Episode 25: What types of lashing are there for load securing?
The vehicle is ready. The goods are packed and ready for loading. But what type of lashing do I use to secure my load on the truck? How many belts do I need and in which directions can the goods move?
What sounds simple requires prior expertise in physics, dynamics and also knowledge of the different ways of lashing cargo.
- How can the coefficient of friction be increased?
- When do the forces act directly, when are they reduced?
- How do you lash round goods safely?
- Are there options for attachment to the goods?
Below we show you the most common types of lashing and what is important.
In principle, these can be divided into the four areas of direct lashing, diagonal lashing, diagonal lashing and sling lashing. But let's take a closer look at these.
Differences between direct lashing and tie-down lashing
- Direct lashing
Here, the lashing force (LC) secures the load. The force applied determines the performance of the securing.
- Tie-down lashing
With this type of securing, the frictional force (between the cargo unit and the vehicle floor) secures the load. The applied pretensioning forces (STF) are the decisive factor here.
This occurs relatively frequently and only requires low pretensioning forces (in contrast to tie-down lashing). The actual load only occurs during heavy braking, cornering and starting.
The most important point when lashing diagonally is the correct angle of the lashing equipment. These must not be applied too steeply, as otherwise the forces that occur during cornering or braking/starting up would be too great. One lashing means always secures one of the four corners of the load.
A reliable aid here is a lashing calculator. It reliably provides you with both the correct angles and the required number (at least four, but often more) of lashings. You are welcome to have this sent to you by us.
The lashing equipment is attached diagonally, but not necessarily crosswise. There are four different ways to attach a diagonal lashing.
This has the advantage for the user that the lashing angle (lashing means at an angle to the loading floor edge) can be influenced more favorably if necessary.
As you can see, the lashing angles vary depending on how the lashing equipment is positioned. The securing force depends on the following factors:
- LC (Lashing Capacity) of the lashing means in straight pull
- The permissible tensile force of the lashing points used
- The vertical and horizontal lashing angles in which the lashing straps are tightened
Influence of the lashing angle
- If an angle in one direction is better secured, the angle in the other direction is neglected.
- Unfavorable lashing angles mean that a higher LC is required to secure the goods
- If the angles are chosen very unfavorably, it is even possible that a higher LC is necessary to the side than to the front
- When calculating/loading, it is therefore very important that all angles are remeasured
This type of load securing is frequently used in practice. The lashing strap is placed over the goods (overtensioning) and these are pressed onto the vehicle floor during tensioning. The friction between the load and the vehicle floor creates a frictional connection that secures the goods.
Naturally, this type of load securing often requires a higher number of lashing materials, etc. The shipper can reduce the number of these by using friction-enhancing intermediate layers, e.g. anti-slip mats or anti-slip paper. The shipper can reduce their number by using friction-enhancing intermediate layers, e.g. Anti-slip Mats or anti-slip paper.
Without the use of these anti-slip agents, 0.8 times the weight of the load acts in the direction of the driver during emergency braking and 0.5 times the weight acts to the outside of the curve during cornering. With a load weight of 5,000 kg, for example, this would be 4,000 kg or approx. 4,000 daN toward the front. In the case of a curve, this would correspond to 2,500 kg or approx. 2,500 daN.
Pro Tip: When buying anti-slip mats, pay attention to the VDI guideline 2700 sheet 15. Only if you make sure that the anti-slip agents comply with this standard, you can also assume that you can apply a friction value of 0.6. In addition to the general durability, the binder content of a "cheap" rubber anti-slip mat may be too low. As a result, individual rubber granules may come loose and even cause the goods to accelerate during braking.
This is a type of direct lashing. In this case, the lashing material is placed as a loop in front of, behind or to the side of the load and fastened to the lashing points on the loading floor.
Head lashing with palette
With head lashing, you can create rear load securing relatively easily. Or if, for example, no tight fit to the end wall could be achieved due to load distribution, an artificial end wall would be possible. Pallets standing on edge are placed with the "smooth" side against the goods. This ensures maximum force transmission to the load. In addition, the base of the pallets provides a holding-up function for the lashing strap when it is passed through there.
Here too, as with all types of lashing, the correct angle of the lashing strap is very important. In the case of head lashing, this should be less than 45° in order to achieve a high degree of positive securing force. The center of gravity of the goods must always be below the lashing.
For more information on how to apply a head lashing, check out our blog post Episode 6: Bay or head lashing - what does it mean?
Head lashing with retaining strap
Alternatively, a head lashing can also be created with a retaining strap (red in the picture) if, for example, no pallet is available.
The retaining strap takes over the function of holding up the goods, which in the previous example was performed by the pallet. The horizontal lashing strap is guided through the retaining strap (which has a loop at both ends) and past the goods at the front.
When determining the correct angle, we recommend using a lashing calculator here as well. Head lashing can be carried out in or against the direction of travel, or only in one of the two longitudinal directions of the vehicle. Lateral load securing must be carried out separately in this case.
If the load is suitable for this, e.g. with block goods, a head-cross lashing can also be attached.
To do this, the attached lashing strap is guided upwards over the goods and then back under the goods on the front side to the other side. Proceed in the same way with the second lashing strap.
This creates a frontal cross lashing with a high retention force. In order to achieve the required values according to the loading plan, this variant can be supplemented with additional tie-down lashing over the goods.
Book lashing (side loop lashing)
Book lashing is also explained in more detail in our blog post episode 6 so here is just the most important information about it. In principle, loop lashing serves here as a kind of "dropside substitute", since no tight-fit loading can be implemented. However, a strapping lashing can only secure the goods laterally. Securing in the longitudinal direction of the vehicle must be carried out separately here, e.g. by a combination with head lashing.
Like many types of lashing, this variant originally comes from seafaring. Loops are placed around the goods and both ends are fastened to the vehicle. It is important to attach the slings opposite each other and symmetrically. Only in this way can the forces work against each other and reliably secure the cargo. At the very least, however, a minimum of 3 slings should be used.
In the direction of travel, bay lashing is almost ineffective, so it is best to use a form fit here to prevent slippage.
Example of application
- Bay lashing using lashing straps (applied to two different anchor points).
- combined with a head lashing from chains (with tether) in the direction of the vehicle
Label on the lashing strap
The label of a DIN lashing strap gives you information about the pretensioning forces, or the maximum load weights to be secured with it. On the drawing next to it, you can see the different effects when specifying the values of direct lashing and head lashing as opposed to tie-down lashing.
When lashing down, the forces are diverted, so that we are only talking here about the pretensioning forces to be applied by hand.
SHF = Standard Hand Force (The standard hand force to be applied to tighten the ratchet)
STF = Standard Tension Force (This is the standard force that is transferred to the lashing equipment by tensioning).
LC = Lashing Capacty (Describes the tensile strength of a lashing strap, i.e. the maximum load capacity of a lashing in straight pull).
What must be printed on a lashing strap label and what has no place on it is regulated in the European standard EN 12195-2. Nevertheless, mistakes are made here again and again, especially with inferior goods from Asia.
Opposite you can see an example that with a trained eye can be quickly identified as a fake and not in accordance with the standard.
- Error 1:
- The label does not indicate the forces to be applied in daN but in kg. An indication in kilograms has no place on the label, the information must always be given in decaNewton .
- Error 2:
- The CE logo is not consistent with the official signet of the label. The original is made in a semi-curved shape, on the label this is only printed in writing (probably for China export). Of course, this does not correspond to an EU marking according to CE.
TIP: When buying lashing straps, make sure that they have the correct specifications, such as EN 12195-2, CE marking and the correct specification in daN. Only in this way can you be sure that the lashing equipment delivers what it promises. If you save money in the wrong place, it can quickly become expensive - and not only during an inspection.