The Overweight Container at the Port Gate
You drive a 6-axle articulated combination (3-axle tractor, 3-axle semi-trailer) for a licensed road transport operator in Bahrain. At the port you collect a sealed 40-foot container. The shipping document states a gross cargo mass of 24,500 kg. Your tractor's kerb mass is 8,900 kg, the empty trailer is 7,200 kg, and the permitted maximum gross combination mass on your vehicle registration is 44,000 kg. The permitted maximum axle mass is 11,500 kg for the drive axle group and 24,000 kg for the tri-axle trailer group. The container is loaded with the heavy items concentrated at the doors end. You have a 90 km motorway run and a 15:00 delivery slot. At the port weighbridge the combination reads 42,300 kg total, but the trailer group reads 26,100 kg and the drive axle group reads 10,200 kg. The gate officer waves you through because the total is legal.
1. Using the figures given, assess whether the combination may lawfully proceed. Show your arithmetic and identify which limit is breached.
Read the worked answer
Total combination mass: 42,300 kg against a permitted 44,000 kg - legal, with 1,700 kg to spare. That is the only figure the gate officer checked, and it is not the binding constraint.
Trailer tri-axle group: 26,100 kg against a permitted 24,000 kg - over by 2,100 kg. This is a breach regardless of the total being legal. Axle and axle-group limits are separate absolute limits; a light drive axle does not offset a heavy trailer group.
Drive axle group: 10,200 kg against 11,500 kg - legal, 1,300 kg spare. Note how the load has been distributed: the heavy items at the doors end sit almost directly over the trailer bogie, which is why the trailer group is overloaded while the drive axles are lightly loaded.
Conclusion: you may not proceed as loaded. The correct action is to refuse the load in its present condition, report it to your operator, and have the cargo re-stowed or the container repacked so mass is moved forward over the drive axles and the trailer group falls to 24,000 kg or less. Do not attempt to 'fix' it by sliding the trailer bogie or the fifth wheel alone without re-weighing - those adjustments change axle shares but not total mass, and the result must be verified on a weighbridge before you leave the port area.
2. The consignor says the shipping document mass is 'close enough' and offers to sign a note accepting responsibility. Explain why this does not resolve your position, and what you should do before moving.
Read the worked answer
A note from the consignor does not transfer the legal duty. The driver and the operator remain responsible for the vehicle being within permitted axle and gross limits on the road, and an indemnity note is not a defence against an overload prohibition, a prohibition notice, or a prosecution. It also does not make the vehicle safe: an overloaded trailer group degrades braking performance, increases tyre and suspension stress, and changes handling.
Before moving you should:
- Record the evidence - retain the weighbridge ticket showing 26,100 kg on the trailer group, note the time, the axle configuration and the load description.
- Notify your operator immediately and let them instruct the consignor; the commercial conversation is theirs, not yours at the gate.
- Request re-stowing or repacking so the trailer group comes within 24,000 kg, then re-weigh. Do not accept a verbal assurance - insist on a ticket.
- Do not sign anything accepting the overload, and do not accept a document that misstates the mass.
- If the load cannot be made legal, leave it and record the refusal in writing, including who instructed what.
- Advise your customer that the 15:00 slot will be missed; delay is the correct outcome, not a workaround.
If you had already departed overloaded and were stopped, the fact you were waved through at the gate would not assist you.