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Cargo is secured two ways: by tie-down, pressing the load onto the floor with straps, and by blocking (form-fit), wedging it against walls, bars or other units. In practice you combine them with anti-slip mats that raise friction and corner protectors that shield both the strap and the goods. The reference for the calculation is EN 12195. Good securing means matching force to mass and friction, not counting straps by habit.
Why securing decides whether the goods arrive
A loader rarely sees what happens to a pallet once the trailer doors close. Yet on the first hard brake a force of up to 80 percent of the load's weight drives it forward. A tonne of goods then pushes like eight hundred kilograms shoving toward the cab. If nothing holds it, it slides, tips or punches through the trailer headboard. The stakes are double: destroyed goods and a shipment stopped at a roadside check, because an unsecured load is grounds for immobilising the vehicle. Who carries that responsibility is covered in who is liable for load securing, and what happens on the road in the roadside inspection. This article is about something else: how you actually secure a load.
Two methods: tie-down versus blocking
Every securing job comes down to one of two principles, or their combination.
- Tie-down (friction) securing. A strap thrown over the load and tensioned by a ratchet presses the goods onto the floor. It does not hold the load directly; it increases the downward force and therefore the friction that resists movement. The decisive figure is the standard tension force STF stamped on the strap label: the higher it is and the greater the friction, the fewer straps you need. Universal, but weak on a slippery floor with a light, tall load.
- Blocking (form-fit) securing. The load rests against the headboard, the walls, blocking bars, stanchions or neighbouring units so it has nowhere to move. It relies on a physical barrier, not on friction. The safest method whenever the goods can be loaded tight, with no gaps. A gap between pallets is an invitation for the load to build up speed.
In practice both are combined: tight blocking plus tie-down straps wherever free space remains. EN 12195 gives the formulas that tell you how many straps of a given STF are needed for a given mass and friction coefficient. You do not need to know it by heart; you need to know the strap count comes from a calculation, not from habit.
Lashing straps and ratchets: what to check
A strap is not a piece of rope. Each carries a label, and the label, not the look of the webbing, decides whether it is fit for use.
- LC (Lashing Capacity) is the permitted lashing force of the strap, in daN. It matters most in blocking securing.
- STF (Standard Tension Force) is the pre-tension the ratchet actually delivers. It governs the effectiveness of tie-down securing.
- SHF is the hand force assumed when deriving STF. A supporting figure on the label.
A strap with frayed webbing, a cut edge, a deformed hook or no readable label is out of service, because its real strength is unknown. Tighten the ratchet firmly by hand, without extension pipes that overload the mechanism and let go just as fast. Route the strap through the lashing points on the trailer frame, never over a sharp cargo edge without protection.
Anti-slip mats: friction that replaces straps
The friction coefficient between load and floor is the cheapest way to need fewer straps. A dry steel trailer floor and a wooden pallet give a friction value treated cautiously in the calculation, and a wet or frosted floor gives even less. A rubber anti-slip mat placed under the load raises the coefficient enough that, at the same mass, clearly fewer tie-down straps are required. That is a real lever, not an accessory. Lay the mat clean, over the full contact area, and replace it when oiled or worn, because dirty rubber loses grip.
Blocking bars, beams and corner protectors
- Blocking bars and beams. Cross bars braced between the trailer walls close the free space behind the load and turn a loosely standing unit into a blocked one. Use them when the trailer is not filled to the headboard, so the last pallet has nowhere to go under braking.
- Corner protectors (edge protectors). They play two roles at once. They shield the strap from chafing against the sharp edge of a pallet or crate, which without them can snap the strap at the first jolt. At the same time they spread the strap pressure over a wider area, protecting the goods from being crushed. Hard plastic or metal protectors for sharp edges, cardboard ones for lighter pressure and more delicate packaging.
- Chocks and dunnage. For loads that want to roll, and to level the surface so the strap pressure stays even.
Pallets, loose cargo, pipes and coils: different rules
| Load type | Main risk | Recommended approach |
|---|---|---|
| Uniform pallets | sliding and tipping, layer collapse | tight blocking to the headboard, stretch-wrapped layers, tie-down with corner protectors, mat under slippery pallets |
| Loose cargo, cartons, bags | slumping, migration into gaps | even stacking with no voids, layer boards, nets and tie-down straps, gap filling |
| Pipes, shafts, cylindrical parts | rolling lengthwise and sideways | chocks and dunnage against rolling, stanchions, loop lashing to prevent rotation |
| Steel coils | heavy concentrated mass, rolling | placed in a coil well or cradle, chocks, blocking against the rolling axis |
The common rule: the more a load wants to roll or tip, the less downward pressure alone will do, and the more a physical barrier matters. A pipe held only by a tie-down strap can still rotate under it. How to choose packaging and palletisation for transport is covered in pallets, packaging and load securing.
Common loader mistakes
- Counting straps by eye. Two straps per pallet because that is always how, with no link to mass or friction. A heavy pallet on a slippery floor needs more, a light one on a mat fewer.
- Tie-down only on a slippery floor. Without a mat and without blocking, downward pressure slides away together with the load.
- Strap over a sharp edge without a protector. The webbing breaks at the friction point on the first jolt.
- Gaps in the load. Free space between units lets the load build up speed before it hits its neighbour.
- Worn equipment. A frayed strap, a deformed hook, an oiled mat: gear without reliable strength is only the appearance of securing.
- Ignoring weight distribution. Even pressure needs even stacking; a leaning pallet loads a single strap.
Before you sign the consignment note, run through a loading checklist. A practical set sits in our tools section.
The OTSL role
As an international freight forwarder we arrange transport where securing is part of the order, not an accident on the ramp: we select carriers with the right equipment, agree the securing method for the specific load and make sure loading in our warehouses in Kielce, Legnica and Milton Keynes follows the rules of carriage. We run traffic between Poland, the United Kingdom, Switzerland and the rest of Europe. More on the hazards in transit sits in our transport risks section, and you can discuss a specific load through the contact form.
How do inertia forces affect cargo securing calculations?
Inertia forces acting on cargo during movement are calculated as multiples of its weight, reaching up to 0.8 g forward and 0.5 g rearward and sideways. Proper load securing must be calculated to withstand these dynamic forces during heavy braking, acceleration and cornering rather than merely holding the goods while the vehicle is parked.
Step by step
- Assess cargo parameters. Check the mass, dimensions and physical stability of the goods before choosing the securing method.
- Clean the loading floor. Remove dirt, sand and debris from the deck to ensure maximum base friction.
- Position anti-slip mats. Place friction mats directly beneath the contact points of the cargo.
- Fit corner protectors and straps. Protect the cargo edges with corners and route lashing straps through approved anchor points.
- Tension and re-check straps. Tighten the straps using a ratchet handle and inspect the tension after the first few kilometres of travel.
Definitions
- Tie-down securing: Pressing the load onto the vehicle floor using lashing straps to increase friction.
- Blocking (form-fit): Securing cargo by wedging it directly against vehicle walls, blocking bars or adjacent load units.
- Anti-slip mats: High-friction rubber inserts placed under the cargo to prevent sliding during transit.
- Corner protectors: Protective elements designed to shield strap webbing from abrasion and protect cargo edges from crushing.
- EN 12195 standard: The European standard defining the calculation of securing forces for cargo on road vehicles.
When does this rule not apply?
Standard calculations for lashing forces do not apply to bulk transport, liquid tankers or heavy machinery secured on specialized low-loader trailers with dedicated twist-lock systems.
