Weighbridges or truckscales are scales used to weigh bulk items and unlike regular scales, they are designed to measure heavy items at large weight intervals. This means that the scales are not designed to measure to the nearest milligram like your kitchen or bathroom scale. Most truck scales have nominal capacities of 20,000kg, 30,000kg, 60,000kg, 80,000kgs to over 300,000kgs.
At Coastal Transport we provide a 140 Tonne (140,000kg) 4 platform registered public weighbridge which is suited for caravans, horse floats, cars and trucks of all sizes.
This means that our bridge services both the Company fleet, other transportation vehicles as well as public vehicles and even animals. Our most frequently weighed public vehicles are caravans and trailers, as it is vital that owners are aware of their towing capacity and ball weights.
Understanding the weight of your rig is of vital importance to any owner of a caravan or camper – for safety and security, and to avoid penalties. Obviously, the onus is on the driver to ensure the weight of the van doesn’t exceed the capacity of the tow vehicle and strict regulations apply to towing with illegal weights.
Always remember that modifications made to a trailer, float or caravan can effect its weight and therefore its road-worthiness.
It should also be noted that if you haven’t independently verified the weight of your loaded van and can prove it was within acceptable limits and you’re involved in an accident (regardless of fault), your insurance is looking extremely shaky and any claim is likely to be rejected.
An overloaded vehicle, either on its own or when towing something, is not only illegal but also unsafe, because its handling ability and braking distances can be seriously compromised. It also means that engines, drivetrains, suspensions, axles, brakes, tyres etc are all working harder than they should, resulting in not only premature wear-and-tear but also increased risk of a mechanical failure and at worst an accident.
The only way to really know is to take your rig – all loaded up, ready to tour – to a public weighbridge and have it weighed.
How does it work?
Weighbridges are relatively easy to use and while at the weighbridge it’s essential to consider at least four important weights: Aggregate Trailer Mass (ATM), Gross Trailer Mass (GTM), Tare and Tow Ball Maximum.
The ATM is the most your caravan can weigh, with everything in and on it, as it stands, unhitched. It is the weight that each wheel and the jockey wheel impose on the ground all added together, at the very most. The maximum allowable ATM will have been set by your vehicle manufacturer and stamped on the compliance plate.
In order to ensure the accuracy of your weight make sure the gas cylinder(s), water tank(s) and fuel tank contain about the same amount of liquids as the next time you do a full payload weight check. Every litre of gas, water or fuel weighs approximately 1kg and may alter your readings.
You will need to take all extra items and luggage out of the vehicle to obtain an accurate tare weight. First, weigh your car and towed vehicle to get a complete weight of your set-up and check the weight distribution on the axles when the car is hooked up to the tow vehicle.
After this, weigh the towed vehicle by itself with the jockey wheel to obtain the tare weight and compare the weight on the axles.
When measuring ball weight (i.e. vertical weight the caravan is exerting on the towbar), position the tow vehicle (connected to a car but on separate platform) and record the weight of the tow vehicle. Then disconnect the car and solely record the weight of the tow vehicle. The differential is the ball weight.
This is the same for all vehicles looking to understand their ball weights – not just caravans.