Loading Steel Coils for a Border Crossing
You are to collect three steel coils, each 4.2 tonnes, from a depot and deliver them 180 km away, crossing into another country. Your semi-trailer is a curtainsider with a plywood-lined floor, rated for a maximum gross combination weight of 40 tonnes. The tractor unit weighs 8.4 tonnes with full tanks and driver; the empty trailer weighs 7.1 tonnes. The coils are 1.2 m in diameter and must lie on their curved surface or in cradles - the depot has steel cradles but no coil wells. You have web lashing straps rated at 2 000 daN lashing capacity each, and anti-slip mats. The load must be secured for a journey that includes motorway and urban sections.
1. Calculate the available payload and decide how the coils should be arranged and secured. Justify the arrangement.
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Payload. Tractor 8.4 t + empty trailer 7.1 t = 15.5 t tare. At 40 t GCW the maximum payload is 40 − 15.5 = 24.5 t. Three coils at 4.2 t = 12.6 t, so weight is not the constraint - volume, floor loading and securement are.
Arrangement. Place the coils in cradles, axis transverse to the direction of travel, so that the curved surface cannot roll forward under braking. Spread them along the trailer floor rather than clustering them: this keeps the centre of gravity low and central, avoids overloading one axle group, and reduces the yaw effect if one shifts. Do not place a coil directly against the headboard if it would concentrate load on the trailer neck; check the floor's rated point load.
Securement. A coil in a cradle still needs to be prevented from tipping and sliding. Use the cradles as the primary restraint against rolling, then lash each coil down over the top with straps taken to both sides, and place anti-slip mats under the cradles. Because the load can shift, check the lashings again after the first few kilometres.
2. How many lashing straps would you plan to use, and what checks must you make before departure?
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Work from the principle that the lashing system must resist the forces the load will see in service - typically taken as a proportion of the load's weight forward, backward and sideways. For 4.2 t per coil, the required restraining force in the forward direction is roughly half the weight, about 2.1 t ≈ 20.6 kN per coil. A strap with a 2 000 daN (20 kN) lashing capacity does not deliver 20 kN of restraint once geometry is accounted for: the restraint depends on the angle and on friction. With a top-over lashing at a shallow angle, the effective contribution is a fraction of the lashing capacity, so a single strap per coil is not enough. Plan on at least two straps per coil taken in a crossed or opposed pattern, giving four anchorage points, and rely on anti-slip mats to raise the friction contribution.
Before departure check: strap condition (no cuts, no UV damage, labels legible), correct tensioning, ratchets locked, anchor points rated and undistorted, cradles seated on the floor, coil surfaces free of oil that would let the strap slip, and the load height within the legal maximum. Re-check tension after 10–20 km and after any border stop.
3. What documentation and regulatory points must you confirm before crossing the border with this load?
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Confirm the driving and rest time position - the 180 km each way plus loading time must fit within the daily driving limit and the break rules, and the tachograph must be recording correctly with the correct mode selected during loading. Check that the vehicle's technical inspection is valid in the destination country and that any national access rules (weight or dimension limits on the route) are respected. Confirm the CMR consignment note is completed with the correct gross weight and nature of the goods, and that the load is within the permitted axle and gross weights for the countries crossed - steel is dense, so a weighbridge check before departure is prudent. Finally, verify that the cargo securement meets the standards enforced at the border, since an inspector may require the lashings to be demonstrated and the load to be re-checked.