A swap body (including swap bodies (WB), swap , swap body , swap body bridge (WAB), swap bodies , in Switzerland also change loading container or shortly WELAB ) is a replaceable carriers, which - similar to an ISO container - of the carrier vehicle under driving (truck, Truck trailer) or crane (rail wagon) and can also be separated.
For use in combined transport , the swap body must be equipped with facilities that allow transshipment to the railroad (UIC 592-4). This is made possible by gripping edges located on the underside of the swap body. Cranes at the container terminals have special gripping arms with which the swap bodies can be grasped at the sides and lifted from below. Like ISO containers , the swap bodies are connected to the trucks, trailers ( carriages ) and freight wagons provided for their transport by pins (so-called twistlocks ). The basic locking dimensions of a swap body correspond to that of a 20-foot ISO container with a length of 5820 mm, so that swap bodies and ISO containers can be transported on the same carrier vehicles without having to convert them. The advantages of the swap body compared to ISO containers are its inner width suitable for pallets and the more flexible dimensions available.
The C-containers with a total weight of 16 t ( EN 284 from 1992 and 2006/2007: lengths 7150 mm (C715, no longer in the edition of the standard DIN EN 284: 2007-01)), 7450 mm (C745 ), 7820 mm (C782). With these containers, four support legs are folded down on the sides, after which the vehicle can be lowered - by venting the bellows of the air suspension - and driven out from under the parked structure. This form is often referred to as a swap body.
C containers are usually not stackable. Possibly two to three pairs of guide rollers - one almost at the front and one at the back of the carrier vehicle, at a distance of about 60 cm, slightly conical, on almost vertical axes, so that the outer contour of the rollers is vertical, so that no lifting force is applied when rolling onto the WAB exercise - help threading the carrier vehicle. Parking legs are available for different parking heights (820–1320 mm) and can be telescopic, possibly in steps of several 50 mm.
Another variant of the C-containers are the stackable swap bodies. These are being prepared by European standardization; they are available in lengths of 7450 and 7820 mm.
Other swap bodies are the A-containers . These are suitable for transport on semi-trailer chassis, have no support legs, have a total weight of up to 34 t and a length of up to 13,670 mm (with a tunnel-shaped recess at the front on the underside that accommodates the stiffening struts of the semi-trailer via its coupling).
The structural peculiarity of the supports is that they are housed in a recess on the lateral lower edges of the WAB and thus within the WAB width and above the WAB lower edge along the direction of travel while driving. When standing, they are first pulled out a little laterally parallel - by hand - then turned downwards on a pipe, fixed with a strut and, at least on earth-soft ground, underlaid with a stable block. By pulling it out to the side by around 20-30 cm, there is also enough space at the side to extend the supporting chassis.
Maneuvering the trailer of an articulated train under a MCS takes practice, accuracy, patience and space. However, train trucks usually have a shunting coupling at the front, with which the trailer can be maneuvered back geometrically more easily and with a direct view.
Like ISO containers, swap bodies are suitable for road and rail transport, but, in contrast, are not approved for ship transport
There are swap bodies with tarpaulin, sliding tarpaulin, closed box bodies and a number of special bodies . Similar to megatrailers, there is also a variant with a clear interior height of 3 m. These so-called jumbo swap bodies are equipped with a lifting roof in order to make optimum use of the volume.
For the transport of liquids, cylindrical containers are held in steel frames (liquitainers) and can then be treated like swap bodies. However, tank containers are usually dimensioned according to ISO standards.
DIN EN 283: 1991-08 - Swap bodies; Exam - regulates the testing.
The development of the modern swap body began in the early 1950s. At this time, the US freight forwarder Malcom McLean began developing interchangeable bodies that could be transported by truck on the road as well as by ship. His ideas finally led to the ISO containers that are used around the world today and have become an integral part of international transport. In Europe, the German Federal Post Office began introducing the so-called Weber container at the beginning of the 1950s . These were standardized parcel containers for road and rail vehicles, which were placed on the transport vehicles in a pre-loaded state. Both McLean's ideas and the Deutsche Bundespost were primarily concerned with finding a way to accelerate the handling of goods and avoid long idle times for the vehicles used.
In 1971 the German freight forwarder Dachser developed the swap body, a swap body with fold-out support legs. While the previously common swap bodies still required a crane or special forklift to change the body, this development now made it possible to remove or pick up the entire swap body from the truck without any further aids. Since the swap body, unlike the ISO container, is a European development, its dimensions are adapted to the dimensions of Euro pallets . The C-containers according to EN 284 in the version with a length of 7150 mm have 17 Euro pallet spaces, with 7450 mm over 18 and with 7820 mm over 19 spaces. Nowadays there are also suitcase and refrigerated box swap bodies that have a double-decker loading facility. Such equipment makes it possible to better use the volume of the swap body with correspondingly low pallets and to load it in two layers without having to stack the pallets directly on top of one another.
- Interesting facts about BDF changing systems at www.mls-online.de, accessed on November 9, 2012
- DIN EN 284 , Beuth-Verlag, accessed May 8, 2016
- 2-axle BDF trailer chassis , Schwarzmüller.com, accessed May 8, 2016.
- Support legs according to DIN EN 284 in a rigid or telescopic design, Bowmann, accessed May 8, 2016.
- Introduction of the swap body by Dachser at dachser.com, accessed on August 6, 2018