Episode 23: Positive locking for trucks
Securing the cargo with positive locking methods is the best, simplest and safest solution in most cases. In practice, however, there is often a lack of clarity as to which boundary conditions have to be met for this to actually work.
About the author:
In a series of specialist articles from the field, on topics relating to containers and trucks, you will receive first-hand professional knowledge.
How to secure cargo correctly and what are the basics of cargo securing?
They are developed and presented by Sigurd Ehringer, owner of SE-LogCon:
- VDI certified instructor for load securing
- Reference book author
- 8 years Project Manager
- 12 years with the Bundeswehr (company commander)
- 20 years of sales experience
- since 1996 consultant/trainer in logistics
- 44 years instructor/trainer in various fields
Episode 23: Positive locking for trucks
EN-12642 has been around since 2007 with the unwieldy title: "Load securing on road vehicles - Superstructures on commercial vehicles - Minimum requirements; German version EN 12642:2016".
Most of them use the common short title "EN-12642 Code XL". During the development of the standards, the superstructures were divided into two groups. The so-called standard superstructure Codel L with maximum strengths of the superstructure and the reinforced superstructure Code XL with minimum strengths.
The specifications refer to the end wall, the side walls and the rear portal. Testing of the floor load is not included because this is already covered by EN-283. The standard gives body manufacturers a great deal of freedom, as long as the tested strengths are within the specifications.
The following overview is an excerpt from the standard with the current specifications. The letter "P" stands for the technical payload of the
vehicle or the superstructure. For the standard semitrailer, this is usually the value 27,000 kg.
The strength of the end wall must be checked over the entire width and up to three quarters of the height. In order to secure positively, this area must be taken into account. Particular attention must be paid to the loading width.
For the shipper, there are also three important control aspects, namely
- the labeling requirement specified in the standard,
- the proof of each structure with a certificate and
- the requirement of the manufacturers that the superstructures must be tested once a year.
This type of spacer acts on the end wall like a can opener.
In the event of emergency braking, the end wall would simply be pushed through.
The loader must therefore ensure that the end wall is loaded at least across its entire width.
So much for the boundary conditions specified by the standard. To ensure that the superstructures can absorb the forces, the manufacturers have also formulated boundary conditions. These are described in the certificate in relation to the respective superstructure.
In practice, it has been shown that these boundary conditions are essentially the same for all manufacturers.
- Sliding friction coefficient of at least μD=0.30
- Positive loading in the direction of travel
- Load width at least 240cm
- Max. permissible distance load/back wall 15 cm
In most cases, special specifications are made for special loads, such as beverages, to which both the vehicle owner and the shipper must adhere.
What does the whole thing look like in practice? The truck enters the loading zone, the driver opens the left tarpaulin, the forklift driver places the load on the loading area, the driver closes the tarpaulin again and drives off. That's roughly how most loads are handled.
Actual measures required are as follows:
1. The shipper should check whether the driver has the Code XL certificate with him and read it to determine what special features should be
Then an eye check is required to ensure that the body strength is not affected by damage. The last thing to check is the evidence for the annual inspection.
Vehicles with damage as shown in the picture on the right should not be loaded under any circumstances.
2. Such marking would not replace the certificate, but would be sufficient as Code XL proof for the time being. According to the newer marking regulation, the load-bearing capacity of the end wall must even be specified at different heights.
3. The last thing to check is the proof for the annual inspection. They could look like this or similar, but the paper form would also be fine.
4. The manufacturer specifies that the coefficient of sliding friction should be at least μD=0.30. This condition can be achieved if the driver sweeps the loading area properly with a broom.
Broom clean, that's the magic word. In load securing, many screws can be turned, but the "friction screw" moves a lot. The loader must therefore demonstrably ensure that the loading area has been swept before loading.
Form-fit loading in the direction of travel means that the load units are lined up without gaps, starting at the end wall. The important thing here is that the forces from the individual load units are transmitted continuously to the end wall.
Unstable, overbuilt or underbuilt cargo units do not. Example of this:
Such a load will move into any free gap. The load unit securing is completely inadequate.
Overbuilt pallets transfer forces via the product to the end wall or other load units. The case of damage is pre-programmed.
Whether the superstructure strength can actually secure the load via form fit depends crucially on the type of cargo units and how they are secured. It is grossly negligent to talk of a tight fit for a load unit of this type, because the end wall will inevitably be damaged.
Form-fit loading to the side means that, according to the manufacturer's specifications, the loading width must be at least 2.40 m. The internal width of today's standard bodies is between 2.40 m and 2.50 m, depending on the design and body type. The specification of 2.40 m can be traced back to the Euro dimension.
This means that two europallets can be placed crosswise or three lengthwise in a loading row. Of course, the same requirements are placed on the load units again: they must be dimensionally stable and stable against tipping, so that the centrifugal forces are transmitted without gaps during cornering or evasive movements.
The sum of the permissible gaps results from the maximum inside width of the superstructure, minus 2.40 m. A common measurement is 8 cm as the gap sum.
Form-fit loading to the rear means that the distance to the rear portal must not exceed 15 cm. If the distance is greater, it must either be
filled or the load must be secured to the rear. To fill the gap, there are several solutions. The most common solution is the use of Euro pallets.
If the pallets are stowed upright, care must be taken to ensure that they do not fall out when the rear door is opened.
So it is better to position the pallets before the last row of loaders.
The following excerpt can be found in most certificates:
This means that if the requirements I have described above are not met, the manufacturer cannot guarantee that the body can withstand the securing forces. The responsible shipper is therefore required to demonstrably ensure that the necessary measures/checks are carried out.
If not, he has to apply according to §22 StVO "Load", using the methods according to "VDI-2700 "Load securing on road vehicles", (the recognized rules of technology). He must also provide evidence in the case of how the load securing looked at the time when the truck left the area of responsibility of the loader.
Unfortunately, practice shows that there is often a lot of luck involved.
As shippers, we share in the liability when it comes to load securing. Every day. That's a good thing to understand your craft.
On our own account:
Rothschenk. That's us.
Rothschenk is a manufacturer of load securing equipment for overseas containers. In the tranquil town of Aub in central Franconia, we develop, test and sell our own load securing equipment such as dunnage bags/padding, Lashing restraint systems, Edge Protectors, Anti-slip Mats, Lashing Straps and drum securement. You can get a small insight into our product world in our Online Shop: [R] SHOP24.
We develop for our customers, to whom also large corporations e.g. from the CHEMICALS-, BEVERAGES- and Automotive industry belong, individual load securing. Therefore we are used to come up with new products and solutions in our own research and test department.
We stand for quality "Made in Germany„. Not only in development, but also in production. Because we are the only manufacturer for load securing with our own production site in Germany. Real "Made in Germany" even.
>> Please use the comment function below for suggestions, additions and also for further questions.
We will, of course, respond promptly and professionally. Your Rothschenk Team
Summary of the article:
A tight fit is a form-fit load securing method in which the load is secured by placing it against the vehicle body. This can be done by loading the load flush and without gaps or by using aids such as wedges, locking bars or lashing nets.
To create a form fit, the following steps must be performed:
- The load must be distributed on the loading area so that it is evenly loaded. This prevents the load from shifting or tipping over.
- The load must rest against the vehicle body. This can be done by loading the cargo flush and without gaps or by using aids such as wedges, locking bars or lashing nets.
- The load must be secured against slipping and rolling. This can be done by using lashing straps, lashing chains or lashing wire ropes.
Here are some tips for creating a form fit:
- Use the right tools. The aids must be suitable for the weight of the load and the expected loads.
- Tighten the tools properly. The aids must fit tightly to secure the load.
- Check the load securing regularly. Load securing must be checked before each transport to ensure that it is safe.
If you are not sure how to create a form fit, you should seek advice from a professional.
Here are some examples of how to create a form fit:
- A loading area with fixed side walls is completely filled with general cargo on Euro pallets without any gaps. In this case, the load is secured against slipping and rolling by the side walls of the vehicle.
- A free-standing palletized good is secured on the loading area with a lashing net. The lashing net is attached to the side walls of the vehicle and to the load.
- An excavator is fixed to a low loader by diagonal lashing with lashing chains. The lashing chains are attached to the load and the vehicle at an angle of 45° to 60°.
Shape locks are a safe and effective method of securing loads. They should always be used when possible.