The 1 050 kg Problem on the Tail of the Truck
You are booked to leave the depot at 05:10 on a wet Friday with bagged cement for a site 180 km away. The rigid truck has a GVM of 8 000 kg and a tare mass of 4 200 kg; the front axle is rated at 3 200 kg and the rear axle at 6 000 kg. The loader has put 4 500 kg of cement on the deck and then swung a 350 kg concrete mixer onto the tail, about 1,2 m behind the rear axle line. The tarpaulin is on, but two of the six lashing straps are missing. The yard weighbridge gives front axle 3 450 kg and rear axle 5 600 kg. There is a permanent weighbridge 40 km along the route, rain is forecast all morning, and the customer rejects late loads. The dispatcher tells you to "just go, we will sort it out later".
1. Using the figures given, work out whether this vehicle may legally be taken onto the public road. Identify every mass limit that is exceeded and state exactly what has to change before you leave the yard.
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Start with the permitted payload, not with the load:
- Payload capacity = GVM − tare = 8 000 − 4 200 = 3 800 kg.
- Mass actually loaded = 4 500 + 350 = 4 850 kg, i.e. 1 050 kg over what the vehicle may carry.
- The weighbridge confirms it: 3 450 + 5 600 = 9 050 kg, again 1 050 kg above the 8 000 kg GVM.
- Front axle: 3 450 kg against a 3 200 kg rating = 250 kg over.
- Rear axle: 5 600 kg against 6 000 kg = 350 kg under, but that spare capacity cannot be used to "absorb" the excess because the GVM is the binding limit.
So three separate limits are breached: GVM, payload and front-axle rating. The trap is thinking you can redistribute your way out. With only 350 kg of rear-axle headroom and the front already 250 kg over, no amount of shuffling gets 1 050 kg of extra mass legal. Mass has to come off.
Action: offload at least 1 050 kg (removing the mixer alone leaves you 700 kg over), then re-weigh on the yard bridge and record the printout. The 40 km weighbridge, the rain and the delivery deadline are commercial pressure, not a legal argument.
2. Explain what the missing lashings and the position of the mixer do to braking and stability on a wet road, and describe how you would secure this load properly.
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A tarpaulin contains nothing - it only keeps water out. At 60 km/h, a harsh stop at about 0,7 g turns every unsecured kilogram into a projectile with roughly its own weight acting forward. A 350 kg mixer 1,2 m behind the rear axle is worse than its mass suggests: it levers weight off the front axle, unloads the steer tyres, and pivots the vehicle around the rear axle if it shifts sideways. On wet tar with reduced grip, that is a jack-knife or a roll-over waiting for the first bend or emergency stop.
Securing it properly means:
- Place the heavy mixer low and forward of the rear axle line, not on the overhang.
- Use rated load-restraint equipment - straps with a marked lashing capacity whose combined working load limit comfortably exceeds the mass being held, in a direct lashing or diagonal pattern, with edge protectors.
- Chock or block the mixer so it cannot walk, and lock bagged cement against a headboard so it cannot slide forward.
- Re-check tension after the first 10–20 km, then at every stop.
Also remember that an overloaded vehicle has already invalidated its own braking and tyre design assumptions; restraint is not a substitute for removing the excess mass.
3. You drive anyway and are stopped at the weighbridge. What are the consequences for you personally and for the operator, and how does the overloading change your insurance position if you then have a collision?
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Overloading is a criminal offence under the National Road Traffic Act and its regulations, and the driver is personally liable - you cannot transfer the fault to a dispatcher who told you to go. Realistically you face a fine or a court appearance, the vehicle is prohibited from proceeding until the load is corrected, and the consignment is delayed anyway, which defeats the original reason for taking the risk.
The operator carries separate exposure: failing to ensure that a vehicle is operated within its GVM and axle ratings, and permitting an unroadworthy vehicle on the road. Expect an administrative penalty, possible suspension of the operator card, and a much harder conversation at the next audit.
On insurance, overloading is a material breach. The vehicle was outside the design envelope the underwriters rated: braking distances, tyre loading and stability all change. A short-term insurer can repudiate a third-party or own-damage claim, and the Road Accident Fund will still compensate innocent victims but may pursue recovery. If someone is injured or killed, the fact that you knew the mass was 1 050 kg over and drove anyway is precisely the kind of evidence that turns a collision into a culpable homicide charge. The only defensible decision was at the weighbridge in the yard.