In this article, we gain an understanding of the functionality at a generic level and learn from Craig Henry, AL-KO General Manager of Innovation, about the specific features of Tow Assist and how it benefits a caravan owner.
Tow Assist is a collaborative effort between AL-KO and Bosch. These two companies are a strong match to bring this product to market. AL-KO is the leading running gear supplier to the Australian caravan industry and Bosch is synonymous with automotive safety systems.
Tow Assist has two key functions, ABS (Anti-lock Braking System) and ESC (Electronic Stability Control). ABS and ESC are not new ideas. They have been available in cars for many years. In fact, Bosch helped pioneer ABS in cars in the 1970s. There are also a number of ESC systems available for caravans now. Craig tells us what makes Tow Assist special is that it’s the world’s first caravan braking system with ABS and sway mitigation (AL-KO’s name for ESC).
WHAT IS ABS AND WHAT ARE THE BENEFITS?
In simple terms, ABS prevents a vehicle from skidding when the brakes are applied. This increases safety dramatically because a skidding vehicle has longer stopping distances and will also tend to veer off sideways. ABS works by comparing the speed at which the wheels are turning and the speed at which the vehicle is moving. If the system detects that a wheel is rotating significantly slower than the vehicle it interprets this as an impending skid. The system will momentarily back off the brakes to stop the skid and then reapply the brakes. An additional benefit of avoiding skids is preventing flat spots from developing on your tyres.
Alternately, if the system detects one wheel rotating significantly faster than other wheels it will apply more braking to that wheel until wheel speeds are matched. This process of backing off and reapplying the brakes is repeated multiple times per second until the wheel speed matches the vehicle speed. A driver can feel car ABS kick in through the pulsation of the brake pedal under heavy braking or low traction conditions.
The takeaway on ABS is it manages braking when you push hard on the brake pedal. We will contrast this with ESC shortly. ABS has been mandated on passenger vehicles in Australia since 2003 and all road going motorcycles since 2021 due to the huge impact in reducing accidents. But is not a feature we have seen built into caravans until now.
WHAT IS ESC AND WHAT ARE THE BENEFITS?
ESC is also mandatory on passenger vehicles. A core feature of ESC is it can apply the brakes without you putting your foot on the brake pedal to keep the vehicle stable. ESC senses excessive lateral (side to side) movement and applies the brakes to keep the caravan tracking straight. There are a number of ESC products available on the market for caravans.
According to Craig, Tow Assist is a more sophisticated ESC system because it is capable of applying brakes individually rather than all brakes at once. If the rear of the van is swinging out to the right, the right brake/s will be automatically applied to pull the van straight. Unlike other systems, Tow Assist can also respond to varying degrees of lateral force where small forces trigger moderate braking and larger forces trigger harder braking. AL-KO describe the benefits of Tow Assist as Sway Mitigation and Evasive Action Control.
Sway mitigation can prevent the caravan from developing a dangerous side-to-side swinging action. Swaying can occur without any input from the driver. An example is when a large truck passes the caravan and the air displaced by the truck pushes the caravan sideways. Swaying is very dangerous as the caravan can move out of its lane and come into the path of other traffic. Swaying can also rapidly escalate to the point where the van is pushing the tow vehicle around or the van rolls over, potentially flipping the car with it.
Evasive Action Control assists the driver in a swerving scenario. Swerving is different than swaying in that it is initiated by driver input. The classic conditions are where the driver rapidly changes direction to avoid a traffic hazard. Craig tells us the weight of the caravan shifts dramatically, reducing stability and traction. This can cause the vehicle to drift, slide, jack-knife or in severe cases rollover. Again, the lateral sensors detect a significant sideways movement in the van and apply the brakes to level the caravan out and keep it tracking straight. The system is smart enough to manage the ABS and stability control simultaneously if sudden braking is attempted while swerving.
ARE THERE ANY OTHER FEATURES?
Tow Assist has another interesting feature – a built-in odometer. Information on kilometres travelled can be accessed by your mobile phone via BlueTooth. This is a very handy tool for keeping track of when important service work should be done such as servicing brakes or wheel bearings.
WHAT IS IT LIKE IN PRACTICE?
So, we’ve covered the theory. Tim van Duyl, Creative Director at Caravan World, has had the good fortune to see the system in action at the Australian Automotive Research Centre Proving Ground. He reckons it’s a game changer. “Under controlled conditions, we observed caravans put into emergency braking and swerving scenarios with and without Tow Assist activated. Without Tow Assist we saw how easy it is to quickly lose control of a caravan with the test van sometimes swinging as much as ninety degrees behind the test car. With Tow Assist, we saw the real-world safety of shorter braking distances by avoiding skidding and the van tracking behind the tow vehicle in swerving scenarios. The control Tow Assist gives the driver is unlike any ESC I've seen and a real game-changer.”
THE NITTY GRITTY
We put our caravan owner’s hat on and hit Craig up with a bunch of questions. This is what we learned.
Q. How much does it cost to have it fitted as part of a new van build?
A. We have partnered with a few leading caravan manufacturers as early adopters of the system. We are finding it is generally being offered as an optional extra. There is no additional labour to install this system from new and the recommended retail price for a single axle van is $2,995 and $3,495 for a twin axle van. With many vans selling for over $100,000 these days it is quite a small percentage of the initial outlay.
Q. Can it be retrofitted to an existing van?
It can be retrofitted provided a few components are swapped out. New brakes with wheel speed sensors and hub drums compatible with ABS need to be fitted. The system also needs to be hooked up to a power supply, usually the house battery. The pricing is as above plus about half a day of labour to do the swap.
Q. Are the running costs any higher?
With Tow Assist fitted, a brake service is no more expensive than a traditional brake set-up.
Q. How do you check the system is functioning?
Tow Assist has an indicator light to show it is active. If the caravan stands stationary for a period of time, without a braking signal detected, the system will go into a low-power sleep mode and the light will go off. The system is reactivated by tapping the brake pedal in the car. You can then check the indicator light has come back on.
Q. Should the system ever be turned off?
Tow assist can’t be turned off apart from disconnecting the power supply, and there is no need to. The ABS feature is monitoring and reacting under all conditions and the sway feature is disabled under 60km/h. It is important to note that should your power supply battery go flat your brakes will still work but the ABS and ESC safety features will not work.
Q. How does it respond/interact with tow vehicle trailer anti-sway systems?
The research performed indicates there is no conflict or concern. Tow vehicle trailer anti-sway systems work by detecting forces at the towball. As Tow Assist is mounted on the caravan, it corrects issues at the source before the tow vehicle system kicks in.
Q. Is it compatible with brake control units?
Yes, Tow Assist is compatible with most OEM/Aftermarket brake control units.
Q. Do insurance companies offer discounts for safety systems such as Tow Assist?
Yes, major insurance companies such as CIL and RACV currently offer policy discounts for our system.
WHAT DOES THE FUTURE HOLD?
We spoke to Wayne Coleman from JB Caravans which is one of the early adopters of this system. Wayne tells us Tow Assist is currently optional, but interest is growing. He expects more and more people will ask for the system as they become aware of it.