Load securing, weight distribution and cargo safety
Securing a load on a CE vehicle is a calculation, not a feeling. The examiner tests the standard forces, the difference between lashing capacity and tension force, and the practical checks you make before and during a journey.
The forces you must resist
- Under EN 12195-1, a load must be secured against 0.8 g forward, 0.5 g rearward and 0.5 g sideways.
- Friction is part of the calculation. Dry wood on a wooden deck gives roughly μ = 0.2–0.3; anti-slip mats raise it to around 0.6.
- Securing force needed = (acceleration factor × weight) − friction contribution.
Lashing capacity and tension force
- LC (lashing capacity) is the strength of the strap, given in daN. STF is the tension force you apply with the tensioner. They are different numbers and confusing them is the classic error.
- A top-over lashing contributes roughly 2 × STF × μ, so its effective hold collapses when friction is low.
- Form-fit (positive fit) against a headboard or a side wall is always more effective than lashing alone.
Worked example - 10,000 kg pallet, forward force. Acceleration factor 0.8, so 8,000 daN is required. On bare decking with μ = 0.2, friction gives 2,000 daN, leaving 6,000 daN to be lashed. With straps of STF 400 daN, each contributes about 2 × 400 × 0.2 = 160 daN, so you would need roughly 37 straps - impossible in practice. With anti-slip mats giving μ = 0.6, friction covers 6,000 daN and only 2,000 daN remains, which five straps of that type can supply. Reasoning: the mats, not the straps, do the work.
Weight distribution and checks
- Spread the load so no axle or tyre is overloaded; keep the centre of gravity low and central.
- Check lashings shortly after setting off and again at the first proper stop; straps slacken as the load settles.
- The load must not obstruct lights, plates, mirrors or the driver's view, and doors and tarpaulins must be closed properly.
Traps that cost marks
- Quoting LC where the question asks about STF.
- Ignoring friction and securing only for the vertical weight.
- Forgetting rearward and sideways forces, which matter in emergency braking and on roundabouts.
- Loading against the rear doors so a heavy item can shift forward onto the kingpin and overload the drive axle.