floor and
roof. Thermal swap bodies may be insulated, but not necessarily equipped with
mechanical device for cooling. A variant is the mechanically refrigerated swap
reefer.
6.4.8 A swap tank is a swap body that consists of two basic elements, the tank or
tanks, and the framework. The tank shell of a swap tank is not always fully enclosed
by the frame work.
6.4.9 A swap bulker is a swap body that consists of the containment for 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.
6.5 Roll trailers
6.5.1 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 king-pin for coupling the trailer to the fifth wheel
of an articulated truck.
6.5.2 The packing of a roll trailer with cargo or cargo units should be planned and
conducted under the conception that the cargo should be secured entirely by
lashings. However, roll trailers are available equipped with standardized locking
devices for the securing of freight containers and swap bodies.
6.6 Road vehicles
6.6.1 Road vehicles are available in a number of different formats and designs.
6.6.2 Most 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.
6.6.3 Semi-trailers suitable for combined road/rail transport are generally equipped
with standardized recesses for being lifted by suitable cranes, stackers or forklift
trucks, to enable the lifting transfer from road to rail or vice versa.
6.6.4 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 never be exceeded.
6.6.5 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 should 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 (see annex 7, subsection 3.1.7). Applicable national regulations
on this matter should be observed. In particular closed freight 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 packed toward its
full payload.
6.6.6 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.
6.6.7 In Europe, European standard EN 12642 would apply. According to this, there are
two levels of requirements of vehicle sides and ends: Code L and Code XL. The
strength requirements of the side walls for the Code L vehicles are similar to the
requirements for sides of swap bodies according to the standard EN 283 (see
paragraph 6.4.4). The side walls of Code XL vehicles are designed to withstand a
force equal to 40% of the permitted payload uniformly distributed over the side up
to 75% of the height of the side, independently of the type of vehicle. The front
wall of Code L vehicles is designed to take up a force equal to 40% of the permitted
payload, the maximum however is 50 kN. For Code XL vehicles the front wall is
designed to withstand a force equivalent to 50% of the payload without any further
limit. The rear wall of Code L vehicles is designed to withstand a force equal to
30% of the permitted payload, the maximum however is 31 kN. For Code XL vehicles the
rear wall is designed to withstand a force equivalent to 40% of the payload without
any further limit.
6.6.8 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 devices are 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. Modern vehicles are often equipped with continuous connecting
points for lashing bars on each side, thus to enable the affixing of the lashing
bars exactly in the required positions to block the cargo against movement towards
the rear side.
6.7 Railway wagons
6.7.1 In intermodal transport, railway wagons are used for two different purposes:
First, they may be used as carrier unit to transport other CTUs such as freight
containers, swap bodies or semi-trailers. Second, they may be used as a CTU
themselves which is packed or loaded with cargo and run by rail or by sea on a
railway ferry.
6.7.2 The first mentioned purpose is exclusively served by open wagons, which are
specifically fitted with devices for securing freight 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.
6.7.3 On board ferries the shunting twin hooks are normally used for securing the
wagon to the ship's deck. These twin hooks have a limited strength and therefore
some wagons are equipped with additional stronger ferry eyes. These external lashing
points should never be used for securing cargo to the wagon.
6.7.4 The maximum payload is generally not a fixed value for the
distinguished wagon, but allocated case by case by means of the intended track
category and the speed category. More details are provided in annex 4, subsection 5.1.5.
6.7.5 In case of concentrated loads a reduction of the payload is
required, which depends on the loaded length and the way of bedding the concentrated
load. The applicable load figures are marked on each wagon. Also any longitudinal or
transverse eccentricity of concentrated loads is limited by the individual axle load
capacity or the wheel load capacity. More details are provided in annex 4, subsection 5.1.6.
6.7.6 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.
6.7.7 When a railway ferry is operating between railway systems of different gauges,
wagons which are capable for 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.