Overloaded steel coils at the checkpoint
At 06:40 a driver leaves Umm Qasr with a three-axle tractor and three-axle flatbed trailer carrying six steel coils, each weighing 5.2 t. The weighbridge ticket shows gross 53,600 kg against a permitted gross of 48,000 kg. Axle readings are front 7,200 kg (limit 7,500), drive group 19,600 kg (limit 18,000), and trailer group 26,800 kg (limit 24,000). Each coil is held by two 50 mm web straps rated at 2,500 daN working load, passed over the top and hooked to the deck; there are no chocks, no edge protectors, and one strap crosses a sharp coil edge. The driver must pass a checkpoint 40 km ahead and then climb a mountain grade. The loader says the load 'has never moved before' and the straps are 'new'. The driver has no load chart or reweighing receipt.
1. Identify every weight limit breach and explain why the axle readings, not just gross weight, decide whether the vehicle may proceed.
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Gross is 53,600 − 48,000 = 5,600 kg over, about 11.7%. The drive group is 19,600 − 18,000 = 1,600 kg over, and the trailer group is 26,800 − 24,000 = 2,800 kg over. The front axle is only 300 kg under its limit, so sliding coils forward is not a safe cure: it could overload the steering axle and reduce steering grip. Offloading 5,600 kg from the rear alone would fix the trailer group but leave the drive group over. The load must be reduced by at least 5,600 kg gross and the remaining coils repositioned so that front, drive and trailer groups are all within limits, then reweighed. Until then the vehicle is not fit to pass a checkpoint or climb a grade: excess axle load damages tyres, bridges and brakes, and a rearward-biased load can unload the steering axle on a climb or under braking.
2. Assess the cargo securement. Is two straps per 5.2 t coil adequate? Explain the forces and defects.
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No. Each coil weighs 5.2 t, about 51 kN. Two straps with a working load of 2,500 daN each give 50 kN total in ideal straight-line tension - already less than the coil weight and marginal before any angle loss. Passing straps over a round top reduces their effective capacity, and a strap crossing a sharp edge can be cut or worn through. There are no chocks or side blocks, so under braking or on a curve the coils can roll or slide as a group. A 0.5 g braking event on one 5.2 t coil needs about 25.5 kN of forward restraint, and the straps are not arranged to resist that with an adequate safety margin. The load is not acceptable: fit coil chocks/blocking, edge protectors and correctly rated straps in sufficient number, then inspect and re-tension before movement.
3. What should the driver do before moving, and what should be recorded?
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The driver should not move to the checkpoint. He should notify the loader and dispatcher, arrange offloading of at least 5,600 kg and reposition the remaining coils, then reweigh all axle groups. Securement must be rebuilt with chocks, edge protection and adequate rated straps. Only after the weighbridge ticket and a visual securement check are satisfactory should he proceed. He should record the original weights, the overload and insecure load, the corrective action and the new ticket in the vehicle file/defect record. He should also check tyre pressures and brake condition after the excess load, and not accept a verbal assurance that the load 'never moves'. Passing a checkpoint with a known overload creates legal, insurance and safety consequences, and the mountain grade is exactly where overloaded brakes and tyres are most likely to fail.