No matter what the salesperson told you, you must expect that the “featherweight, easy to tow” trailer is going to act like an anchor when going off-road. There are several things to consider when towing and this article will cover some of these.
What is right for me?
If one was to choose the main theme around selecting a trailer, it must be to select a trailer that firstly matches your vehicle’s towing capabilities and then only fulfil your wish list. This means choosing a trailer with a similar track width as that of the tow vehicle; and that is within the towing mass limitations. Before going further, though: one piece of critical advice is that you should always choose the lightest trailer you can. As long as it is well constructed, you won’t be sorry!
Break over angle and jack-knifing
As with any 4×4 vehicle, which has a break over angle under its belly, the vehicle/trailer (or caravan) combination has an additional break over angle between the rear wheels of the tow vehicle and the trailer or caravan’s wheels. The difference is that this break over angle will continuously change when obstacles are negotiated and the trailer/caravan and tow vehicle will twist, turn and bump up and down. Similarly, the trailer/caravan also has a departure angle, which must be considered when off-roading. The other critical aspect is the fact that the trailer/caravan is hinged to the vehicle. This means that the distance between the front of the trailer/caravan and the rear of the tow vehicle is continuously changing, as it is negotiating deep ditches or dongas. This could lead to the trailer/caravan to collide with the tow vehicle, which is due to it being raised too high in relation to the tow vehicle or the tow vehicle’s nose climbing a very steep incline. Drivers must also take care not to turn too sharply as the trailer can jack-knife into the back of the tow vehicle.
A trailer/caravan with a similar track width to the tow vehicle will allow its wheels to follow in the tracks of the tow vehicle most of the time. However, driving off-road, one will inevitably encounter sharp turns. The trailer/caravan will follow a smaller turning circle. This means that different to when travelling in a straight line, its wheels will not follow the tow vehicle tracks, but will be closer to the turn’s inside. As a result, the trailer wheels can easily hit objects at the side of the trail, damaging the tyres and even breaking the axles or springs. The tow vehicle must turn wider than normal to compensate for this, sticking to the extreme outside of the trail, allowing sufficient room on the inside for the trailer/caravan’s wheels. However, this exposes the tow vehicle’s front wheel to damage, so lots of care must be taken when manoeuvring tight and sharp turns. It is thus clear that towing a trailer/caravan requires a huge amount of extra care and concentration.
Consider the mass
Nowadays, it is incorrect to speak about a trailer/caravan’s weight – the correct terms to use is mass. When considering a trailer/ caravan, take special note of the D/T rating of the tow vehicle. This figure may not be exceeded by the total towed mass, which means the empty trailer/caravan’s mass AND its entire load. Do spare a thought for the poor tow vehicle. For example, let’s say that the D/T rating on the tow vehicle is about 4 000kg. When towing on road, this is already a significant load and the vehicle has to work very hard to pull away and stop with this load behind it. A sizeable off-road trailer/caravan can have a GVM (Gross Vehicle Mass) of 2 500kg when it is fully loaded. On paper, the tow vehicle can handle this load fairly competently on dust roads and tracks, but as soon as any deep sand is encountered, you may find yourself in trouble. Even with the tyres on the tow vehicle and trailer deflated, you will get stuck badly. Not only that, towing these heavy trailers and caravans off-road puts a lot of strain on the mechanical components of the vehicle and especially the cooling systems. At the lower speeds encountered off-road, there is less airflow over the radiators and oil coolers, resulting in potential overheating of the engine and gearbox. To summarise then, as a guideline, the off-road trailer/caravan’s mass should not exceed about a quarter to a third of the D/T of the tow vehicle if you plan to do any real off-roading. Another aspect where the mass of the trailer/caravan is a huge problem is when climbing slopes. Because it is essentially dead weight, the vehicle/trailer combination will only be capable of ascending milder slopes. Additionally, the surface of the slope plays a more significant role. If the tow vehicle loses traction on a slope due to mud, the trailer/caravan’s added mass may result in the brakes not being able to halt the descent. So, when inspecting the obstacle, take into consideration that should something go wrong, you may have to reverse back down the slope with the trailer/caravan attached. More often than not, the biggest problem one encounters is judging the capability of your vehicle/trailer (or caravan). No textbook can assist you with this, as there are just too many variables. Even the experts get caught off-guard at times. The secret is never to attempt an obstacle if you have not walked it, and even then, take baby steps!
Putting a stop to it
One of the first things one will notice is that the vehicle will be slower when pulling away with the additional mass behind it. Off-road, this will become even more pronounced as the trailer/caravan’s rolling resistance increases in areas of poor flotation. However, this is the easy part: stopping with your trailer/caravan in tow is an even bigger challenge. In the SA Licensing system, two distinct categories of “light” trailers are found. With an added-up mass of less than 750Kg, the first trailer is not required to have a braking system. Trailers and caravans exceeding that mass are required by law to have a braking system that is automatically activated by the tow vehicle’s braking action. This is called an overrun brake or run-in brake. To see if your trailer/caravan is fitted with one of these units, firstly take a look at the axle. If rods or cables are running from the drawbar to the axle, your trailer/caravan is probably fitted with a braking system. Then look at the tow hitch. A trailer/caravan with an overrun hitch is easily distinguishable as the tow hitch is mounted on a shaft, which can be “pushed” in (towards the trailer/caravan), thus applying force on the cable or rod system, and applying its brakes. Most times, a braking system includes a hand brake which allows the trailer/caravan to be stored without rolling away. When reversing with an overrun fitted trailer/caravan, one must realise that reversing can apply the brakes in the same way as braking would activate them. To prevent this, the overrun hitch system is normally fitted with a locking device which often must be activated by a second person, standing next to the hitch as you start reversing. Once the lock has engaged, you will be able to reverse the trailer/caravan. However, some of these systems will disengage the locking device if the trailer/caravan runs faster than the tow vehicle for a few seconds. Then it will have to be reactivated before continuing to reverse the trailer. Some trailers are fitted with an automatic locking system, which disengages the brakes if the wheels rotate in reverse. A word of warning, though: this system works very well when reversing, but it may disengage the trailer’s handbrake when pushing the trailer backwards by hand. While on the point of braking systems: experts recommended that any off-road trailer/caravan, irrespective of size, be fitted with at least an overrun braking system. It will make it much easier to manage on those steep, solid, dry slopes as the trailer/ caravan will automatically brake, which will in turn assist the tow vehicle’s braking effort. Descending steep muddy slopes with a trailer/caravan can result in it swinging to one side and jack-knifing against the vehicle. If the wheels lock up in the mud, the trailer/caravan still becomes uncontrollable. Try to avoid these situations at all costs.
Lights and reflective gear
Most off-road trailers/caravan’s are now fitted with the round LED “truck-lite” type of lights. These are far superior to the older style lunchbox-shaped lights. Not only are they brighter and more visible, but they are much more reliable, especially those that are sealed units. Remember, though, that the lights are only as effective as the wiring servicing them. Check that the wires are fitted within the chassis and protected from flying stones, bushes and branches. In the exposed sections – for or example, where they couple to the towing vehicle – they must have additional sheathing to protect them from sand and stone damage. Make sure that the wires are long enough to allow the vehicle to turn without putting a strain on them, but they must not be too long as they will drag on the ground when you go over obstacles. If possible, make a small hook out of a short piece of wire that will lift them up to the height of the tow hitch. One of the most common problems with trailer/caravan lights occurs when the earth wire – either on the tow vehicle’s socket or on the trailer/caravan – is damaged or poorly connected. Before departure, check this in the following way. Couple the trailer/caravan and insert the light coupler properly into the female socket on the tow vehicle. With the ignition switched on, switch on the park or headlights, and one of the flashers. Now inspect the trailer lights. If the taillights are on and only the indicator light is flashing, you should be okay, but ask someone to assist you in checking all the lights. Don’t forget to check the number plate light! However, if several or all of the trailer/caravan’s lights seem to flash randomly in time to the car’s indicator lights, chances are you have a bad earth connection. Start tracing this by checking the earth wire on the tow vehicle as it is usually the culprit. All trailers/caravan’s must be fitted with reflectors. The minimum number is two white reflectors facing the front, two red ones facing the rear and three yellow ones per side which brings the total to six. Additionally, a trailer must either have a chevron plate at the back, two large red reflectors, or a minimum of seven red reflectors in a specific pattern. In South Africa, all trailers and caravans must have yellow reflective tape applied to the sides and rear of the trailer. However, all countries have different requirements – for example, in Mozambique, owners must fix a yellow diamond on a blue background (of a specific size) on the rear of the trailer/caravan and on the front of the tow vehicle. Before towing in neighbouring countries, check which particular regulations are applicable.
Simple levelling device
Jockey wheels, fitted to the nose of the trailer, must be equipped with a winding mechanism so that they can be used to raise or lower the tow hitch onto the ball of the tow vehicle and to level the trailer/caravan when camping. They must be well constructed since they may have to withstand being dragged through the sand under the front of the trailer/caravan’s full weight if the trailer is stuck. A jockey wheel should be able to retract until it is at least level with the bottom of the trailer/caravan’s chassis (it may not protrude below the chassis), or alternately be completely removable with a place to stow it out of harm’s way. Recovery Just as drivers should fit a vehicle with appropriate recovery points, front and rear, trailers/caravans require the same care. You should fit your trailer/caravan with a strong tow eye (front and rear), mounted to the chassis. It should also have jacking points which will take the high lift jack for hoisting and recovery.
Checklist for towing
- Learn to reverse with the trailer/caravan attached, using only side mirrors
- Match the tyres, rims and track (axle width) of the trailer/caravan to that of the tow vehicle
- Make sure the trailer/caravan (when over 750kg loaded mass) is equipped with overrun brakes and teach your co-driver how to engage the reverse lock if fitted
- Make sure the electrical cables are well protected and clear of the ground or snags
- Keep in mind that the acceleration is impeded by the mass of the trailer, as is braking, so leave more space for stopping and increase following distances
- Trailers/caravans typically have a high centre of gravity, so consider that when swerving to avoid potholes and crossing steep side slopes
- Plan your route carefully and take wider turns, allowing more space for the inner wheel to turn, and avoid very narrow places
- Make provision for the extra mass by avoiding steep inclines and descents
- Keep the speed low, both on- and off-road
- Never overload the trailer/caravan and balance the load carefully
- Load heavy items lowest
- Remember that water and fuel is consumed during the trip, which changes the balance of the load • When trying to manoeuvre a trailer/caravan in thick sand using a tow strap, lower the nose onto a shovel so that it can slide along as the jockey wheel will dig into the sand.
- Drive slower when towing, and make sure you leave enough room to manoeuvre.
- One thing you will need to learn and learn well is reversing with a trailer/caravan. If you cannot master this, do not even consider buying one, as every off-road trip will be a nightmare.
- When purchasing a trailer/caravan, speak to your dealer and make sure which braking system is fitted. Make sure you understand how to use it and what its limitations are.
- Keep the light sockets in good condition – when not in use, stow them well out of the way so that the jockey wheel does not run over them, and they do not get rusty.
- Always carry one or two spare globes for the trailer/caravan (ask your dealer to include them in the trailer’s cost – they usually are very cheap) as repairing them as and when they are damaged can avoid a heavy fine.
- Keep one or two spare reflectors as stones often destroy them.
- Take a spare spring or spring main blade along. Even if you do not have the skills to fit it, someone else in the group may be able to fit it for you in an emergency.
Take a spare spring or spring main blade along. Even if you do not have the skills to fit it, someone else in the group may be able to fit it for you in an emergency.