Caravan sway can be scary and rightly so. Whether you have experienced caravan sway or only heard the stories and seen dash cam footage, most people that tow caravans are aware that sway may occur. But do you know how to avoid it or what to do if your caravan does start to sway?
The most common cause of trailer sway is an incorrectly loaded caravan. When packing, it is important that heavy items are placed as close to the caravan axle as possible. Packing too heavily towards the rear of the caravan can result in instability.
Generally, you should aim to keep your tow ball weight between around 10% of your ATM or Aggregate Trailer Mass. Going below 10% can result in trailer sway and going above 10% can put excessive weight on the back of your car and will affect your vehicles handling. Learn more about tow ball weight here.
Keep in mind also that sway can be caused by wind. This can be from the weather and on a high wind day, avoid towing if possible. Even an unexpected strong gust can cause some sway.
A large vehicle travelling at speed and overtaking can also cause sway. The rush of air between the vehicles can cause instability.
Speed also causes instability.
As speed increases, stability decreases.
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Stick to a safe speed for your vehicle and the conditions.
Also ensure that you have the correct tyre pressures for your combination by checking your manufacturers recommendations. Underinflated tyres will have excess movement in the tyre wall. Overinflated tyres will not be able to minimise shocks from the road surface and lead to instability.
The most effective way to minimise sway is to decrease speed by removing your foot from the accelerator and applying your trailer brakes. The effect of this will pull the trailer straight behind the tow vehicle and you will begin to regain control.
Stability always decreases as speed increases and sudden moves will always make the situation worse. Ensure you hold the steering wheel steady and don’t make any sudden turns.
It is a great idea to practice reaching for the trailer brakes when stationery. That way you instinctively know where the control is. You can also get the control fitted so that it is central in the vehicle and your passenger can apply the trailer brakes if your hands are too busy holding the steering wheel steady.
Also ensure that you have your electric brakes set up suitably for your trailer. There are various models available so check your manufacturer’s instructions to work out what is right for you.
Electronic Stability Control (ESC) is a great safety feature to reduce the chance of caravan sway. The ESC system installed on a caravan uses a sensor underneath the van to monitor sideways movements, small oscillations or sudden jerks. When these forces cause the van to lurch to a critical point, the system applies selective braking to bring the van back into line. Essentially ESC will apply the trailer brakes for you if things start to get a bit hairy and are likely to be able react faster than you as the driver.
Many new caravans come with ESC already installed or it may be an optional extra. If you have an older van, its easy to have a system retrofitted.
It should also be mentioned that as good as ESC systems are, they aren’t infallible and are not a replacement for careful driving. Careful driving is still the most effective tool to combat the dreaded sway and keep you and your family safe on the road. However, in the event that things do get a bit wobbly, it’s nice to know there’s an ESC system doing its bit to help out.
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