How To Stop The Fish-Tailing And Snaking Of Your Caravan.
There is nothing more frightening than the feeling of your caravan or trailer starting to sway or ‘snake’ behind your tow vehicle. There have been many reported accidents and roll-overs as a result of loss of control of the tow vehicle steering due to uncontrollable sway of the caravan or trailer.
When packing the caravan or trailer ensure the load is distributed correctly as an incorrectly packed RV may not handle well and be the cause of the swaying. Other forces such as uneven road surfaces, cross-winds, overtaking trucks and buses (where there may be significant side thrust forces) can also create swaying or ‘snaking’.
You insure your tow vehicle, you insure your caravan or camper trailer and now there is an additional ‘safety’ option you can buy for more peace of mind designed to reduce “snaking” when towing. These sway control devices or stabilisers limit excess movement when towing and ensure good tracking of the caravan or camper trailer behind the tow vehicle.
If your tow vehicle is fitted with self-levelling suspension then you must follow the manufacturer’s recommendations when hitching up your caravan or camper trailer.
Sway control devices should not be confused with weight-distribution hitches (See article on Hitches & Weight Distribution)
Hayman Reese manufacture a friction sway control bar. The sway control unit comes with a metal plate, with a small ball mount. This sway control plate can be bolted onto the A frame or draw bar of your caravan or trailer. The hitch receiver can be modified by welding on a small ball mount for the other end of the sway control bar to attach to, or purchase their integrated Friction Sway control tab for easy upgrade to basic sway control. For safety reasons any welding should be done by a qualified person or Hayman Reese distributor. The manufacturer claims this friction sway control bar can be used for ball weights from zero kgs upwards to 545 kg. Bolt on kits are available to avoid the need to drill into the A-frame.
Hayman Reese also have a Dual Cam High-Performance sway control device or straight line hitch to suit ball loads over 160 kgs. The manufacturer claims it will keep your tow vehicle and caravan in a straight line at highway speed when sway might develop due to wheels running off the edge of the road, passing trucks or cross winds. If there is a sudden manoeuvre such as a short swerve the cams seek a straight line that helps the tow vehicle retain control. When cornering the cams automatically slide out of their fixed position to permit full radius turns.
AL-KO also have a AKS 3004 Stabiliser Coupling that the manufacturer claims reduces even small snaking movements in both horizontal and vertical directions. It has a maximum capacity 2,500 kg loaded trailer weight and 250 kg maximum towball weight. AL-KO also have an AKS hitch lock to prevent theft.
Other brand names for stabilisers are Reese, AL-KO, Curt Manufacturing, EAZ-Lift, Husky, Draw-Tight, Bulldog and Equal-i-zer. These sway control devices are available from distributors, caravan accessory stores and on-line RV stores.
Some imported European caravans come standard with stabilisers. For example, Adria Caravans use the AL-KO AKS Stabiliser and Geist Caravans provide an option for the AKS Stabiliser or the Winterhoff Stabiliser which incorporates friction pads and are suitable up to 3000 kg.
Winterhoff also have a hitch lock which secures the towing hitch and mounting bolts plus a ‘Stronghold”, ‘Bulldog” or ‘Robstop’ anti-theft devices.
AL-KO Electronic Stability Control (ESC)
AL-KO have manufactured electronic stability control technology for electric braked caravans to control instability by monitoring for lateral movements that occur at any time. The ESC brakes all four wheels to reduce speed and stopping distances, doesn’t deactivate in off-road conditions and is fully calibrated and customised to each caravan’s specifications. For extreme 4WD off-road conditions AL-KO recommend that the ESC is connected to the tow vehicle using a separate 2 pin connector rather than the 12 pin connector as this enables the user to disconnect the ESC during periods of serious off-road 4WD use. (AL-KO acknowledge severe tilting of trailers and bumps during serious off-road travelling, such as those experienced by camper trailers, may inadvertently activate the brakes).
The AL-KO ESC is suitable for both single axle and tandem axle caravans and can also be retrofitted to to existing caravans with 10″ and 12″ Dexter electric brakes and compatible brake controller and compatible independent suspension (listed on AL-KO website under FAQ). AL-KO has also tested and approved Vehicle Components of Geebung Qld, Melbourne Axle Sales and Simplicity Suspension brake drums when used with genuine AL-KO brakes as being compatible with the ESC. More information, including a list of certified installers, is available on their website.
Warranty is for a period of 12 months or 20,000 km, whichever occurs first. The warranty is not transferable if the product is sold by the original purchaser during the warranty period.
Some insurers may offer a price reduction on your insurance premium if your caravan is fitted with the AL-KO ESC.
Dexter Sway Control
The American-built Dexter Sway Control, released by Dexter Axle Co of Indiana, is available through Australian distributor Melbourne Trailer & Caravan Supplies (currently setting up a network of certified installers). The DSC is a one-size-fits-all system. Dexter Sway Control media releases states the DSC “… is a critical safety item to stabilize the sway of a trailer or RV by continuously monitoring trailer yaw – the side-to-side movement, left and right of the tow vehicle” AND “The next generation technology detects trailer sway and applies either left or right brakes dampening the sway much quicker than other systems that apply brakes on both sides at the same time”.
The Dexter Sway Control comes with a 2 year limited warranty.
Some insurers may offer a price reduction on your insurance premium if your caravan is fitted with the Dexter Sway Control.
What Is The Difference Between The AL-KO ESC (ESC) And Dexter Sway Control (DSC)?
Origin – the ESC was developed in Australia. The DSC is made in Indiana in the USA.
Compatibility – the ESC must be compatible with 10″ and 12″ electric brakes, certain brake controllers, certain independent suspension and is customised to each caravan. The DSC is one-size-fits-all system, it counts wheel revolutions and selectively applies whatever brakes fitted and it is not size load sensitive.
Power/Electrics – the ESC draws power from the tow vehicle for the brakes and the ESC sway system by way of a 12 pin plug. The DSC draws the power from the caravan battery and does not have to be plugged into the tow vehicle for the sway control feature to work (but it does need the caravan brakes to be plugged into the tow vehicle to work). The DSC has a “Sleep” mode to reduce power consumption if there has been no activity (movement or braking) after 30 minutes.
Application – the ESC monitors lateral (left to right) movement and applies braking to all two (single axle) or four wheels (tandem axle) at the same time to bring it under control. The braking force applied is a pre-set maximum force, short of lock-up to all brakes, simultaneously customised on the caravan or trailer’s weight and size. The DSC however, monitors side-to-side movement (left to right) and selectively applies the brakes on either side of the caravan or camper trailer. The DSC also monitors vertical (up and down) movement allowing the system to be shut off automatically when severe off-road conditions are experienced. The DSC can also deliver up to 100% braking force even up to the point of locking wheels.
On/Off Feature – the DSC has an automatic ‘On/Off’ feature for ‘off-road’ or unsealed road 4WD conditions. One reported difficulty for the vehicle driver, was to know if this feature was ‘on’ or ‘off’ as the green light (system ‘on’) is located on the A-frame and this colour changes to ‘Red’ when vertical movement is encountered and power is automatically disconnected. For the AL-KO ESC however, they recommend that the ESC is connected to the tow vehicle using a separate 2 pin connector rather than the 12 pin connector as this enables the user to disconnect the ESC during periods of serious off-road 4WD use.
Both the ESC and DSC may save your life in a dangerous situation and thereby also limit damage to your caravan or tailer and tow vehicle.