Safety Product Review: Dexter Sway Control

Victorian manufacturer Van Cruiser has become the first manufacturer in Australia to fits its caravans with the new Dexter Sway Control (DSC) system as standard.

DSC which arrived in Australia from North America late last year, is a caravan stability control system that which joins the popular Al-Ko Electronic Stability Control (ESC) in the marketplace.

Van Cruiser's latest 5.53m (18ft 2in) Interceptor Bumble Bee was the first caravan in Australia to be fitted with DSC as standard. Weighing up to 2660kg fully-laden, the semi-offroad, single-axle Bumble Bee was the perfect candidate for DSC.

BRAKING

Instead of braking all two, four (or six) wheels together on an errant caravan once sway is determined, the Dexter system applies the brakes on either side of the caravan selectively to bring it under control. In this respect, it is more like the skid and traction control systems used on many of today’s cars.

The degree of braking force applied is also different. Al-Ko’s ESC applies a pre-set maximum force short of lock-up to all brakes simultaneously, with that customised calculation based on the specific caravan’s pre-determined weight, size and even its tyres once unacceptable lateral G-forces are detected. In contrast, DSC can deliver up to 100 per cent of brake force, even up to the point of wheel locking.
The Dexter system will function on any type of serviceable electric trailer braking system.

SIDEWAYS MOVEMENT

The final feature unique to DSC is that it not only monitors trailer ‘yaw’ – the side-to-side movement, left to right – but also vertical movement. This permits DSC to switch off when offroad conditions are encountered, avoiding ‘nuisance’ braking than can occur if the lateral sensor decides the sideways movement that might occur on corrugations or rough terrain is trailer ‘sway’. The DSC system operates automatically, with the motion sensor in the control unit switching off its power to the brakes in less than five seconds after continuous vertical movement is detected. It then switches DSC back on once it detects no further vertical movement over a similar five second period.

RETROFITTING

DSC is a one-size-fits-all system – it counts wheel revolutions and then selectively applies a progressive proportion of whatever brakes the trailer is fitted with and can also be fitted retrospectively to many older caravans. So it is not size or load sensitive, which means it works regardless of how much your caravan is carrying, how well (or badly) you have loaded it and whether your water tanks are full or empty.

POWER DRAW

DSC draws its power from the caravan’s battery and, hence, does not have to be plugged into the tow car for its anti-sway feature to work (although it needs the trailer plug to power its electric brakes in the conventional way).